Engine

Abstract

To provide an engine that is compact while avoiding fracture of a component or the like due to heat expansion.SOLUTION: An engine includes: a supercharger; an exhaust emission control system; and a connection pipe for connecting the supercharger to the exhaust emission control system. The connection pipe overlaps on the supercharger in plan view.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an engine including a supercharger and an exhaust gas purification device. Specifically, it relates to the arrangement of a connecting pipe that connects the supercharger and the exhaust gas purification device.

Background Art

[0002] Conventionally, an engine in which an exhaust gas purification device is arranged above the engine body is known. Patent Document 1 discloses this type of engine.

[0003] In the engine of Patent Document 1, the exhaust gas inlet of the DPF as the exhaust gas purification device is provided on the side closer to the exhaust gas outlet of the supercharger, and the exhaust gas passage between the supercharger and the DPF is formed short. DPF is an abbreviation for Diesel Particulate Filter.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the temperature of the exhaust gas is generally high, in the configuration of Patent Document 1 above, thermal expansion occurs in each of the exhaust gas inlet pipe of the DPF and the housing support that constitute the exhaust gas passage, and there is a risk of damage at the connection part with other parts.

[0006] On the other hand, when the exhaust gas inlet of the DPF is provided on a side different from the exhaust gas outlet of the supercharger, by forming the exhaust gas passage portion connecting the supercharger and the DPF long, thermal expansion due to the exhaust gas can be absorbed. However, in this case, it is difficult to rationally layout the exhaust gas passage portion while considering the compactness of the engine.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a compact engine while avoiding damage to components or the like due to thermal expansion.

Means for Solving the Problems

[0008] The problem to be solved by the present invention is as described above. Next, means for solving this problem will be described.

[0009] According to an aspect of the present invention, an engine having the following configuration is provided. That is, this engine includes a supercharger, an exhaust gas purification device, and a connecting pipe that connects the supercharger and the exhaust gas purification device, and the connecting pipe overlaps with the supercharger in a plan view.

[0010] The connecting pipe has a straight portion, and the straight portion may overlap with the supercharger in a plan view.

[0011] The connecting pipe has a downstream portion, and one end of the downstream portion may be connected to the straight portion and the other end may be connected to the exhaust gas purification device.

[0012] The connecting portion has an upstream portion, and one end of the upstream portion may be connected to the straight portion and the other end may be connected to the supercharger.

[0013] The straight portion is connected to the supercharger via the upstream portion, and of both ends of the straight portion, one end may be connected to the downstream portion and the other end may be connected to the upstream portion. Further, the exhaust gas purification device may be attached above the engine body.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0015] Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the configuration of an engine 100 according to an embodiment of the present invention. FIG. 2 is a side view of the engine 100 as viewed in the direction along the width direction of the engine 100. FIG. 3 is a side view of the engine 100 as viewed from the flywheel housing 61 side. FIG. 4 is a conceptual diagram showing the intake and exhaust flows in the engine 100. FIG. 5 is a perspective view showing the oil filling port 90.

[0016] The engine 100 shown in FIG. 1 is a diesel engine and is mounted on, for example, agricultural machines such as tractors and construction machines such as skid steer loaders. The engine 100 is configured as, for example, an in-line four-cylinder engine having four cylinders. Note that the number of cylinders is not limited to four.

[0017] First, the basic configuration of the engine body 1 included in the engine 100 will be described. In the following description, the vertical direction of the engine 100 shown in FIG. 1 is referred to as the height direction. The engine 100 has a substantially rectangular shape that is elongated in plan view, and its longitudinal direction coincides with the direction in which the crankshaft 10 extends. In the following description, when referring to the longitudinal direction of the engine 100, it means the axial direction of the crankshaft 10. Also, the direction orthogonal to both the height direction and the longitudinal direction is referred to as the width direction of the engine 100. The height direction of the engine 100 corresponds to the first direction, the longitudinal direction corresponds to the second direction, and the width direction corresponds to the third direction.

[0018] As shown in FIG. 1 and the like, the engine body 1 mainly includes an oil pan 11, a cylinder block 12, a cylinder head 13, and a head cover 14, which are arranged in order from bottom to top.

[0019] The oil pan 11 is provided at the lower part (lower end) of the engine 100. The oil pan 11 is formed in a container shape with an open upper part. Engine oil for lubricating the engine 100 is stored inside the oil pan 11.

[0020] The engine oil stored in the oil pan 11 is sucked by a schematic engine oil pump provided in the engine body 1 and then supplied to each part of the engine body. After lubricating the engine body 1, it is returned to the oil pan 11 and stored.

[0021] By the way, when the vehicle body on which the engine 100 is mounted is not used and stored for a long time, the engine oil moves downward due to gravity, and there is a phenomenon that the amount of oil film in each movable part to be lubricated becomes insufficient.

[0022] As a countermeasure against this phenomenon, when the engine 100 has not been operating for a long time, before starting, by replenishing the engine oil from a relatively high position, a method can achieve a sufficient amount of oil film for lubricating each part of the engine 100 in a short time when the engine 100 starts.

[0023] In the engine 100 of this embodiment, a plurality of oil replenishment ports 90 for replenishing engine oil are provided. Specifically, as shown in FIG. 5, oil replenishment ports 90 are provided on both sides of the head cover 14 in the longitudinal direction of the engine 100, and oil replenishment ports 90 are provided on both upper sides of the flywheel housing 61 in the width direction. That is, in the engine 100 of this embodiment, a total of four oil replenishment ports 90 are provided at different positions in the longitudinal direction and different positions in the width direction.

[0024] Accordingly, it becomes possible to select an oil replenishment port 90 that facilitates replenishment of engine oil according to the attitude of the vehicle body on which the engine 100 is mounted and the arrangement position of surrounding obstacles, and the convenience of the engine 100 can be improved.

[0025] The cylinder block 12 is attached above the oil pan 11. A recess for accommodating the crankshaft 10 and the like is formed in the lower part of the cylinder block 12. Although omitted in FIG. 1, a plurality of cylinders 30 are formed in the upper part of the cylinder block 12 as shown in FIGS. 3 and 4. The four cylinders 30 are arranged side by side along the axial direction of the crankshaft 10.

[0026] A piston is accommodated in each cylinder 30. The piston inside the cylinder 30 can move in the vertical direction. The piston is connected to the crankshaft 10 via a connecting rod (not shown). The crankshaft 10 rotates when the piston reciprocates in each cylinder 30.

[0027] As shown in FIG. 2 and the like, the cylinder head 13 is attached above the cylinder block 12. The cylinder head 13 and the cylinder block 12 form a combustion chamber 31 as shown in FIG. 4 corresponding to each cylinder 30.

[0028] The head cover 14 is provided above the cylinder head 13. Inside the head cover 14, a valve operating mechanism including a push rod and a rocker arm (not shown) for operating an intake valve and an exhaust valve (not shown) is accommodated.

[0029] On one side of the engine body 1 in the longitudinal direction of the engine 100, a cooling fan 6 is rotatably attached. The cooling fan 6 rotates when power from the crankshaft 10 is transmitted. By rotating, the cooling fan 6 generates an air flow, passes the air through a radiator (not shown) for cooling the cooling water of the engine 100, and blows the wind against the engine 100. As a result, the engine 100 is cooled.

[0030] In the longitudinal direction of the engine 100, on the side opposite to the cooling fan 6, a flywheel housing 61 is arranged. Although not shown, a flywheel of the engine 100 is arranged inside the flywheel housing 61.

[0031] Subsequently, while paying attention to the intake and exhaust flows, the configuration of the engine 100 of this embodiment will be briefly described with reference to FIG. 4 and the like.

[0032] As shown in FIG. 4, the engine 100 includes an intake section 2, a power generation section 3, and an exhaust section 4 as main components.

[0033] The intake section 2 sucks air from the outside. The intake section 2 includes an intake pipe 21, a throttle valve 22, an intake manifold 23, and a supercharger 24.

[0034] The intake pipe 21 constitutes an intake passage and can allow the air inhaled from the outside to flow inside.

[0035] The throttle valve 22 is arranged in the middle of the intake passage. The throttle valve 22 changes its opening degree according to a control command from a control device (not shown), thereby changing the cross-sectional area of the intake passage. Thereby, the amount of air supplied to the intake manifold 23 can be adjusted.

[0036] The intake manifold 23 is connected to the downstream end of the intake pipe 21 in the direction in which the intake air flows. The intake manifold 23 distributes the air supplied through the intake pipe 21 according to the number of cylinders 30 and supplies it to the combustion chambers 31 formed in the respective cylinders 30.

[0037] As shown in FIG. 3, the intake manifold 23 is attached to the lateral surface of the cylinder head 13 formed in a substantially rectangular parallelepiped shape. When considering a virtual plane P1 including the rotation center of the crankshaft 10 and the four cylinders 30 as shown in FIG. 3, the intake manifold 23 is disposed on one side of the virtual plane P1.

[0038] On the surface of the lateral side of the cylinder head 13 opposite to the side to which the intake manifold 23 is attached, an exhaust manifold 42 described later is attached. The exhaust manifold 42 is disposed on the side opposite to the intake manifold 23 with reference to the virtual plane P1. In the following description, in the width direction of the engine 100, the side on which the intake manifold 23 is disposed may be referred to as the intake side, and the side on which the exhaust manifold 42 is disposed may be referred to as the exhaust side. FIG. 2 depicts the side surface of the exhaust side of the engine 100.

[0039] The power generation unit 3 is composed of a plurality (four in this embodiment) of cylinders 30. The power generation unit 3 generates power for reciprocating the piston by burning fuel in the combustion chamber 31 formed in each cylinder 30.

[0040] Specifically, in each combustion chamber 31, after the air supplied from the intake manifold 23 is compressed, the fuel supplied from a fuel supply unit (not shown) is injected. Thereby, combustion occurs in the combustion chamber 31, and the piston can be reciprocated up and down. The power thus obtained is transmitted to an appropriate device on the downstream side of the power through the crankshaft 10 or the like.

[0041] As shown in Fig. 4, the supercharger 24 includes a turbine 25, a shaft 26, and a compressor 27. The compressor 27 is connected to the turbine 25 via the shaft 26. In this way, as the turbine 25 rotates using the exhaust gas discharged from the combustion chamber 31, the compressor 27 rotates, and the air purified by an air cleaner (not shown) is compressed and forcibly sucked in.

[0042] As shown in Fig. 1 and the like, the supercharger 24 is disposed above the exhaust manifold 42. The supercharger 24 is disposed between the exhaust manifold 42 and an ATD 43 (described later) on the side surface (the side surface on the exhaust side) shown in Fig. 2. Further, as shown in Fig. 3, when viewed in the direction along the longitudinal direction of the engine 100, the supercharger 24 is located outside the engine 100 in the width direction with respect to the exhaust manifold 42.

[0043] As shown in Fig. 3, when viewed in the direction along the longitudinal direction of the engine 100, the supercharger 24 is disposed such that at least a part thereof is located below the ATD 43 (specifically, a DPF device 44 described later). Thereby, the engine 100 can be made compact in the width direction.

[0044] The supercharger 24 is disposed such that the rotation axis of the shaft 26 extends along the longitudinal direction of the engine 100. As shown in Fig. 2, the turbine 25 included in the supercharger 24 is disposed on the side closer to the flywheel housing 61, and the compressor 27 is disposed on the side closer to the cooling fan 6.

[0045] The exhaust section 4 shown in Fig. 4 discharges the exhaust gas generated in the combustion chamber 31 to the outside. The exhaust section 4 includes an exhaust pipe 41, an exhaust manifold 42, and an ATD (exhaust gas purification device) 43. ATD is an abbreviation for After Treatment Device.

[0046] The exhaust pipe 41 forms an exhaust gas passage, and the exhaust gas discharged from the combustion chamber 31 can flow inside it. The exhaust pipe 41 includes a first exhaust pipe 51, a second exhaust pipe (connecting pipe) 52, and a third exhaust pipe 53. The first exhaust pipe 51, the second exhaust pipe 52, and the third exhaust pipe 53 are composed of metal pipes.

[0047] The first exhaust pipe 51 connects the exhaust manifold 42 and the supercharger 24, and guides the exhaust gas from the exhaust manifold 42 to the turbine 25 of the supercharger 24. The second exhaust pipe 52 connects the supercharger 24 and the ATD 43, and guides the exhaust gas that has passed through the turbine 25 of the supercharger 24 to the ATD 43. The third exhaust pipe 53 guides the exhaust gas that has passed through the ATD 43 to the outside.

[0048] The exhaust manifold 42 is connected to the upstream end of the exhaust pipe 41 (i.e., the first exhaust pipe 51) in the direction in which the exhaust gas flows. The exhaust manifold 42 collects the exhaust gas generated in each combustion chamber 31 and guides it to the first exhaust pipe 51.

[0049] The ATD 43 is a device for post-treating the exhaust gas discharged from the cylinder 30. As shown in FIG. 4, the ATD 43 is disposed on the outlet side of the second exhaust pipe 52 in the flow of the exhaust gas. The ATD 43 purifies the exhaust gas by removing harmful components such as NOx (nitrogen oxides), CO (carbon monoxide), HC (hydrocarbons), and particulate matter contained in the exhaust gas.

[0050] The ATD 43 includes a DPF device 44 and an SCR device 45. SCR is an abbreviation for Selective Catalytic Reduction. The DPF device 44 and the SCR device 45 are connected to each other by a connecting pipe 54.

[0051] The DPF device 44 removes carbon monoxide, nitrogen monoxide, particulate matter, etc. contained in the exhaust gas through a schematic oxidation catalyst and a filter housed in the DPF case 44a shown in FIG. 1 and the like. The oxidation catalyst is composed of platinum or the like and is a catalyst for oxidizing (burning) unburned fuel, carbon monoxide, nitrogen monoxide, etc. contained in the exhaust gas. The filter is arranged on the downstream side of the exhaust gas from the oxidation catalyst and is configured as, for example, a full-flow type filter. The filter collects particulate matter contained in the exhaust gas treated by the oxidation catalyst.

[0052] As shown in FIGS. 1 and 2, the DPF case 44a is composed of an elongated substantially cylindrical hollow member. The DPF case 44a is attached above the engine body 1 so as to extend in the longitudinal direction of the engine 100. The DPF case 44a is attached on the exhaust side (the side where the supercharger 24 and the exhaust manifold 42 are located) in the width direction of the engine 100 rather than the SCR case 45a described later.

[0053] As shown in FIG. 2, the inlet of the exhaust gas in the DPF case 44a (that is, the portion connected to the exhaust pipe 41) is formed at the end portion on the side closer to the cooling fan 6 in the longitudinal direction of the DPF case 44a.

[0054] In this way, the inlet of the exhaust gas of the DPF device 44 and the outlet of the exhaust gas of the supercharger 24 are located on different sides from each other in the longitudinal direction of the engine 100. Thereby, the second exhaust pipe 52 connecting the DPF device 44 and the supercharger 24 can be formed relatively long.

[0055] Inside the DPF device 44, the exhaust gas flows from the side closer to the cooling fan 6 toward the side closer to the flywheel housing 61. The exhaust gas that has passed through the DPF device 44 flows into the connecting pipe 54. The connecting pipe 54 has a linear portion arranged substantially parallel to the DPF device 44 and the SCR device 45. In the connecting pipe 54, the exhaust gas flows from the side closer to the flywheel housing 61 toward the side closer to the cooling fan 6. In the connecting pipe 54, the exhaust gas is mixed with urea supplied from a urea supply device (not shown). Then, the exhaust gas flows from the connecting pipe 54 into the SCR device 45.

[0056] The SCR device 45 removes NOx contained in the exhaust gas through an SCR catalyst and a slip catalyst housed in an SCR case 45a shown in FIG. 1 and the like. The SCR catalyst is composed of a material such as ceramic that adsorbs ammonia. NOx contained in the exhaust gas is reduced by contacting the SCR catalyst that has adsorbed ammonia and is changed into nitrogen and water. The slip catalyst is used to prevent ammonia from being released to the outside. The slip catalyst is a catalyst such as platinum that oxidizes ammonia and changes ammonia into nitrogen and water.

[0057] As shown in FIG. 1, the SCR case 45a is composed of an elongated substantially cylindrical hollow member, similar to the DPF case 44a. The SCR case 45a is attached above the engine body 1 so as to extend in the longitudinal direction of the engine 100. The SCR case 45a is attached on the intake side in the width direction of the engine 100 rather than the DPF case 44a. That is, the DPF case 44a and the SCR case 45a are attached side by side in the width direction of the engine 100.

[0058] As shown in FIG. 1, the inlet of the exhaust gas in the SCR case 45a is formed at the end closer to the cooling fan 6 in the longitudinal direction of the SCR case 45a. The outlet of the exhaust gas in the SCR case 45a is formed at the end closer to the flywheel housing 61 in the longitudinal direction of the SCR case 45a.

[0059] Inside the SCR device 45, the exhaust gas flows from the side closer to the cooling fan 6 toward the side closer to the flywheel housing 61. The exhaust gas that has passed through the SCR device 45 is discharged to the outside through the third exhaust pipe 53 connected to the exhaust gas outlet of the SCR case 45a.

[0060] The DPF case 44a and the SCR case 45a are arranged side by side in the width direction of the engine 100. Both the DPF case 44a and the SCR case 45a are mounted on a support base 8 disposed above the head cover 14. The support base 8 is attached to the engine body 1 via a support bracket 9.

[0061] In this way, the ATD43 (DPF device 44 and SCR device 45) is attached above the engine body 1 in a posture in which its longitudinal direction is parallel to the longitudinal direction of the engine 100 (that is, a posture parallel to the crankshaft 10). As described above, by arranging the elongated ATD43 along the longitudinal direction of the engine 100, even if the length of the ATD43 changes according to the specifications of the engine 100, the width direction of the engine 100 can be shortened. Therefore, the engine 100 of the present embodiment can achieve compactness in the width direction, and is preferably applied to, for example, a small tractor that needs to accommodate the engine inside a narrow bonnet.

[0062] Subsequently, the configuration and arrangement of the second exhaust pipe 52 that connects the supercharger 24 and the DPF device 44 of the ATD43 will be described with reference to FIGS. 1 to 3.

[0063] As shown in FIGS. 1 and 2, the second exhaust pipe 52 is formed so as to bypass the lower side of the supercharger 24. The second exhaust pipe 52 includes an upstream portion 52a, an intermediate portion (linear portion) 52b, and a downstream portion 52c.

[0064] As shown in FIG. 2, when viewed in the direction along the width direction of the engine 100, the upstream portion 52a has a horizontally U-shaped bent configuration. One end of the upstream portion 52a in the longitudinal direction is connected to the turbine 25 side of the supercharger 24, and the other end in the longitudinal direction is connected to the intermediate portion 52b. The upstream portion 52a guides the exhaust gas that has passed through the turbine 25 of the supercharger 24 to the intermediate portion 52b.

[0065] The upstream portion 52a is arranged closer to the flywheel housing 61 than the supercharger 24 in the longitudinal direction of the engine 100. As shown in FIG. 3, when viewed in the direction along the longitudinal direction of the engine 100, the upstream portion 52a is arranged to extend in a direction including the height direction component of the engine 100.

[0066] The intermediate portion 52b is a portion that connects the upstream portion 52a and the downstream portion 52c, and guides the exhaust gas led from the upstream portion 52a to the downstream portion 52c. The intermediate portion 52b is composed of a straight pipe. The intermediate portion 52b is arranged to extend in the longitudinal direction of the engine 100. The exhaust gas in the intermediate portion 52b flows from the side closer to the flywheel housing 61 to the side closer to the cooling fan 6.

[0067] As shown in FIGS. 1 and 2, the intermediate portion 52b is in the vicinity of the upper end portion of the cylinder block 12 and is arranged below the supercharger 24. When viewed in the direction along the width direction of the engine 100, as shown in FIG. 2, the intermediate portion 52b is arranged in the vicinity below the supercharger 24. That is, the supercharger 24 and the intermediate portion 52b are arranged adjacent to each other in the vertical direction.

[0068] As shown in FIG. 3, when viewed in the direction along the longitudinal direction of the engine 100, the intermediate portion 52b is arranged inside the supercharger 24. Focusing on the end portion 24a on the side far from the cylinder 30 among both ends of the supercharger 24 in the third direction, the intermediate portion 52b is arranged closer to the cylinder 30 than the end portion 24a. Therefore, when viewed from above along the height direction of the engine 100 (i.e., in plan view of the engine 100), the intermediate portion 52b has a portion completely hidden by the supercharger 24.

[0069] As shown in FIGS. 1 and 3, the middle portion 52b is disposed laterally of the exhaust manifold 42 positioned below the supercharger 24. The middle portion 52b is disposed outside the exhaust manifold 42 in the width direction of the engine 100.

[0070] As shown in FIG. 3, the middle portion 52b is disposed adjacent to the exhaust manifold 42 in the width direction of the engine 100. When looking at the exhaust side surface of the engine 100 in the direction along the width direction of the engine 100, as shown in FIG. 2, the middle portion 52b overlaps a part of the exhaust manifold 42. That is, a part (lower portion) of the exhaust manifold 42 is hidden by the middle portion 52b.

[0071] Specifically, the lower end of the middle portion 52b is positioned below the lower end of the exhaust manifold 42. The upper end of the middle portion 52b is positioned below the upper end of the exhaust manifold 42. That is, the supercharger 24 and the exhaust manifold 42 are disposed above the lower end of the middle portion 52b.

[0072] As shown in FIG. 2, when viewed in the direction along the width direction of the engine 100, the downstream portion 52c has a shape bent in a substantially L shape. One end in the longitudinal direction of the downstream portion 52c is connected to the middle portion 52b, and the other end is connected to the exhaust gas inlet of the DPF device 44. The downstream portion 52c guides the exhaust gas that has passed through the middle portion 52b to the DPF device 44.

[0073] In the longitudinal direction of the engine 100, the downstream portion 52c is disposed closer to the cooling fan 6 than the supercharger 24. The downstream portion 52c has a portion disposed so as to extend in a direction including a component in the height direction of the engine 100, as shown in FIG. 2.

[0074] With the above configuration, in the vicinity of the exhaust manifold 42, the supercharger 24 and the second exhaust pipe 52 can be arranged compactly, and the length of the engine 100 in the width direction can be made compact.

[0075] Also, as shown in FIGS. 1 and 3, by arranging the second exhaust pipe 52 near the upper end of the cylinder block 12, a wide space for arranging other devices can be formed below the supercharger 24 and the second exhaust pipe 52. These other devices can include, for example, auxiliary machines such as an air compressor. Thus, even on the premise that the length of the engine 100 in the width direction hardly changes, various auxiliary machines can be attached to the engine body 1 of the engine 100 as necessary, so that the degree of freedom in the layout of the components around the engine 100 can be increased.

[0076] Next, the protection structure of the oil seal 63 in the engine 100 of the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a partial cross-sectional view showing the oil seal 63 and the seal cover 64. FIG. 7 is a partial perspective view showing the scale for identifying the phase of the crankshaft 10.

[0077] As shown in FIG. 6, in the engine 100 of the present embodiment, an oil seal 63 is provided to fill the gap between the outer peripheral surface of the crankshaft 10 and the crankcase 62 attached to the cylinder block 12. The oil seal 63 is composed of, for example, resin (rubber).

[0078] By providing this oil seal 63, it is possible to prevent the engine oil in the crankcase 62 from scattering to the outside due to the rotation of the crankshaft 10.

[0079] The engine 100 of the present embodiment is provided with a seal cover 64 for protecting the oil seal 63. As shown in FIGS. 2 and 6, this seal cover 64 is provided on the opposite side of the cylinder block 12 across the oil seal 63 in the axial direction of the crankshaft 10. The seal cover 64 is arranged in the vicinity of the crankcase 62.

[0080] This can avoid the adhesion of dust from the outside and paint or the like during the painting of the engine 100 to the oil seal 63, so that the deterioration of the oil seal 63 can be suppressed and its lifespan can be maintained for a long time.

[0081] As shown in FIG. 6, the seal cover 64 is fixed to the crankshaft 10 via bolts or the like together with a pulley 65 for transmitting the power from the crankshaft 10 to the cooling fan 6. That is, the seal cover 64 rotates as the crankshaft 10 rotates.

[0082] As shown in FIG. 7, a rotation-side scale 64a, which is a scale for externally checking the phase of the crankshaft 10, is formed on the outer peripheral surface of the seal cover 64. Thereby, the rotation-side scale 64a can be provided at a position close to the fixed-side scale 62a formed on the crankcase 62, making it easier to check the positional deviation between the fixed-side scale 62a and the rotation-side scale 64a and improving visibility. As a result, during the assembly and maintenance of the engine 100, the phase of the crankshaft 10 can be easily checked, improving workability.

[0083] As described above, the engine 100 of the present embodiment includes an engine body 1, a crankshaft 10, a cooling fan 6, an exhaust manifold 42, a supercharger 24, an ATD 43, and a second exhaust pipe 52. When the height direction of the engine 100 is defined as the first direction, the crankshaft 10 extends in a second direction perpendicular to the first direction. The cooling fan 6 is disposed on one side of the engine body 1 in the second direction. The supercharger 24 is driven by the exhaust gas from the exhaust manifold 42. The ATD 43 purifies the exhaust gas from the exhaust manifold 42. The second exhaust pipe 52 connects the supercharger 24 and the ATD 43. The ATD 43 is disposed in a posture where its longitudinal direction is parallel to the second direction. The second exhaust pipe 52 is connected to the cooling fan 6 side of the ATD 43 in the second direction. The second exhaust pipe 52 is disposed on the side of the exhaust manifold 42 and passes below the supercharger 24.

[0084] As a result, the second exhaust pipe 52 can be arranged so as not to project outside the supercharger 24, and while making the engine 100 more compact, a more reasonable layout of the second exhaust pipe 52 can be obtained. Also, since the second exhaust pipe 52 can be formed relatively long, it can absorb thermal expansion due to high-temperature exhaust gas.

[0085] Further, in the engine 100 of the present embodiment, the second exhaust pipe 52 has an intermediate portion 52b extending parallel to the second direction. The exhaust manifold 42 and the supercharger 24 are disposed above the lower end of the intermediate portion 52b.

[0086] As a result, by arranging the supercharger 24 having a relatively large outer shape upward, it is possible to easily secure a space for arranging the second exhaust pipe 52 and other devices below it.

[0087] Further, in the engine 100 of the present embodiment, when a direction perpendicular to both the first direction and the second direction is defined as the third direction, the supercharger 24 is disposed on one side of the engine body 1 in the third direction. When viewed in the direction along the third direction, the intermediate portion 52b is disposed such that at least a part thereof overlaps with the exhaust manifold 42 and is vertically adjacent to the supercharger 24. When viewed in the direction along the second direction, the intermediate portion 52b is disposed adjacent to the exhaust manifold 42 in the third direction.

[0088] In this way, by arranging the second exhaust pipe 52, the supercharger 24, and the exhaust manifold 42 in a collective space in the middle portion of the engine 100 in the first direction, the length of the engine 100 in the third direction can be made compact. Also, a wide space can be secured for arranging other devices below the second exhaust pipe 52.

[0089] Further, in the engine 100 of the present embodiment, the supercharger 24 is disposed on one side of the engine body 1 in the third direction. The second exhaust pipe 52 is disposed closer to the engine body 1 in the third direction than the end portion 24a of the supercharger 24 that is far from the engine body 1 in the third direction.

[0090] As a result, in the third direction, the second exhaust pipe 52 can be arranged so as to be housed inside the supercharger 24. Therefore, the engine 100 can be made more compact in the third direction.

[0091] Although the preferred embodiments of the present invention have been described above, the above configuration can be modified as follows, for example.

[0092] The middle portion 52b of the second exhaust pipe 52 may be arranged to extend not parallel to the second direction but in an oblique direction including a component in the second direction.

[0093] ATD43 may be provided with only the DPF device 44. In this case, the second exhaust pipe 52 may be arranged so that the middle portion 52b of the second exhaust pipe 52 passes above the supercharger 24.

[0094] When looking at the exhaust side surface of the engine 100 in a direction along the width direction of the engine 100, all of the exhaust manifold 42 may be arranged so as to be hidden by the middle portion 52b. In other words, the upper end of the middle portion 52b may be located above the upper end of the exhaust manifold 42.

[0095] When viewed in plan, the longitudinal direction of the substantially rectangular engine 100 may be perpendicular to the direction in which the crankshaft 10 extends. Also, the engine 100 may be substantially square when viewed in plan.

Explanation of Reference Numerals

[0096] 6 Cooling fan 10 Crankshaft 24 Supercharger 42 Exhaust manifold 43 ATD (Exhaust gas purification device) 52 Second exhaust pipe (connection pipe) 100 Engine

Claims

1. A supercharger, An exhaust gas purification device; a connecting pipe that connects the turbocharger and the exhaust gas purification device, The engine, wherein the connecting pipe overlaps with the turbocharger in a plan view.

2. 2. The engine of claim 1, The connecting pipe has a straight portion, The engine, wherein the straight portion overlaps with the turbocharger in a plan view.

3. 3. The engine of claim 2, the connecting pipe has a downstream portion; an engine, wherein one end of the downstream portion is connected to the straight portion, and the other end is connected to the exhaust gas purification device.

4. 4. The engine of claim 3, The connection portion has an upstream portion, an upstream portion having one end connected to the straight portion and another end connected to the turbocharger;

5. 5. An engine according to claim 4, The straight portion is connected to the turbocharger via the upstream portion, An engine, wherein one end of the straight portion is connected to the downstream portion and the other end is connected to the upstream portion.

6. 6. An engine according to any one of claims 1 to 5, The engine is characterized in that the exhaust gas purification device is attached to an upper side of an engine body.

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