engine

Abstract

To provide a compact engine while avoiding damage of components or the like due to thermal expansion.SOLUTION: An engine includes an exhaust manifold, a supercharger, an exhaust emission control device, and a connecting pipe for connecting the supercharger and the exhaust emission control device. The connecting pipe guides exhaust gas discharged from the exhaust manifold through a turbine of the supercharger to the exhaust emission control device. The connecting pipe has a downstream portion having one end connected to the supercharger and the other end connected to the exhaust emission control device. The one end of the downstream portion is positioned on a width direction outer side of the engine relative to the other end of the downstream portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine equipped with a turbocharger and an exhaust gas purification device, and more particularly to the arrangement of a connecting pipe that connects the turbocharger and the exhaust gas purification device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, engines in which an exhaust gas purification device is disposed above the engine body have been known. Patent Document 1 discloses this type of engine.

[0003] The engine of Patent Document 1 is configured such that the exhaust gas inlet of the DPF as an exhaust gas purification device is provided close to the exhaust gas outlet of the turbocharger, forming a short exhaust gas passage between the turbocharger and the DPF. DPF is an abbreviation for Diesel Particulate Filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-72722 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the temperature of exhaust gas is generally high, the configuration of Patent Document 1 above generates thermal expansion in the exhaust gas inlet pipe of the DPF and the housing support, which constitute the exhaust gas passage, and there is a risk of damage to the connections with other parts.

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

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a compact engine while avoiding damage to parts, etc. due to thermal expansion. [Means for solving the problem]

[0008] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0009] According to an aspect of the present invention, there is provided an engine having the following configuration: That is, this engine includes an exhaust manifold, a turbocharger, an exhaust gas purification device, and a connecting pipe connecting the turbocharger and the exhaust gas purification device, the connecting pipe directs exhaust gas from the exhaust manifold, which has passed through a turbine of the turbocharger, to the exhaust gas purification device, the connecting pipe has a downstream portion having one end connected to the turbocharger and the other end connected to the exhaust gas purification device, and the one end of the downstream portion is located outside the other end of the downstream portion in the width direction of the engine.

[0010] The connecting pipe may have a straight portion, and one end of the downstream portion may be connected to the turbocharger via the straight portion, and the straight portion may be arranged to pass through one side of the turbocharger in a height direction.

[0011] The downstream portion may have a curved shape with the one end connected to the straight portion and the other end connected to the exhaust gas purification device.

[0012] The turbocharger may be located outboard of the exhaust manifold in the width direction of the engine.

[0013] The exhaust gas purification device may be attached to an upper side of an engine body. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a configuration of an engine according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a side view taken along the width direction of the engine. [Diagram 3] Side view of the engine seen from the flywheel housing side. [Figure 4] 1 is a conceptual diagram showing the flow of intake and exhaust air in an engine. [Diagram 5] FIG. [Figure 6] FIG. 4 is a partial cross-sectional view showing an oil seal and a seal cover. [Figure 7] FIG. 4 is a partial perspective view showing a crankshaft phase scale; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0016] 1 is a diesel engine that is mounted on, for example, agricultural machinery such as tractors and construction machinery 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, a basic configuration of the engine body 1 of the engine 100 will be described. In the following description, the up-down direction of the engine 100 shown in FIG. 1 will be referred to as the height direction. The engine 100 has a generally elongated rectangular shape in a plan view, and its longitudinal direction coincides with the direction in which the crankshaft 10 extends. In the following description, the longitudinal direction of the engine 100 means the axial direction of the crankshaft 10. A direction perpendicular to both the height direction and the longitudinal direction will be 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 etc., the engine body 1 is mainly composed of an oil pan 11, a cylinder block 12, a cylinder head 13, and a head cover 14, which are arranged in this order from the bottom.

[0019] The oil pan 11 is provided under (at the lower end of) the engine 100. The oil pan 11 is formed in the shape of a container with an open top. 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 in by an engine oil pump (not shown) provided in the engine body 1, and then supplied to various parts of the engine body. After lubricating the engine body 1, the engine oil is returned to the oil pan 11 and stored therein.

[0021] However, if a vehicle equipped with engine 100 is stored for a long period of time without being used, the engine oil may move downward due to gravity, resulting in an insufficient amount of oil film on each moving part that needs to be lubricated.

[0022] As a countermeasure to this phenomenon, if engine 100 has not been operated for a long period of time, there is a method in which engine oil is replenished from a relatively high position before starting, so that when engine 100 is started, a sufficient amount of oil film is achieved in a short period of time to lubricate each part of engine 100.

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

[0024] This makes it possible to select an oil refill port 90 that facilitates refilling of engine oil depending on the posture of the vehicle body on which the engine 100 is mounted and the positions of surrounding obstacles, thereby improving the convenience of the engine 100.

[0025] The cylinder block 12 is attached to the upper side of the oil pan 11. A recess is formed in the lower part of the cylinder block 12 for accommodating the crankshaft 10 and the like. 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 housed in each cylinder 30. The piston inside the cylinder 30 can move up and down. The piston is connected to the crankshaft 10 via a connecting rod (not shown). The crankshaft 10 rotates as the piston reciprocates in each cylinder 30.

[0027] 2 and other figures, the cylinder head 13 is attached to the upper side of the cylinder block 12. The cylinder head 13 and the cylinder block 12 form combustion chambers 31 shown in FIG.

[0028] The head cover 14 is provided on the upper side of the cylinder head 13. A valve mechanism including push rods and rocker arms (not shown) for operating intake valves and exhaust valves (not shown) is housed inside the head cover 14.

[0029] A cooling fan 6 is rotatably attached to one side of the engine body 1 in the longitudinal direction of the engine 100. The cooling fan 6 rotates when power is transmitted from the crankshaft 10. The cooling fan 6 generates an air flow as it rotates, and passes the air through a radiator (not shown) for cooling the coolant of the engine 100, while blowing the air against the engine 100. As a result, the engine 100 is cooled.

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

[0031] Next, the configuration of the engine 100 of this embodiment will be briefly described with reference to FIG. 4 etc., focusing on the flow of intake air and exhaust gas.

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

[0033] The intake section 2 draws in air from the outside and 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 allows air drawn in from the outside to flow inside.

[0035] The throttle valve 22 is disposed in the middle of the intake passage. The throttle valve 22 changes its opening in accordance with a control command from a control device (not shown) to change the cross-sectional area of ​​the intake passage. This makes it possible to adjust the amount of air supplied to the intake manifold 23.

[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 the air to the combustion chambers 31 formed in each cylinder 30.

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

[0038] An exhaust manifold 42, which will be described later, is attached to the lateral surface of the cylinder head 13 opposite the side to which the intake manifold 23 is attached. The exhaust manifold 42 is disposed on the opposite side to the intake manifold 23 with respect to the imaginary 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 illustrates the exhaust side of the engine 100.

[0039] The power generating unit 3 is composed of a plurality of (four in this embodiment) cylinders 30. The power generating unit 3 burns fuel in a combustion chamber 31 formed in each cylinder 30, thereby generating power for reciprocating a piston.

[0040] Specifically, in each combustion chamber 31, air supplied from the intake manifold 23 is compressed, and then fuel supplied from a fuel supply unit (not shown) is injected. This causes combustion in the combustion chamber 31, causing the piston to reciprocate up and down. The power thus obtained is transmitted to an appropriate device downstream of the power via the crankshaft 10, etc.

[0041] 4, the turbocharger 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 manner, the compressor 27 rotates in accordance with the rotation of the turbine 25, which rotates using the exhaust gas discharged from the combustion chamber 31, whereby air purified by an air cleaner (not shown) is compressed and forcibly sucked in.

[0042] As shown in Fig. 1 etc., the turbocharger 24 is disposed above the exhaust manifold 42. The turbocharger 24 is disposed between the exhaust manifold 42 and an ATD 43 described below on the side surface (exhaust side) shown in Fig. 2. In addition, as shown in Fig. 3, when viewed in a direction along the longitudinal direction of the engine 100, the turbocharger 24 is located outside the exhaust manifold 42 in the width direction of the engine 100.

[0043] 3, the turbocharger 24 is disposed such that at least a portion of it is located below the ATD 43 (specifically, the DPF device 44 described later) when viewed in the longitudinal direction of the engine 100. This allows the engine 100 to be made compact in the width direction.

[0044] The turbocharger 24 is disposed so 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 of the turbocharger 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] 4 exhausts 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 constitutes an exhaust gas passage, and allows the exhaust gas discharged from the combustion chamber 31 to flow inside the exhaust pipe 41. 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 made of metal pipes.

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

[0048] The exhaust manifold 42 is connected to an 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 that performs aftertreatment of 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 exhaust gas. The ATD 43 purifies the exhaust gas by removing harmful components such as NOx (nitrogen oxides), CO (carbon monoxide), and 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 an oxidation catalyst and a filter (not shown) housed in a DPF case 44a shown in Fig. 1 etc. The oxidation catalyst is made 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 disposed downstream of the oxidation catalyst in the exhaust gas flow, and is configured as, for example, a fall-flow type filter. The filter collects particulate matter contained in the exhaust gas treated by the oxidation catalyst.

[0052] 1 and 2, the DPF case 44a is made of an elongated, generally cylindrical, hollow member. The DPF case 44a is attached to the upper side of the engine body 1 so as to extend in the longitudinal direction of the engine 100. The DPF case 44a is attached closer to the exhaust side (the side where the turbocharger 24 and the exhaust manifold 42 are located) in the width direction of the engine 100 than an SCR case 45a described later.

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

[0054] In this manner, the exhaust gas inlet of the DPF device 44 and the exhaust gas outlet of the turbocharger 24 are located on different sides in the longitudinal direction of the engine 100. This allows the second exhaust pipe 52 connecting the DPF device 44 and the turbocharger 24 to be formed relatively long.

[0055] Inside the DPF device 44, exhaust gas flows from the side closer to the cooling fan 6 to the side closer to the flywheel housing 61. The exhaust gas that has passed through the DPF device 44 flows into a connecting pipe 54. The connecting pipe 54 has a straight portion disposed generally 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 to 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). The exhaust gas then flows from the connecting pipe 54 to the SCR device 45.

[0056] The SCR device 45 removes NOx contained in exhaust gas through an SCR catalyst and a slip catalyst housed in an SCR case 45a shown in FIG. 1 etc. The SCR catalyst is made of a material such as ceramic that adsorbs ammonia. When NOx contained in exhaust gas comes into contact with the SCR catalyst that has adsorbed ammonia, it is reduced and changes 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 oxidizes the ammonia and changes it into nitrogen and water.

[0057] 1, the SCR case 45a is configured from an elongated, generally cylindrical, hollow member, similar to the DPF case 44a. The SCR case 45a is attached to the upper side of the engine body 1 so as to extend in the longitudinal direction of the engine 100. The SCR case 45a is attached closer to the intake side in the width direction of the engine 100 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] 1, the exhaust gas inlet of the SCR case 45a is formed at an end of the SCR case 45a that is closer to the cooling fan 6 in the longitudinal direction. The exhaust gas outlet of the SCR case 45a is formed at an end of the SCR case 45a that is closer to the flywheel housing 61 in the longitudinal direction.

[0059] Inside the SCR device 45, the exhaust gas flows from the side closer to the cooling fan 6 to the side closer to the flywheel housing 61. The exhaust gas that has passed through the SCR device 45 is discharged to the outside via a third exhaust pipe 53 connected to an 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 attached onto a support base 8 arranged on the upper side of the head cover 14. The support base 8 is attached to the engine body 1 via a support bracket 9.

[0061] In this manner, the ATD 43 (the DPF device 44 and the SCR device 45) is attached to the upper side of the engine body 1 with its longitudinal direction parallel to the longitudinal direction of the engine 100 (i.e., parallel to the crankshaft 10). By arranging the elongated ATD 43 along the longitudinal direction of the engine 100 as described above, the width direction of the engine 100 can be shortened even if the length of the ATD 43 changes depending on the specifications of the engine 100. Therefore, the engine 100 of this embodiment can be made compact in the width direction, and is suitable for application to, for example, a small tractor or the like that needs to house the engine inside a narrow bonnet.

[0062] Next, the configuration and arrangement of the second exhaust pipe 52 that connects the turbocharger 24 and the DPF device 44 of the ATD 43 will be described with reference to FIGS.

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

[0064] 2, the upstream section 52a has a sideways U-shaped bent shape when viewed in the width direction of the engine 100. One longitudinal end of the upstream section 52a is connected to the turbine 25 side of the turbocharger 24, and the other longitudinal end is connected to the intermediate section 52b. The upstream section 52a guides the exhaust gas that has passed through the turbine 25 of the turbocharger 24 to the intermediate section 52b.

[0065] The upstream portion 52a is disposed on a side closer to the flywheel housing 61 than the turbocharger 24 in the longitudinal direction of the engine 100. As shown in Fig. 3, the upstream portion 52a is disposed so as to extend in a direction including a height component of the engine 100 when viewed in a direction along the longitudinal direction of the engine 100.

[0066] The intermediate section 52b is a section that connects the upstream section 52a and the downstream section 52c, and guides the exhaust gas guided from the upstream section 52a to the downstream section 52c. The intermediate section 52b is configured of a straight pipe. The intermediate section 52b is disposed so as to extend in the longitudinal direction of the engine 100. The exhaust gas in the intermediate section 52b flows from the side close to the flywheel housing 61 to the side close to the cooling fan 6.

[0067] 1 and 2, the intermediate portion 52b is disposed near the upper end portion of the cylinder block 12 and below the turbocharger 24. When viewed in the width direction of the engine 100, the intermediate portion 52b is disposed near the lower portion of the turbocharger 24 as shown in Fig. 2. That is, the turbocharger 24 and the intermediate portion 52b are disposed adjacent to each other in the up-down direction.

[0068] 3, the intermediate portion 52b is disposed on the inside of the supercharger 24 when viewed in a direction along the longitudinal direction of the engine 100. When focusing on the end 24a, which is farther from the cylinder 30, of both ends of the supercharger 24 in the third direction, the intermediate portion 52b is disposed closer to the cylinder 30 than the end 24a. Therefore, when viewed from above along the height direction of the engine 100 (i.e., in a plan view of the engine 100), the intermediate portion 52b has a portion that is completely hidden by the supercharger 24.

[0069] 1 and 3, the intermediate portion 52b is disposed on a side of the exhaust manifold 42 located below the turbocharger 24. The intermediate portion 52b is disposed outside the exhaust manifold 42 in the width direction of the engine 100.

[0070] As shown in Fig. 3, the intermediate portion 52b is disposed adjacent to the exhaust manifold 42 in the width direction of the engine 100. When the exhaust side surface of the engine 100 is viewed in a direction along the width direction of the engine 100, the intermediate portion 52b overlaps with a part of the exhaust manifold 42, as shown in Fig. 2. In other words, a part (lower part) of the exhaust manifold 42 is hidden by the intermediate portion 52b.

[0071] Specifically, the lower end of the intermediate portion 52b is located lower than the lower end of the exhaust manifold 42. The upper end of the intermediate portion 52b is located lower than the upper end of the exhaust manifold 42. In other words, the turbocharger 24 and the exhaust manifold 42 are disposed above the lower end of the intermediate portion 52b.

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

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

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

[0075] 1 and 3, by arranging the second exhaust pipe 52 near the upper end of the cylinder block 12, a large space is formed below the turbocharger 24 and the second exhaust pipe 52 in which other devices can be arranged. Examples of such other devices include auxiliary devices such as an air compressor. This allows various auxiliary devices to be attached to the engine body 1 of the engine 100 as needed, even under the assumption that the width of the engine 100 remains almost constant, thereby increasing the degree of freedom in the layout of parts around the engine 100.

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

[0077] 6, the engine 100 of this embodiment is provided with an oil seal 63 for filling the gap between the outer circumferential surface of the crankshaft 10 and a crankcase 62 attached to the cylinder block 12. The oil seal 63 is made of, for example, resin (rubber).

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

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

[0080] This makes it possible to prevent external debris, paint when painting the engine 100, and the like from adhering to the oil seal 63, thereby suppressing deterioration of the oil seal 63 and maintaining its lifespan longer.

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

[0082] 7, a rotation-side scale 64a is formed on the outer circumferential surface of the seal cover 64 as a scale for checking the phase of the crankshaft 10 from the outside. This allows the rotation-side scale 64a to be provided in 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, the phase of the crankshaft 10 can be easily checked during assembly and maintenance of the engine 100, improving workability.

[0083] As described above, the engine 100 of this embodiment includes the engine body 1, the crankshaft 10, the cooling fan 6, the exhaust manifold 42, the turbocharger 24, the ATD 43, and the second exhaust pipe 52. When the height direction of the engine 100 is defined as a 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 turbocharger 24 is driven by 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 turbocharger 24 and the ATD 43. The ATD 43 is disposed in a position in which the 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 so as to pass below the turbocharger 24.

[0084] This allows the second exhaust pipe 52 to be positioned so as not to protrude outward from the turbocharger 24, thereby achieving a more rational layout of the second exhaust pipe 52 while achieving a compact engine 100. In addition, since the second exhaust pipe 52 can be formed relatively long, it is possible to absorb thermal expansion due to high-temperature exhaust gas.

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

[0086] As a result, by disposing the turbocharger 24, which has a relatively large outer shape, on the upper side, it is possible to easily ensure space below it for disposing the second exhaust pipe 52 and other devices.

[0087] In addition, in the engine 100 of this embodiment, when a direction perpendicular to both the first direction and the second direction is defined as a third direction, the supercharger 24 is disposed on one side of the engine body 1 in the third direction. When viewed in a direction along the third direction, the intermediate portion 52b is disposed so as to overlap at least a portion with the exhaust manifold 42 and adjacent to the supercharger 24 in the vertical direction. When viewed in a 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 turbocharger 24, and the exhaust manifold 42 in a compact space in the middle part 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 below the second exhaust pipe 52 in which other devices can be arranged.

[0089] In the engine 100 of this 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 on a side closer to the engine body 1 in the third direction than an end 24a of the supercharger 24 on a side farther from the engine body 1 in the third direction.

[0090] This allows the second exhaust pipe 52 to be disposed so as to be housed inside the turbocharger 24 in the third direction. Therefore, the engine 100 can be made more compact in the third direction.

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

[0092] The middle portion 52b of the second exhaust pipe 52 may be disposed so as to extend in an oblique direction that does not extend parallel to the second direction, but includes a component of the second direction.

[0093] The ATD 43 may include only the DPF device 44. In this case, the second exhaust pipe 52 may be disposed so that the middle portion 52b of the second exhaust pipe 52 passes above the turbocharger 24.

[0094] When the exhaust side of engine 100 is viewed in the direction along the width direction of engine 100, exhaust manifold 42 may be disposed so that exhaust manifold 42 is entirely hidden by intermediate portion 52b. In other words, the upper end of intermediate portion 52b may be located higher than the upper end of exhaust manifold 42.

[0095] When viewed from above, the longitudinal direction of the approximately rectangular engine 100 may be perpendicular to the extension direction of the crankshaft 10. Also, when viewed from above, the engine 100 may be approximately square. [Explanation of symbols]

[0096] 6 Cooling Fan 10 Crankshaft 24 Turbocharger 42 Exhaust manifold 43 ATD (Exhaust Gas Purification Device) 52 Second exhaust pipe (connecting pipe) 100 Engine

Claims

1. An exhaust manifold; A supercharger, An exhaust gas purification device; an engine including a connecting pipe connecting the turbocharger and the exhaust gas purification device, the connecting pipe directing exhaust gas from the exhaust manifold that has passed through a turbine of the turbocharger to the exhaust gas purification device, The connecting pipe has a straight portion and a downstream portion, One end of the downstream portion is connected to the turbocharger via the straight portion, The other end of the downstream portion is connected to the exhaust gas purification device, the one end of the downstream portion is located outside the other end of the downstream portion in a width direction of the engine, The engine is characterized in that both ends of the straight portion are located outside the exhaust manifold in a width direction of the engine.

2. 2. The engine of claim 1, The engine, wherein the straight portion is disposed so as to pass through one side of the turbocharger in a height direction.

3. 3. The engine of claim 2, The downstream portion has one end connected to the straight portion and the other end connected to the exhaust gas purification device and has a curved shape.

4. An engine according to any one of claims 1 to 3, The engine, wherein the turbocharger is located outside the exhaust manifold in the width direction of the engine.

5. An engine according to any one of claims 1 to 4, The engine is characterized in that the exhaust gas purification device is attached to an upper side of an engine body.

6. An engine as claimed in any one of claims 1 to 5, The straight portion is connected to the turbocharger via an 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.

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