engine

Abstract

The present invention provides an engine that can simultaneously suppress heat damage to components located outside the intake passage and prevent damage to the relief valve. [Solution] The engine comprises an intake passage through which intake air flows, an intercooler provided in the intake passage to cool the intake air, and a relief valve that releases a portion of the intake air from inside the intercooler to outside the intake passage. The relief valve is attached to the intercooler.

Description

Technical Field

[0001] The present invention relates to an engine.

Background Art

[0002] A diesel engine including an intake passage and a relief valve having one end attached to the intake passage and discharging a part of the intake air to the outside is known as a conventional technique (for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, an engine has been proposed in which an intercooler for cooling intake air is provided in an intake passage (intake air passage). Here, for example, if the relief valve is attached upstream of the intercooler in the intake air passage, the intake air before cooling (relatively high temperature) will be discharged by the relief valve, so there is a risk of heat damage to components located outside the intake air passage (for example, electronic components). In addition, the position where the relief valve can be attached downstream of the intercooler in the intake air passage (for example, the intake manifold) is often more likely to vibrate than the intercooler. Therefore, if the relief valve is attached to the above position, there is also a risk of breakage of the relief valve (due to vibration).

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an engine capable of achieving both suppression of heat damage to components located outside the intake air passage and suppression of breakage of the relief valve.

Means for Solving the Problems

[0006] An engine according to one aspect of the present invention comprises an intake passage through which intake air flows, an intercooler provided in the intake passage for cooling the intake air, and a relief valve for releasing a portion of the intake air from inside the intercooler to outside the intake passage, wherein the relief valve is attached to the intercooler. [Effects of the Invention]

[0007] The above configuration makes it possible to suppress both heat damage to components located outside the intake passage and damage to the relief valve. [Brief explanation of the drawing]

[0008] [Figure 1] This is a right side view showing a schematic configuration of an engine according to one embodiment of the present invention. [Figure 2] This is a left side view showing the general configuration of the engine described above. [Figure 3] This is a rear view showing the general configuration of the engine described above. [Figure 4] This is a block diagram schematically showing the configuration of the aftertreatment system for the above engine. [Figure 5] This is a block diagram schematically showing the intake airflow in the intake passage of the engine described above. [Figure 6] This is a bottom view showing the configuration of the intercooler and relief valve installed in the intake passage described above. [Figure 7] This is a front view showing the configuration of the intercooler and the relief valve described above. [Figure 8] This is a cross-sectional view showing the configuration of the intercooler and the relief valve described above. [Figure 9] This is a perspective view from the right rear showing the configuration of the intercooler and relief valve described above. [Figure 10] This is a rear view showing the configuration of the intercooler and the relief valve described above. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] [1. General Engine Configuration] Figures 1, 2, and 3 are a right side view, a left side view, and a rear view, respectively, showing the schematic configuration of an engine 1 according to one embodiment of the present invention. Note that, for convenience, the generator 101 is omitted from Figure 3.

[0011] Engine 1 is installed, for example, on a ship. Engine 1 is connected to a generator 101, which is a driven device 100 installed on the ship. The generator 101 is driven by the rotational power of engine 1 and generates electricity. The electricity generated by the generator 101 is supplied to, for example, power-using equipment (not shown) installed on the ship.

[0012] Furthermore, the engine 1 may be mounted not only on ships, but also on agricultural machinery such as combine harvesters, construction machinery such as hydraulic excavators, etc. Also, the driven device 100 connected to the engine 1 is not limited to a generator 101. For example, the driven device 100 may be a (mechanical) propulsion device that generates thrust for the ship using the rotational power of the engine 1.

[0013] Engine 1 comprises an engine body 2, an intake passage 3, an exhaust passage 4, a turbocharger 5, and an aftertreatment device 6. The engine body 2 includes a cylinder block 21, a cylinder head 22, a crankshaft 23, a flywheel 24, and an oil pan 25.

[0014] Here, the directions in this embodiment are defined as follows. The direction in which the center line 23C of the crankshaft 23 extends (also referred to as the axial direction of the crankshaft 23) is defined as the front-rear direction. The direction in which the flywheel 24 is located with respect to the cylinder block 21 is defined as "rear", and the opposite direction is defined as "front". Further, the direction in which the cylinder block 21 and the oil pan 25 are arranged in parallel is defined as the vertical direction. The direction in which the oil pan 25 is located with respect to the cylinder block 21 is defined as "down", and the opposite direction is defined as "up". Furthermore, the direction perpendicular to the front-rear direction and the vertical direction is defined as the left-right direction. When viewed from the rear to the front, the left side is defined as "left", and the right side is defined as "right". In the drawings, if necessary, the front is indicated by the symbol "F", the rear by "B", the left by "L", the right by "R", the upper by "U", and the lower by "D".

[0015] The cylinder block 21 is composed of a metal member extending in the front-rear direction and has two cylinder rows 211 (see also FIG. 5 described later). The number of cylinder rows 211 is not limited to two, and for example, it may be one, or it may be a plurality other than two. One cylinder row 211 is arranged in the upper left part of the cylinder block 21, and the other cylinder row 211 is arranged in the upper right part of the cylinder block 21.

[0016] Each cylinder row 211 extends and is located in the front-rear direction. More specifically, each cylinder row 211 is composed of a plurality of cylinders (not shown) arranged in the front-rear direction. As an example, the engine 1 is a V-type 12-cylinder engine. Therefore, the number of cylinders is 12. That is, each cylinder row 211 includes six cylinders. However, the engine 1 is not limited to a V-type 12-cylinder engine. For example, the engine 1 may be a single-cylinder engine or a multi-cylinder engine of an in-line type (that is, a single cylinder row 211). Inside each cylinder, a piston (not shown) composed of a cylindrical metal member is slidably arranged. Above each cylinder, a cylinder head 22 is arranged.

[0017] Each cylinder head 22 has an intake port (not shown) for supplying intake air to the combustion chamber and an exhaust port (not shown) for discharging exhaust gas from the combustion chamber. The above-mentioned combustion chamber is composed of the top surface of the piston, the inner peripheral surface of the cylinder, and the bottom surface of the cylinder head 22.

[0018] An injector (not shown) is attached to each cylinder head 22. More specifically, the above-mentioned injector is attached to the cylinder head 22 such that the tip portion is located in the combustion chamber. The injector injects fuel into the combustion chamber at a predetermined timing from an injection port provided at the tip portion. In this embodiment, the above-mentioned fuel is light oil. However, the fuel is not limited to light oil, and may be, for example, heavy oil, biofuel, and gaseous fuels such as hydrogen gas, etc. The piston reciprocates by the force generated by the combustion of the fuel injected into the combustion chamber. The reciprocating motion of this piston is converted into a rotational motion by the crankshaft 23.

[0019] The supply of fuel to the injector is performed by a fuel supply device (not shown). The above-mentioned fuel supply device is arranged, for example, between the left cylinder bank 211 and the right cylinder bank 211 in the left-right direction.

[0020] The crankshaft 23 is rotatably arranged inside the cylinder block 21 and is connected to each piston. The crankshaft 23 enables the extraction of the rotational power of the engine 1. The rear end of the crankshaft 23 is connected to the generator 101 via the flywheel 24. That is, the crankshaft 23 is connected to the driven device 100 (the generator 101 in this embodiment). The flywheel 24 is provided to absorb the rotational fluctuations of the engine 1 and prevent torsional vibrations and the like.

[0021] The generator 101 is arranged behind the engine body 2. That is, the driven device 100 (the generator 101 in this embodiment) is located on one axial side (the rear in this embodiment) of the crankshaft 23 with respect to the engine body 2.

[0022] The oil pan 25 is made up of a box-shaped metal member with at least an opening at the top. The oil pan 25 stores lubricating oil used to lubricate various parts of the engine body 2.

[0023] The intake passage 3 includes an intake pipe 31, an intercooler 32, a relief valve 33, and an intake manifold 34. In other words, the engine 1 comprises an intake pipe 31, an intercooler 32, a relief valve 33, and an intake manifold 34. The intake pipe 31, intercooler 32, relief valve 33, and intake manifold 34 are provided in the intake passage 3. The configuration of the relief valve 33 will be described later.

[0024] The intake pipes 31 and intake manifolds 34 are provided corresponding to two cylinder rows 211. That is, there are two intake pipes 31 and two intake manifolds 34. One intake pipe 31 is located at the left rear of the engine body 2, and the other intake pipe 31 is located at the right rear of the engine body 2.

[0025] Each intake pipe 31 is made of a tubular metal member. One end of each intake pipe 31 opens to the atmosphere via an intake silencer 31a, and the other end is connected to an intercooler 32. The intake silencer 31a is provided to reduce the noise generated when each intake pipe 31 draws in air and to remove dust and other particles contained in the inhaled air.

[0026] The intercooler 32 is positioned above and rear of the engine body 2. That is, the intercooler 32 is positioned on one side of the axial direction (rear in this embodiment) relative to the center of the engine body 2 in the axial direction of the crankshaft 23 (front-rear direction in this embodiment). The configuration of the intercooler 32 will be described later.

[0027] Each intake manifold 34 extends in the front-to-back direction. One intake manifold 34 (the left one) is positioned closer to the left cylinder row 211, and the other intake manifold 34 (the right one) is positioned closer to the right cylinder row 211. Specifically, one intake manifold 34 (the left one) is positioned to the upper right of the left cylinder row 211, and the other intake manifold 34 (the right one) is positioned to the upper left of the right cylinder row 211. Details of the intake airflow in the intake passage 3 will be described later.

[0028] The exhaust passage 4 includes an exhaust manifold 41 and an exhaust pipe 42. The exhaust manifold 41, like the intake manifold 34, is provided to correspond to two cylinder rows 211. That is, there are two exhaust manifolds 41. Each exhaust manifold 41 is positioned extending in the front-rear direction.

[0029] One (left) exhaust manifold 41 is positioned closer to the left cylinder row 211, and the other (right) exhaust manifold 41 is positioned closer to the right cylinder row 211. Specifically, one (left) exhaust manifold 41 is positioned to the lower left of the left cylinder row 211, and the other (right) exhaust manifold 41 is positioned to the lower right of the right cylinder row 211.

[0030] Each exhaust manifold 41 collects the exhaust gas discharged from each combustion chamber and discharges it into the exhaust pipe 42. The exhaust pipe 42 discharges the exhaust gas collected in each exhaust manifold 41 to the outside of the engine 1 via the aftertreatment device 6. The exhaust gas contains nitrogen oxides such as nitric oxide, carbon monoxide, and PM (Particulate Matter; particulate matter) such as soot.

[0031] The turbocharger 5 enables an increase in the amount of intake air supplied to each combustion chamber. More specifically, the turbocharger 5 includes a compressor 51 located in the intake pipe 31 and a turbine 52 located in the exhaust pipe 42. The turbine 52 rotates when struck by exhaust gas flowing through the exhaust pipe 42. The compressor 51 is driven by the rotational power of the turbine 52, transmitted via a connecting shaft (not shown) that connects the compressor 51 and the turbine 52, and compresses the air (intake) drawn in from outside the engine 1. This increases the amount of intake air supplied to each combustion chamber.

[0032] Furthermore, the engine 1 may be configured in which the turbocharger 5 is removed. Alternatively, the engine 1 may be configured to have a supercharging mechanism other than the turbocharger 5 instead of the turbocharger 5.

[0033] The aftertreatment device 6 purifies the exhaust gas discharged from the engine body 2. More details are as follows. Figure 4 is a schematic block diagram showing the configuration of the aftertreatment device 6. In Figure 4, the exhaust flow is indicated by solid arrows, and the supply of urea solution is indicated by dashed arrows. The aftertreatment device 6 includes a urea solution injection device 61 and a selective reduction catalyst 62.

[0034] The urea water injection device 61 injects urea water into the exhaust gas that is discharged from the engine body 2 and passes through the exhaust passage 4. Ammonia is generated from the injected urea water. The generated ammonia flows with the exhaust gas toward the selective reduction catalyst 62.

[0035] The selective reduction catalyst 62 selectively reduces nitrogen oxides contained in the exhaust gas in the presence of ammonia. Specifically, nitrogen oxides are reduced to nitrogen and water. The selective reduction catalyst 62 is housed in the SCR case 62C. The SCR case 62C also contains a catalyst (not shown) that prevents the release of ammonia to the outside of the engine 1 by oxidizing the ammonia that flows through without being used in the above reduction and converting it into nitrogen, nitric oxide, water, etc.

[0036] [2. Intake airflow in the intake passage] Figure 5 is a schematic block diagram showing the intake airflow in the intake passage 3. In Figure 5, the intake airflow is indicated by solid arrows. The intake air flows through the intake passage 3. More specifically, the intake manifold 31 draws in air from outside the engine 1, causing the air to flow into the intake passage 3 (intake manifold 31). The air drawn into the intake manifold 31, i.e., the intake air, is compressed by the compressor 51, becoming high temperature and high pressure, and then flows into the intercooler 32.

[0037] When the relief valve 33 is driven (connecting the inside of the intercooler 32 to the outside of the intake passage 3), some of the intake air that flows into the intercooler 32 is released into the atmosphere. In other words, the relief valve 33 releases a portion of the intake air from inside the intercooler 32 to the outside of the intake passage 3, particularly into the atmosphere. The remaining intake air that flows into the intercooler 32 flows into each intake manifold 34. Each intake manifold 34 supplies the incoming intake air to each cylinder row 211 via the intake port of each cylinder head 22 (see Figure 1, etc.). This supplies intake air to each combustion chamber. The intake air supplied to each combustion chamber is used for the combustion of fuel.

[0038] Furthermore, when a portion of the intake air that has flowed into the intercooler 32 is released into the atmosphere by the relief valve 33, the temperature of the exhaust gas discharged from the engine body 2 rises. This suppresses the deterioration of the selective reduction catalyst 62. Therefore, when the engine 1 is equipped with an aftertreatment device 6 that purifies the exhaust gas discharged from the engine body 2, the following configuration is desirable from the viewpoint of realizing a configuration that suppresses the deterioration of the aftertreatment device 6 using the relief valve 33. That is, as in this embodiment, it is desirable that the aftertreatment device 6 has a selective reduction catalyst 62 that selectively reduces nitrogen oxides contained in the exhaust gas.

[0039] [3. Configuration of the intercooler and relief valve] The configuration of the intercooler 32 and the relief valve 33 will be explained based on Figures 6, 7, 8, 9, and 10. Figures 6, 7, 9, and 10 are a bottom view, front view, perspective view from the right rear, and rear view showing the configuration of the intercooler 32 and the relief valve 33. Figure 8 is a cross-sectional view of the intercooler 32 and the relief valve 33 cut vertically at the position through which the line A-A' in Figure 7 passes. In Figures 7, 8, and 10, the intake air flow is indicated by solid arrows.

[0040] In particular, as shown in Figure 6, the intercooler 32 comprises a housing 321 and a heat exchange section 322. The housing 321 is made of a hollow metal member. The heat exchange section 322 is located inside the housing 321 (see also Figure 8). In other words, the housing 321 houses the heat exchange section 322.

[0041] An inlet 321a is provided on the lower surface of the housing 321, opening downwards. More specifically, the inlet 321a is composed of a first inlet 321a1 and a second inlet 321a2, which are located side by side in the left-right direction. In particular, the first inlet 321a1 is located to the left of the second inlet 321a2. The first inlet 321a1 and the second inlet 321a2 are formed in a circular shape when viewed from below the housing 321, but are not limited to this, and may be, for example, elliptical, rectangular, square, or a polygonal shape other than a rectangle and a square.

[0042] The first inlet 321a1 is connected to the left intake pipe 31 (see Figure 3), and the second inlet 321a2 is connected to the right intake pipe 31. Therefore, intake air flows into the housing 321 from each intake pipe 31 via the first inlet 321a1 and the second inlet 321a2. In other words, the intercooler 32 has inlet 321a into which intake air flows. Note that the number of inlet 321a is not limited to two; for example, there may be one or more than two.

[0043] A cooling water inlet 321c is provided on the lower left side of the housing 321, opening downwards. The cooling water inlet 321c is connected to an intake channel (not shown) for taking in seawater from outside the ship.

[0044] In particular, as shown in Figure 7, an outlet section 321b opening forward is provided at the front upper part of the housing 321. More specifically, the outlet section 321b is composed of a first outlet section 321b1 and a second outlet section 321b2 located side by side in the left-right direction. That is, the intercooler 32 has a first outlet section 321b1 and a second outlet section 321b2. In particular, the first outlet section 321b1 is located to the left of the second outlet section 321b2. The first outlet section 321b1 and the second outlet section 321b2 are formed in a rectangular shape when viewed from the front of the housing 321, but are not limited to this, and may be, for example, a square, a rectangle and other polygons, a circle, or an ellipse.

[0045] The first outlet section 321b1 is connected to the left intake manifold 34 (see Figure 2), and the second outlet section 321b2 is connected to the right intake manifold 34 (see Figure 1). Note that the number of outlet sections 321b is not limited to two; for example, there may be one or more than two.

[0046] A cooling water outlet 321d is provided on the front left side of the housing 321, opening forward. The cooling water outlet 321d is connected to a drainage channel (not shown) that opens outwards from the ship.

[0047] The seawater taken into the above intake channel flows into the housing 321 via the cooling water inlet 321c (see Figure 6). The seawater that flows into the housing 321 flows through the heat exchange section 322.

[0048] In particular, as shown in Figure 8, the intercooler 32 of this embodiment is composed of a multi-tube heat exchanger. Therefore, the heat exchange section 322 is composed of a plurality of circular pipes 322a extending in the left-right direction. Seawater flowing into the housing 321 flows from left to right through the lower circular pipes 322a and into the right side of the housing 321. The right side of the housing 321 reverses the flow of the incoming seawater and guides it to the upper circular pipes 322a. The seawater guided by the right side of the housing 321 flows from right to left through the upper circular pipes 322a. The seawater that has flowed through the upper circular pipes 322a flows out of the housing 321 via the cooling water outlet section 321d. The seawater that has flowed out of the housing 321 is discharged to the outside of the ship through the drainage channel described above.

[0049] Furthermore, the configuration of the intercooler 32 is not limited to a multi-tube heat exchanger; for example, it may be a plate-type heat exchanger or a fin-type heat exchanger.

[0050] Air drawn into the left intake pipe 31 flows into the housing 321 via the first inlet 321a1. Air drawn into the right intake pipe 31 flows into the housing 321 via the second inlet 321a2.

[0051] The intake air flowing into the housing 321 flows from bottom to top within the housing 321. More specifically, the intake air flows towards the outlet 321b, passing through a plurality of circular pipes 322a included in the heat exchange section 322. Heat exchange takes place between the intake air passing through the circular pipes 322a and the seawater flowing through the circular pipes 322a. Since the temperature of the seawater is usually lower than the temperature of the intake air, the intake air is cooled by the above heat exchange. Therefore, the seawater functions as a refrigerant to cool the intake air. In other words, the heat exchange section 322 exchanges heat between the intake air and the refrigerant (seawater in this embodiment). That is, the intercooler 32 cools the intake air.

[0052] The heat exchange section 322 is located within the housing 321, near the center in the vertical direction of the housing 321. An upward-bulging portion 321e is formed on the upper part of the housing 321 that is located above the heat exchange section 322. That is, the housing 321 includes an upward-bulging portion 321e formed on the downstream side (upward in this embodiment) of the intake air flow direction (vertical direction in this embodiment) relative to the heat exchange section 322.

[0053] The bulge portion 321e includes a base portion 321e1, a mounting portion 321e2, and a curved surface portion 321e3. The base portion 321e1 is located below the bulge portion 321e. More specifically, the base portion 321e1 is provided extending in the left-right direction at a position offset upward from the vertical center of the front end of the housing 321.

[0054] The mounting portion 321e2 is located above the bulging portion 321e. More specifically, the mounting portion 321e2 is provided on the rear upper part of the housing 321. That is, the base portion 321e1 is located upstream (downward in this embodiment) of the intake air flow direction (up and down in this embodiment) relative to the mounting portion 321e2.

[0055] The mounting portion 321e2 is configured to allow the attachment of the relief valve 33. Additionally, support portions 321e4 capable of supporting the relief valve 33 are located on either side of the mounting portion 321e2 (see Figure 10). The support portions 321e4 are integrally formed with the bulging portion 321e.

[0056] In this embodiment, the portion where the mounting portion 321e2 and each support portion 321e4 are located and which faces the inlet portion 321a (first inlet portion 321a1, second inlet portion 321a2) provided on the lower surface of the housing 321 is called the opposing surface portion 321f. That is, the intercooler 32 has an opposing surface portion 321f that faces the inlet portion 321a.

[0057] The curved surface portion 321e3 is constructed by bending a plate-like member extending in the vertical direction forward as it extends upward. The rear end (lower end) of the curved surface portion 321e3 is connected to the base portion 321e1, and the front end (upper end) is connected to the mounting portion 321e2. In other words, the curved surface portion 321e3 curves from the base portion 321e1 to the mounting portion 321e2.

[0058] The bulging portion 321e is provided with a third outlet portion 321e5 that penetrates the mounting portion 321e2 in the vertical direction. Note that the third outlet portion 321e5 is different from the outlet portions 321b (first outlet portion 321b1, second outlet portion 321b2). The third outlet portion 321e5 is formed in a rectangular shape when viewed from above the housing 321, but is not limited to this, and may be, for example, a square, a polygon other than a rectangle and square, a circle, or an ellipse. The third outlet portion 321e5 is connected to the relief valve 33.

[0059] In particular, as shown in Figure 9, the relief valve 33 includes a valve inlet 331, a plurality of valve body portions 332, a plurality of coupling members 333, and a plurality of silencers 334. In this embodiment, two of each of the valve body portion 332, coupling members 333, and silencer 334 are provided. However, the number of these is not limited to two; for example, there may be one or more than two.

[0060] The relief valve 33 is positioned above the intercooler 32. That is, the valve inlet 331, the multiple valve body portions 332, the multiple joint members 333, and the multiple silencers 334 are located above the intercooler 32. Also, as described above, in the intercooler 32, the bulge portion 321e of the housing 321 is located above the heat exchange portion 322 (see Figure 8). In other words, the relief valve 33 is positioned (in the vertical direction) on the opposite side of the heat exchange portion 322 from the bulge portion 321e.

[0061] From the viewpoint of reducing the horizontal installation space for the relief valve 33 and intercooler 32, and improving the mountability of other equipment, components, etc. installed on the vessel, the following configuration is desirable. That is, as in this embodiment, it is desirable to position the relief valve 33 above the intercooler 32.

[0062] The valve inlet section 331 is composed of a bifurcated metal member. More specifically, the lower surface of the valve inlet section 331 is provided with a valve inlet section 331a (see Figures 7 and 8) that opens downwards. The valve inlet section 331a is connected to a third outlet section 321e5 located on the upper side of the housing 321. As described above, the third outlet section 321e5 is provided separately from the first outlet section 321b1 and the second outlet section 321b2, but is located near the first outlet section 321b1 and the second outlet section 321b2. Therefore, the valve inlet section 331a is located near the first outlet section 321b1 and the second outlet section 321b2. In detail, in the left-right direction, the valve inlet section 331a is located between the first outlet section 321b1 and the second outlet section 321b2 (see Figure 7). In other words, the relief valve 33 has a valve inlet portion 331a, which is located between the first outlet portion 321b1 and the second outlet portion 321b2.

[0063] Furthermore, a left connection port 331b (see Figures 7 and 10) is provided on the left side of the valve introduction section 331, opening to the left. In addition, a right connection port 331c (see Figures 7 and 10) is provided on the right side of the valve introduction section 331, opening to the right. The valve inlet section 331a and the left connection port 331b are in communication, and the valve inlet section 331a and the right connection port 331c are in communication.

[0064] One valve body 332 is positioned to the left of the valve inlet 331. The right side of the valve body 332 is connected to the left connection port 331b of the valve inlet 331, and the left side is connected to the silencer 334 via one joint member 333.

[0065] To the right of the valve inlet 331 is the other valve body 332. The left side of the other valve body 332 is connected to the right connection port 331c of the valve inlet 331, and the right side is connected to the other silencer 334 via the other joint member 333.

[0066] The joint member 333 is constructed by bending one end of a metal piping member extending in the left-right direction forward. The silencer 334 is provided to reduce the noise level and the pressure of the released intake air when a portion of the intake air is released from the relief valve 33. Each silencer 334 is provided with a discharge port 334a (see Figure 7) that opens forward at its tip. That is, the relief valve 33 has a discharge port 334a. The discharge port 334a is formed in a circular shape when viewed from the front of the silencer 334, but is not limited to this, and may be, for example, elliptical, rectangular, square, or a polygonal shape other than a rectangle and a square.

[0067] The valve body 332 contains a valve element (not shown). This valve element switches the communication between the valve inlet 331 and the silencer 334 on and off. In the following, the state in which the communication between the valve inlet 331 and the silencer 334 is on in the valve body 332 will be referred to as the "communication state," and the state in which the communication between the valve inlet 331 and the silencer 334 is off will be referred to as the "non-communication state."

[0068] Each valve body 332 is fitted with a valve drive unit 332a that protrudes rearward (horizontally) from the valve body 332. That is, the relief valve 33 has a valve drive unit 332a, which is positioned to protrude rearward from the valve body 332. The valve drive unit 332a drives the valve body based on a drive command output from a control device (not shown) which is provided separately from the engine 1. That is, the valve drive unit 332a drives the valve body 332. The valve drive unit 332a is composed of, for example, a coil, electronic components, etc.

[0069] The control device described above determines the drive command to output to each valve drive unit 332a based on the temperature state of the exhaust gas discharged from the engine body 2. Specifically, the control device determines whether or not to connect each valve body 332. Furthermore, if the control device decides to connect the valve bodies 332, it determines which of the valve bodies 332 to connect. For example, if the exhaust gas is relatively cold, the control device connects one valve body 332, and if the exhaust gas is relatively hot, it connects the other valve body 332. It is also possible to configure the device so that all of the valve bodies 332 are connected. The control device may also be included in the engine 1.

[0070] For example, when the left valve drive unit 332a drives the left valve body 332 based on a drive command from the control device, the communication between the valve inlet 331 and the left silencer 334 is turned on. As a result, a portion of the intake air flowing inside the housing 321 is released into the atmosphere. In other words, the valve body 332 allows a portion of the intake air flowing inside the intercooler 32 to escape into the atmosphere. More specifically, a portion of the intake air flowing inside the intercooler 32 flows into the valve inlet 331 via the third outlet 321e5 and the valve inlet 331a. That is, the valve inlet 331a is an opening for a portion of the intake air to flow into the relief valve 33 (specifically, the valve inlet 331).

[0071] Furthermore, the remaining intake air flowing through the housing 321 (the intake air flowing through the housing 321 that does not flow into the valve inlet 331) flows into each intake manifold 34 via the first outlet 321b1 and the second outlet 321b2. In other words, the first outlet 321b1 and the second outlet 321b2 are openings through which the intake air flowing through the intercooler 32 flows out, except for a portion (that flows into the relief valve 33).

[0072] The intake air flowing into the valve inlet 331 flows along the inner surface of the valve inlet 331, moving upwards towards the left. If the right valve body 332 is in communication, the intake air flowing into the valve inlet 331 flows along the inner surface of the valve inlet 331, moving upwards towards the right. In other words, the valve inlet 331 receives a portion of the intake air flowing inside the housing 321 and guides this portion of the intake air in one direction included in the horizontal direction (in this embodiment, the left-right direction). However, the configuration of the valve inlet 331 is not limited to the above, and for example, it may be configured to guide a portion of the intake air to only one side of the one direction included in the horizontal direction. In other words, the valve inlet 331 guides a portion of the intake air flowing inside the housing 321 to at least one side (in this embodiment, both the left and right sides) of one direction included in the horizontal direction (in this embodiment, the left-right direction).

[0073] In a configuration where the relief valve 33 positioned above the intercooler 32 has a valve inlet 331 into which a portion of the intake air flowing through the intercooler 32 flows, the following configuration is desirable from the viewpoint of suppressing an increase in the height of the relief valve 33 and realizing a vertically compact engine 1. That is, as in this embodiment, it is desirable that the valve inlet 331 guide a portion of the intake air to at least one side (both left and right in this embodiment) of one direction included in the horizontal direction (left and right direction in this embodiment).

[0074] The intake air flowing through the valve inlet 331 flows into the left silencer 334 via the left connection port 331b, the left valve body 332, and the left joint member 333. The intake air that flows into the silencer 334 is released into the atmosphere from the outlet 334a. In other words, the outlet 334a is an opening for releasing a portion of the intake air flowing inside the intercooler 32 to the outside of the intake air passage 3 (in this embodiment, into the atmosphere).

[0075] As described above, in this embodiment, the discharge port 334a opens toward the front. However, the discharge port 334a may also open toward the rear. That is, the discharge port 334a opens toward either one side in the axial direction (rear in this embodiment) or the other side in the axial direction (forward in this embodiment).

[0076] For example, a workspace WS (see Figure 3) for workers performing maintenance work near the engine 1 is often provided on both sides of the engine 1 in a direction perpendicular to the axial direction of the crankshaft 23 (left-right in this embodiment), extending in the axial direction of the crankshaft 23. As described above, when a workspace WS is provided, if the release of intake air into the workspace WS is avoided, the (relatively high-pressure) intake air will not hit the workers located in the workspace WS. Therefore, even if the relief valve 33 has a discharge port 334a that releases a portion of the intake air flowing through the intercooler 32 to the outside of the intake passage 3, the following configuration is desirable from the viewpoint of ensuring worker safety. That is, as in this embodiment, it is desirable that the discharge port 334a opens toward either one axial side (rear in this embodiment) or the other axial side (forward in this embodiment).

[0077] In particular, when performing maintenance work while the engine 1 is running, to ensure safety, workers often enter and exit the work space WS from the opposite side (the front side in this embodiment) from the side where the driven device 100 is located. Therefore, in the work space WS, workers are often positioned on the side opposite to the side where the driven device 100 is located, relative to the center of the engine body 2 in the axial direction of the crankshaft 23. Consequently, in a configuration where the crankshaft 23 of the engine body 2 is connected to the driven device 100 located on one side in the axial direction of the crankshaft 23 (the rear in this embodiment), the following configuration is desirable from the viewpoint of ensuring worker safety. That is, as in this embodiment, it is desirable that the intercooler 32 be positioned on one side in the axial direction of the engine body 2 in the axial direction of the crankshaft 23 (the front-rear direction in this embodiment).

[0078] The lower end of the valve inlet 331 is fixed to the mounting portion 321e2 by a plurality of bolts B1. In other words, the relief valve 33 is attached to the mounting portion 321e2. Each joint member 333 is supported by the support portion 321e4 via a bracket 333a (see Figure 10). To prevent the joint member 333 from separating from or shifting relative to the bracket 333a, the joint member 333 is pressed against the bracket 333a by U-shaped bolts B2. In short, the relief valve 33 is attached to the intercooler 32.

[0079] With the above configuration, the intake air cooled by the intercooler 32 can be released outside the intake passage 3. Therefore, since the intake air released by the relief valve 33 is relatively cold, it is possible to suppress heat damage to components located outside the intake passage 3 (for example, electronic components attached to the engine 1). In addition, the relief valve 33 can be positioned downstream of the intercooler 32 in the intake passage 3 in a location that is less prone to vibration compared to a position where the relief valve 33 can be installed (for example, the intake manifold 34). Therefore, it is possible to suppress damage to the relief valve 33 (itself) (due to vibration). As a result, it is possible to achieve both the suppression of heat damage to components located outside the intake passage 3 and the suppression of damage to the relief valve 33.

[0080] Furthermore, as in this embodiment, if the engine 1 is an engine having multiple (two in this embodiment) cylinder rows 211 (for example, a V-type engine), the intake air will be released outside the intake passage 3 before it is supplied to each cylinder row 211. Therefore, it becomes unnecessary to provide multiple relief valves 33 corresponding to each cylinder row 211. As a result, the engine 1 is constructed simply with a small number of parts. In addition, since it is unnecessary to provide a relief valve 33 for each cylinder row 211, variations in intake air volume between each cylinder row 211 due to variations in the responsiveness of each relief valve 33 are suppressed. From this viewpoint as well, it is preferable that the relief valves 33 are attached to the intercooler 32, as in this embodiment.

[0081] The relief valve 33, specifically the mounting portion 321e2 to which the valve introduction portion 331 is attached, is located on the opposing surface portion 321f, as described above. Therefore, the relief valve 33 is attached to the opposing surface portion 321f.

[0082] The intercooler 32 has an inlet portion 321a into which intake air flows and an opposing surface portion 321f facing the inlet portion 321a. From the viewpoint of smoothly releasing the intake air flowing inside the intercooler 32 to the outside of the intake air passage 3, the following configuration is desirable. That is, as in this embodiment, it is desirable that the relief valve 33 be attached to the opposing surface portion 321f.

[0083] In the intercooler 32, if the housing 321 includes a bulge 321e formed downstream of the heat exchange section 322 in the direction of intake air flow (upward in this embodiment), a space is created within the bulge 321e through which intake air cooled by the heat exchange section 322 flows. As the intake air flows through this space, it is gradually cooled. That is, the temperature of the intake air after flowing through this space is lower than the temperature of the intake air before flowing through this space (immediately after passing through the heat exchange section 322). Therefore, even when a portion of the intake air flowing through the intercooler 32 is released into the atmosphere outside the intake air passage 3, the following configuration is desirable in order to ensure that the temperature of the intake air released into the atmosphere is kept as low as possible and that heat damage to components outside the intake air passage 3 is reliably suppressed. That is, as in this embodiment, it is desirable that the relief valve 33 that releases a portion of the intake air flowing through the intercooler 32 into the atmosphere is positioned on the opposite side of the bulge 321e from the heat exchange section 322.

[0084] From the viewpoint of reliably realizing the configuration in which the relief valve 33 is attached to the intercooler 32, it is desirable that the bulge portion 321e includes a mounting portion 321e2 to which the relief valve 33 is attached, as in this embodiment. Furthermore, from the viewpoint of smoothly guiding the intake air flowing through the bulge portion 321e to the relief valve 33, the following configuration is desirable. That is, as in this embodiment, it is desirable that the bulge portion 321e includes a base portion 321e1 located upstream (downward in this embodiment) in the direction of intake air flow relative to the mounting portion 321e2, and a curved surface portion 321e3 that curves from the base portion 321e1 to the mounting portion 321e2.

[0085] From the viewpoint of ensuring that all intake air flowing through the intercooler 32, except for the portion that flows into the relief valve 33, flows out of the intercooler 32 and into the intake air passage 3 downstream of the intercooler 32, the following configuration is desirable. That is, as in this embodiment, it is desirable that the intercooler 32 has a first outlet section 321b1 and a second outlet section 321b2 through which all intake air (flowing through the intercooler 32), except for the portion that flows into the relief valve 33, flows out. Furthermore, from the viewpoint of ensuring that a portion of the intake air flowing through the intercooler 32 flows into the relief valve 33, it is desirable that the relief valve 33 has a valve inlet section 331a through which a portion of the intake air flows, as in this embodiment. Moreover, from the viewpoint of efficiently (smoothly) separating the intake air flow toward the relief valve 33 from the intake air flow toward the intake air passage 3 downstream of the intercooler 32, the following configuration is desirable. In other words, as in this embodiment, it is desirable that the valve inlet portion 331a be positioned between the first outlet portion 321b1 and the second outlet portion 321b2.

[0086] As described above, the valve introduction portion 331 is fixed to the mounting portion 321e2, which is connected to the rear end (upper end) of the curved surface portion 321e3. Valve body portions 332 are located to the left and right of the valve introduction portion 331. Therefore, the valve body portion 332 is located at the front end (upper end) of the curved surface portion 321e3. Furthermore, the valve drive portion 332a is positioned to protrude rearward from the valve body portion 332. In other words, the valve body portion 332 is located at one end (the front end in this embodiment) of the curved surface portion 321e3, and the valve drive portion 332a is positioned to protrude from the valve body portion 332 toward the other end (the rear end in this embodiment) of the curved surface portion 321e3.

[0087] Since the temperature of the intake air flowing through the housing 321 is higher than the ambient temperature (even after being cooled by the heat exchange unit 322), the temperature of the housing 321 itself rises, causing the housing 321 to generate heat. Therefore, in order to prevent heat damage to the valve drive unit 332a of the relief valve 33 due to the heat emitted from the housing 321, it is desirable to position the valve drive unit 332a as far away from the housing 321 as possible. However, as the valve drive unit 332a is moved further away from the housing 321, it becomes necessary to secure a larger installation space for the intercooler 32 with the relief valve 33. However, there is a limit to how much this installation space can be expanded. For this reason, even if the relief valve 33 has a valve body 332 that is driven by the valve drive unit 332a and allows a portion of the intake air to escape into the atmosphere, it is desirable that the relief valve 33 be compactly mounted on the intercooler 32. From this perspective, it is desirable that, as in this embodiment, the valve body portion 332 is positioned on one end of the curved surface portion 321e3, and the valve drive portion 332a is positioned to protrude from the valve body portion 332 toward the other end of the curved surface portion 321e3.

[0088] [4. Supplement] In this embodiment, the front end of the curved surface portion 321e3 is described as "one end of the curved surface portion 321e3" and the rear end of the curved surface portion 321e3 is described as "the other end of the curved surface portion 321e3", but the embodiment is not limited to this. For example, the rear end of the curved surface portion 321e3 may be "one end of the curved surface portion 321e3" and the front end of the curved surface portion 321e3 may be "the other end of the curved surface portion 321e3".

[0089] In this embodiment, the case in which the rear is defined as "one axial side of the crankshaft 23" and the front is defined as "the other axial side of the crankshaft 23" has been described, but the embodiment is not limited to this. For example, the front may be defined as "one axial side of the crankshaft 23" and the rear may be defined as "the other axial side of the crankshaft 23".

[0090] [5. Addendum] The engine 1 described in this embodiment can also be described as the engine shown in the following appendix.

[0091] The engine in Appendix (1) is The intake air passage through which the intake air flows, An intercooler provided in the intake air passage for cooling the intake air, The system includes a relief valve that releases a portion of the intake air from inside the intercooler to outside the intake air passage, The relief valve is attached to the intercooler.

[0092] The engine in Appendix (2) is the same as the engine described in Appendix (1), The aforementioned intercooler is The inlet portion into which the intake air flows, It has an opposing surface portion that faces the aforementioned inlet portion, The relief valve is attached to the opposing surface.

[0093] The engine in Appendix (3) is the engine described in Appendix (1) or (2), The aforementioned intercooler is A heat exchange unit that exchanges heat between the intake air and the refrigerant, It has a housing that accommodates the heat exchange section, The housing includes a bulge formed downstream of the heat exchange section in the direction of the intake air flow, The relief valve, which releases a portion of the intake air into the atmosphere, is positioned on the opposite side of the bulging portion from the heat exchange portion.

[0094] The engine in Appendix (4) is the same as the engine described in Appendix (3), The aforementioned bulge is, The mounting portion to which the relief valve is attached, A base portion located upstream of the mounting portion in the flow direction, It includes a curved surface portion that curves from the base portion to the mounting portion.

[0095] The engine in Appendix (5) is the same as the engine described in Appendix (4), The aforementioned relief valve is, A valve body that allows a portion of the intake air to escape into the atmosphere, It includes a valve drive unit that drives the valve body, The valve body is positioned on one end of the curved surface portion. The valve drive unit is positioned to protrude from the valve body toward the other end of the curved surface.

[0096] The engine in Appendix (6) is the engine described in any of Appendix (1) to (5), The relief valve is positioned above the intercooler.

[0097] The engine in Appendix (7) is the same as the engine described in Appendix (6), The relief valve has a valve inlet into which a portion of the intake air flows, The valve introduction section guides a portion of the intake air to at least one side of one direction included in the horizontal direction.

[0098] The engine in Appendix (8) is the engine described in any of Appendix (1) to (7), The intercooler has a first outlet and a second outlet through which the intake air, except for the portion mentioned above, flows out. The relief valve has a valve inlet portion into which a portion of the intake air flows, The valve inlet is positioned between the first outlet and the second outlet.

[0099] The engine in Appendix (9) is the engine described in any of Appendix (1) to (8), Equipped with the engine body, The engine body has a crankshaft, The crankshaft is connected to a driven device located on one axial side of the crankshaft relative to the engine body. The intercooler is positioned on one side in the axial direction relative to the center of the engine body in the axial direction of the crankshaft.

[0100] The engine in Appendix (10) is the same as the engine described in Appendix (9), The relief valve has a discharge port that discharges a portion of the intake air outside the intake air passage, The discharge port opens toward either one of the axial directions or the other axial direction of the crankshaft.

[0101] The engine in Appendix (11) is the engine described in Appendix (9) or (10), The engine is equipped with an aftertreatment device for purifying exhaust gas discharged from the engine body, The aftertreatment device has a selective reduction catalyst that selectively reduces nitrogen oxides contained in the exhaust gas.

[0102] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it can be expanded or modified without departing from the spirit of the invention. [Industrial applicability]

[0103] The present invention can be used, for example, in engines used in ships and working machinery (construction machinery, agricultural machinery, etc.). [Explanation of Symbols]

[0104] 1 Engine 2. Engine body 3. Intake passage 6. Post-processing equipment 23 Crank Axle 32 Intercooler 33. Release valve 62 Selective Reduction Catalyst 100 Driven device 321 cabinet 321a Entrance section 321b1 1st exit section 321b2 2nd exit section 321e bulge 321e1 base 321e2 Mounting part 321e3 Curved surface section 321f Opposing surface part 322 Heat exchange section 331 Valve introduction section 331a Valve inlet 332 Valve body 332a Valve drive unit 334a Outlet part

Claims

1. The intake air passage through which the intake air flows, An intercooler provided in the intake air passage for cooling the intake air, The system includes a relief valve that releases a portion of the intake air from inside the intercooler to outside the intake air passage, The relief valve is attached to the intercooler of the engine.

2. The aforementioned intercooler is The inlet portion into which the intake air flows, It has an opposing surface portion that faces the aforementioned inlet portion, The relief valve is attached to the opposing surface portion, as described in claim 1.

3. The aforementioned intercooler is A heat exchange unit that exchanges heat between the intake air and the refrigerant, It has a housing that accommodates the heat exchange section, The housing includes a bulge formed downstream of the heat exchange section in the direction of the intake air flow, The relief valve, which releases a portion of the intake air into the atmosphere, is positioned on the opposite side of the bulge from the heat exchange section, according to claim 1.

4. The aforementioned bulge is, The mounting portion to which the relief valve is attached, A base portion located upstream of the mounting portion in the flow direction, The engine according to claim 3, comprising a curved surface portion that curves from the base portion to the mounting portion.

5. The aforementioned relief valve is, A valve body that allows a portion of the intake air to escape into the atmosphere, It includes a valve drive unit that drives the valve body, The valve body is positioned on one end of the curved surface portion. The engine according to claim 4, wherein the valve drive unit is arranged to protrude from the valve body toward the other end of the curved surface.

6. The relief valve is positioned above the intercooler, as described in claim 1.

7. The relief valve has a valve inlet into which a portion of the intake air flows, The engine according to claim 6, wherein the valve introduction section guides the portion of the intake air to at least one side of one direction included in the horizontal direction.

8. The intercooler has a first outlet and a second outlet through which the intake air, except for the portion mentioned above, flows out. The relief valve has a valve inlet portion into which a portion of the intake air flows, The engine according to claim 1, wherein the valve inlet is located between the first outlet and the second outlet.

9. Equipped with the engine body, The engine body has a crankshaft, The crankshaft is connected to a driven device located on one axial side of the crankshaft relative to the engine body. The engine according to any one of claims 1 to 8, wherein the intercooler is positioned on one side in the axial direction relative to the vicinity of the center of the engine body in the axial direction of the crankshaft.

10. The relief valve has a discharge port that discharges a portion of the intake air outside the intake air passage, The engine according to claim 9, wherein the discharge port opens toward either one of the axial directions or the other axial direction of the crankshaft.

11. The engine is equipped with an aftertreatment device for purifying exhaust gas discharged from the engine body, The engine according to claim 9, wherein the aftertreatment device has a selective reduction catalyst that selectively reduces nitrogen oxides contained in the exhaust gas.

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