JP2024069703A - Engine device - Google Patents

Abstract

To arrange a supercharger and its related parts compactly.SOLUTION: An engine device comprises a supercharger, and an intake relay pipe that connects the supercharger and an intake manifold. The intake relay pipe has an inclined part that is inclined downward from an upstream portion of an airflow flowing through the relay pipe to a downstream portion.SELECTED DRAWING: Figure 18

Description

This invention relates to an engine device equipped with a turbocharger.

Conventionally, in order to increase the air density inside the cylinder of an engine in order to improve engine output and fuel economy, a turbocharger that compresses fresh air using exhaust energy has been installed in an engine device (see Patent Document 1). In a diesel engine, supplying a large amount of high-density air into the cylinder burns a large amount of fuel, not only increasing engine output and engine torque, but also suppressing premixed combustion by promoting the mixing of fuel and air, thereby reducing NOx (nitrogen oxide) emissions.

JP 2013-133796 A

The space available for mounting an engine varies depending on the work vehicle (construction machinery, agricultural machinery, etc.) on which it is to be mounted, but in recent years, due to demands for lighter weight and compactness, mounting space is often restricted (narrow). For this reason, it is necessary to layout the engine components compactly. In particular, when mounting a turbocharger on a small-displacement engine, the turbocharger takes up a large proportion of the engine surface, so it is necessary to layout the turbocharger and its associated parts compactly.

The technical objective of the present invention is to provide an engine device that has been improved upon based on the current situation described above.

The engine device of the present invention includes a turbocharger and an intake relay pipe that connects the turbocharger to an intake manifold, and the intake relay pipe has a slope that slopes downward from the upstream portion of the airflow flowing through the relay pipe to the downstream portion.

The engine device of the present invention allows the turbocharger and its related parts to be laid out in a compact manner.

FIG. FIG. FIG. FIG. FIG. FIG. 2 is a perspective view of the engine as seen obliquely from the front. FIG. 2 is a perspective view of the engine as seen obliquely from the rear. FIG. 2 is a plan view showing a partial cross-section of the intake manifold with an integrated valve arm chamber. FIG. 4 is a left cross-sectional view of the intake manifold with integrated valve arm chamber. FIG. 2 is a rear cross-sectional view of the intake manifold with integrated valve arm chamber. FIG. 2 is a perspective view showing a cross section of an intake manifold integrated with a valve arm chamber. 2 is a perspective view showing a cross section of a valve arm chamber and a blow-by gas reduction device of an intake manifold with an integrated valve arm chamber; FIG. FIG. 2 is a perspective view of the intake manifold with integrated valve arm chamber as viewed from the bottom side. FIG. 2 is a cross-sectional perspective view of the blow-by gas reduction device. FIG. 2 is a plan view showing the configuration of the intake pipe and its surroundings. FIG. 2 is a front view showing the configuration of the intake pipe and its surroundings. FIG. 2 is a perspective view showing the configuration of the intake pipe and its surroundings. FIG. 2 is a perspective view showing an intake manifold with an integrated valve arm chamber, an intake pipe, and a blow-by gas return pipe. FIG. 2 is a cross-sectional perspective view of an intake pipe and a blow-by gas return pipe. FIG. 2 is a left side view showing exhaust system components. FIG. 2 is a perspective view showing exhaust system components. FIG. 2 is an exploded perspective view showing a mounting structure for exhaust system components. FIG. 2 is a rear view showing the cylinder block together with exhaust system components, partially in cross section.

The following describes an embodiment of the present invention with reference to the drawings. First, the schematic structure of the engine (engine device) 1 will be described with reference to Figs. 1 to 7. In the following description, both sides along the output shaft 3 are referred to as the left and right, the side where the cooling fan 9 is located is referred to as the front side (one side), the side where the flywheel 11 is located is referred to as the rear side, the side where the exhaust manifold 7 is located is referred to as the left side (one side), and the side where the fuel injection pump device 14 is located is referred to as the right side (the other side), and for convenience, these are used as the basis for the positional relationships of the four sides and the top and bottom of the engine 1.

As shown in Figures 1 to 7, an engine 1 as a prime mover mounted on a work machine such as a construction machine or an agricultural machine has a cylinder block 4 incorporating an output shaft 3 (crankshaft) and a piston (not shown). A cylinder head 5 is mounted on the cylinder block 4. An exhaust manifold 7 is disposed on the left side of the cylinder head 5. An intake manifold 8 (head cover) with an integrated valve arm chamber is disposed on the upper surface of the cylinder head 5. The intake manifold 8 with an integrated valve arm chamber is provided with an intake manifold section 6 extending in the front-rear direction at a left-leaning portion, and an intake arm chamber section 90 extending in the front-rear direction at a right-leaning portion. That is, above the cylinder head 5, the intake manifold section 6 is disposed on the left side of the output shaft 3 of the engine 1, and the valve chamber 90 is disposed on the right side (near the exhaust manifold 7). The intake arm chamber section 90 covers the intake valve and exhaust valve (not shown) provided on the upper surface of the cylinder head 5.

A cooling fan 9 is provided on one side of the engine 1 that intersects with the output shaft 3, specifically, on the front side of the cylinder block 4. A mounting plate 10 is provided on the rear side of the cylinder block 4. A flywheel 11 is arranged so as to overlap the mounting plate 10. The flywheel 11 is journaled on the output shaft 3. The engine 1 is configured to extract power via the output shaft 3 to the working section of the work machine. An oil pan 12 is also provided below the cylinder block 4. Lubricating oil in the oil pan 12 is supplied to each lubricating section of the engine 1 via an oil filter 13 provided on the right side of the cylinder block 4. The oil pan 12 is connected to the cylinder block 4 via a spacer 71. The spacer 71 extends from the rear end of the cylinder block 4 to below the gear case 54. The gear case 54, which is connected to the front of the cylinder block 4, is also connected to the spacer 71.

An injector (fuel injection valve) 15 is provided on the right side of the top surface of the cylinder head 5. In this embodiment, the injectors 15 are provided for three cylinders. In the following, this embodiment will be described using a three-cylinder engine 1 as an example, but the number of cylinders in the engine device of the present invention is not limited to three. A fuel tank (not shown) mounted on the work machine is connected to each injector 15 via a fuel injection pump device 14 and a fuel filter 17. The base end of a front hanging bracket 55 is bolted to the left side of the front of the cylinder head 5. The front hanging bracket 55 also serves as a support member for the alternator 23, which will be described later.

A fuel injection pump device 14 for supplying fuel into a combustion chamber in the cylinder block 4 is attached to the right side surface of the cylinder block 4 above the oil filter 13 (below the intake manifold portion 6). The fuel injection pump device 14 includes an injection pump main body 32 for supplying fuel to each injector 15 via a fuel injection pipe 36, a governor housing case 33 housing a governor for adjusting the fuel injection amount, an actuator portion 34 for controlling the operation of the governor, and a fuel feed pump 35 for feeding fuel. The governor housing case 33 is detachably fastened to the rear surface of the injection pump main body 32 with bolts. The actuator portion 34 is detachably fastened to the rear surface of the governor housing case 33 with bolts. The fuel feed pump 35 is detachably fastened to the right side surface of the injection pump main body 32 with bolts.

The fuel injection pump device 33 is attached to the engine 1 by having the front of the injection pump body 32 removably bolted to the rear of the gear case 54, and the rear of the governor housing case 33 removably bolted to the rear part of the right side of the cylinder head 5 via an L-shaped pump device bracket 41. The gear case 54, which is attached to the lower part of the front of the cylinder block 4, houses a gear train (not shown) including a crank gear, cam gear, pump gear, idle gear, etc.

By driving the fuel feed pump 35, fuel in the fuel tank (not shown) is sent from the fuel feed pump 35 through the fuel feed pipe 37, the fuel filter 17, and the fuel relay pipe 38 to the injection pump body 32. Then, fuel is supplied from the injection pump body 32 to each injector 15 through the fuel injection pipe 36. A fuel return pipe 39 is connected between the injection pump body 32 and the fuel filter 17. A fuel return pipe 40 that returns surplus fuel from the injector 15 joins the fuel return pipe 39 near the injection pump body 32. Surplus fuel from the engine 1 is returned to the fuel tank (not shown) through the fuel return pipes 39, 40 and a fuel return pipe joint 57 provided on the top of the fuel filter 17. The base end of the rear hanging bracket 56 is bolted to the right part of the rear surface of the cylinder head 5. The fuel filter 17 is detachably bolted to the upper right side of the rear hanging bracket 56.

The engine starter 18 is mounted on the mounting plate 10. The pinion gear of the engine starter 18 meshes with the ring gear of the flywheel 11. When starting the engine 1, the output shaft 3 starts to rotate by rotating the ring gear of the flywheel 11 with the torque of the engine starter 18 (so-called cranking is performed).

On the front side (cooling fan 9 side) of the cylinder head 5, a cooling water pump 21 is arranged coaxially with the fan shaft of the cooling fan 9. On the left side of the engine 1, specifically to the left of the cooling water pump 21, an alternator 23 is provided as a generator that generates electricity using the power of the engine 1. The cooling water pump 21 and the alternator 23 are driven together with the cooling fan 9 via a V-belt 22 for driving the cooling fan by the rotation of the output shaft 3. The cooling water in the radiator 19 mounted on the work machine side is supplied to the inside of the cylinder block 4 and the inside of the cylinder head 5 by the driving of the cooling water pump 21, thereby cooling the engine 1. A part of the cooling water from the cooling water pump 21 is flowed through a passage in the cylinder block 4 and cooling water relay pipes 81, 82 to an oil cooler 83 arranged at the base of the oil filter 13.

As shown in Figures 3 and 4, two engine mount attachment parts 24 are provided at the front and rear of the lower portion of each of the left and right side surfaces of the cylinder block 4. An engine mount (not shown), for example having anti-vibration rubber, can be bolted to each engine mount attachment part 24. In the embodiment, the cylinder block 4 is sandwiched between a pair of left and right engine support chassis 25 of the work machine, and the engine mount attachment parts 24 are bolted to each engine support chassis 25 via the engine mounts (not shown), so that both engine support chassis 25 of the work machine support the engine 1.

A radiator 19 with a fan shroud 20 attached to its rear side is erected on the pair of left and right engine support chassis 25 so as to be located on the front side of the engine 1. The fan shroud 20 surrounds the outside (outer periphery) of the cooling fan 9 and connects the radiator 19 to the cooling fan 9. As the cooling fan 9 rotates, the cooling air blows against the radiator 19, and then flows from the radiator 19 through the fan shroud 20 toward the engine 1.

An air cleaner (not shown) is connected to the inlet of the intake manifold 6 via an intake relay pipe 66, the compressor case 62 of the turbocharger 60, and intake pipes 91, 92, etc. Fresh air (outside air) sucked into the air cleaner is cleaned and purified by the air cleaner, then sent to the intake manifold 6 via the intake pipes 91, 92, the compressor case 62 (details of which will be described later), and the intake relay pipe 66, and supplied to each cylinder of the engine 1.

In the above configuration, fresh air is supplied from the air cleaner to the intake pipes 91 and 92, while blow-by gas is merged into the first intake pipe 91 through the blow-by gas return pipe 68 from the blow-by gas outlet 67 provided in the intake manifold 8 with the arm chamber. As described above, the intake manifold 8 with the arm chamber is formed by integrally molding the intake manifold section 6 formed on the left side of the intake manifold 8 with the arm chamber section 90 formed on the right side of the intake manifold 8 with the arm chamber. In addition, a blow-by gas reduction device 69 that separates lubricating oil from the blow-by gas protrudes from the upper surface of the arm chamber section 90. The blow-by gas provided in the blow-by gas reduction device 69 is returned to the first intake pipe 91 and sent to the combustion chamber again, so that the blow-by gas containing exhaust gas and unburned mixture is not released into the atmosphere.

A turbocharger 60 is disposed on the left side of the cylinder head 5 and above the exhaust manifold 7. The turbocharger 60 comprises a turbine case 61 with a built-in turbine wheel, a compressor case 62 with a built-in blower wheel, and a center housing 63 which is the connecting portion between the turbine case 61 and the compressor case 62. A lubricating oil feed pipe 64 (lubricating pipe) which branches off from the lubricating oil feed passage 79 (see FIG. 23) inside the cylinder block 4 and feeds lubricating oil to the rotating parts inside the center housing 63 is connected to the upper part of the center housing 63. A lubricating oil return pipe 65 which returns the lubricating oil fed into the center housing 63 to the lubricating oil return passage (not shown) inside the cylinder block 4 is connected to the lower part of the center housing 63.

The exhaust side inlet 61a of the turbine case 61 is connected to the exhaust gas outlet of the exhaust manifold 7. That is, the exhaust gas discharged from each cylinder of the engine 1 to the exhaust manifold 7 is released to the outside via the turbocharger 60. In addition, a silencer or tail pipe, for example, is connected to the exhaust side outlet 61b of the turbine case 61 via an exhaust pipe, and the exhaust gas is discharged to the outside from the exhaust side outlet 61b of the turbocharger 60 via the silencer or tail pipe.

The intake inlet 62a (inlet on the intake side of the turbocharger) of the compressor case 62 is connected to the fresh air outlet side of the air cleaner (not shown) via the second intake pipe 92 and the first intake pipe 91. The intake outlet 62b (outlet on the intake side of the turbocharger) of the compressor case 62 is connected to the intake manifold section 6 of the intake manifold 8 with integrated valve arm chamber via the intake relay pipe 66. That is, the fresh air that has been cleaned of dust by the air cleaner is sent from the compressor case 62 to the intake manifold section 6 via the intake relay pipe 66, and is then supplied to each cylinder of the engine 1.

Next, the configuration of the intake manifold 8 with integrated arm chamber will be described with reference to Figures 8 to 14. As described above, the intake manifold 8 with integrated arm chamber has an intake manifold section 6 (intake manifold) arranged to extend in the front-rear direction at a position shifted to the left, and an arm chamber section 90 (arm chamber) arranged to extend in the front-rear direction at a position shifted to the right. The intake manifold 8 with integrated arm chamber separates the intake manifold section 6 and the arm chamber section 90 with a partition wall 101, making the intake manifold section 6 and the arm chamber section 90 into mutually closed spaces.

The upper surface of the intake manifold section 6 is covered with an intake lid section 102. The intake lid section 102 is screwed to the upper surface of the side wall of the intake manifold section 6 at two points, and is bolted to the cylinder head 5 at six points via the intake manifold section 6. The intake manifold 8 with integrated valve arm chamber is also bolted to the cylinder head 5 at three points on the periphery of the valve arm chamber section 90 side.

An intake inlet 103 is provided on the upper surface of the intake lid 102, protruding upward. In addition, three intake outlets 104 connected to the intake inlets for three cylinders provided on the upper surface of the cylinder head 5 are formed on the bottom surface of the intake manifold 6 in a line in the front-rear direction of the engine 1. Two injector installation recesses 125 are provided on the right side surface of the intake manifold 6. The injector installation recesses 125 are disposed between adjacent intake outlets 104, 104. That is, in the example of this embodiment, in the intake manifold 6 of the intake manifold 8, the two injector installation recesses 125 and the three intake outlets 104 are alternately disposed in the direction along the output shaft 3 of the engine 1.

The injector installation recess 125 is formed by cutting out the bottom side of the intake manifold 6 from the right side to the partition wall 101. The cylinder head 5 and the injector installation recess 125 form a space for installing the injector 15, with the right side open. The injector 15 is inserted into the cylinder head 5 below the injector installation recess 125. Because the right side of the injector installation recess 125 is open, the fuel injection pipe 36 and fuel return pipes 39, 40 that connect the fuel injection pump device 14 and the injector 15 installed on the right side of the cylinder head 5 can be arranged in a short route, and the piping work can be simplified.

A blow-by gas return device 69 that returns blow-by gas to the intake system protrudes from the upper part of the arm chamber 90. The blow-by gas return device 69 has a gas outlet section 111, which is a part of the upper surface of the arm chamber-integrated intake manifold 8 that bulges upward. A gas pressure regulating valve 112 is disposed on the upper surface of the gas outlet section 111. A blow-by gas outlet 67 is also provided on the left side of the gas outlet section 111.

Inside the gas outlet portion 111, there are formed a gas outlet passage 111a, a part of which also serves as a pressure control chamber, and a gas outlet passage 111b, which is connected to the blow-by gas outlet 67. The gas outlet passage 111a extends from the lower part of the gas outlet portion 111 to the upper part inside the gas outlet portion 111. A part of the gas outlet passage 111a is formed in an annular shape so as to surround the periphery of the opening of the gas outlet passage 111b on the upper part of the gas outlet portion 111, and also serves as a pressure control chamber. The gas outlet passage 111b is led downward from the upper part of the gas outlet portion 111, and then bent to the left side of the gas outlet portion 111 and connected to the blow-by gas outlet 67.

The gas pressure regulating valve 112 is equipped with a valve case 122 and a diaphragm 123 for pressure control. The valve case 122 is disposed on the upper surface of the gas outlet section 111. The valve body 124 of the diaphragm 123 is disposed between the gas outlet passage 111a, which also serves as a pressure control chamber, and the gas outlet passage 111b, which is connected to the blow-by gas outlet port 67. Communication between the gas outlet passage 111a and the gas outlet passage 111b is normally blocked by the valve body 124, and when the pressure in the outlet passage 111a exceeds a certain pressure, the diaphragm 123 is pressed upward, causing the valve body 124 to move upward and open, connecting the outlet passages 111a and 111b.

A gas introduction chamber 113 and an internal passage 114 are formed in the bottom of the gas lead-out portion 111 within the arm chamber 90. Blow-by gas leaking from the combustion chamber of the engine 1 to the upper side of the cylinder head 5 is taken into the gas introduction chamber 113. The internal passage 114 connects the gas lead-out passage 111a and the gas introduction chamber 113. A shield plate 115 is fixed to the bottom of the gas lead-out portion 111 with a screw 117. The bottom sides of the gas introduction chamber 113 and the internal passage 114 are closed off from the upper side of the arm chamber 90 by the shield plate 115.

A cylindrical gas introduction part 116 is fixed to the bottom side opening of the gas introduction chamber 113 provided in the shielding plate 115. The gas introduction part 116 is located close to the left side inner wall in the valve arm chamber 90. The gas outlet of the gas introduction part 116 is located in the gas introduction chamber 113. The gas inlet of the gas introduction part 116 is located in the valve arm chamber 90 at a position closer to the cylinder head 5. The gas introduction part 116 has a cover member at the upper end, and while preventing liquid lubricating oil from directly entering the gas introduction chamber 113 from the cylinder head 5 side, it introduces the blow-by gas in the valve arm chamber 90 from a position closer to the cylinder head 5 in the valve arm chamber 90 into the gas introduction chamber 113 of the blow-by gas reduction device 69 above.

A partition wall 118 is provided at the bottom of the gas outlet section 111 to separate the gas introduction chamber 113 from the internal passage 114. The partition wall 118 is provided at a distance from the peripheral wall 119 of the blow-by gas reduction device 69, and forms the gas introduction chamber 113 and multiple internal passages 114 between the partition wall 118 and the peripheral wall 119. The multiple internal passages 114 are arranged in a maze-like pattern to form a labyrinth structure.

Oil trap materials 120, such as steel wool, that capture mist-like lubricating oil in the blow-by gas are disposed at two locations between the partition wall 118 and the peripheral wall 119. In this embodiment, the oil trap materials 120 are disposed in the front-rear direction of the engine 1, sandwiching the partition wall 118. The oil trap materials 120 are disposed between the gas introduction chamber 113 and the internal passage 114.

As shown in FIG. 9, beam-shaped partition walls 121 are provided at two locations on the inner upper surface of the gas introduction chamber 113, hanging down and protruding, sandwiching the gas introduction section 116. The beam-shaped partition walls 121 are installed between the oil trap material 120 and the gas introduction chamber 113, at a position above the oil trap material 120. The space surrounded by the peripheral wall 119, the upper surface of the oil trap material 120, and the beam-shaped partition walls 121 constitute a part of the internal passage 114 through which the blow-by gas flows.

The blow-by gas in the valve arm chamber 90 is introduced into the blow-by gas reduction device 69 from the gas outlet 111, and is sent to the blow-by gas outlet 67 via the gas introduction chamber 113, the labyrinth-like internal passage 114, the gas outlet passage 111a, the valve body 124 of the diaphragm 123, and the gas outlet passage 111b, while lubricating oil components are removed in each passage and the oil trap material 120. The blow-by gas from which the lubricating oil components have been removed is returned to the intake system from the blow-by gas outlet 67 through the blow-by gas return pipe 68 (see FIG. 6).

In the engine 1 of this embodiment, the intake manifold 8, which is integrally formed with the intake manifold section 6 and the arm chamber section 90, is disposed on the top surface of the cylinder head 5, allowing the intake manifold section 6 and the arm chamber section 90 to be laid out compactly. Furthermore, the blow-by gas reduction device 69 is provided protruding from the top of the arm chamber section 90, and the blow-by gas is guided to the intake side inlet 62a of the turbocharger 60 through a blow-by gas return pipe 68 (gas pipe) connected to a blow-by gas outlet 67 provided on the side of the blow-by gas reduction device 69, allowing the turbocharger 60 and the blow-by gas reduction device 69 to be arranged close to each other, allowing for a compact layout.

Furthermore, by providing the blow-by gas outlet 67 on the side of the blow-by gas reduction device 69, it is possible to provide freedom in the arrangement of the blow-by gas return pipe 68 connected to the blow-by gas outlet 67. Furthermore, by providing the blow-by gas reduction device 69 protruding from the upper part of the arm chamber 90, it is possible to prevent the arrangement of the blow-by gas reduction device 69 from reducing the volume inside the arm chamber 90. As a result, it is possible to ensure a sufficient arm chamber volume for the increase in blow-by gas accompanying the installation of the turbocharger 60, without significantly increasing the volume of the arm chamber 90, and thus the external dimensions of the arm chamber-integrated intake manifold 8.

Furthermore, the blow-by gas outlet 67 provided on the side of the blow-by gas reduction device 69 and the turbocharger 60 can be arranged close to each other, which simplifies the layout of the blow-by gas return pipe 68 and shortens the piping length. By shortening the length of the blow-by gas return pipe 68, it is possible to avoid blockage of the blow-by gas return pipe 68 due to freezing or bending of the blow-by gas return pipe 68.

In addition, in the engine 1 of this embodiment, the multiple internal passages 114 in the blow-by gas reduction device 69 form a maze-like labyrinth structure, so by forming the labyrinth structure in the blow-by gas reduction device 69, the volume of the valve arm chamber 90 and therefore the external dimensions of the valve arm chamber-integrated intake manifold 8 are not significantly increased, and the labyrinth structure can be made compact, and lubricating oil and unburned fuel contained in the blow-by gas can be removed by the labyrinth structure.

In addition, in the engine 1 of this embodiment, an oil trap material 120 is disposed between the partition wall 118 separating the gas introduction chamber 113 and the internal passage 114 and the peripheral wall 119 of the blow-by gas reduction device 69, so that the blow-by gas that bypasses the partition wall 118 and flows from the gas outlet of the gas introduction section 116 to the internal passage 114 can pass through the oil trap material 120, and lubricating oil and the like contained in the blow-by gas can be removed by the oil trap material 120.

In addition, in the engine 1 of this embodiment, the space surrounded by the beam-shaped partition wall 121, which is installed between the oil trap material 120 and the gas introduction chamber 113 at a position above the oil trap material 120, the upper surface of the oil trap material 120, and the peripheral wall 119 is considered as part of the internal passage 114, so that the blow-by gas can flow from the gas outlet of the gas introduction section 116 through the gas introduction chamber 113 and the inside of the oil trap material 120 to the upper surface side of the oil trap material 120, and lubricating oil and the like contained in the blow-by gas can be removed by the oil trap material 120.

Next, the configuration of the intake pipe and its surroundings will be described with reference to Figures 15 to 19. In the engine 1 of this embodiment, a first intake pipe 91, one end (upstream side) of which is connected to an air cleaner (not shown), is disposed between the cooling fan 9 and the blow-by gas outlet 67. Specifically, the first intake pipe 91 is disposed above the cooling water pump 21 on the front side of the engine 1 (one of the front and rear sides). One end of the first intake pipe 91 forms a fresh air inlet 91a.

The first intake pipe 91 is made of metal, for example, and has a roughly T-shaped appearance. The fresh air inlet 91a of the first intake pipe 91 opens toward the right side of the engine 1 (the other left or right side). The fresh air outlet 91b, which is provided at the other end (downstream side) of the first intake pipe 91 opposite the fresh air inlet 91a, opens toward the left side of the engine 1 (one left or right side). The appearance of the first intake pipe 91 between the fresh air inlet 91a and the fresh air outlet 92b has a linear, roughly cylindrical shape.

A generally cylindrical connection portion 91c is integrally formed on the outer circumferential surface of the first intake pipe 91 so as to protrude outward. The connection portion 91c is provided in a portion close to the fresh air outlet 91b in the center of the first intake pipe 91. A blow-by gas inlet 91d at the tip end of the connection portion 91c opens toward the blow-by gas outlet 67 (the rear side of the engine 1). The blow-by gas inlet 91d is connected to the blow-by gas return pipe 68, the other end of which is connected to the blow-by gas outlet 67.

The fresh air outlet 91b of the first intake pipe 91 is connected to a fresh air inlet 92a provided at one end of the second intake pipe 92. The second intake pipe 92 is made of, for example, resin, and is approximately L-shaped. The fresh air outlet 92b provided at the other end of the second intake pipe 92 is connected to the intake inlet 62a of the compressor case 62 of the turbocharger 60. The intake inlet 62a of the compressor case 62 opens toward the cooling fan 9. The second intake pipe 92 is formed so that one end 92a is longer than the curved portion, and the other end 92b is shorter.

In this way, in the engine 1 of this embodiment, the upstream portion of the second intake pipe 92 connected to the intake inlet 62a of the turbocharger 60 and the first intake pipe 91 are piped in the left-right direction and extend to the right side of the engine 1, so that the intake pipes 91, 92 connected to the turbocharger 60 can be laid out compactly without protruding from the front side of the engine 1.

In the past, when a turbocharger was installed in a small-displacement engine, for example, with three cylinders or less, if a straight intake pipe was attached to the intake side inlet of the turbocharger, the space between the intake side inlet of the turbocharger and engine components such as a cooling fan, fan shroud, and radiator arranged on one side of the front or rear of the engine was narrow, making it difficult to attach the intake pipe. In the engine 1 of this embodiment, even if the space between the intake inlet 62a of the turbocharger 60 and the engine components such as the cooling fan 9, fan shroud 20, and radiator 19 (see Figures 3 and 4) arranged on the front side of the engine 1 is narrow, it is possible to secure space to connect the fresh air pipe 99 (see Figure 17) connected to the air cleaner (not shown) to the first intake pipe 91, and the ease of installation and removal of the fresh air pipe 99 to the first intake pipe 91 is improved.

As shown in Figures 15 to 18, the blow-by gas return pipe 68 extends from the blow-by gas outlet 67 toward the front of the engine 1 and is connected to the connection part 91c of the first intake pipe 91, and is inclined upward toward the connection part 91c of the first intake pipe 91. This prevents lubricating oil and unburned fuel adhering to the inner wall of the blow-by gas return pipe 68 from flowing into the first intake pipe 91, reducing the mixing of lubricating oil and the like into the combustion air (fresh air) supplied to the engine 1 and the contamination of the intake system path including the compressor case 62 of the turbocharger 60 by lubricating oil and the like. Furthermore, since the upstream parts of the series of intake pipes 91, 92 are extended in the left-right direction toward the right side of the engine 1, the blow-by gas return pipe 68 connected to the connection part 91c of the first intake pipe 91 can be arranged in a straight line from the blow-by gas outlet 67 in a plan view, making it easy to layout the blow-by gas return pipe 68 and shortening the piping length. By shortening the length of the blow-by gas return pipe 68, it is possible to prevent the blow-by gas return pipe 68 from being blocked due to freezing or bending. In addition, since the blow-by gas return pipe 68 is disposed directly above the intake manifold 8 with the valve arm chamber integrated therein, it is possible to prevent the blow-by gas return pipe 68 from being blocked due to freezing caused by heat dissipation from the engine 1. In addition, most of the blow-by gas return pipe 68 is disposed overlapping the first intake pipe 91 in a front view, and the area of the blow-by gas return pipe 68 exposed to the cooling fan 9 is small, which contributes to preventing the blow-by gas return pipe 68 from freezing due to the cooling wind.

As shown in Figures 15 to 17, the intake manifold 6 having an intake inlet 103 on its upper surface is disposed on the upper surface of the cylinder head 5, and the intake outlet 62b of the turbocharger 60 opens obliquely upward toward the right side surface of the engine 1. The intake inlet 103 and the intake outlet 62b are connected by an intake relay pipe 66. The intake relay pipe 66 extends obliquely upward from the intake outlet 62b toward the right side surface of the engine 1, is led to above the blow-by gas return pipe 68, and is curved horizontally above the blow-by gas return pipe 68. Furthermore, the intake relay pipe 66 is led above a front portion of the intake manifold 6 and is curved toward the rear side of the engine 1, is further led above the intake inlet 103, is curved downward, and is connected to the intake inlet 103. As a result, compared to configuration examples in which the intake manifold is disposed on the side of the cylinder head or the intake inlet is disposed on the side of the intake manifold, the length of the intake relay pipe 66 can be shortened to reduce intake resistance, and combustion air can be introduced into the engine 1 without compromising the boost pressure obtained by the turbocharger 60. Furthermore, since both the intake outlet 62b of the turbocharger 60 and the intake inlet 103 of the intake manifold portion 6 are open facing upward (diagonally upward), the layout of the intake relay pipe 66 is simplified and the installation work of the intake relay pipe 66 is made easier.

As shown in Figures 5, 6 and 15 to 17, the intake relay pipe 66 passes above the intake manifold 8 with integrated valve arm chamber and above the blow-by gas return pipe 68. This allows the intake relay pipe 66 to be separated from the head cover to suppress the rise in temperature of the combustion air caused by heat radiation from the engine 1, while making effective use of the space above the intake manifold 8 with integrated valve arm chamber to arrange the intake relay pipe 66 and the blow-by gas return pipe 68. The blow-by gas return pipe 68 can also be arranged in a straight line to shorten the piping length of the blow-by gas return pipe 68.

As shown in Figures 16 and 17, the cooling water pump 21 has a thermostat case 85 that houses a thermostat. A thermostat cover 86 having a cooling water outlet 21b that is connected to a cooling water pipe leading to the radiator 19 is provided on the top of the thermostat case 85. The thermostat cover 86 is disposed below the first intake pipe 91. The thermostat case 85 and the thermostat cover 86 form part of the cooling water pump 21.

The cooling water pump 21 has a cooling water inlet 21a and a cooling water outlet 21b to which a cooling water feed pipe 87 and a cooling water return pipe 88, which are connected to the radiator 19 (see Figures 3 and 4), are connected. The cooling water inlet 21a is provided in the main body of the cooling water pump 21. The cooling water outlet 21b is provided in the thermostat cover 86. Both the cooling water inlet 21a and the cooling water outlet 21b are open toward the right side of the engine 1.

As shown in FIG. 16, the upstream portion of the series of intake pipes 91, 92 is inclined upward from the left side of the engine 1 to the right side of the engine 1. This allows for a compact configuration in which the height of the turbocharger 60 is suppressed without increasing the height of the intake inlet 62a of the turbocharger 60, and thus the height of the turbocharger 60 itself, while still providing space for arranging other components of the engine 1, in this embodiment, the thermostat cover 86 having the cooling water outlet 21b, below the upstream portion of the intake pipes 91, 92. In addition, the space between the fresh air inlet 91a provided in the upstream portion of the intake pipes 91, 92 and the other components arranged below it, in this embodiment, the thermostat cover 86, can be made larger, and a space is provided for an operator to insert his/her hands when attaching/detaching the fresh air piping 99 connected to the air cleaner (not shown) to the fresh air inlet 91a of the first intake pipe 91, improving the ease of operation.

In addition, in the engine 1 of this embodiment, the fresh air inlet 91a of the first intake pipe 91 and the cooling water inlet 21a and cooling water outlet 21b of the cooling water pump 21 are open toward the right side of the engine 1. This allows the installation and maintenance work of the fresh air piping 99 connected to the fresh air inlet 91a, the cooling water feed pipe 87 connected to the cooling water inlet 21a, and the cooling water return pipe 88 connected to the cooling water outlet 21b to be performed from the same side of the engine 1 (the right side of the engine 1 in this embodiment), improving the efficiency of these operations.

As shown in Figures 15 and 19, a partition wall 91e is formed inside the first intake pipe 91. The partition wall 91e is formed from the fresh air inlet 91a toward the fresh air outlet 91b, and divides the internal space of the first intake pipe 91 into a fresh air circulation space 91f connecting the fresh air inlet 91a to the fresh air outlet 91b and a blow-by gas circulation space 91g connecting the blow-by gas inlet 91d to the fresh air outlet 91b. Since the first intake pipe 91 has such a structure, it is also called a three-way valve. Due to such a structure of the first intake pipe 91, the backflow of the blow-by gas introduced from the blow-by gas inlet 91d to the first intake pipe 91 toward the fresh air inlet 91a is suppressed.

As shown in Figures 15 to 17, in this embodiment, the first intake pipe 91 is formed with a sensor mounting seat 94 for mounting a temperature sensor 93. The temperature sensor 93 is attached to the sensor mounting seat 94 and the sensor portion is inserted into the first intake pipe 91 to measure the air temperature flowing through the fresh air flow space 91f. The sensor portion of the temperature sensor 93 is disposed in the fresh air flow space 91f separated from the blow-by gas flow space 91g, so that the sensor portion is prevented from becoming dirty with lubricating oil components contained in the blow-by gas.

Next, the exhaust system components and the surrounding structure will be described with reference to Figures 20 to 23. The exhaust inlet 61a of the turbocharger 60 is connected to the exhaust gas outlet 130 (exhaust side outlet) provided on the upper surface of the exhaust manifold 7. The exhaust manifold 7, which has exhaust gas inlets 131 for three cylinders, is fixed to the left side surface of the cylinder head 5 with six mounting bolts 132. The exhaust manifold 7 has two bolt insertion holes that sandwich the exhaust gas inlet 131 in the upper and lower directions, one for each periphery of the exhaust gas inlet 131. The bottom side of the exhaust manifold 7 is bifurcated into a front branch portion 133 and a rear branch portion 134 below the exhaust gas outlet 130. The exhaust gas inlet 131 for one cylinder is arranged in the front branch portion 133, and the exhaust gas inlets 131 for two cylinders are arranged in the rear branch portion 134.

A lubricating oil feed pipe 64 and a lubricating oil return pipe 65 are connected to the center housing 63 of the turbocharger 60. One end of the lubricating oil feed pipe 64 is connected to the lubricating oil feed passage 79 (see Figure 23) inside the cylinder block 4 at a location toward the rear of the center of the right side of the cylinder block 4 by a lubricating oil introduction joint 135. The other end of the lubricating oil feed pipe 64 is connected to the upper part of the center housing 63 by a lubricating oil discharge joint 136.

The lubricating oil feed pipe 64 is led upward from the lubricating oil introduction joint 135, then bent diagonally upward and rearward, and led to the vicinity of the rear portion of the upper end of the right side surface of the cylinder block 4. Furthermore, the lubricating oil feed pipe 64 is led along the upper end of the cylinder block 4 from the right side surface of the cylinder block 4 through the rear side surface to the left side surface. The middle part of the lubricating oil feed pipe 64 is fixed at a position facing the upper end of the rear side surface of the cylinder block 4 by a pipe locking member 137 bolted to the cylinder head 5. The lubricating oil feed pipe 64 led to the left side surface of the cylinder block 4 is bent upward behind the exhaust manifold 7, then led to a position higher than the upper surface of the cylinder head 5 and bent forward. Furthermore, the lubricating oil feed pipe 64 passes above the rear branching portion 134 of the exhaust manifold 7 and is led to a position between the exhaust gas outlet 130 and the left side of the intake manifold 8 with integrated valve arm chamber, from there it is led diagonally upwards and forwards, then bent diagonally upwards and left, and further bent approximately horizontally to connect to a lubricating oil outlet joint 136 attached to the center housing 63 of the turbocharger 60.

In this way, the lubricating oil feed pipe 64 is routed from the right side of the engine 1 to the left side, bypassing the rear side of the engine 1, and is routed from the rear side of the exhaust manifold 7 on the left side of the engine 1, bypassing the outer periphery of the exhaust manifold 7, toward the top of the exhaust manifold 7, and is compactly arranged along the side of the engine 1. Furthermore, since the lubricating oil feed pipe 64 is routed bypassing the outer periphery of the exhaust manifold 7, even when the lubricating oil feed pipe 64 is attached to the engine 1 by the lubricating oil introduction joint 135 and the pipe locking member 137, the lubricating oil feed pipe 64 does not become an obstacle during the installation work of the exhaust manifold 7, and the efficiency of the assembly work of the engine 1 is improved.

One end of the lubricating oil return pipe 65 is connected to a pipe flange member 138 that is bolted to the bottom of the center housing 63, and the other end is connected to a lubricating oil return joint 140 via an elastic piping member 139 made of, for example, rubber resin and having elasticity. The lubricating oil return pipe 65 is led downward from the pipe flange member 138, then bent diagonally downward and rearward, and led to the left side of the exhaust manifold 7 and below the exhaust gas outlet 130. Furthermore, the lubricating oil return pipe 65 is led diagonally downward to the right along the left side surface of the exhaust manifold 7 toward the branching portion of the front branching portion 133 and the rear branching portion 134, bent diagonally forward and diagonally downward to the right below the exhaust manifold 7, led to the vicinity of the left side surface of the cylinder block 4, and further bent downward to connect to one end of the elastic piping member 139. The elastic piping member 139 is cylindrical and is piped vertically. The other end of the elastic piping member 139 is connected to a lubricating oil return joint 140 arranged in the front central portion of the right side surface of the cylinder block 4. The lubricant return joint 140 is located below the center housing 63 when viewed from the left side.

In this embodiment of the engine 1, the lubricant return pipe 65 that extracts the lubricant from the turbocharger 60 is routed downward along the bifurcated portion at the bottom of the exhaust manifold 7, so that the lubricant return pipe 65 can be routed compactly close to the left side of the engine 1.

In recent years, market demands for lower fuel consumption and lower costs have led to the compactification of engines through the addition of turbochargers, and a significant increase in the number of small-displacement turbocharged engines produced is expected. In contrast, the number of turbocharged versions and production of small-displacement industrial diesel engines has traditionally been low, and when turbochargers are installed on such engines, the assembly of the turbocharger peripheral parts is set up in stages, as an extension of a naturally aspirated engine, with the exhaust manifold, turbocharger, and lubricating oil pipes. Therefore, the assembly of the turbocharger peripheral parts is carried out in a separate assembly cell for turbocharger specifications, which takes time, and the traditional assembly method is too time-consuming to meet the required production volume.

In response to such demands, the engine 1 of this embodiment has been improved so that the exhaust manifold 7, turbocharger 60, and lubricant return pipe 65 can be assembled to the engine 1 in a structured state. As shown in FIG. 20, the layout of the exhaust manifold 7, turbocharger 60, and lubricant return pipe 65 exposes the mounting bolts 132 when viewed from the left side of the engine 1 so as not to impede the installation of the exhaust manifold 7 to the cylinder head 5. In addition, the lubricant return pipe 65 is connected to the lubricant return joint 140 via an elastic piping member 139 so that a worker can tighten the bolts of the exhaust manifold 7 by himself when the exhaust manifold 7, turbocharger 60, and lubricant return pipe 65 are assembled. The worker first connects the lubricant return joint 140 to the cylinder block 4, so that the lubricant return pipe 65, elastic piping member 139, and lubricant return joint 140 can be used as one of the supports during assembly, and irreversible plastic deformation of the lubricant return pipe 65 can be prevented by the deformation of the elastic piping member 139.

This makes it easy for a single worker to assemble the exhaust manifold 7, turbocharger 60, and lubricant return pipe 65 into the engine 1, and by assembling the exhaust system components in advance according to the production schedule, it is possible to centralize the assembly work and make the line work smoother. Furthermore, the increase in assembly man-hours for turbocharged engines compared to naturally aspirated specifications can be minimized on the line, making it possible to respond to increased production. Furthermore, by limiting the assembly process carried out in the assembly space dedicated to turbocharged specifications to the installation process of exhaust system components such as the exhaust manifold 7, turbocharger 60, and lubricant return pipe 65, and the lubricant feed pipe 64, it is possible to save space at the assembly site.

The configuration of each part in the present invention is not limited to the illustrated embodiment, and various modifications are possible without departing from the spirit of the present invention. The engine device of the present invention is mounted on a work machine such as a lawnmower, a construction machine, an agricultural machine, or an engine generator.

<Additional Notes>
The engine device of the present invention may be an engine device in which a head cover is provided on the top of an engine and a supercharger is provided on one side of the engine, wherein the head cover and the supercharger at least partially overlap in a side view, and at least a portion of an intake pipe connected to an intake side inlet of the supercharger is positioned above the head cover.

In the above configuration, the intake pipe may have a bent portion, the portion downstream of the bent portion may be piped in the front-rear direction of the engine and connected to the intake side inlet of the turbocharger, and the portion upstream of the bent portion may be piped in the left-right direction of the engine.

Furthermore, in the above configuration, the upstream portion of the intake pipe may be inclined upward from one left or right side of the engine where the supercharger is provided to the other left or right side.

In addition, in the above configuration, a blow-by gas outlet for returning blow-by gas leaking from the combustion chamber to the intake system may be provided in the head cover, and a blow-by gas return pipe may be extended from the blow-by gas outlet in the fore-and-aft direction of the engine, connected to the intake pipe, and inclined upward toward the intake pipe.

1 Engine 4 Cylinder block 5 Cylinder head 6 Intake manifold section (intake manifold)
7 Exhaust manifold 8 Intake manifold with valve arm chamber (head cover)
19 Radiator 20 Fan shroud 21 Cooling water pump 21a Cooling water inlet 21b Cooling water outlet 60 Turbocharger 61a Exhaust inlet (exhaust side inlet)
61b Exhaust outlet 62a Intake inlet (intake side inlet)
62b Intake outlet (intake side outlet)
64 Lubricating oil feed pipe (lubrication pipe)
65 Lubricating oil return pipe (return pipe)
66 Intake relay pipe 67 Blow-by gas outlet 68 Blow-by gas return pipe 69 Blow-by gas reduction device 90 Valve arm chamber (valve arm chamber)
91 First intake pipe 91a Fresh air inlet 92 Second intake pipe 92b Fresh air outlet 101 Partition wall 130 Exhaust gas outlet (exhaust side outlet)
131 Exhaust gas inlet 139 Elastic piping member

Claims (5)

An engine device,
A supercharger,
an intake relay pipe connecting the turbocharger and an intake manifold;
Equipped with
An engine apparatus, wherein the intake relay pipe has a sloped portion which slopes downward from an upstream portion to a downstream portion of an airflow flowing through the relay pipe. An intake pipe connected to the turbocharger,
The engine apparatus according to claim 1 , wherein at least a portion of the intake relay pipe is provided above the intake pipe. The engine device according to claim 2, wherein the intake inlet of the intake pipe is provided below the top of the intake relay pipe. The engine device according to claim 2 or 3, wherein the intake inlet of the intake pipe is provided above the intake inlet of the intake manifold. The engine device according to any one of claims 1 to 3, wherein the intake manifold has an intake inlet that opens upward on its upper surface and is connected to the intake relay pipe.