JP7566820B2 - Engine equipment - Google Patents

Description

The present invention relates to an engine device.

In recent years, engine drive control has rapidly become electronic, and engines are now equipped with a large number of electronic devices (see, for example, Patent Document 1). As a result, a large number of wire harnesses (electrical wires) are attached to the engine.

JP 2013-76367 A

Conventionally, various methods have been used to make wire harnesses easier to handle, such as bundling multiple wire harnesses into a harness assembly or providing a relay connector in the middle of the wire harness, but further improvements in the ease of handling of wire harnesses are desired.

In view of the above problems, the present invention aims to improve the ease of handling of harness connectors that are electrically connected to wire harnesses.

The engine device of the present invention is an engine device equipped with an electronic device and a wire harness electrically connected thereto, the wire harness being electrically connected to a harness connector, and the harness connector being attached to one side of a cylinder block via a connector bracket.

The engine device of the present invention may, for example, have an intake manifold attached to one side of the cylinder head, and the harness connector may be disposed below the intake manifold.

Furthermore, for example, the wire harness electrically connected to the harness connector may be a harness assembly, and the harness assembly may be branched into a plurality of wire harnesses on the one side of the cylinder block.

Also, for example, a common rail may be disposed on the one side of the cylinder block, and the plurality of wire harnesses may be connected to at least the common rail.

The above configuration improves the ease of handling of the harness connector.

FIG. 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 the cylinder block and the flywheel housing. FIG. 2 is a left side view showing the cylinder block and the flywheel housing. FIG. 4 is a right side view showing the cylinder block and the flywheel housing. FIG. 10 is a cross-sectional view taken along the line AA in FIG. 9. 10 is a cross-sectional view taken along the line BB in FIG. 9. FIG. 4 is a perspective view showing the inside of the flywheel housing. FIG. 4 is a perspective view showing the mounting position of a fuel supply pump. FIG. 2 is an explanatory diagram of a fuel system of the engine. FIG. FIG. FIG. FIG. FIG. FIG. 4 is a bottom view showing the common rail connector with the oil pan and cylinder block partially cut away. FIG. 2 is a plan view showing the oil cooler bracket. FIG. 2 is a perspective view showing an oil cooler bracket. FIG. 4 is an exploded perspective view showing the mounting structure of the oil cooler bracket and the oil cooler. FIG. 4 is a right side view showing the oil cooler bracket mounting seat. FIG. 4 is a right side view showing the attached state of the oil cooler bracket. FIG. 2 is a rear view showing the cylinder block in partial cross section. 4 is an enlarged partial cross-sectional rear view showing the periphery of an oil cooler bracket mounting seat. FIG. FIG. 2 is a plan view showing the wire harness and the harness bracket. FIG. 4 is a right side view showing the wire harness and the harness bracket. FIG. 2 is a perspective view showing a wire harness and a harness bracket. 2 is an enlarged perspective view showing the harness connector and its periphery; FIG. FIG. 2 is an enlarged perspective view of a wire harness and a harness bracket. FIG. 2 is an enlarged perspective view of a wire harness and a harness bracket. 4 is an enlarged right side view showing the harness connector and its periphery. FIG.

The following describes an embodiment of the present invention with reference to the drawings. First, the overall structure of an engine (engine device) 1, which is a diesel engine, will be described with reference to Figs. 1 to 8. In the following description, the two sides parallel to the crankshaft 5 (the two sides sandwiching the crankshaft 5) will be referred to as the left and right, the side where the flywheel housing 7 is installed will be referred to as the front side, and the side where the cooling fan 9 is installed will be referred to as the rear side, and for convenience, these will be 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 8, the intake manifold 3 is disposed on one side parallel to the crankshaft 5 of the engine 1, and the exhaust manifold 4 is disposed on the other side. In this embodiment, the intake manifold 3 is molded integrally with the cylinder head 2 on the right side of the cylinder head 2, and the exhaust manifold 4 is installed on the left side of the cylinder head 2. The cylinder head 2 is mounted on a cylinder block 6 that houses the crankshaft 5 and pistons (not shown). The cylinder block 6 supports the crankshaft 5 so that it can rotate freely.

The front and rear ends of the crankshaft 5 protrude from both the front and rear side surfaces of the cylinder block 6. A flywheel housing 7 is fixed to one side of the engine 1 that intersects with the crankshaft 5 (the front side surface of the cylinder block 6 in this embodiment). A flywheel 8 is disposed within the flywheel housing 7. The flywheel 8 is journaled on the front end side of the crankshaft 5 and is configured to rotate integrally with the crankshaft 5. The engine 1 is configured to extract power from the flywheel 8 to a working part of a work machine (e.g., a hydraulic excavator, a forklift, etc.). A cooling fan 9 is provided on the other side of the engine 1 that intersects with the crankshaft 5 (the rear side surface of the cylinder block 6 in this embodiment). The rotational force is transmitted from the rear end side of the crankshaft 5 to the cooling fan 9 via a V-belt 10.

An oil pan 11 is placed on the underside of the cylinder block 6. Lubricating oil is stored in the oil pan 11. The lubricating oil in the oil pan 11 is sucked up by an oil pump 12 (see FIG. 11) located on the right side of the cylinder block 6, which is the connecting portion between the cylinder block 6 and the flywheel housing 7, and is supplied to each lubricated part of the engine 1 via an oil cooler 13 and an oil filter 14 located on the right side of the cylinder block 6. The lubricating oil supplied to each lubricated part is then returned to the oil pan 11. The oil pump 12 is configured to be driven by the rotation of the crankshaft 5.

A fuel supply pump 15 for supplying fuel is attached to the connecting portion of the cylinder block 6 with the flywheel housing 7, and is disposed below the EGR device 24. A common rail 16 is fixed to the side of the cylinder block 6 below the intake manifold 3 of the cylinder head 2, and is disposed above the fuel supply pump 15. On the top surface of the cylinder head 2, which is covered by the head cover 18, injectors 17 (see FIG. 17) for each of the four cylinders, each having an electromagnetically controlled fuel injection valve, are provided.

Each injector 17 is connected to a fuel tank 118 (see FIG. 17) mounted on the work vehicle via a fuel supply pump 15 and a cylindrical common rail 16. Fuel from the fuel tank is pumped from the fuel supply pump 15 to the common rail 16, and high-pressure fuel is stored in the common rail 16. By controlling the opening and closing of the fuel injection valves 119 (see FIG. 17) of each injector 17, the high-pressure fuel in the common rail 16 is injected from each injector 17 into each cylinder of the engine 1.

A blow-by gas reduction device 19 is provided on the top surface of a head cover 18 that covers the intake valve and exhaust valve (not shown) on the top surface of the cylinder head 2, and takes in blow-by gas that leaks from the combustion chamber of the engine 1 to the top surface side of the cylinder head 2. The blow-by gas outlet of the blow-by gas reduction device 19 is connected to the intake section of the two-stage turbocharger 30 via a reduction hose 68. The blow-by gas from which the lubricating oil components have been removed in the blow-by gas reduction device 19 is reduced to the intake manifold 3 via the two-stage turbocharger 30.

A starter 20 for starting the engine is attached to the flywheel housing 7, and the starter 20 is positioned below the exhaust manifold 4. The starter 20 is attached to the flywheel housing 7 at a position below the connection between the cylinder block 6 and the flywheel housing 7.

A cooling water pump 21 for circulating cooling water is located below the cooling fan 9 at a position toward the left of the rear surface of the cylinder block 6. The cooling water pump 21 is driven together with the cooling fan 9 via the cooling fan drive V-belt 10 by the rotation of the crankshaft 5. Cooling water in a radiator (not shown) mounted on the work vehicle is supplied to the cooling water pump 21 by the drive of the cooling water pump 21. The cooling water is then supplied to the cylinder head 2 and cylinder block 6 to cool the engine 1.

The cooling water inlet pipe 22, which is disposed below the exhaust manifold 4 and communicates with the cooling water outlet of the radiator, is fixed to the left side surface of the cylinder block 6 at the same height as the cooling water pump 21. Meanwhile, the cooling water outlet pipe 23, which communicates with the cooling water inlet of the radiator, is fixed to the rear of the cylinder head 2. The cylinder head 2 has a cooling water drainage section 35 that protrudes from the rear of the intake manifold 3, and the cooling water outlet pipe 23 is installed on the upper surface of the cooling water drainage section 35.

The inlet side of the intake manifold 3 is connected to an air cleaner (not shown) via a collector 25 of an EGR device 24 (exhaust gas recirculation device) described later. Fresh air (outside air) sucked into the air cleaner is cleaned and purified by the air cleaner, then sent to the intake manifold 3 via the collector 25 and supplied to each cylinder of the engine 1. In this embodiment, the collector 25 of the EGR device 24 is connected to the right side of the intake manifold 3, which is integrally molded with the cylinder head 2 and forms the right side of the cylinder head 2. That is, the outlet opening of the collector 25 of the EGR device 24 is connected to the inlet opening of the intake manifold 3 provided on the right side of the cylinder head 2. In this embodiment, the collector 25 of the EGR device 24 is connected to the air cleaner via an intercooler (not shown) and a two-stage turbocharger 30, as described later.

The EGR device 24 has a collector 25 as a relay pipe that mixes the recirculated exhaust gas (EGR gas from the exhaust manifold 4) of the engine 1 with fresh air (external air from the air cleaner) and supplies it to the intake manifold 3, an intake throttle member 26 that connects the collector 25 to the air cleaner, a recirculated exhaust gas pipe 28 that is part of the return pipe that connects to the exhaust manifold 4 via an EGR cooler 27, and an EGR valve member 29 that connects the collector 25 to the recirculated exhaust gas pipe 28.

The EGR device 24 is disposed on the right side of the intake manifold 3 in the cylinder head 2. That is, the EGR device 24 is fixed to the right side surface of the cylinder head 2 and communicates with the intake manifold 3 inside the cylinder head 2. The EGR device 24 is fixed such that the collector 25 is connected to the intake manifold 3 on the right side surface of the cylinder head 2, and the EGR gas inlet of the recirculated exhaust gas pipe 28 is connected and fixed to the front part of the intake manifold 3 on the right side surface of the cylinder head 2. In addition, an EGR valve member 29 and an intake throttle member 26 are connected to the front and rear of the collector 25, respectively, and the EGR gas outlet of the recirculated exhaust gas pipe 28 is connected to the rear end of the EGR valve member 29.

The EGR cooler 27 is fixed to the front side of the cylinder head 2, and the cooling water and EGR gas flowing inside the cylinder head 2 flow in and out of the EGR cooler 27, where the EGR gas is cooled. EGR cooler connection seats 33, 34 that connect the EGR cooler 27 are protrudingly provided at the left and right positions of the front side of the cylinder head 2, and the EGR cooler 27 is connected to the connection seats 33, 34. In other words, the EGR cooler 27 is disposed above the flywheel housing 7 and in front of the cylinder head 2, with the rear end face of the EGR cooler 27 separated from the front side of the cylinder head 2.

The two-stage turbocharger 30 is disposed to the side (left side in the embodiment) of the exhaust manifold 4. The two-stage turbocharger 30 includes a high-pressure turbocharger 51 and a low-pressure turbocharger 52. The high-pressure turbocharger 51 has a high-pressure turbine 53 incorporating a turbine wheel (not shown) and a high-pressure compressor 54 incorporating a blower wheel (not shown), while the low-pressure turbocharger 52 has a low-pressure turbine 55 incorporating a turbine wheel (not shown) and a low-pressure compressor 56 incorporating a blower wheel (not shown).

The exhaust gas inlet 57 of the high-pressure turbine 53 is connected to the exhaust manifold 4, the exhaust gas inlet 60 of the low-pressure turbine 55 is connected to the exhaust gas outlet 58 of the high-pressure turbine 53 via a high-pressure exhaust gas pipe 59, and the exhaust gas intake side end of the exhaust gas discharge pipe (not shown) is connected to the exhaust gas outlet 61 of the low-pressure turbine 55. On the other hand, the fresh air supply side (fresh air outlet side) of the air cleaner (not shown) is connected to the fresh air intake port (fresh air inlet) 63 of the low-pressure compressor 56 via an air supply pipe 62, the fresh air intake port 66 of the high-pressure compressor 54 is connected to the fresh air supply port (fresh air outlet) 64 of the low-pressure compressor 56 via a low-pressure fresh air passage pipe 65, and the fresh air intake side of the intercooler (not shown) is connected to the fresh air supply port 67 of the high-pressure compressor 54 via a high-pressure fresh air passage pipe (not shown).

The high-pressure turbocharger 51 is connected to the exhaust gas outlet 58 of the exhaust manifold 4 and fixed to the left side of the exhaust manifold 4, while the low-pressure turbocharger 52 is connected to the high-pressure turbocharger 51 via a high-pressure exhaust gas pipe 59 and a low-pressure fresh air passage pipe 65 and fixed above the exhaust manifold 4. That is, the small-diameter high-pressure turbocharger 51 and the exhaust manifold 4 are arranged side by side below the large-diameter low-pressure turbocharger 52, so that the two-stage turbocharger 30 is arranged to surround the left side and top of the exhaust manifold 4. That is, the exhaust manifold 4 and the two-stage turbocharger 30 are arranged in a rectangular shape when viewed from behind (when viewed from the front), and are compactly fixed to the left side of the cylinder head 2.

Next, the configuration of the cylinder block 6 will be described with reference to Figures 9 to 13. In the cylinder block 6, a left housing bracket part 304 and a right housing bracket part 305 (protruding parts) to which the flywheel housing 7 is fixed by a plurality of bolts are molded at the ends of the front side surface 303 side of the left side surface 301 and the right side surface 302 along the crank axis 300 direction of the crankshaft 5. A first left reinforcing rib 306, a second left reinforcing rib 307, a third left reinforcing rib 308, and a fourth left reinforcing rib 309 are molded between the side wall of the left side surface 301 and the left housing bracket part 304, in that order from the upper side (top deck part side) to the lower side (oil pan rail part side). In addition, a first right reinforcing rib 310 and a second right reinforcing rib 311 are molded between the side wall of the right side surface 302 and the right housing bracket part 305, in that order from the upper side to the lower side. The housing bracket parts 304, 305 and the reinforcing ribs 306 to 311 are integrally molded with the cylinder block 6.

The reinforcing ribs 306-311 each extend along the crankshaft axis 300, and have a generally triangular shape in which the housing bracket portions 304, 305 are wider in plan view. The left reinforcing ribs 307, 308, 309 and the right second reinforcing rib 311 each have linear portions 307a, 308a, 309a, 311a that extend from the generally triangular portion toward the rear side surface 312 of the cylinder block 6 (see also Figures 7 and 8). The reinforcing ribs 306, 307, 308 are disposed in the cylinder portion of the cylinder block 6. The reinforcing ribs 309, 310, 311 are disposed in the skirt portion of the cylinder block 6.

On the left side surface 301 and the right side surface 302, two mount attachment seats 317 for attaching engine mounts that connect the engine 1 to the vehicle body are each provided in a protruding manner in the front-rear direction near the oil pan rail. The left fourth reinforcing rib 309 is connected to the two mount attachment seats 317 provided in the protruding manner on the left side surface 301. The right second reinforcing rib 311 is connected to the two mount attachment seats 317 provided in the protruding manner on the right side surface 302. As shown in FIG. 2, a crankcase cover member 326 that covers the periphery of the crankshaft 5 is fixed to the rear side surface 312 of the cylinder block 6 by bolts so that the inside of the crankcase is not exposed to the outside of the engine 1. The oil pan 11 is bolted to the underside of the crankcase cover member 326.

The housing bracket parts 304, 305 and reinforcing ribs 306-311, which are integrally molded with the cylinder block 6, improve the rigidity of the cylinder block 6, particularly the rigidity and strength near the front side surface 303 of the cylinder block 6, thereby reducing vibration and noise of the engine 1. Furthermore, the housing bracket parts 304, 305 and reinforcing ribs 306-311 increase the surface area of the cylinder block 6, thereby improving the cooling efficiency of the cylinder block 6 and, ultimately, the cooling efficiency of the engine 1.

In addition, a cooling water pump mounting portion 319 to which the cooling water pump 21 (see FIG. 2, etc.) is attached and an inlet pipe mounting seat 320 to which the cooling water inlet pipe 22 (see FIG. 3, etc.) is attached are protrudingly provided on the left side surface 301 of the cylinder block 6 near the rear side surface 312. The cooling water pump mounting portion 319 and the inlet pipe mounting seat 320 are integrally molded with the cylinder block 6. The inlet pipe mounting seat 320 is connected to the cooling water pump mounting portion 319 at the rear side surface 312 side. The cooling water pump mounting portion 319 and the inlet pipe mounting seat 320 are protrudingly provided in a direction away from the crankshaft 5, which can improve the rigidity, strength, and cooling efficiency of the cylinder block 6.

Inside the cylinder block 6, a camshaft case 314 (see FIG. 13) that houses the camshaft 313 is formed. Although details are omitted, a crank gear 331 fixed to the crankshaft 5 and a cam gear 332 fixed to the camshaft 313 are arranged on the front side surface 303 of the cylinder block 6. The cam gear 332 and the camshaft 313 are rotated in conjunction with the crank gear 331, and a valve mechanism (not shown) associated with the camshaft 313 is driven, thereby opening and closing the intake valves and exhaust valves (not shown) of the engine 1. The engine 1 of this embodiment has a so-called overhead valve system.

The camshaft case portion 314 is disposed near the left side surface 301 of the cylinder portion of the cylinder block 6. The camshaft 313 and the camshaft case portion 314 are disposed along the crankshaft axis 300. The approximately triangular and linear portions 307a, 308a of the second left reinforcing rib 307 and the third left reinforcing rib 308 formed on the left side surface 301 of the cylinder block 6 are disposed close to the position of the camshaft case portion 314 in a side view, and more specifically, are disposed at a position overlapping the position of the camshaft case portion 314.

In this embodiment, the rigidity around the camshaft case portion 314 is improved by the left second reinforcing rib 307 and the left third reinforcing rib 308, so distortion of the camshaft case portion 314 can be prevented. This prevents fluctuations in the rotational resistance and rotational friction of the camshaft 313 caused by distortion of the camshaft case portion 314, and allows the camshaft 313 to rotate appropriately to properly open and close the intake valve and exhaust valve (not shown).

In addition, some of the lubricating oil passages formed in the cylinder block 6, here the lubricating oil suction passage 315 and the lubricating oil supply passage 316, are located near the right side surface 302 of the skirt portion of the cylinder block 6. The lubricating oil supply passage 316 is located near the cylinder portion of the skirt portion of the cylinder block 6. The lubricating oil suction passage 315 is located near the oil pan rail portion relative to the lubricating oil supply passage 316.

One end of the lubricating oil suction passage 315 opens to the underside of the oil pan rail of the cylinder block 6 (the surface facing the oil pan 11) and is connected to a lubricating oil suction pipe (not shown) arranged in the oil pan 11. The other end of the lubricating oil suction passage 315 opens to the front side surface 303 of the cylinder block 6 and is connected to the suction port of the oil pump 12 (see FIG. 11) fixed to the front side surface 303. One end of the lubricating oil supply passage 316 opens to the front side surface 303 of the cylinder block 6 at a position different from the opening of the lubricating oil suction passage 315 and is connected to the discharge port of the oil pump 12. The other end of the lubricating oil supply passage 316 opens to an oil cooler bracket mounting seat 318 protruding from the right side surface 302 of the cylinder block 6 and is connected to the suction port of the oil cooler 13 (see FIG. 4, etc.) arranged on the oil cooler bracket mounting seat 318. In addition to the lubricating oil suction passage 315 and the lubricating oil supply passage 316, other lubricating oil passages are formed in the cylinder block 6.

On the right side surface 302 of the cylinder block 6, the right first reinforcing rib 310 is disposed adjacent to the position of the lubricating oil supply passage 316 in a side view, and more specifically, is disposed so as to overlap the position of the lubricating oil supply passage 316 in a side view. The right second reinforcing rib 311 is disposed adjacent to the position of the lubricating oil suction passage 315 in a side view. The reinforcing ribs 310, 311 and the passages 315, 316 each extend along the crank shaft center 300.

In this embodiment, the right housing bracket portion 305, the right first reinforcing rib 310, and the right second reinforcing rib 311 can improve the cooling efficiency near the lubricating oil suction passage 315, the oil pump 12, and the lubricating oil supply passage 316. In particular, the right first reinforcing rib 310, which is positioned to overlap the lubricating oil supply passage 316 in a side view, efficiently dissipates heat near the lubricating oil supply passage 316 to the outside. This can reduce the temperature of the lubricating oil flowing into the oil cooler 13, and the amount of heat exchange required in the oil cooler 13.

Next, the gear train structure of the engine 1 will be described with reference to Figures 10 to 16. A gear case 330 is formed in a space surrounded by the front side surface 303 of the cylinder block 6, the housing bracket parts 304, 305, and the flywheel housing 7. As shown in Figures 12 and 14, the front ends of the crankshaft 5 and the camshaft 313 are arranged to protrude from the front side surface 303 of the cylinder block 6. A crank gear 331 is fixed to the front end portion of the crankshaft 5. A cam gear 332 is fixed to the front end portion of the camshaft 313. A donut-shaped camshaft pulsar 339 is bolted to the side surface of the cam gear 332 facing the flywheel housing 7 so as to rotate integrally with the cam gear 332.

As shown in Figures 12, 13 and 16, the fuel supply pump 15 provided on the right housing bracket part 305 of the cylinder block 6 has a fuel supply pump shaft 333 as a rotating shaft extending parallel to the rotation axis of the crankshaft 5. The front end side of the fuel supply pump shaft 333 is arranged to protrude from the front side surface 305a of the right housing bracket part 305. A fuel supply pump gear 334 is fixed to the front tip part of the fuel supply pump shaft 333. As shown in Figure 13, the right housing bracket part 305 of the cylinder block 6 has a fuel supply pump mounting seat 323 for mounting the fuel supply pump 15 at a position above the right first reinforcing rib 310. The fuel supply pump mounting seat 323 has a fuel supply pump shaft insertion hole 324 formed in a size that allows the fuel supply pump gear 334 to pass through.

As shown in Figures 11 and 12, the oil pump 12 is disposed on the front side surface 305a of the right housing bracket part 305 below the fuel supply pump gear 334 and has an oil pump shaft 335 as a rotating shaft that extends parallel to the rotation axis of the crankshaft 5. An oil pump gear 336 is fixed to the front end of the oil pump shaft 335.

An idle shaft 337 extending parallel to the rotation axis of the crankshaft 5 is provided in a portion of the front side surface 303 of the cylinder block 6 surrounded by the crankshaft 5, the camshaft 313, the fuel supply pump shaft 333, and the oil pump shaft 335. The idle shaft 337 is fixed to the front side surface 303 of the cylinder block 6. An idle gear 338 is rotatably supported on the idle shaft 337.

The idle gear 338 is engaged with the crank gear 331, the cam gear 332, the fuel supply pump gear 334, and the oil pump gear 336. The rotational power of the crankshaft 5 is transmitted from the crank gear 331 to the cam gear 332, the fuel supply pump gear 334, and the oil pump gear 336 via the idle gear 338. Therefore, the camshaft 313, the fuel supply pump shaft 333, and the oil pump shaft 335 rotate in conjunction with the crankshaft 5. In the embodiment, the gear ratios between the gears 331, 332, 334, 336, and 338 are set so that the camshaft 313 rotates once for every two rotations of the crankshaft 5, and the fuel supply pump shaft 333 and the oil pump shaft 335 rotate once for every one rotation of the crankshaft 5.

In this case, the cam gear 332 and the camshaft 313 are rotated in conjunction with the crank gear 331 that rotates together with the crankshaft 5, and a valve mechanism (not shown) provided in association with the camshaft 313 is driven, thereby opening and closing the intake valves and exhaust valves (not shown) provided in the cylinder head 2. In addition, the fuel supply pump gear 334 and the fuel supply pump shaft 333 are rotated in conjunction with the crank gear 331, and the fuel supply pump 15 is driven, thereby pumping fuel from the fuel tank 118 to the common rail 16, and storing the high-pressure fuel in the common rail 16. In addition, the oil pump gear 336 and the oil pump shaft 335 rotate in conjunction with the crank gear 331 to drive the oil pump 12, so that the lubricating oil in the oil pan 11 is supplied to each sliding part, etc. through a lubricating oil intake passage 315, a lubricating oil supply passage 316, an oil cooler 13, an oil filter 14, etc. (details omitted) including the lubricating oil circuit.

As shown in FIG. 16, the fuel supply pump 15, which is an auxiliary device that operates in conjunction with the rotation of the crankshaft 5, is fixed by bolts to the fuel supply pump mounting seat 323 of the right housing bracket part 305. A right-side first reinforcing rib 310 is disposed adjacent to the fuel supply pump mounting seat 323. In addition, the right-side first reinforcing rib 310 is disposed directly below the fuel supply pump 15, and a right-side second reinforcing rib 311 is disposed directly below the right-side first reinforcing rib 310. The reinforcing ribs 310, 311 improve the rigidity of the fuel supply pump mounting seat 323 and can protect the fuel supply pump 15 by preventing foreign objects such as muddy water and flying stones from coming into contact with the fuel supply pump 15 from below.

Next, the gear case 330 that houses the gear train will be described with reference to Figures 10 to 12, 14, and 15. A block side ridge 321 that is joined to the flywheel housing 7 is erected along the periphery of the area including the front sides 303, 304a, and 305a of the cylinder block 6 and the left and right housing bracket parts 304 and 305. The block side ridge 321 has a notch 321a formed in the part between the left and right oil pan rail parts of the cylinder block 6. When viewed from the side, the space between the end face of the block side ridge 321 and the front sides 303, 304a, and 305a forms the block side gear case part 322.

As shown in Figures 14 and 15, the flywheel housing 7, for example made of cast iron, has a flywheel accommodating section 401 that accommodates the flywheel 8. The flywheel accommodating section 401 has a bottomed cylindrical shape formed by connecting a substantially cylindrical peripheral wall surface section 402 that covers the outer periphery of the flywheel 8 and a rear wall surface section 403 that covers the rear side (the surface on the cylinder block 6 side), and accommodates the flywheel 8 in the space surrounded by the peripheral wall surface section 402 and the rear wall surface section 403. The peripheral wall surface section 402 is formed in a substantially truncated cone shape with a smaller radius toward the rear wall surface section 403 side. A crankshaft insertion hole 404 into which the crankshaft 5 is inserted is formed in the center of the rear wall surface section 403.

A ring-shaped housing side ridge 405 that corresponds to the shape of the block side ridge 321 of the cylinder block 6 is connected to the rear wall surface 403 so as to surround the position of the crankshaft insertion hole 404. The center of the housing side ridge 405 is positioned at a position shifted upward relative to the crankshaft insertion hole 404. The lower part of the housing side ridge 405 extends in the left-right direction and is connected to the rear wall surface 403 near the crankshaft insertion hole 404.

The upper portion and the left and right portions of the housing side protruding portion 405 are disposed outside the rear wall surface portion 403. The front portion of the housing side protruding portion 405 located outside the rear wall surface portion 403 and the front portion of the surrounding wall surface portion 402 are connected by the outer wall portion 406. The outer wall portion 406 has a curved, inclined shape that is convex in the direction away from the crankshaft 5. In the flywheel housing 7, the lower portion of the flywheel accommodating portion 401 is disposed so as to protrude in the direction away from the crankshaft 5 relative to the housing side protruding portion 405.

When viewed from the side, the space between the rear wall portion 403 and the end face of the housing side ridge portion 405 forms the housing side gear case portion 407. The gear case 330 is formed by the housing side gear case portion 407 and the block side gear case portion 322 described above.

Inside the flywheel housing 7, a hollow space 408 is formed between the outer wall of the peripheral wall portion 402 of the flywheel accommodating portion 401 and the inner wall of the outer wall portion 406. A plurality of ribs 409 connecting the peripheral wall portion 402 and the outer wall portion 406 are arranged in the hollow space 408. In addition, the flywheel housing 7 is formed with a starter mounting portion 411 that is connected to the peripheral wall portion 402 and the housing side convex portion 405 on the outside of the housing side convex portion 405 and has a starter mounting seat 410 that is flush with the housing side convex portion 405. The starter mounting portion 411 has a through hole 412 that penetrates between the inner wall of the peripheral wall portion 402 and the starter mounting seat 410. The flywheel housing 7 is bolted to the front side 303 of the cylinder block 6 through 13 bolt holes 351 in the block side ridge 321 of the cylinder block 6 and through each bolt hole 353 in two housing bolt bosses 352 on the front side 303.

As shown in Figures 10, 12 and 13, the left housing bracket part 304 of the cylinder block 6 has a bracket recessed part 325 whose periphery is recessed relative to the periphery of the flywheel housing 7. When the flywheel housing 7 is fixed to the cylinder block 6, the starter 20 is placed on the starter mounting seat 410 of the flywheel housing 7 exposed below the bracket recessed part 325. As shown in Figure 14, an annular ring gear 501 for the starter 20 and a crankshaft pulsar 502 are fitted and fixed to the outer periphery of the flywheel 8 from opposite sides along the thickness direction of the flywheel 8. The starter 20 has a pinion gear 503 (see Figure 12) that is placed in the through hole 412 and releasably meshes with the ring gear 501.

Around the starter mounting seat 410, the cast iron flywheel housing 7 is bolted to the block side protruding portion 321 (see Figures 12 and 14) erected on the peripheral portion of the front side surface 304a of the left housing bracket portion 304. Furthermore, in the cylinder block 6, a left fourth reinforcing rib 309 that connects the left housing bracket portion 304 and the left side surface 301 is arranged near the bracket recessed portion 325 of the left housing bracket portion 304 that is adjacent to the starter mounting seat 410. This improves the rigidity around the starter mounting seat 410. In addition, the bracket recessed portion 325 of the left housing bracket portion 304 and the block side protruding portion 321 (see Figure 12) that is provided near the starter mounting seat 410 and continues to the bracket recessed portion 325 on the front side surface 303 also improve the rigidity around the starter mounting seat 410.

In this embodiment, the starter 20 can be attached to a location with high rigidity, such as the left fourth reinforcing rib 309, which prevents the starter 20 from shifting or deforming due to distortion of the starter mounting seat 410 or the left housing bracket portion 304, and prevents failure of the starter 20 and poor meshing between the pinion gear 503 of the starter 20 and the ring gear 501 of the flywheel 8.

Next, the common rail system 117 and the fuel system structure of the engine 1 will be described with reference to FIG. 17. As shown in FIG. 17, a fuel tank 118 is connected to each of the injectors 17 for the four cylinders provided in the engine 1 via a fuel supply pump 15 and a common rail system 117. Each injector 17 has an electromagnetic opening/closing control type fuel injection valve 119. The common rail system 117 has a cylindrical common rail 16. The common rail 16 is provided on the right side surface 302 of the cylinder block 6 and is disposed adjacent to the intake manifold 3.

The fuel tank 118 is connected to the intake side of the fuel supply pump 15 via a fuel filter 121 and a low-pressure pipe 122. Fuel in the fuel tank 118 is sucked into the fuel supply pump 15 via the fuel filter 121 and the low-pressure pipe 122. On the other hand, the common rail 16 is connected to the discharge side of the fuel supply pump 15 via a high-pressure pipe 123. A high-pressure pipe connector 124 is provided in the middle of the cylindrical common rail 16 in the longitudinal direction, and the end of the high-pressure pipe 123 is connected to the high-pressure pipe connector 124 by screwing a high-pressure pipe connector nut 125.

The common rail 16 is also connected to the injectors 17 for each of the four cylinders via four fuel injection pipes 126. Fuel injection pipe connectors 127 for the four cylinders are provided in the longitudinal direction of the cylindrical common rail 16, and the ends of the fuel injection pipes 126 are connected to the fuel injection pipe connectors 127 by screwing fuel injection pipe connector nuts 128.

In addition, a return pipe connector 129 (pipe joint member) for returning surplus fuel, which limits the pressure of the fuel in the common rail 16, is connected to the longitudinal end of the common rail 16. The return pipe connector 129 is connected to the fuel tank 118 via a fuel return pipe 130. The surplus fuel of the fuel supply pump 15 is sent to the return pipe connector 130 via a pump surplus fuel return pipe 131. The surplus fuel of each injector 17 is sent to the return pipe connector 130 via an injector surplus fuel return pipe 132. That is, the surplus fuel of the fuel supply pump 15, the surplus fuel of the common rail 16, and the surplus fuel of each injector 17 are joined at the return pipe connector 129 and collected in the fuel tank 118 via the fuel return pipe 130. The return pipe connector 129 may also be connected to the fuel tank 118 via a filter surplus fuel return pipe joint member (not shown) provided on the fuel filter 121.

A fuel pressure sensor 601 for detecting the fuel pressure in the common rail 16 is provided at the end of the common rail 16 opposite to the return pipe connector 129. Under the control of the engine controller 600, the fuel pressure in the common rail 16 is monitored from the output of the fuel pressure sensor 601, and the opening degree of the intake metering valve 602 of the fuel supply pump 15 is adjusted to adjust the fuel intake amount of the fuel supply pump 15 and thus the fuel discharge amount, while the fuel in the fuel tank 118 is pumped by the fuel supply pump 15 to the common rail 16, and the high-pressure fuel is stored in the common rail 16. By controlling the opening and closing of each fuel injection valve 119 under the control of the engine controller 600, the high-pressure fuel in the common rail 16 is injected from each injector 17 to each cylinder of the engine 1. That is, by electronically controlling each fuel injection valve 119, the injection pressure, injection timing, and injection period (injection amount) of the fuel supplied from each injector 17 can be controlled with high precision. Therefore, it is possible to reduce nitrogen oxides (NOx) emitted from the engine 1. It is also possible to reduce noise and vibration of the engine 1. The engine controller 600 is also electrically connected to an electromagnetic pressure reducing valve 603 that adjusts the pressure in the common rail 16, and a fuel temperature sensor 604 that detects the fuel temperature in the fuel supply pump 15. Although not shown, the engine controller 600 is also electrically connected to other devices, such as various sensors provided in the engine 1.

Next, referring to Figure 18, a portion of the harness structure attached to the engine 1 will be described. A harness connector 701 (main harness connector) that connects each part of the engine 1 to the engine controller 600 (see Figure 17) and the battery (not shown) is fixed to the right side surface 302 of the cylinder block 6 via a connector bracket 702. The harness connector 701 and connector bracket 702 are located in an area surrounded by the oil cooler 13, oil filter 14, fuel supply pump 15, and common rail 16.

The main harness assembly 703 extending from the harness connector 701 is led to the lower side of the engine 1 through between the right side surface 302 of the cylinder block 6 and the connector bracket 702, and then led to the rear side of the engine 1 along the straight portion 311a of the right second reinforcing rib 311, passing between the right side surface 302 and the oil filter 14. Furthermore, the main harness assembly 703 curves upward on the engine 1 rearward of the oil filter 14, passes behind the engine 1 rearward of the oil cooler 13, and is led to the cylinder head 2 side.

The main harness assembly 703 branches into an intake and exhaust system harness assembly 704 and a fuel system harness assembly 705 near the joint surface between the cylinder head 2 and the cylinder block 6. The intake and exhaust system harness assembly 704 is led along the right side of the cylinder head 2 toward the upper side of the engine 1, and branches into an intake system harness assembly 706 and an exhaust system harness assembly 707 near the upper rear portion of the right side of the head cover 18. The intake system harness assembly 706 is led along the right side of the head cover 18 toward the front side of the engine 1. The exhaust system harness assembly 707 is led from the right side of the head cover 18 along the rear side to the left side of the engine 1.

The fuel system harness assembly 705 is led to the front side of the engine 1 through between the oil cooler 13 and the collector 25 of the EGR device 24, and branches into harnesses that are connected to the fuel pressure sensor 601 and pressure reducing valve 603 of the common rail 16, and the intake metering valve 602 and fuel temperature sensor 604 of the fuel supply pump 15, as shown in FIG. 17.

The layout of the common rail 16 will be described with reference to Figures 19 to 23. The generally cylindrical common rail 16 is attached to the upper front portion of the right side surface 302 of the cylinder block 6, with its longitudinal direction aligned with the crankshaft 300 (see Figure 11). The common rail 16 is disposed below the intake manifold 3, which is molded integrally with the cylinder head 2 on the right side surface of the cylinder head 2. The front end (one end) of the common rail 16 is disposed on the gear case 330 and the flywheel housing 7. The common rail 16 is provided at its front end with a return pipe joint 129 (pipe joint member) for returning surplus fuel, which limits the pressure of the fuel in the common rail 16. For example, the return pipe joint 129 is disposed on the flywheel housing 7.

A bracket recess 620 provided on the right housing bracket 305 of the cylinder block 6 and a housing recess 621 provided on the flywheel housing 7 are disposed near the upper front corner of the right side surface 302 of the cylinder block 6. As shown in FIG. 19, the recesses 621 and 622 are formed so that the joint between the flywheel housing 7 and the right housing bracket 305 near the upper front corner of the right side surface 302 is lower than the top surface of the cylinder block 6. This allows the front end of the common rail 16 attached to the right side surface 302 of the cylinder block 6 to pass over the recesses 621 and 622 and extend upward toward the flywheel housing 7.

The return pipe joint 129 has a connection part 130a to which one end of the fuel return pipe 130 (see FIG. 17) is connected, a connection part 131a to which one end of the pump surplus fuel return pipe 131 (see FIG. 17) is connected, and a connection part 132a to which one end of the injector surplus fuel return pipe 132 (see FIG. 17) is connected. Inside the return pipe joint 129, there is an internal flow path (not shown) that connects the connection parts 130a, 131a, and 132a, and a fuel pressure regulating valve (not shown) arranged between the internal flow path and the internal space of the common rail 16. In addition, in the cylinder head 2, in the cylinder form, near the corner where the right side surface and the front side surface of the cylinder head 2 intersect, more specifically, in the area near the upper part of the front end of the right side surface of the cylinder head 2, near the intersection of the right side surface 302 of the block 6 from the injector 17 (see FIG. 17) and the front side surface 303 (see FIG. 12), in this embodiment, an excess fuel outlet 132b is provided. An injector surplus fuel return pipe 132c is connected between the surplus fuel outlet 132b and the connection part 132a of the return pipe joint 129. The surplus fuel outlet 132b is connected to a surplus fuel passage (not shown) formed inside the side wall of the cylinder head 2 and to the surplus fuel outlet of each injector 17 (see FIG. 17) via an injector surplus fuel return pipe 132 (see FIG. 17) that is disposed inside the cylinder head 2.

The connector 601a of the fuel pressure sensor 601 of the common rail 16 and the connector 603a of the pressure reducing valve 603, which are electrically connected to the engine controller 600 (see FIG. 17), are disposed below the intake manifold 3 of the cylinder head 2. As shown in FIG. 13 and FIG. 23, an uneven surface portion 611 corresponding to the shape of the water rail 610 (cooling water passage) inside the cylinder block 6 is formed on the right side surface 302 of the cylinder block 6. The connector 601a of the fuel pressure sensor 601 is disposed above a concave portion 612 of the uneven surface portion 611, and the connection portion of the connector 601a is disposed facing the concave portion 612 in a side view. The connection portion of the connector 603a of the pressure reducing valve 603 is disposed, for example, facing toward the right side of the engine 1.

Four fuel injection pipes 126 extending from the common rail 16 to the cylinder head 2 are connected to each injector 17 (see FIG. 17) through between the cylinder head 2 and the EGR device 24 (exhaust gas recirculation device). As shown in FIG. 22, the middle parts of the four fuel injection pipes 126 are attached to the cylinder head 2 by a fuel injection pipe fixing device 614 attached directly to the cylinder head 2 or via a spacer member 613. By fixing the middle parts of the fuel injection pipes 126 to the cylinder head 2, the vibration of the fuel injection pipes 126 is reduced and damage to the fuel injection pipes 126 due to the vibration is prevented. In this embodiment, the middle parts of the two fuel injection pipes 126 on the front side of the engine 1 out of the four fuel injection pipes 126 are fixed to the cylinder head 2 via a substantially cylindrical spacer member 613. By adjusting the spacer member 613 to the desired length, the middle part of the fuel injection pipe 126 can be fixed at a position any distance away from the side of the cylinder head 2, and the fuel injection pipe 126 can be routed in any shape without having to change the design of the surface shape of the cylinder head 2.

As shown in FIG. 20, the fuel supply pump 15 attached to the right housing bracket portion 305 of the cylinder block 6 is disposed below the EGR device 24. As described above, the right-side first reinforcing rib 310 is disposed directly below the fuel supply pump 15, and the right-side second reinforcing rib 311 is disposed directly below the right-side first reinforcing rib 310, preventing foreign objects such as muddy water or flying stones from coming into contact with the fuel supply pump 15 from below (see FIG. 16).

In the engine 1 of this embodiment, one end of the common rail 16 attached to the right side surface 302 (one side) of the cylinder block 6 is disposed above the flywheel housing 7, so that the area occupied by the common rail 16 on the right side surface 302 of the cylinder block 6 can be made smaller than in a configuration in which the entire common rail 16 is disposed on the right side surface 302 of the cylinder block 6. This improves the freedom of layout of other components on the right side surface 302 of the cylinder block 6. For example, in the engine device 1 of this embodiment, the oil cooler 13 is disposed on the rear side of the engine 1 at the rear end of the common rail 16, and the oil cooler 13 can be placed close to the intake manifold 3 and the EGR device 24 to realize a compact arrangement of these components.

In addition, in the engine 1 of this embodiment, the connector 601a of the fuel pressure sensor 601 of the common rail 16 and the connector 603a of the pressure reducing valve 603, which are electrically connected to the engine controller 600, are disposed below the intake manifold 3 that is integrally molded with the cylinder head 2, so that the intake manifold 3 can protect the connectors 601a, 603a from contact with foreign objects. In addition, the EGR device 24 attached to the intake manifold 3 also protects the connectors 601a, 603a in the same manner.

In addition, the connection port of the connector 601a is arranged facing the concave portion 612 of the uneven surface portion 611 that corresponds to the shape of the water rail 610 when viewed from the side, so the harness side connector can be attached to the connector 601a along the concave portion 612, improving the workability of attaching the harness. Furthermore, compared to a configuration in which the connection port of the connector 601a is arranged facing the outside of the engine 1, the connector 601a can be arranged closer to the cylinder block 6, thereby reducing the overall width of the engine 1.

In addition, in the engine 1 of this embodiment, the common rail 16 is provided with a return pipe connector 129 for returning surplus fuel at its front end, and in the cylinder head 2, surplus fuel outlets 132b from each injector 17 are provided near the intersection of the right side surface 302 and the front side surface 303 of the cylinder block 6 in a plan view. Since the return pipe connector 129 is disposed above the flywheel housing 7, the injector surplus fuel return pipe 132c (surplus fuel return path) connecting the connection portion 132a of the return pipe connector 129 and the surplus fuel outlet 132b can be made short and simple. This eliminates the problem of the conventional technology in which the surplus fuel return path from the injector 17 was long and complicated. In addition, for example, when a fuel filter 121 (see FIG. 17) is installed on a work machine or vehicle on which the engine 1 is mounted, the empty space above the flywheel housing 7 can be used to shorten and simplify the piping path between the connection part 130a of the return pipe connector 129 and the fuel filter 121, and the degree of freedom in designing the piping path is improved.

In addition, in the engine 1 of this embodiment, an EGR device 24 that mixes a portion of the exhaust gas discharged from the exhaust manifold 4 into fresh air is connected to the intake manifold 3, and four fuel injection pipes 126 extending from the common rail 16 toward the cylinder head 2 pass between the cylinder head 2 and the EGR device 24. This allows each fuel injection pipe 126 to be protected by the EGR device 24, and eliminates problems that occurred in the conventional technology in which the fuel injection pipes are attached to the outer periphery of the engine device, such as deformation of the fuel injection pipes or fuel leakage due to contact with other parts or falling of foreign objects during transportation of the engine device.

In addition, in this embodiment of the engine 1, the fuel supply pump 15 that is attached to the cylinder block 6 and supplies fuel to the common rail 16 is disposed below the EGR device 24, so that the fuel supply pump 15 can be protected from contact with foreign objects from above, for example, when tools are dropped during assembly, and damage to the fuel supply pump 15 can be prevented.

Furthermore, the fuel supply pump 15 is attached to the right housing bracket part 305 protruding from the right side surface 302 of the cylinder block 6, and reinforcing ribs 310, 311 are arranged below the fuel supply pump 15 to connect the right side surface 302 and the right housing bracket part 305. This makes it possible to protect the fuel supply pump 15 from contact with foreign objects from below, such as flying stones, and further prevents damage to the fuel supply pump 15.

In addition, in this embodiment, as shown in FIG. 20, a space is provided between the oil cooler 13 and the fuel supply pump 15 so that the fuel supply pump 15 with the fuel supply pump gear 334 (see FIG. 12) fixed thereto can be removed from the right housing bracket portion 305 without removing the oil cooler 13. As shown in FIG. 18, by arranging a harness connector 701 and a connector bracket 702 between the oil cooler 13 and the fuel supply pump 15, the space between the oil cooler 13 and the fuel supply pump 15 can be effectively utilized while the harness connector 701 can be arranged in a position surrounded by the oil cooler 13, oil filter 14, fuel supply pump 15, and EGR device 24 for protection.

Next, the mounting structure of the oil cooler 13 and the oil filter 14 will be described with reference to Figures 24 to 28. The oil cooler 13 and the oil filter 14 are arranged on the right side surface 302 of the cylinder block 6 via an oil cooler bracket 631 (bracket member). In this embodiment, the oil cooler 13 is a multi-plate laminated heat exchanger in which oil flow paths and cooling water flow paths are formed alternately in the stacking direction by stacking multiple plate members. The oil cooler bracket 631 is fastened and fixed to the oil cooler bracket mounting seat 318 (mounting portion) protruding from the right side surface 302 by bracket bolts 632.

The oil cooler bracket 631 is broadly composed of an oil cooler mounting part 633, a connecting part 634, and an oil filter mounting part 635. The oil cooler bracket 631 is a casting, and the oil cooler mounting part 633, the connecting part 634, and the oil filter mounting part 635 are integrally molded.

The oil cooler mounting portion 633 is generally flat and has an oil cooler mounting surface 637 on the side opposite to the joint surface 636 with the oil cooler bracket mounting seat 318. A plurality of flanges are provided on the periphery of the oil cooler mounting portion 633, protruding outward along the joint surface 636, and the flanges are provided with bolt insertion holes 638 through which the bracket bolts 632 are inserted. In addition, two bolt placement recesses 639 that accommodate the heads of the bracket bolts 632 are provided in the center of the oil cooler mounting surface 637. The bottom of the bolt placement recesses 639 is provided with bolt insertion holes 638 that penetrate to the joint surface 636.

The connecting portion 634 is erected on the peripheral portion of the oil cooler mounting portion 633 and protrudes toward the opposite side of the joint surface 636 in a direction approximately perpendicular to the oil cooler mounting surface 637. The connecting portion 634 is located at the portion of the oil cooler mounting portion 633 that is located on the lower side when the oil cooler bracket 631 is attached to the oil cooler bracket mounting seat 318.

An oil filter mounting portion 635 is provided at the tip side of the connecting portion 634. The oil filter mounting portion 635 has an annular oil filter mounting surface 640. The oil filter mounting surface 640 is provided at a portion of the oil filter mounting portion 635 opposite the oil cooler 13 that is attached to the oil cooler mounting surface 637.

The oil cooler mounting portion 633 is provided with a cooling water inlet hole 641 connected to the cooling water inlet 13a of the oil cooler 13, a cooling water outlet hole 642 connected to the cooling water outlet 13b of the oil cooler 13, a lubricating oil inlet hole 643 connected to the lubricating oil inlet 13c of the oil cooler 13, and a lubricating oil outlet hole 644 connected to the lubricating oil outlet 13d of the oil cooler 13. The cooling water inlet hole 641, the cooling water outlet hole 642, the lubricating oil inlet hole 643, and the lubricating oil outlet hole 644 penetrate between the joint surface 636 and the oil cooler mounting surface 637. The flow path cross-sectional area (diameter) of the cooling water outlet hole 642 is smaller than the flow path cross-sectional area of the cooling water inlet hole 641.

The oil cooler bracket 631 is provided with a lubricating oil introduction passage 645 and a lubricating oil discharge passage 646 that connect from the joint surface 636 of the oil cooler mounting portion 633 through the inside of the connecting portion 634 to the oil filter mounting surface 640 side of the oil filter mounting portion 635. The lubricating oil introduction passage 645 and the lubricating oil discharge passage 646 are each extended from the joint surface 636 to the oil filter mounting portion 635 in a direction perpendicular to the joint surface 636. The lubricating oil introduction passage 645 is bent in a direction perpendicular to the oil filter mounting surface 640 inside the oil filter mounting portion 635 and opens at the center position of the oil filter mounting surface 640. The lubricating oil discharge passage 646 is connected to a substantially cylindrical passage formed around the lubricating oil introduction passage 645 inside the oil filter mounting portion 635, and opens in a circular shape around the lubricating oil introduction passage 645 inside the circular oil filter mounting surface 640.

As shown in Figure 27, the oil cooler bracket mounting seat 318 is provided with a cooling water outlet 647 connected to the water rail 610 inside the cylinder block 6 (see Figures 13 and 23), a cooling water return port 648 connected to the cooling water return passage (not shown) inside the cylinder block 6, a lubricating oil outlet 649 connected to the lubricating oil supply passage 316 inside the cylinder block 6 (see Figures 11 and 13), and a lubricating oil return port 650 connected to the lubricating oil feed passage (not shown) inside the cylinder block 6.
In addition, the oil cooler bracket mounting seat 318 is formed with a cooling water inflow passage 651 that guides the cooling water from the cooling water outlet 647 to the cooling water inflow hole 641 of the oil cooler bracket 631, a lubricant oil inflow passage 652 that guides the lubricant oil from the lubricant oil outlet 649 to the lubricant oil inflow hole 643, a lubricant oil relay passage 653 that guides the lubricant oil from the lubricant oil outflow hole 644 to the lubricant oil introduction passage 645, and a lubricant oil outflow passage 654 that guides the lubricant oil from the lubricant oil discharge passage 646 to the lubricant oil return port 650. In addition, a bypass passage 655 is formed between the lubricant oil inflow passage 652 and the lubricant oil relay passage 653.

These passages 651, 652, 653, 654, and 655 are formed as concave grooves formed on the surface of the oil cooler bracket mounting seat 318, and are covered by the joint surface 636 of the oil cooler bracket 631 to form a passage through which the fluid can flow. The bypass passage 655 is a passage that bypasses the lubricating oil from the lubricating oil outlet 649 from the lubricating oil inlet passage 652 to the lubricating oil relay passage 653 in order to prevent excessive hydraulic pressure rise inside the oil cooler 13. The groove width and groove depth of the bypass passage 655, that is, the flow path cross-sectional area, are formed smaller than those of the lubricating oil inlet passage 652 and the lubricating oil relay passage 653. In addition, the oil cooler bracket mounting seat 318 has a bracket bolt hole 656 into which the bracket bolt 632 is inserted, at a position corresponding to the bolt insertion hole 638 of the oil cooler bracket 631.

25, on the joint surface 636 of the oil cooler bracket 631, when the oil cooler bracket 631 is attached to the oil cooler bracket mounting seat 318, a seal member housing groove 657 surrounding the outer periphery of the cooling water inlet passage 651, a seal member housing groove 658 surrounding the outer periphery of the cooling water return port 648, a seal member housing groove 659 surrounding the outer periphery of the lubricant inlet passage 652, the lubricant relay passage 653, and the bypass passage 655, and a seal member housing groove 660 surrounding the outer periphery of the lubricant outlet passage 654 are formed. By mounting the oil cooler bracket 631 to the oil cooler bracket mounting seat 318 with, for example, a seal member (not shown) made of an elastic member housed in these seal member housing grooves 657, 658, 659, and 660, the seal between the oil cooler bracket 631 and the oil cooler bracket mounting seat 318 is ensured.

24 and 25, a plurality of cooler bolt holes 661 are formed on the periphery of the oil cooler mounting surface 637 of the oil cooler bracket 631. Cooler bolts 662 are inserted into bolt insertion holes formed on the periphery of the oil cooler 13 and fastened to the cooler bolt holes 661, thereby fixing the oil cooler 13 to the oil cooler bracket 631. Four circular seal member accommodation grooves 663 are formed on the oil cooler mounting surface 637, surrounding the outer periphery of each of the cooling water inlet hole 641, the cooling water outlet hole 642, the lubricating oil inlet hole 643, and the lubricating oil outlet hole 644. The oil cooler 13 is attached to the oil cooler bracket 631 with a seal member (not shown) made of an elastic member such as an O-ring accommodated in each seal member accommodation groove 663, thereby ensuring sealing between the oil cooler 13 and the oil cooler bracket 631. The oil filter 14 is attached to the oil filter mounting surface 640 by fastening the female threads on the periphery of the casing to the male threads on the periphery of the oil filter mounting surface 640 of the oil cooler bracket 631.

The engine 1 of this embodiment is equipped with an oil cooler bracket 631 that supports the oil cooler 13 and the oil filter 14 and is attached to the cylinder block 6, and a cooling water outlet 647, a cooling water return port 648, a lubricating oil outlet 649, and a lubricating oil return port 650 are provided on the oil cooler bracket mounting seat 318 of the cylinder block 6, and cooling water and lubricating oil are circulated to the oil cooler 13 through the oil cooler bracket 631, and lubricating oil is circulated to the oil filter 14. Therefore, the engine 1 of this embodiment does not need to provide a cooling water pipe connected to the oil cooler 13 or a lubricating oil pipe member connecting the oil cooler 13 and the oil filter 14, and the number of parts can be reduced. Furthermore, since the oil cooler 13 and the oil filter 14 are supported by the same oil cooler bracket 631, the arrangement of the oil cooler 13 and the oil filter 14 can be made compact. Furthermore, since the oil cooler 13 and the oil filter 14 are supported by a single oil cooler bracket 631, the mounting structure of the oil cooler 13 and the oil filter 14 can be simplified.

The oil cooler bracket 631 also has a cooling water inlet 641 connected to the cooling water outlet 647 and a cooling water outlet 642 connected to the cooling water return port 648, and the flow path cross-sectional area of the cooling water outlet 642 is smaller than the flow path cross-sectional area of the cooling water inlet 641. This makes it possible to increase the water pressure in the cooling water path from the cooling water outlet 647 provided in the oil cooler bracket mounting seat 318 through the cooling water inlet 641 and the cooling water passage in the oil cooler 13 to the cooling water outlet 642. This prevents the cooling water from flowing out from the cooling water inlet 642 to the cooling water return port 648 more than necessary, thereby preventing a decrease in the water pressure in the cooling water passage inside the cylinder block 6, and thus prevents a decrease in the cooling efficiency of the engine 1.

The oil cooler bracket 631 also includes an oil cooler mounting portion 633 for mounting the oil cooler 13 on an oil cooler mounting surface 637 that is parallel to a joint surface 636 with the oil cooler bracket mounting seat 318, and an oil filter mounting portion 635 for mounting the oil filter 14 on the opposite side to the oil cooler 13 at the tip side of a connecting portion 634 erected on the oil cooler mounting portion 635. This allows the oil filter 14 to protrude approximately parallel to the right side surface 302 (side) of the cylinder block 6, allowing the oil cooler 13 and oil filter 14 to be arranged compactly, and the protruding distance of the oil filter 14 from the right side surface 302 of the cylinder block 6 to be reduced, thereby making the engine 1 more compact.

As shown in Figures 29 and 30, by supporting the oil filter 14 on the oil cooler bracket 631, a space can be formed between the right side surface 302 of the cylinder block 6 and the oil filter 14, which cannot be realized in a configuration example in which the oil filter 14 is directly attached to the cylinder block 6. For example, the straight portion 311a of the right second reinforcing rib 311 can be arranged in the space between the right side surface 302 and the oil filter 14 to improve the strength and heat dissipation performance of the cylinder block 6, or the wiring distance of the main harness assembly 703 can be shortened through the main harness assembly 703. The space between the right side surface 302 and the oil filter 14 can also be used for other purposes. In this way, the oil filter 14 is arranged away from the cylinder block 6 by the oil cooler bracket 631, which improves the design freedom of the engine 1.

In addition, by arranging the main harness assembly 703 along the straight portion 311a of the right-side second reinforcing rib 311, the main harness assembly 703 can be arranged without installing a bracket, reducing the number of parts, and the main harness assembly 703 can be protected from dust and other particles from below while preventing interference from foreign objects such as other parts.

Next, the harness structure attached to the engine 1 will be described with reference to Figures 31 to 37. As described with reference to Figure 18, the harness connector 701 is fixed to the right side surface 302 of the cylinder block 6 via a connector bracket 702, and the main harness assembly 703 extending from the harness connector 701 is guided along the straight portion 311a of the right second reinforcing rib 311, passing between the right side surface 302 and the oil filter 14, toward the cylinder head 2.

The connector bracket 702 is made of, for example, sheet metal, and has a generally L-shape when viewed from the right side of the engine 1. The upper end is bent at a right angle toward the cylinder block 6, and two parts of the part bent at a right angle toward the upper side of the engine 1 are bolted to the cylinder block 6, and the lower right end is bent at a right angle toward the cylinder block 6, and one part of the part bent at a right angle toward the front side of the engine 1 is bolted to the cylinder block 6. The connector bracket 702 is separated from the cylinder block 6 except for the bolted part, and the harness connector 701 attached to the connector bracket 702 is separated from the cylinder block 6 by the space between the cylinder block 6 and the connector bracket 702.

The main harness assembly 703 is fixed to the cylinder block 6 at four locations: two locations between the oil cooler bracket 631 and the straight portion 311a, and two locations on the rear side of the engine 1 of the oil cooler bracket 631. The main harness assembly 703 is fixed to the cylinder block 6 at four locations: two locations between the oil cooler bracket 631 and the straight portion 311a, and two locations on the rear side of the engine 1 of the oil cooler bracket 631, by locking members 801, such as harness clamps.

The main harness assembly 703 branches into an intake and exhaust system harness assembly 704, a fuel system harness assembly 705, and an intake temperature sensor harness 708 near the joint surface between the cylinder head 2 and the cylinder block 6. The intake temperature sensor harness 708 is electrically connected to an intake temperature sensor 751 inserted into the intake manifold 3.

The fuel system harness assembly 705 is led to the front side of the engine 1 through between the oil cooler 13 and the collector 25 of the EGR device 24. The tip side of the fuel system harness assembly 705 is fixed to the lower end portion of the collector 25 by a locking member 802. The fuel system harness assembly 705 branches above the connector bracket 702 into a second fuel system harness assembly 709 and a pressure reducing valve harness 710 that is connected to the pressure reducing valve 603 (see FIG. 20) of the common rail 16. The tip side of the second fuel system harness assembly 709 is fixed to the upper surface of the connector bracket 702 by a locking member 803.

The second fuel system harness assembly 709 is connected to the fuel pressure sensor 601 (see FIG. 2) of the common rail 16.
10) of the fuel supply pump 15; an intake metering valve harness 712 electrically connected to an intake metering valve 602 (see FIG. 16) of the fuel supply pump 15; and a fuel temperature sensor harness 713 electrically connected to a fuel temperature sensor 604 (see FIG. 16) of the fuel supply pump 15.

The base end of the intake and exhaust system harness assembly 704 is fixed to the right side of the cylinder head 2 by a locking member 804. The intake and exhaust system harness assembly 704 is led along the right side of the cylinder head 2 toward the upper side of the engine 1 and branches into an intake system harness assembly 706 and an exhaust system harness assembly 707. A coolant temperature sensor harness 714 electrically connected to a coolant temperature sensor 752 that detects the temperature inside the coolant passage in the cylinder head 2, and an intake throttle valve harness 715 electrically connected to the intake throttle member 26 branch out from the middle of the intake and exhaust system harness assembly 704.

The intake system harness assembly 706 is led to the front side of the engine 1 along the right side surface (side portion) of the head cover 18 and fixed to the right harness bracket 731. The right harness bracket 731 is bolted at four points on the right side of the top surface of the head cover 18 by harness bracket fixing bolts 750. The right harness bracket 731 is made of sheet metal, for example, and has a harness fixing surface 732 that is partially curved and extended along the right side surface of the head cover 18, a connecting portion 733 that is vertically erected at two points, the front end and the rear end of the harness fixing surface 732, and three bolt fastening portions 734 that protrude toward the top surface of the head cover 18 from the front and rear ends of the tip of the front connecting portion 733 and the tip of the rear connecting portion 733. A portion of the harness fixing surface 732 near its rear end is cut out, and the tip of the intake and exhaust system harness assembly 704 is placed in the cutout portion. The intake system harness assembly 706 is fixed to the upper surface of the harness fixing surface 732 by five locking members 805.

A blow-by gas pressure sensor harness 716 branches off from the middle of the intake system harness assembly 706 and is electrically connected to a blow-by gas pressure sensor 753 that detects the blow-by gas pressure inside the head cover 18.

The intake system harness assembly 706 is branched into an EGR valve harness 718 that is electrically connected to the EGR valve member 29 near the corner where the front side and right side of the head cover 18 intersect, an EGR gas temperature sensor harness 719 that is electrically connected to an EGR gas temperature sensor 755 that detects the exhaust gas temperature in the recirculation exhaust gas pipe 28, a rotation angle sensor harness assembly 720, and a first exhaust gas temperature sensor harness 721 that is electrically connected to an exhaust gas temperature sensor 756 that detects the exhaust gas temperature in the exhaust manifold 4.

The rotation angle sensor harness assembly 720 is curved from the tip of the intake system harness assembly 706 diagonally downward to the left of the engine 1, passes through the front of the front side of the head cover 18, is led to the center of the upper end of the front side of the cylinder head 2, is led from there approximately horizontally to the left side of the engine 1, is curved downward near the upper left front corner of the cylinder head 2, passes through the left side of the EGR cooler 27, and is led to the upper surface of the flywheel housing 7. The middle part of the rotation angle sensor harness assembly 720 is fixed to the harness fixing surface 736 of the front harness bracket 735 arranged on the front side of the head cover 18 at two points on the left and right of the harness fixing surface 736 by locking members 806. The tip of the rotation angle sensor harness assembly 720 is fixed to the upper surface of the flywheel housing 7 by locking members 807. The rotation angle sensor harness assembly 720 is branched into a crankshaft rotation angle sensor harness 724 located above the flywheel housing 7 in the upper left front portion of the flywheel housing 7 and electrically connected to a crankshaft rotation angle sensor 413 that detects the rotation angle of the crankshaft 5 (see FIG. 12), and a camshaft rotation angle sensor harness 725 located above the flywheel housing 7 in the upper left rear portion of the flywheel housing 7 and electrically connected to a camshaft rotation angle sensor 416 that detects the rotation angle of the cam gear 332 (see FIG. 12).

The front harness bracket 735 is made of, for example, sheet metal, and has a harness fixing surface 736 arranged opposite the front side surface of the head cover 18, and a bolt fastening portion 737 that protrudes from the upper end of the harness fixing surface 736 toward the top surface of the head cover 18. The bolt fastening portion 737 is divided into left and right halves with a central portion cut out. The left and right rear ends of the bolt fastening portion 737 are each bolted to the front portion of the top surface of the head cover 18 by harness bracket fixing bolts 750.

The first exhaust gas temperature sensor harness 721 is curved from the tip of the intake system harness assembly 706 toward the left side of the engine 1 and led to the front side of the head cover 18, where it is electrically connected to the exhaust gas temperature sensor 756 via a relay connector 722 and a second exhaust gas temperature sensor harness 723. The relay connector 722 is fixed to the right side of the center of the harness fixing surface 736 of the front harness bracket 735 by a locking member (not shown). The middle part of the second exhaust gas temperature sensor harness 723 is fixed to the left peripheral portion of the harness fixing surface 736 by a locking member 808.

The second exhaust gas temperature sensor harness 723 is led from the relay connector 722 to the left side along the front side surface of the head cover 18, curved diagonally rearward to the left near the left front corner of the head cover 18, and led to the left side surface of the head cover 18 where it is electrically connected to the exhaust gas temperature sensor 756. The second exhaust gas temperature sensor harness 723 is electrically connected to the first exhaust gas temperature sensor harness 721 by the relay connector 722 in a freely detachable manner.

The exhaust system harness assembly 707, which branches off from the intake and exhaust system harness assembly 704, is led from the rear portion of the right side of the head cover 18 along the side of the head cover 18 to the rear side of the head cover 18 and connected to the relay connector 726. The base end of the exhaust system harness assembly 707 is fixed to the rear end of the harness fixing surface 732 of the right harness bracket 731 by a locking member 809. An injector harness assembly 728, which is electrically connected to an injector connector 727, branches off from the middle of the exhaust system harness assembly 707. The injector connector 727 is inserted into the rear side of the cylinder head 2 and electrically connected to each injector 17 (see FIG. 17).

A rear harness bracket 738 is disposed on the rear side of the head cover 18, and the relay connector 726 is fixed to the harness fixing surface 739 of the rear harness bracket 738 by a locking member (not shown), while the base end side of the injector harness assembly 728 is fixed to the harness fixing surface 739 by a locking member 810.

The rear harness bracket 738 is made of, for example, sheet metal, and includes a harness fixing surface 739 arranged opposite the rear side surface of the head cover 18, a bolt fastening portion 740 protruding from the upper end of the harness fixing surface 736 toward the top surface of the head cover 18, and a harness fixing surface 741 protruding from the left end of the harness fixing surface 739 along the left side surface of the head cover 18 toward the front of the engine 1. The bolt fastening portion 740 is divided into left and right halves by cutting out a part of the center. The left and right rear ends of the bolt fastening portion 740 are bolted to the rear portions of the top surface of the head cover 18 by harness bracket fixing bolts 750, respectively.

A second exhaust system harness assembly 729 extends from the relay connector 726 along the side of the head cover 18. The second exhaust system harness assembly 729 is led from the relay connector 726 to the left side of the engine 1 along harness fixing surfaces 736, 739 of the rear harness bracket 738, and then led to the front side of the engine 1. Although not shown, the second exhaust system harness assembly 729 branches into wire harnesses that are electrically connected to various sensors provided in the two-stage turbocharger 30. The second exhaust system harness assembly 729 is fixed to the harness fixing surface 739 by a locking member 811.

As shown in FIG. 37, the harness connector 701 is connected to a connector member 743 connected to the engine controller 600 (see FIG. 17). The end of the electric wire 744 between the connector member 743 and the engine controller 600 on the connector member 743 side is fixed to the connector bracket 702 by a locking member 746 attached to a fixing hole 745 provided in the connector bracket 702. As a result, the harness connector 701, the connector member 743, and the end of the electric wire 744 on the connector member 743 side are fixed to the connector bracket 702, so that the vibration systems of these members become the same, and poor connection between the harness connector 701 and the connector member 743 can be prevented. In addition, since the harness connector 701 and the connector member 743 are arranged below the exhaust manifold 4 and the collector 25 of the EGR device 24, the harness connector 701 and the connector member 743 can be protected from the intrusion of water such as rainwater even when the engine 1 is mounted on a work machine, for example.

In the engine 1 of this embodiment, a plurality of wire harnesses, such as an intake system harness assembly 706, an exhaust system harness assembly 707, a rotation angle sensor harness assembly 720, first and second exhaust gas temperature sensor harnesses 721, 723, and a second exhaust system harness assembly 729, are extended along the side of a head cover 18 mounted on a cylinder block 6 via a cylinder head 2, and are fixed to harness brackets 731, 735, 738 bolted to the upper surface of the head cover 18. This allows the installation and removal of the harness bracket fixing bolts 750 from above the engine 1, improving the ease of assembly and removal of the harness brackets 731, 735, 738 and the harness assemblies 706, 707, 720, 729 and wire harnesses 721, 723 fixed thereto, and thus improving the ease of handling of the wire harnesses. For example, when opening the head cover 18 to perform maintenance on the engine 1, the wire harness around the head cover 18 can be easily removed from the head cover 18 together with the harness brackets 731, 735, and 738 by removing the harness bracket fixing bolts 750, improving the ease of maintenance work on the engine 1.

In addition, in the engine 1 of this embodiment, multiple wire harnesses are grouped together as a main harness assembly 703 on the right side of the cylinder block 2 and electrically connected to one main harness connector 701, so that each electronic device mounted on the engine 1 can be easily electrically connected to the engine controller 600 simply by detachably connecting one connector member 743 (see FIG. 37) connected to the engine controller 600 (see FIG. 17) to the harness connector 701. Furthermore, the harness connector 701 and the main harness assembly 703 are arranged on the intake manifold 3 side, away from the exhaust manifold 4 side where the surrounding environment is harsh, such as being hot, so that deterioration of the harness connector 701 and the main harness assembly 703 due to heat can be reduced, and manufacturing costs can be reduced by using the harness connector 701 and the main harness assembly 703 made of a material with a relatively low heat resistance temperature.

The harness connector 701 is disposed below the intake manifold 3 and the collector 25 of the EGR device 24, and is disposed in a location surrounded by the fuel supply pump 15, oil cooler 13, and oil filter 14 installed on the right side surface 302 of the cylinder block 6. Therefore, the intake manifold 3, collector 25, fuel supply pump 15, oil cooler 13, and oil filter 14 can prevent foreign objects from coming into contact with the harness connector 701 and connector member 743, and prevent damage to or poor contact with the harness connector 701 and connector member 743.

In addition, a relay connector 722 is provided in the middle of the series of first and second exhaust gas temperature sensor harnesses 721, 723 that extend from the right side of the cylinder head 2 along the side of the head cover 18 to the left side of the cylinder head 2. In addition, a relay connector 726 is provided in the middle of the series of air system harness assembly 707 and second exhaust system harness assembly 729 that extend from the right side of the cylinder head 2 along the side of the head cover 18 to the left side of the cylinder head 2. As a result, when changing the configuration of the wire harness due to a change in the engine 1 components on the exhaust manifold 4 side, it is possible to respond by simply changing the configuration of the second exhaust gas temperature sensor harness 723 and the second exhaust system harness assembly 729 that are detachably connected to the relay connectors 722, 726. For example, if only the configuration of the turbocharger-related parts on the exhaust manifold 2 side is different, the second exhaust system harness assembly 729 is prepared for each model, and the wire harnesses on the intake manifold 3 side, such as the main harness assembly 703, fuel system harness assembly 705, and intake system harness assembly 706, are standardized across multiple models, reducing the number of steps required to manage and assemble the wire harnesses.

In addition, the second exhaust gas temperature sensor harness 723 and the second exhaust system harness assembly 729 on the exhaust manifold 4 side can be separated from the wire harness on the intake manifold 3 side, such as the main harness assembly 703, and appropriate wire specifications can be selected for each. For example, if the second exhaust gas temperature sensor harness 723 and the second exhaust system harness assembly 729 are made of a material with a relatively high heat resistance temperature, damage caused by heat can be reduced. In addition, for the wire harness on the intake manifold 3 side, such as the main harness assembly 703, a material with a relatively low heat resistance temperature can be used to reduce manufacturing costs.

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.

REFERENCE SIGNS LIST 1 Engine 2 Cylinder head 3 Intake manifold 4 Exhaust manifold 5 Crankshaft 6 Cylinder block 13 Oil cooler 14 Oil filter 15 Fuel supply pump 18 Head cover 300 Crankshaft axis 413 Crankshaft rotation angle sensor 416 Camshaft rotation angle sensor 701 Harness connector 702 Connector bracket 703 Main harness assembly 706 Intake system harness assembly 707 Exhaust system harness assembly 716 Blow-by gas pressure sensor harness 718 EGR valve harness 719 EGR gas temperature sensor harness 720 Rotation angle sensor harness assembly 721 First exhaust gas temperature sensor harness 722 Relay connector 723 Second exhaust gas temperature sensor harness 724 Crankshaft rotation angle sensor harness 725 Camshaft rotation angle sensor harness 726 Relay connector 727 Injector connector 728 Injector harness assembly 729 Second exhaust system harness assembly 731, 735, 738 Harness bracket 751 Intake air temperature sensor 752 Cooling water temperature sensor 753 Blow-by gas pressure sensor 755 EGR gas temperature sensor 756 Exhaust gas temperature sensor

Claims (2)

In an engine device in which a harness connector is connected to a wire harness,
the wire harness is branched at a side portion extending in a crankshaft direction and extends along the side portion extending in the crankshaft direction and a side portion extending in an intake/exhaust direction ,
a part of the wire harness is provided from the intake side to the exhaust side along a side portion on which a cooling fan is installed , among the side portions extending in the intake and exhaust directions ;
A portion of the wire harness extending along the side where the cooling fan is installed is further branched off and connected to an injector . 2. The engine apparatus according to claim 1 , wherein the branched wire harness is electrically connected to various sensors provided in a supercharger.