Engine equipment

Abstract

Reduces contact of foreign objects with the starter. A starter (20) is provided in a flywheel housing (7) provided on one side of a cylinder block (6). The starter (20) is provided below a rib (309) provided on the cylinder block (6).

Description

[Technical field]

[0001] The present invention relates to an engine device, and more particularly to an engine device in which a flywheel that rotates integrally with a crankshaft is disposed on one side of a cylinder block, and a starter is provided for transmitting rotational force to the flywheel when the engine is started. [Background technology]

[0002] There is a well-known engine device in which a flywheel that rotates integrally with the crankshaft is disposed on one side of a cylinder block (see, for example, Patent Document 1). A ring gear that meshes with a pinion gear of a starter for starting the engine is attached to the outer periphery of the flywheel, and when the engine is started, the crankshaft is rotated by the starter via the flywheel to start the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-189027 A Summary of the Invention [Problem to be solved by the invention]

[0004] The engine starter has a complex structure, including a mechanism for sliding the pinion gear to releasably mesh the pinion gear with the ring gear of the flywheel, and a mechanism for reducing the rotation speed of the motor to obtain high torque for the rotation of the pinion gear, etc. Therefore, there is a problem that the starter is prone to failure due to contact with foreign objects.

[0005] In view of the above-mentioned problems, the present invention has an object to reduce contact of foreign matter with a starter. [Means for solving the problem]

[0006] The engine device of the present invention is an engine device in which a flywheel that rotates integrally with the crankshaft is disposed on one side of a cylinder block, and a starter is provided for transmitting rotational force to the flywheel when the engine is started, a flywheel housing that accommodates the flywheel and has a starter mounting seat for mounting the starter is attached to the one side, and the starter is disposed inward of the outermost part of the flywheel housing in a direction perpendicular to the crankshaft center direction and parallel to the cylinder head joint surface of the cylinder block.

[0007] In the engine device of the present invention, for example, a pair of housing bracket portions protruding from the ends of one side portions on both sides of the cylinder block aligned in the crankshaft direction, and a reinforcing rib provided between each side wall of both sides and the housing bracket portions so as to widen the housing bracket portion side, may be integrally molded with the cylinder block, the flywheel housing may have the starter mounting seat at a portion exposed to a bracket concave portion formed so that the peripheral portion of the housing bracket portions is concave relative to the peripheral portion, and the cylinder block may have the reinforcing rib adjacent to the bracket concave portion.

[0008] Furthermore, the engine device of the present invention may be configured to include, for example, a turbocharger lubricating oil piping that circulates lubricating oil to a turbocharger, and an EGR cooler that cools EGR gas that is part of the exhaust gas and is mixed into fresh air, and the starter may be disposed at a position that does not overlap with the turbocharger lubricating oil piping and the EGR cooler when viewed from the cylinder head joint surface side.

[0009] In the engine apparatus of the present invention, for example, a motor axis of the starter may be disposed below the crank axis in a direction perpendicular to the cylinder head joint surface. Effect of the Invention

[0010] In the engine device of the present invention, a flywheel housing which accommodates a flywheel and has a starter mounting seat for mounting the starter is attached to one side, and the starter is positioned in a direction perpendicular to the crankshaft direction and parallel to the cylinder head joint surface of the cylinder block, and more inside the engine than the outermost part of the flywheel housing. This reduces contact of foreign objects with the starter and suppresses failure of the starter or displacement of its mounting position due to contact with foreign objects.

[0011] Furthermore, in the engine device of the present invention, a pair of housing bracket portions protruding from the ends of one side portions of both sides of the cylinder block aligned in the crankshaft direction, and reinforcing ribs provided between each side wall of both sides and the housing bracket portion so that the housing bracket portion side widens, are integrally molded with the cylinder block, and the flywheel housing has a starter mounting seat at a portion exposed to a bracket concave portion formed so that the peripheral edge of the housing bracket portion is concave relative to its peripheral edge, and the cylinder block has a reinforcing rib adjacent to the bracket concave portion; this improves the rigidity around the starter mounting seat and prevents displacement or deformation of the starter due to distortion of the starter mounting seat, and prevents starter failure and poor meshing between the starter pinion gear and the flywheel ring gear.

[0012] Furthermore, the engine device of the present invention is configured to include, for example, a turbocharger lubricating oil piping that circulates lubricating oil to the turbocharger, and an EGR cooler that cools EGR gas, which is part of the exhaust gas and is mixed into fresh air, and if the starter is positioned so as not to overlap with the turbocharger lubricating oil piping and the EGR cooler when viewed from the cylinder head joint surface side, it is possible to prevent liquid such as lubricating oil from leaking from the turbocharger or cooling water from leaking from the EGR cooler from adhering to the starter, and to prevent contamination and failure of the starter caused by the adhesion of the liquid.

[0013] Furthermore, in the engine device of the present invention, if the motor axis of the starter is positioned below the crank axis in a direction perpendicular to the cylinder head joint surface, the center of gravity of the engine device can be lowered compared to when the motor axis, which accounts for a large proportion of the total weight of the starter, is positioned above the crank axis, and therefore the center of gravity of the vehicle when the engine device is mounted on the vehicle can be lowered. [Brief description of the drawings]

[0014] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a perspective view of the engine as seen obliquely from the front. [Figure 8] FIG. 2 is a perspective view of the engine as seen obliquely from the rear. [Figure 9] FIG. 2 is a plan view showing the cylinder block and the flywheel housing. [Figure 10] FIG. 2 is a left side view showing the cylinder block and the flywheel housing. [Figure 11] FIG. 4 is a right side view showing the cylinder block and the flywheel housing. [Figure 12] FIG. [Figure 13] 10 is a cross-sectional view taken along the line AA in FIG. 9. [Figure 14] FIG. 10 is a cross-sectional view taken along the line BB in FIG. 9 . [Figure 15] FIG. 4 is a perspective view showing the inside of the flywheel housing. [Figure 16] FIG. 4 is a perspective view showing the mounting position of a fuel supply pump. [Figure 17]FIG. 4 is a rear view for explaining the mounting position of the starter. [Figure 18] FIG. 4 is a perspective view showing the mounting position of the starter. [Figure 19] FIG. 4 is a left side view, partially in cross section, showing the mounting position of the starter. [Figure 20] FIG. 4 is a bottom view showing a cross section of the mounting position of the starter. [Figure 21] FIG. 4 is a left side view for explaining the mounting position of the starter. [Figure 22] FIG. 4 is a left side view showing the mounting position of the external accessories. [Figure 23] FIG. 4 is a perspective view showing the mounting position of an external auxiliary device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the overall structure of a diesel engine (engine device) 1 will be described with reference to Figs. 1 to 8. In the following description, both sides parallel to the crankshaft 5 (both 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 the sake of convenience, these will be used as the basis for the four sides and the vertical positional relationship of the diesel engine 1.

[0016] As shown in Figures 1 to 8, an intake manifold 3 is disposed on one side parallel to a crankshaft 5 of a diesel engine 1, and an 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 thereof, and the exhaust manifold 4 is disposed on the left side thereof. The cylinder head 2 is mounted on a cylinder block 6 that incorporates the crankshaft 5 and pistons (not shown). The cylinder block 6 supports the crankshaft 5 so that it can rotate freely.

[0017] 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 fixedly provided on one side of the diesel 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 journalled on the front end side of the crankshaft 5 and is configured to rotate integrally with the crankshaft 5. The power of the diesel engine 1 is adapted to be extracted via the flywheel 8 to a working section of a work machine (e.g. a hydraulic excavator, a forklift, etc.). A cooling fan 9 is provided on the other side of the diesel engine 1 that intersects with the crankshaft 5 (the rear side surface of the cylinder block 6 in this embodiment). The rotational force is adapted to be transmitted from the rear end side of the crankshaft 5 to the cooling fan 9 via a V-belt 10.

[0018] An oil pan 11 is disposed under the cylinder block 6. Lubricating oil is stored in the oil pan 11. The lubricating oil in the oil pan 11 is sucked by an oil pump 12 (see FIG. 11) disposed on the right side of the cylinder block 6, which is a connecting portion between the cylinder block 6 and the flywheel housing 7, and is supplied to each lubricated part of the diesel engine 1 via an oil cooler 13 and an oil filter 14 disposed 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.

[0019] 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 the fuel supply pump 15 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 upper surface of the cylinder head 2 covered with a head cover 18, injectors (not shown) for each of the four cylinders, each having an electromagnetic open / close control type fuel injection valve, are provided.

[0020] Each injector is connected to a fuel tank (not shown) 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 the high-pressure fuel is stored in the common rail 16. By controlling the opening and closing of a fuel injection valve of each injector, the high-pressure fuel in the common rail 16 is injected from each injector into each cylinder of the diesel engine 1.

[0021] A blow-by gas reduction device 19 that takes in blow-by gas leaking from the combustion chamber of the diesel engine 1 to the upper side of the cylinder head 2 is provided on the upper surface of a head cover 18 that covers the intake valve and exhaust valve (not shown) provided on the upper surface of the cylinder head 2. A blow-by gas outlet of the blow-by gas reduction device 19 is connected to the intake part of the two-stage turbocharger 30 via a return hose 68. The blow-by gas from which the lubricating oil components have been removed in the blow-by gas reduction device 19 is returned to the intake manifold 3 via the two-stage turbocharger 30.

[0022] A starter 20 for starting the engine is attached to the flywheel housing 7, and the starter 20 is disposed below the exhaust manifold 4. The starter 20 is attached to the flywheel housing 7 at a position below the joint between the cylinder block 6 and the flywheel housing 7.

[0023] A cooling water pump 21 for circulating cooling water is disposed below the cooling fan 9 at a position near the left rear surface of the cylinder block 6. When the crankshaft 5 rotates, a V-belt for driving the cooling fan A cooling water pump 21 is driven together with the cooling fan 9 via the engine 10. Cooling water in a radiator (not shown) mounted on the work vehicle is supplied to the cooling water pump 21 by driving the cooling water pump 21. Then, the cooling water is supplied to the cylinder head 2 and the cylinder block 6, and cools the diesel engine 1.

[0024] A 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, a cooling water outlet pipe 23, which communicates with the cooling water inlet of the radiator, is fixed to the rear part of the cylinder head 2. The cylinder head 2 has a cooling water drainage section 35 that protrudes rearward from the intake manifold 3, and the cooling water outlet pipe 23 is installed on the upper surface of the cooling water drainage section 35.

[0025] 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 diesel 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.

[0026] The EGR device 24 has a collector 25 as a relay pipeline that mixes the recirculated exhaust gas (EGR gas from the exhaust manifold 4) of the diesel engine 1 with fresh air (external air from the air cleaner) and supplies the mixture 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 pipeline connected 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.

[0027] 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 a collector 25 is connected to the intake manifold 3 on the right side surface of the cylinder head 2, and an EGR gas inlet of a recirculation exhaust gas pipe 28 is connected and fixed to a front portion 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 an EGR gas outlet of the recirculation exhaust gas pipe 28 is connected to the rear end of the EGR valve member 29.

[0028] 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 for connecting the EGR cooler 27 are protrudingly provided at left and right positions on 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 and the front side of the cylinder head 2 spaced apart.

[0029] 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 includes 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 includes a low-pressure turbine 55 incorporating a turbine wheel (not shown) and a low-pressure compressor 56 incorporating a blower wheel (not shown).

[0030] An exhaust gas inlet 57 of the high-pressure turbine 53 is connected to the exhaust manifold 4, an exhaust gas inlet 60 of the low-pressure turbine 55 is connected to an exhaust gas outlet 58 of the high-pressure turbine 53 via a high-pressure exhaust gas pipe 59, and an exhaust gas intake end of an exhaust gas discharge pipe (not shown) is connected to an exhaust gas outlet 61 of the low-pressure turbine 55. Meanwhile, a fresh air supply side (fresh air outlet side) of an air cleaner (not shown) is connected to a fresh air intake port (fresh air inlet) 63 of the low-pressure compressor 56 via an air intake pipe 62, a fresh air intake port 66 of the high-pressure compressor 54 is connected to a fresh air supply port (fresh air outlet) 64 of the low-pressure compressor 56 via a low-pressure fresh air passage pipe 65, and a fresh air intake side of an intercooler (not shown) is connected to a fresh air supply port 67 of the high-pressure compressor 54 via a high-pressure fresh air passage pipe (not shown).

[0031] The high-pressure turbocharger 51 is connected to an 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 on the left and right 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.

[0032] Next, the configuration of the cylinder block 6 will be described with reference to Figs. 9 to 13. In the cylinder block 6, a left housing bracket part 304 and a right housing bracket part 305 (projecting parts) to which the flywheel housing 7 is fixed by a plurality of bolts are formed at the ends of the left side surface 301 and the right side surface 302 on the front side surface 303 side 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 formed between the side wall of the left side surface 301 and the left housing bracket part 304 in this 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 formed between the side wall of the right side surface 302 and the right housing bracket part 305 in this order from the upper side to the lower side. The housing bracket portions 304 and 305 and the reinforcing ribs 306 to 311 are integrally formed with the cylinder block 6 .

[0033] The reinforcing ribs 306-311 each extend along the crank shaft center 300 and have a generally triangular shape with the housing bracket portions 304, 305 being 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 extending 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.

[0034] On the left side surface 301 and the right side surface 302, two mount attachment seats 317 for attaching an engine mount that connects 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 a 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 a protruding manner on the right side surface 302. As shown in FIG. 17, 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.

[0035] The housing bracket portions 304, 305 and the reinforcing ribs 306-311 integrally molded with the cylinder block 6 improve the rigidity of the cylinder block 6, particularly the rigidity and strength in the vicinity of the front side surface 303 of the cylinder block 6, thereby reducing vibration and noise of the engine 1. Furthermore, the housing bracket portions 304, 305 and the 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.

[0036] Furthermore, 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 a portion of 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. Furthermore, a portion of the inlet pipe mounting seat 320 on the rear side surface 312 side is connected to the cooling water pump mounting portion 319. 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, thereby improving the rigidity, strength, and cooling efficiency of the cylinder block 6.

[0037] A camshaft case 314 (see FIG. 13) that houses a camshaft 313 is formed inside the cylinder block 6. 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 a front side surface 303 of the cylinder block 6, and the cam gear 332 and the camshaft 313 are rotated in conjunction with the crank gear 331 to drive a valve mechanism (not shown) associated with the camshaft 313, thereby opening and closing intake valves and exhaust valves (not shown) of the engine 1. The engine 1 of this embodiment has a so-called overhead valve system.

[0038] The camshaft case portion 314 is disposed at a position close to the left side surface 301 in the cylinder portion of the cylinder block 6. The camshaft 313 and the camshaft case portion 314 are disposed along the crank shaft center 300. Furthermore, the approximately triangular portion and the linear portion 307a, 308a of the left second reinforcing rib 307 and the left third 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, more specifically, disposed at a position overlapping the position of the camshaft case portion 314.

[0039] 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 that it is possible to prevent distortion of the camshaft case portion 314. This makes it possible to prevent 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 perform appropriate opening and closing operations of the intake valves and exhaust valves (not shown).

[0040] Further, some of the lubricant oil passages formed in cylinder block 6, here lubricant oil suction passage 315 and lubricant oil supply passage 316, are disposed near right side surface 302 in the skirt portion of cylinder block 6. Lubricant oil supply passage 316 is disposed near the cylinder portion in the skirt portion of cylinder block 6. Lubricant oil suction passage 315 is disposed near the oil pan rail portion with respect to lubricant oil supply passage 316.

[0041] One end of the lubricating oil suction passage 315 opens to the lower surface of the oil pan rail part 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 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 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.

[0042] 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, more specifically, disposed so as to overlap the position of the lubricating oil supply passage 316 in a side view. Moreover, 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.

[0043] 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 in the vicinity of the lubricant suction passage 315, the oil pump 12, and the lubricant supply passage 316. In particular, the right first reinforcing rib 310, which is disposed at a position overlapping with the lubricant supply passage 316 in a side view, efficiently dissipates heat in the vicinity of the lubricant supply passage 316 to the outside. This can reduce the temperature of the lubricant flowing into the oil cooler 13, and the amount of heat exchange required in the oil cooler 13.

[0044] Next, the gear train structure of the engine 1 will be described with reference to Figs. 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 Figs. 12 and 14, the front ends of the crankshaft 5 and the camshaft 313 are disposed so as 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.

[0045] As shown in Figs. 12, 13 and 16, the fuel supply pump 15 provided in the right housing bracket portion 305 of the cylinder block 6 includes 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 disposed so as to protrude from the front side surface 305a of the right housing bracket portion 305. A fuel supply pump gear 334 is fixed to the front end portion of the fuel supply pump shaft 333. As shown in Fig. 13, the right housing bracket portion 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 is formed with a fuel supply pump shaft insertion hole 324 large enough to pass the fuel supply pump gear 334 through.

[0046] 11 and 12, oil pump 12 is disposed on the front side surface 305a of right housing bracket part 305 below fuel supply pump gear 334, and includes an oil pump shaft 335 as a rotating shaft extending parallel to the rotational axis of crankshaft 5. An oil pump gear 336 is fixed to the front end portion of oil pump shaft 335.

[0047] 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.

[0048] The idle gear 338 meshes 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 through the idle gear 338 to the cam gear 332, the fuel supply pump gear 334, and the oil pump gear 336. 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.

[0049] 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 intake valves and exhaust valves (not shown) provided in the cylinder head 2. Also, 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 to the common rail 16, and storing the high-pressure fuel in the common rail 16. Also, the oil pump gear 336 and the oil pump shaft 335 are rotated in conjunction with the crank gear 331, and the oil pump 12 is driven, thereby supplying lubricating oil in the oil pan 11 to each sliding part, etc., via a lubricating oil suction passage 315, a lubricating oil supply passage 316, an oil cooler 13, an oil filter 14, etc. (details are omitted).

[0050] 16, the fuel supply pump 15, which serves as an accessory that operates in conjunction with the rotation of the crankshaft 5, is fixed by bolts to a fuel supply pump mounting seat 323 of the right housing bracket portion 305. A first right reinforcing rib 310 is disposed adjacent to the fuel supply pump mounting seat 323. In addition, the first right reinforcing rib 310 is disposed directly below the fuel supply pump 15, and a second right reinforcing rib 311 is disposed directly below the first right 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.

[0051] Next, a gear case 330 that houses a gear train will be described with reference to Figures 10 to 12, 14, and 15. A block-side protruding portion 321 that is joined to the flywheel housing 7 is erected along the periphery of an area including the front sides 303, 304a, and 305a of the cylinder block 6 and the left and right housing bracket portions 304 and 305. The block-side protruding portion 321 has a notch 321a formed in a portion between the left and right oil pan rail portions of the cylinder block 6. The space between the end face of the block-side protruding portion 321 and the front sides 303, 304a, and 305a in a side view forms a block-side gear case portion 322.

[0052] As shown in Figures 14 and 15, the flywheel housing 7, made of cast iron, for example, has a flywheel accommodating section 401 that accommodates the flywheel 8. The flywheel accommodating section 401 has a cylindrical shape with a bottom, which is 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 surface (the surface on the cylinder block 6 side), and accommodates the flywheel 8 in a 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 radius that decreases 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.

[0053] An annular housing side protruding streak 405, which corresponds to the shape of the block side protruding streak 321 of the cylinder block 6, is connected to the rear side wall surface 403 so as to surround the position where the crankshaft insertion hole 404 is disposed. The central portion of the housing side protruding streak 405 is disposed at a position shifted upward relative to the crankshaft insertion hole 404. The lower portion of the housing side protruding streak 405 extends in the left-right direction and is disposed near the crankshaft insertion hole 404 and connected to the rear side wall surface 403.

[0054] Additionally, 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 an outer wall portion 406. The outer wall portion 406 has a curved, inclined shape that is convex in a direction away from the crankshaft 5. In the flywheel housing 7, the lower portion of the flywheel accommodating portion 401 is disposed to protrude in a direction away from the crankshaft 5 relative to the housing side protruding portion 405.

[0055] In a side view, the space between the rear wall portion 403 and the end face of the housing side protruding portion 405 forms a housing side gear case portion 407. The housing side gear case portion 407 and the block side gear case portion 322 described above form a gear case 330.

[0056] A hollow space 408 is formed inside the flywheel housing 7 between the outer wall of the surrounding wall portion 402 and the inner wall of the outer wall portion 406 of the flywheel accommodating portion 401. A plurality of ribs 409 connecting the surrounding wall portion 402 and the outer wall portion 406 are arranged inside the hollow space 408. The flywheel housing 7 is also formed with a starter mounting portion 411 which is connected to the surrounding wall portion 402 and the housing side protruding strip portion 405 on the outer side of the housing side protruding strip portion 405 and has a starter mounting seat 410 which is flush with the housing side protruding strip portion 405. A through hole 412 is formed in the starter mounting portion 411, penetrating between the inner wall of the surrounding 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 via thirteen bolt holes 351 in the block side protrusion 321 of the cylinder block 6 and via bolt holes 353 in two housing bolt bosses 352 on the front side 303.

[0057] As shown in Figs. 10, 12, 13, and 17 to 20, the left housing bracket part 304 of the cylinder block 6 has a bracket recessed part 325 whose periphery is recessed with respect to the periphery of the flywheel housing 7. The starter 20 is disposed in a starter mounting seat 410 of the flywheel housing 7 exposed below the bracket recessed part 325 when the flywheel housing 7 is fixed to the cylinder block 6. As shown in Fig. 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 Figs. 12, 19, and 20) that is disposed in the through hole 412 and releasably meshes with the ring gear 501. Figs. 19 and 20 show a state in which the pinion gear 503 meshes with the ring gear 501. 20, through hole 412 into which the end of starter 20 on the pinion gear 503 side is inserted is separated from the internal space of gear case 330 by housing side protruding portion 405. This prevents lubricating oil and vibration noise from inside gear case 330 from leaking out into through hole 412.

[0058] Around the starter mounting seat 410, the cast iron flywheel housing 7 is bolted to a block side protruding portion 321 (see Figs. 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 connecting the left housing bracket portion 304 and the left side surface 301 is disposed near a bracket recessed portion 325 of the left housing bracket portion 304 adjacent to the starter mounting seat 410. This improves the rigidity around the starter mounting seat 410. Also, the bracket recessed portion 325 of the left housing bracket portion 304 In addition, a block side protruding portion 321 (see FIG. 12) provided adjacent to the starter mounting seat 410 and continuing from the bracket recessed portion 325 on the front side surface 303 also improves the rigidity around the starter mounting seat 410.

[0059] In this embodiment, the starter 20 can be attached to a location with high rigidity provided by the left side fourth reinforcing rib 309, etc., thereby preventing misalignment or deformation of the starter 20 due to distortion of the starter mounting seat 410 or the left side housing bracket portion 304, and preventing malfunction 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.

[0060] 1, 2, 5 and 17, the starter 20 is disposed inside a portion of the flywheel housing 7 located at the outermost position of the engine 1 on the left side surface 301 side of the cylinder block 6 in a horizontal direction perpendicular to the crank axis 300 of the crankshaft 5 and parallel to the block top surface 341 (cylinder head joint surface) of the cylinder block 6. In this way, the starter 20 is not disposed at the outermost position of the engine 1 in the horizontal direction. This makes it possible to make the engine 1 more compact and reduces failure of the starter 20 due to contact with foreign objects.

[0061] 17 and 21, a motor axis 344 of a motor portion 343 of the starter 20 is disposed on the block underside 342 side of the cylinder block 6 relative to the crank axis 300 of the crankshaft 5 in the horizontal direction. This makes the center of gravity of the engine 1 lower than when the starter 20 is disposed above the crank axis 300, and allows the center of gravity of the vehicle to be lowered when the engine 1 is mounted on the vehicle.

[0062] 5, 6 and 21, the starter 20 is disposed in a position not overlapping with the two-stage turbocharger 30 in the direction of the crank axis 300 of the crankshaft 5, particularly in a position not overlapping with the lubricating oil pipe 345 for circulating the lubricating oil to the two-stage turbocharger 30. Furthermore, as described above, the EGR cooler 27 is fixed to the front side surface of the cylinder head 2. This makes it possible to prevent the liquid from adhering to the starter 20 when the liquid such as lubricating oil leaks from the two-stage turbocharger 30 or when the liquid such as cooling water leaks from the EGR cooler 27, and prevents the starter 20 from becoming dirty or breaking down due to the adhesion of the liquid.

[0063] As shown in Figs. 22 and 23, an external accessory 328 that operates in conjunction with the rotation of the crankshaft 5 is disposed on an external accessory mounting seat 327 of the left housing bracket portion 304 of the cylinder block 6. The external accessory 328 is, for example, a pump on the working machine on which the engine 1 is mounted, and is operated by the rotation of an accessory gear (not shown) that is engaged with a cam gear 332 (see Fig. 12) and operates in conjunction with the rotation of the crankshaft 5. A left third reinforcing rib 308 and a left fourth reinforcing rib 309 are disposed near the external accessory mounting seat 327. The reinforcing ribs 308 and 309 improve the rigidity of the external accessory mounting seat 327, and therefore can prevent the external accessory 328 from being displaced or malfunctioning due to distortion of the external accessory mounting seat 327. Furthermore, the external accessory 328 is disposed directly above the starter 20, and therefore has a function of protecting the starter 20. This prevents foreign objects such as tools from coming into contact with the starter 20 from above, and prevents malfunction or displacement of the starter 20 due to contact with the foreign objects.

[0064] 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. [Explanation of symbols]

[0065] 1 Engine 5 Crankshaft 6 Cylinder block 7 Flywheel housing 8 Flywheel 20 Starter 27 EGR cooler 30 Two-stage turbocharger (turbocharger) 300 Crank shaft center 301 Left side (both sides) 302 Right side (both sides) 303 Front side (one side) 304 Left side housing bracket part 305 Right side housing bracket part 306,307,308,309,310,311 Reinforcing ribs 307a, 308a, 309a, 311a Straight portion of reinforcing rib 325 Bracket recess 341 Block top surface (cylinder head joint surface) 344 Motor shaft 345 Turbocharger Lubricating Oil Piping 410 Starter mounting base

Claims

1. A starter is provided in a flywheel housing provided on one side of the cylinder block, Ribs are provided on the right and left sides of the cylinder block, The starter is provided below one of the ribs so as to overlap the one of the ribs in a plan view, and is connected to a mounting portion formed on the flywheel housing.

2. 2. The engine apparatus according to claim 1, wherein a motor axis of the starter is disposed below a crank axis.

3. The engine apparatus according to claim 1 , wherein the rib is provided so that a longitudinal direction of the rib is aligned along a crank axial direction.

4. 4. The engine apparatus according to claim 1, wherein a mount attachment seat for attaching an engine mount connected to a vehicle body is provided so as to overlap at least a portion of the starter in the crankshaft direction when viewed from the side.

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