Water-cooled engine

Abstract

The present invention provides a water-cooled engine in which the cooling performance of a rear end side cover portion (17a) is improved. A plurality of overwater floating ports (18) opening around each cylinder (16) are arranged between the cylinder sleeve (2a) and the cover sleeve (2b), engine cooling water (9) floats from the cylinder sleeve (2a) to the cover sleeve (2b) through the plurality of overwater floating ports (18), and the cover sleeve (2b) is provided with a rear end side sleeve part (2ba). The water-cooled engine has a rear-end-side jacket portion (2ba) facing a rear-end-side overwater floating port (18a) located at a rear-end-side cover portion (17a) of a cylinder head (17) among a plurality of overwater floating ports (18), the water-cooled engine having: a water-cooled oil cooler (19); a cooler water supply pipe (20) extending from the cover sleeve (2b) to the oil cooler (19); and a cooler drain pipe (21) from the oil cooler (19) to the water pump (8). The cooler water supply pipe (20) is led out from the rear end side sleeve part (2ba).

Description

Technical Field

[0001] The present invention relates to a water-cooled engine, and more particularly to a water-cooled engine having improved cooling performance of a rear end side cover portion. Background Art

[0002] Conventionally, there is a water-cooled engine having an engine cooling water circulation path using a water pump (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-105277 (reference Figure 1 ) Summary of the invention

[0006] Problems to be solved by the invention

[0007] <Problem> Sometimes the cooling performance of the rear end side cover part becomes low.

[0008] In the engine of Patent Document 1, the cooler water supply pipe of the water-cooled oil cooler is led out from the rear end side of the cylinder liner. As a result, the floating amount of the engine cooling water from the cylinder liner to the rear end side jacket portion of the cylinder head jacket is insufficient, and the cooling performance of the rear end side cover portion becomes low.

[0009] An object of the present invention is to provide a water-cooled engine with improved cooling performance of a rear end side cover portion.

[0010] Means for solving problems

[0011] The main configuration of the present invention is as follows.

[0012] like Figure 3 (A) Figure 3 As shown in (B), a water-cooled engine is characterized in that the water jacket 2 has a cylinder jacket 2a around the cylinder 16 and a cover jacket 2b in the cylinder head 17, as shown in FIG. Figure 3 As shown in (A), the cylinder sleeve 2a has a sleeve inlet 2c at the front end. Figure 3 As shown in (B), the cover sleeve 2b has a sleeve outlet 2d at the front end, and between the cylinder sleeve 2a and the cover sleeve 2b, there are a plurality of water floating ports 18 opening on the peripheral side of each cylinder 16. The engine cooling water 9 floats from the cylinder sleeve 2a to the cover sleeve 2b via the plurality of water floating ports 18. The cover sleeve 2b has a rear end side sleeve portion 2ba, which faces the rear end side water floating port 18a located at the rear end side cover portion 17a of the cylinder head 17 among the plurality of water floating ports 18.

[0013] like Figure 2As shown, the water-cooled engine has: a water-cooled oil cooler 19; a cooler water supply pipe 20 from the cover jacket 2b to the oil cooler 19; and a cooler drain pipe 21 from the oil cooler 19 to the water pump 8,

[0014] The cooler water supply pipe 20 is led out from the rear end side jacket portion 2ba.

[0015] Effects of the Invention

[0016] The present invention has the following effects.

[0017] <<Effect>> The cooling performance of the rear end side cover portion 17a is improved.

[0018] In this engine, the water suction force of the water pump 8 is applied to the rear end side sleeve part 2ba via the cooler drain pipe 21, the oil cooler 19 and the cooler water supply pipe 20 in sequence. Therefore, a large amount of engine cooling water 9 is sucked into the rear end side sleeve part 2ba from the rear end side water floating port 18a, thereby improving the cooling performance of the rear end side cover part 17a where the engine cooling water 9 is difficult to float.

[0019] 《Effect》The cooling performance of the engine is improved.

[0020] In this engine, a large amount of engine cooling water 9 floats from the rear end side water floating port 18a to the rear end side sleeve part 2ba. Therefore, there is no need to reduce the channel cross-sectional area of ​​other water floating ports 18 for this purpose. The channel resistance of the cooling water circulation path 1 can be reduced, and the cooling performance of the engine is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a front view of a cooling water circulation path of an engine used in a water-cooled engine according to an embodiment of the present invention.

[0022] Figure 2 yes Figure 1 Side view of the cooling water circulation path.

[0023] Figure 3 (A) is Figure 1 A top view of the cylinder block used in the cooling water circulation path. Figure 3 (B) is a top view of the cylinder head. Figure 3 (C) is along Figure 3 (B) is a cross-sectional view of the CC line.

[0024] Figure 4 (A) is along Figure 3 (A) is a cross-sectional view of the IVA-IVA line, Figure 4 (B) is along Figure 4 (A) is a cross-sectional view of line BB, Figure 4 (C) is along Figure 4 (A) is a cross-sectional view of the CC line, Figure 4 (D) is along Figure 4 (A) is a cross-sectional view taken along line DD.

[0025] Figure 5 This is a side view of a fuel supply device and a lubrication device used in a water-cooled engine according to an embodiment of the present invention.

[0026] Figure 6 (A) is a side view of a cylinder block used in a water-cooled engine according to an embodiment of the present invention, Figure 6 (B) is a side view of the auxiliary equipment mounting base. Figure 6 (C) is along Figure 6 (B) is a cross-sectional view of the CC line, Figure 6 (D) is along Figure 6 (B) is a cross-sectional view of the DD line, Figure 6 (E) is along Figure 6 (C) is a cross-sectional view of line EE, Figure 6 (F) is along Figure 6 (D) is a cross-sectional view of the FF line.

[0027] Figure 7 (A) is a side view of a modified example of the auxiliary equipment mounting base, Figure 7 (B) is along Figure 7 (A) is a cross-sectional view of line BB, Figure 7 (C) is a side view of a modified example of the oil branch pipe. Figure 7 (D) is Figure 7 (C) is an enlarged cross-sectional view of portion D.

[0028] Figure 8 It is a front view of the water-cooled engine according to the embodiment of the present invention.

[0029] Fig. 9 It is a rear view of the water-cooled engine according to the embodiment of the present invention.

[0030] Fig.10 It is a side view of the water-cooled engine according to the embodiment of the present invention. DETAILED DESCRIPTION

[0031] Figures 1 to 10 1 is a diagram for explaining a water-cooled engine according to an embodiment of the present invention. In this embodiment, a vertical four-stroke in-line four-cylinder diesel engine is described.

[0032] like Fig.10As shown, the engine comprises: a cylinder block 27; a cylinder head 17, which is mounted on the upper part of the cylinder block 27; a head cover 17d, which is mounted on the upper part of the cylinder head 17; a crankshaft 13, which is accommodated in a crankcase 27c of the cylinder block 27; a gear box 53, which is mounted on the front side of the cylinder block 27 with the mounting direction of the crankshaft 13 as the front-to-back direction, one side of the front-to-back direction as the front and the other side as the rear; an engine cooling fan 14, which is arranged on the front side of the gear box 53; and a flywheel 54, which is mounted on the crankshaft 13 on the rear side of the cylinder block 27.

[0033] The engine cooling fan 14 blows engine cooling air 15 rearward.

[0034] like Figure 3 As shown in (B), when viewed in a direction parallel to the cylinder center axis 16a, the width direction of the cylinder head 17 orthogonal to the front-rear direction is regarded as the horizontal direction. Figure 8 , Fig. 9 As shown, an intake manifold 55 is provided on one lateral side of the cylinder head 17 , and an exhaust manifold 56 is provided on the other lateral side.

[0035] The engine is provided with an air intake device, a fuel supply device, an exhaust device, a valve driving device, a linkage shaft, a lubrication device and a water cooling device.

[0036] like Fig.10 As shown, the air intake device has: an air cleaner 57; an air compressor 49b of a supercharger 49, the supercharger 49 being mounted on the upper portion of the exhaust manifold 56; a supercharger pipe 49c; and Figure 5 The intake manifold 55 is shown.

[0037] Use air compressor 49b to Fig.10 The air purified by the air purifier 57 shown in the figure is compressed and flows from the boost pipe 49c to the Figure 5 Intake manifold 55 is shown pressurized.

[0038] like Figure 5 As shown, the fuel supply device includes a fuel tank 58, a fuel supply pump 59, a common rail 60, a fuel injector 61, and an engine ECU 62. The solenoid valve of the fuel injector 61 is electrically connected to the engine ECU 62. Under the control of the engine ECU 62, the solenoid valve opens for a predetermined time at a predetermined timing, and at a predetermined injection period, a predetermined injection amount of fuel 73 is injected from the fuel injector 61 to each cylinder 16. The fuel 73 is light oil.

[0039] ECU is the abbreviation of Electronic Control Unit, which is a microcontroller.

[0040] The injection timing is set using a crank angle detected based on a pulse signal accompanying engine rotation, which is generated by an electromagnetic pickup 63 electrically connected to the engine ECU 62 .

[0041] like Fig.10 As shown, the exhaust device includes an exhaust manifold 56, an exhaust turbine 49d of a supercharger 49, and an exhaust treatment device 74. The exhaust gas discharged from the exhaust manifold 56 is treated by a DOC and a DPF (not shown) in the exhaust treatment device 74 after driving the exhaust turbine 49d.

[0042] DOC is the abbreviation of diesel exhaust catalyst, and DPF is the abbreviation of diesel particulate filter.

[0043] like Figure 8 , Fig. 9 As shown, the valve operating device includes a valve operating camshaft 64 and intake and exhaust valves (not shown) driven by the valve operating camshaft 64 .

[0044] The valve camshaft 64 is linked to the crankshaft 13 via a timing transmission gear system (not shown).

[0045] The pair of left and right secondary balancer shafts 65 , 65 also move in conjunction with the crankshaft 13 via a timing transmission gear system.

[0046] like Figure 5 As shown, the lubrication device includes: an oil pan 34; an oil filter 66; an oil pump 35; an auxiliary equipment mounting base 36; a base oil supply passage 38, which supplies engine oil 37 from the oil pump 35 to the auxiliary equipment mounting base 36; a crankshaft oil supply passage 39, which supplies engine oil 37 from the base oil supply passage 38 to the bearing portion 13a of the crankshaft 13; a pair of balancer shaft oil supply passages 67, 67, as shown in FIG. Figure 8 As shown, the pair of balancer shaft oil supply passages 67, 67 supply engine oil 37 to the bearing portions 65a of the left and right pair of secondary balancer shafts 65, 65 via the crankshaft oil supply passage 39; and the camshaft oil supply passage 68 supplies engine oil 37 from the bearing portion 65a of the secondary balancer shaft 65 on the exhaust end side to the bearing portion 64a of the valve camshaft 64.

[0047] The oil cooler 19 and the oil filter 44 are mounted on the auxiliary equipment mounting base 36. The oil cooler 19 is located at a higher position than the oil filter 44.

[0048] like Figure 1 As shown, the water cooling device has a cooling water circulation path 1 of the engine.

[0049] The engine cooling water circulation path 1 includes a water jacket 2 in the engine, a valve housing box 4 housing a thermostat valve 3 , a main water channel 5 , a radiator 7 , a water pump 8 , and a bypass water channel 6 .

[0050] During engine operation, when the thermostat valve 3 is closed when the water temperature of the engine cooling water in the water jacket 2 is lower than a specified temperature, all the engine cooling water 9 in the water jacket 2 bypasses the radiator 7 and returns to the water jacket 2 via the valve housing box 4, the bypass water path 6 and the water pump 8 in sequence.

[0051] During engine operation, when the thermostat valve 3 is opened when the water temperature of the engine cooling water 9 in the water jacket 2 is higher than a specified temperature, a large amount of the engine cooling water 9 in the water jacket 2 returns to the water jacket 2 via the valve housing box 4, the main water path 5, the radiator 7 and the water pump 8 in sequence, and a part of the engine cooling water 9 in the water jacket 2 bypasses the radiator 7 and returns to the water jacket 2 via the valve housing box 4, the bypass water path 6 and the water pump 8 in sequence.

[0052] That is, Figure 1 As shown, the engine is configured such that during engine operation, a predetermined amount of engine cooling water 9 in the water jacket 2 bypasses the radiator 7 by the pressure delivery force of the water pump 8 and returns to the water jacket 2 via the valve housing box 4, the bypass water passage 6 and the water pump 8 in sequence.

[0053] like Figure 1 As shown, the engine has: a de-airing passage 10, which is led out from the upper part of the impeller chamber 8a of the water pump 8 in a horizontal direction or an upward direction and reaches the bypass water path 6; and an air passing portion 3a, which allows air to pass from the upstream side of the thermostat valve 3 to the downstream side of the valve.

[0054] Furthermore, during the supply of engine cooling water 9 from the water supply port 7a of the radiator 7 which is performed when the engine is stopped, air 11 which attempts to accumulate in the upper portion of the impeller chamber 8a of the water pump 8 is squeezed out from the upper portion of the impeller chamber 8a through the de-airing passage 10 to the bypass water channel 6 due to the rise in the water level of the cooling water circulation path 1, and is squeezed out from the water supply port 7a of the radiator 7 from the bypass water channel 6 in sequence through the air passing portion 3a and the main water channel 5.

[0055] In this engine, in the water supply of the engine cooling water 9, due to the rise of the water level in the cooling water circulation path 1, the air 11 that attempts to accumulate in the upper part of the impeller chamber 8a of the water pump 8 is squeezed out from the water supply port 7a of the radiator 7, and it is difficult for the air 11 to remain in the cooling water circulation path 1 of the engine. Therefore, during the operation of the engine, it is difficult for the cooling performance to be reduced due to the circulation of the air 11 in the cooling water circulation path 1, and the cooling performance of the engine is improved.

[0056] Furthermore, in this engine, the air 11 is unlikely to circulate in the cooling water circulation path 1 during engine operation, so damage to the cooling water circulation path 1 due to cavitation is unlikely to occur.

[0057] like Figure 1 As shown, in the present embodiment, the de-airing passage 10 is led out from the impeller chamber 8a in a horizontal direction and is formed by a drill hole reaching the bypass water channel 6, and the air passage portion 3a is formed in the thermostat valve 3, but the present invention is not limited to this. The de-airing passage 10 can also be led out from the impeller chamber 8a obliquely upward or vertically upward, and the air passage portion 3a can also be arranged in the valve housing box 4.

[0058] It should be noted that the pump housing 8b of the water pump 8, the terminal part of the water channel wall 6a of the bypass water channel 6 and the channel wall 10a of the de-airing channel 10 erected therebetween are integrally formed from a continuous metal material, and a de-airing channel 10 with a drilled hole is formed on the channel wall 10a of the de-airing channel 10.

[0059] like Figure 1 As shown, the engine has a storage tank 12 connected to the water supply port 7 a of the radiator 7 .

[0060] In this engine, since air 11 is less likely to remain in the cooling water circulation path 1 , the amount of exchange between the engine cooling water 9 and the air 11 in the reservoir tank 12 decreases, and the frequency of replenishing the engine cooling water 9 to the reservoir tank 12 can be reduced.

[0061] like Figure 1 As shown, the radiator 7 has an upper tank 7b, a lower tank 7c and a transversely arranged upright heat dissipation pipe 7d therebetween. The upper tank 7b is connected to the valve housing box 4 via the main water path 5, and the lower tank 7c is connected to the water pump 8 via the return water path 72.

[0062] The water supply port 7a is provided in the upper tank 7b and is covered with a radiator cap 7e.

[0063] like Figure 1 As shown, a valve mechanism 7f is provided on the radiator cap 7e. When the engine is running, due to the increase in temperature, the volume of the engine cooling water 9 in the cooling water circulation path 1 expands and the internal pressure of the cooling water circulation path 1 increases, the main pressure valve of the valve mechanism 7f opens, and a part of the engine cooling water 9 in the cooling water circulation path 1 overflows into the storage tank 12 and accumulates. After the engine stops, when the internal pressure of the cooling water circulation path 1 drops due to the decrease in temperature, the negative pressure valve of the valve mechanism 7f opens, and a part of the engine cooling water 9 accumulated in the storage tank 12 is led back to the cooling water circulation path 1.

[0064] like Figure 3 (A) Figure 3As shown in (B), the water jacket 2 includes a cylinder jacket 2a around the cylinder 16 and a cover jacket 2b in the cylinder head 17. Figure 3 As shown in (A), the cylinder sleeve 2a has a sleeve inlet 2c at the front end. Figure 3 As shown in (B), the cover sleeve 2b has a sleeve outlet 2d at the front end, and between the cylinder sleeve 2a and the cover sleeve 2b, there are a plurality of water floating ports 18 opening on the peripheral side of each cylinder 16. The engine cooling water 9 floats from the cylinder sleeve 2a to the cover sleeve 2b via the plurality of water floating ports 18. The cover sleeve 2b has a rear end side sleeve portion 2ba, which faces the rear end side water floating port 18a located at the rear end side cover portion 17a of the cylinder head 17 among the plurality of water floating ports 18.

[0065] like Figure 2 As shown, the engine has: a water-cooled oil cooler 19; a cooler water supply pipe 20 from the cover jacket 2b to the oil cooler 19; and a cooler drain pipe 21 from the oil cooler 19 to the water pump 8, the cooler water supply pipe 20 being derived from the rear end side jacket portion 2ba.

[0066] In this engine, the water suction force of the water pump 8 is applied to the rear end side jacket part 2ba via the cooler drain pipe 21, the oil cooler 19 and the cooler water supply pipe 20 in sequence. Therefore, a large amount of engine cooling water 9 is sucked into the rear end side jacket part 2ba from the rear end side water floating port 18a, thereby improving the cooling performance of the rear end side cover part 17a where the engine cooling water 9 is originally difficult to float.

[0067] In addition, in this engine, a large amount of engine cooling water 9 floats from the rear end side water floating port 18a to the rear end side sleeve part 2ba. Therefore, there is no need to reduce the channel cross-sectional area of ​​other water floating ports 18 for this purpose. The channel resistance of the cooling water circulation path 1 can be reduced, and the cooling performance of the engine is improved.

[0068] like Figure 2 As shown, the cooler water supply pipe 20 is led out from the upper end side portion 2bb of the rear end side jacket portion 2ba.

[0069] In this engine, when the engine tilts forward and downward, the air 11 and water vapor accumulated in the upper end side portion 2bb of the rear end side sleeve portion 2ba are sucked out through the cooler water supply pipe 20. Therefore, it is difficult for the air 11 and water vapor to stagnate in the rear end side sleeve portion 2ba, and the cooling performance of the rear end side cover portion 17a is improved.

[0070] like Figure 3 As shown in (B), the inlet 22a side of the intake port 22 on both sides is used as the intake end side, and the outlet 32a side of the exhaust port 32 is used as the exhaust end side, and the cooler water supply pipe 20 is led out from the intake end side part 2bc of the rear end side sleeve part 2ba.

[0071] In this engine, the relatively low temperature engine cooling water 9 in the intake end side portion 2bc of the rear end side jacket portion 2ba is supplied from the cooler water supply pipe 20 to the oil cooler 19, so the cooling performance of the oil cooler 19 is improved.

[0072] like Figure 3 As shown in (B), the cover sleeve 2b has: a rear end near-cylinder bore upper water passage 23a located among a plurality of cylinder bore upper water passages 23 between the cylinder bores, near the rear end of the cylinder head 17; a rear end near-cylinder bore upper water passage 18b among a plurality of water floating ports 18 for supplying engine cooling water 9 to the rear end near-cylinder bore upper water passage 23a; a rear end near-cylinder bore upper water passage 23d facing the rear end near-cylinder bore upper water passage 18b; and a partition wall 24.

[0073] The rear end vicinity cover portion 2bd is arranged on the front side of the rear end side cover portion 2ba, and the partition wall 24 is arranged between the rear end vicinity cover portion 2bd and the rear end side cover portion 2ba.

[0074] In this engine, the engine cooling water 9 that floats up from the water floating port 18b near the rear end to the sleeve portion 2bd near the rear end is blocked by the partition wall 24 and will not be sucked out by the cooler water supply pipe 20 led out from the rear end side sleeve portion 2ba, but will be supplied to the upper water channel 23a between the cylinder holes near the rear end. Therefore, the cooling performance of the cover portion 17b near the rear end of the cylinder head 17 is improved.

[0075] It should be noted that if Figure 3 As shown in (B), the upper water passage 23a between cylinder bores near the rear end is located between the cylinder 16 on the rearmost side and the cylinder 16 in front of it.

[0076] like Figure 3 As shown in FIG. 2(C) , in this engine, the lower peripheral wall 22 b of the intake port 22 and the head bottom wall 17 c of the cylinder head 17 are connected via a partition wall 24 .

[0077] In this engine, the heat of the cover bottom wall 17 c is dissipated to the lower peripheral wall 22 b of the intake port 22 via the partition wall 24 , so the cooling performance of the cover bottom wall 17 c is improved.

[0078] In this engine, the rigidity of the cover bottom wall 17 c is increased by the partition wall 24 .

[0079] like Figure 3 As shown in (B), the cylinder head 17 has: an upper water passage 23 between cylinder bores, the upper water passage 23 between cylinder bores being located between the cylinder bores; and a head bolt boss 25, the head bolt boss 25 being as shown in FIG. Figure 4As shown in (A), the cover bolt boss 25 is arranged on both sides of the upper water passage 23 between the cylinder holes, and the cover bolt boss 25 has a cover bolt 26 penetrating therein. By utilizing the tightening force of the cover bolt 26, the cylinder head 17 and the cylinder body 27 sandwich the cover gasket 28 in the middle for tightening.

[0080] The cylinder head 17 has: a reinforcing wall 29 along one of the cover bolt bosses 25 and 25 arranged on the lateral sides of the upper water channel 23 between cylinder holes, and a reinforcing rib 30 along the other cover bolt boss 25. The reinforcing wall 29 is used to connect the water channel bottom wall 23b of the upper water channel 23 between cylinder holes with the sleeve top wall 2be of the cover sleeve 2b, and the reinforcing rib 30 bulges from the water channel bottom wall 23b toward the sleeve top wall 2be.

[0081] In this engine, the heat of the water channel bottom wall 23 b is dissipated from the reinforcing wall 29 and the reinforcing rib 30 to the engine cooling water 9 passing through the inter-cylinder bore upper water channel 23 , thereby improving the cooling performance of the water channel bottom wall 23 b .

[0082] Furthermore, in this engine, since the tightening force of the head bolts 26 is transmitted to the water channel bottom wall 23 b via the reinforcing wall 29 and the reinforcing rib 30 , the sealing performance of the head gasket 28 is improved.

[0083] In addition, in this engine, the reinforcing wall 29 and the reinforcing rib 30 improve the rigidity of the water channel bottom wall 23b.

[0084] like Figure 4 As shown in FIG. 2 (B), the reinforcing wall 29 is connected to the peripheral wall 22 c of the air intake port 22 .

[0085] In this engine, the heat of the water channel bottom wall 23 b is dissipated to the peripheral wall 22 c of the intake port 22 via the reinforcing wall 29 , so the cooling performance of the water channel bottom wall 23 b is improved.

[0086] In addition, in this engine, the reinforcing wall 29 connected to the peripheral wall 22c of the intake port 22 improves the rigidity of the water channel bottom wall 23b.

[0087] like Figure 4 (A) Figure 4 As shown in (C), the reinforcing rib 30 is arranged on the water channel bottom wall portion 23c on the exhaust end side of the water channel bottom wall 23b.

[0088] In this engine, the heat of the water channel bottom wall portion 23c on the exhaust end side, which is prone to overheating, is transferred to the reinforcing rib 30 and dissipated to the engine cooling water 9 passing through a large amount of the reinforcing rib 30 above, thereby improving the cooling performance of the water channel bottom wall portion 23c on the exhaust end side.

[0089] like Figure 4As shown in (A), the raised end surface 30a of the reinforcing rib 30 is inclined downward from the head bolt boss 25 along the reinforcing rib (30) toward the reinforcing wall 29 side.

[0090] Therefore, the tightening force of the cover bolt 26 is transmitted to the water channel bottom wall portion 23c on the exhaust end side via the reinforcing rib 30, and the heat of the water channel bottom wall portion 23c on the exhaust end side is dissipated from the inclined wide raised end surface 30a of the reinforcing rib 30 to the large amount of engine cooling water 9 flowing above the reinforcing rib 30, thereby improving the cooling performance of the water channel bottom wall portion 23c on the exhaust end side.

[0091] like Figure 4 As shown in (A), the engine has a pair of floating holes 31, 31 on both sides of the water channel bottom wall 23b of the upper water channel 23 between cylinder bores, which allows the engine cooling water 9 to float from the cylinder sleeve 2a to the cover sleeve 2b, and the floating hole 31 on the exhaust end side of the pair of floating holes 31, 31 is used as the exhaust end side floating hole 31a, and the floating hole 31 on the intake end side is used as the intake end side floating hole 31b, as shown in FIG. Figure 4 (A) Figure 4 As shown in (C), the floating hole 31a on the exhaust end side is provided in the reinforcing rib 30, as shown in FIG. Figure 4 (A) Figure 4 As shown in (B), the floating hole 31b on the suction end side is provided in the reinforcing wall 29. Figure 4 As shown in (B), the water floating hole outlet 31ba of the air intake end side water floating hole 31b faces the exhaust port peripheral wall 32b.

[0092] like Figure 4 As shown in (B), in this engine, since the engine cooling water 9 flowing out from the water floating hole outlet 31ba of the intake end side water floating hole 31b is directed toward the exhaust port peripheral wall 32b, the cooling performance of the exhaust port peripheral wall 32b is improved.

[0093] like Figure 4 As shown in (A), the cylinder liner 2a has: an inter-cylinder bore water passage 33, which is arranged between adjacent cylinder bores; a liner portion 2aa on the intake end side; and a liner portion 2ab on the exhaust end side, and the engine cooling water 9 is transported from the liner portion 2aa on the intake end side to the liner portion 2ab on the exhaust end side via the inter-cylinder bore water passage 33.

[0094] The inter-cylinder bore water channel 33 includes: a first transverse water channel 33c, which is arranged between the inter-cylinder bore top wall 33a and the first transverse wall 33b directly below it; and a second transverse water channel 33e, which is arranged between the first transverse wall 33b and the second transverse wall 33d directly below it.

[0095] The suction end side wall portion 33ba of the first transverse wall 33b is inclined downward toward the sleeve portion 2aa on the suction end side, so that the lower portion 33ca of the inlet of the first transverse waterway 33c is inclined downward toward the sleeve portion 2aa on the suction end side, and the upper portion 33ea of ​​the inlet of the second transverse waterway 33e is inclined downward toward the sleeve portion 2aa on the suction end side.

[0096] In this engine, Figure 3 As shown in (A), the sleeve inlet 2c on the front end side of the cylinder sleeve 2a faces the lateral center of the front surface of the cylinder 16 on the front end side, and the channel cross-sectional area of ​​the sleeve portion 2aa on the intake end side is larger than the channel cross-sectional area of ​​the sleeve portion 2ab on the exhaust side, as shown in FIG. Figure 3 As shown in (B), the jacket outlet 2d at the front end side of the cover jacket 2b is arranged to be offset to the exhaust end side, so that the engine cooling water 9 is delivered from the jacket portion 2aa at the intake end side to the jacket portion 2ab at the exhaust end side through the inter-cylinder bore water passage 33.

[0097] In this engine, low-temperature engine cooling water 9 located at the lower position of the sleeve part 2aa on the intake end side is introduced upward along the inlet lower part 33ca of the first cross water channel 33c and the inlet upper part 33ea of ​​the second cross water channel 33e, thereby improving the cooling performance between the cylinder bores.

[0098] Figure 4 As shown in (A) of FIG. 1 , the inter-cylinder bore water channel 33 includes a third transverse water channel 33g provided between the second transverse wall 33d and the third transverse wall 33f directly thereunder.

[0099] The suction end side wall portion 33da of the second cross wall 33d is tilted downward toward the sleeve portion 2aa on the suction side, so that the lower inlet portion 33eb of the second cross waterway 33e is tilted downward toward the sleeve portion 2aa on the suction end side, and the upper inlet portion 33ga of the third cross waterway 33g is tilted downward toward the sleeve portion 2aa on the suction end side.

[0100] In this engine, low-temperature engine cooling water 9 located at the lower position of the sleeve part 2aa on the intake end side is introduced upward along the inlet lower part 33eb of the second cross water channel 33e and the inlet upper part 33ga of the third cross water channel 33g, thereby improving the cooling performance between the cylinder bores.

[0101] like Figure 4 As shown in (A), in this engine, the exhaust end side water floating hole 31a forms a larger minimum passage cross-sectional area than the intake end side water floating hole 31b.

[0102] In this engine, the flow of the engine cooling water 9 introduced from the jacket portion 2aa on the intake end side through the inter-bore water passage 33 to the exhaust end side floating hole 31a is promoted, so the cooling performance between the cylinder bores is improved.

[0103] It should be noted that the inter-cylinder bore water channel 33 has a fourth transverse water channel 33k provided between the third transverse wall 33f and the fourth transverse wall 33h directly below the third transverse wall 33f. The fourth transverse water channel 33k is formed in a horizontal direction.

[0104] like Figure 5 As shown, the engine comprises: an oil pan 34; an oil pump 35; an auxiliary equipment mounting base 36, on which an oil cooler 19 is mounted; a base oil supply passage 38, which supplies engine oil 37 of the oil pan 34 from the oil pump 35 to the auxiliary equipment mounting base 36; and a crankshaft oil supply passage 39, which supplies engine oil 37 cooled by the oil cooler 19 from the auxiliary equipment mounting base 36 to the bearing portion 13a of the crankshaft 13.

[0105] like Figure 6 As shown in (B), in this engine, the auxiliary equipment mounting base 36 has an oil cooler supply port 40, an oil cooler supply passage 40a derived from the oil cooler supply port 40, an oil cooler drain port 41, and an oil cooler drain passage 41a derived from the oil cooler drain port 41.

[0106] The higher one of the oil cooler oil supply port 40 and the oil cooler oil discharge port 41 with a height difference is used as the cooler high port 42, and the lower one is used as the cooler low port 43. The one of the oil cooler oil supply passage 40a and the oil cooler oil discharge passage 41a that is led out from the cooler low port 43 is used as the cooler low port oil passage 43a. The cooler low port oil passage 43a is led out upward to a height above the height of the lower edge 42a of the cooler high port 42.

[0107] The height above the height of the lower edge 42 a of the cooler high port 42 refers to a height that is the same as or higher than the height of the lower edge 42 a of the cooler high port 42 .

[0108] In this engine, when the engine is stopped, the engine oil 37 in the oil cooler 19 remains at least to the height of the lower edge 42a of the cooler high port 42. Therefore, when the engine is restarted, the engine oil 37 is supplied to the bearing portion 13a of the crankshaft 13 via the crankshaft oil supply passage 39 in a short time to prevent the bearing portion 13a from burning.

[0109] like Figure 6As shown in (B), in this engine, the side of the oil cooler oil supply passage 40a and the oil cooler oil discharge passage 41a that is led out from the cooler high port 42 is referred to as the cooler high port oil passage 42c. When viewed from a direction parallel to the horizontal direction, the cooler high port oil passage 42c is led out downward from the cooler high port 42. When the engine is stopped, the engine oil 37 in the oil cooler 19 slides from the cooler high port 42 to the oil pan 34 side via the cooler high port oil passage 42c, the filter low port oil passage 48a, the oil filter 44 and the base oil supply passage 38 in sequence. Therefore, the engine oil 37 in the oil cooler 19 only remains to the height of the lower edge 42a of the cooler high port 42.

[0110] Observed from a direction parallel to the horizontal direction, Figure 6 The cooler high port oil passage 42c shown in (B) can be led out upward from the cooler high port 42 and upward to a height above the cooler low port oil passage 43a and the lower edge 42a of the cooler high port 42. In this case, when the engine is stopped, the engine oil 37 in the oil cooler 19 can remain to the same height as the lower edge 42a of the cooler high port 42 or to the height of the lower edge of the upward leading end of the cooler low port oil passage 43a exceeding this height.

[0111] like Figure 6 (B) Figure 6 As shown in (C), the cooler high port 42 is provided in a tube base end portion 42ba of a horizontal tube 42b extending in the lateral direction and inserted into the auxiliary equipment mounting base 36.

[0112] like Figure 6 As shown in (B), when viewed from a direction parallel to the lateral direction, the cooler lower port oil passage 43a is guided upward from the cooler lower port 43 and then guided downward to the oil passage inlet 39a of the crankshaft oil supply passage 39.

[0113] like Figure 6 As shown in (B), the oil cooler oil supply port 40 is used as the cooler high port 42, the oil cooler oil discharge port 41 is used as the cooler low port 43, and the oil cooler oil discharge passage 41a is used as the cooler low port oil passage 43a.

[0114] During engine operation, the engine oil 37 passing through the oil cooler 19 by the pressure-feeding force of the oil pump 35 has its specific gravity increased due to cooling by the oil cooler 19 and smoothly descends in the oil cooler 19 , thereby reducing the pressure-feeding burden of the oil pump 35 .

[0115] like Figure 6 As shown in (C) to (F) of FIG. 1 , the oil cooler 19 is composed of an oil passing layer 19b for passing the engine oil 37 and a water passing layer 19c for passing the engine cooling water 9, which are alternately overlapped. Figure 6As shown in (E), an oil partition wall 19ba is provided in the oil passing layer 19b. Figure 6 As shown in (F) of FIG. 1 , a water partitioning wall 19ca is provided in the water passing layer 19c.

[0116] In the oil passing layer 19 b , the engine oil 37 introduced from the oil cooler oil supply port 40 on the upper rear side is reversed downward and rearward on the front side of the oil partition wall 19 ba , and is discharged from the oil cooler oil discharge port 41 on the lower rear side.

[0117] In the water passing layer 19c, the engine cooling water 9 introduced from the oil cooler water supply port 70 on the front lower side is reversed toward the upper front side at the rear side of the water partition wall 19ca and discharged from the oil cooler drain port (71) on the front upper side.

[0118] like Figure 5 As shown, the engine has an oil filter 44 mounted on the auxiliary equipment mounting base 36 , and the engine oil 37 supplied to the auxiliary equipment mounting base 36 is purified by the oil filter 44 and then supplied to the oil cooler 19 .

[0119] like Figure 6 (B) Figure 6 As shown in (C), the auxiliary equipment mounting base 36 has an oil filter supply port 45, an oil filter supply passage 45a derived from the oil filter supply port 45, an oil filter drain port 46, and an oil filter drain passage 46a derived from the oil filter drain port 46.

[0120] The higher one of the oil filter oil supply port 45 and the oil filter oil drain port 46 with a height difference is used as the filter high port 47, and the lower one is used as the filter low port 48. The one of the oil filter oil supply passage 45a and the oil filter oil drain passage 46a that is led out from the filter low port 48 is used as the filter low port oil passage 48a. The filter low port oil passage 48a is led out upward to a height above the height of the lower edge 47a of the filter high port 47.

[0121] The height above the height of the lower edge 47 a of the filter high port 47 refers to a height that is the same as or higher than the height of the lower edge 47 a of the filter high port 47 .

[0122] like Figure 6As shown in (C), in this engine, the side of the oil filter supply passage 45a and the oil filter drain passage 46a that is led out from the filter high port 47 is used as the filter high port oil passage 47b, and the filter high port oil passage 47b is led out from the filter high port 47 in a horizontal direction. When the engine is stopped, the engine oil 37 in the oil filter 44 slides from the filter high port 47 to the oil pan 34 side through the filter high port oil passage 47b and the base supply passage 38 in sequence, and only remains to the height of the lower edge 47a of the filter high port 47.

[0123] When viewed from a direction parallel to the horizontal direction, the oil passage 47b at the top of the filter can be discharged upward from the top of the filter 47. In this case, when the engine is stopped, the engine oil 37 in the oil filter 44 can remain to the same height as the lower edge 47a of the top of the filter 47 or to the height of the lower edge of the upward discharge end of the oil passage 47b at the top of the filter that exceeds this height.

[0124] like Figure 6 As shown in (C), the filter high port 47 is provided at the oil passage outlet 47 c of the horizontal filter high port oil passage 47 b which faces the lateral direction of the auxiliary equipment mounting base 36 .

[0125] like Figure 6 As shown in (C), the filter high port oil passage 47b is connected to the oil passage outlet (38a) of the base oil supply passage 38.

[0126] like Figure 6 As shown in (B), the filter lower port oil passage 48a is led upward from the filter lower port 48 and connected to the cooler upper port oil passage 42c directed upward.

[0127] In this engine, when the engine is stopped, the engine oil 37 in the oil filter 44 remains at least to the height of the lower edge 47a of the filter high port 47. Therefore, when the engine is restarted, the engine oil 37 is supplied to the bearing portion 13a of the crankshaft 13 via the crankshaft oil supply passage 39 in a short time to prevent the bearing portion 13a from burning out.

[0128] like Figure 6 As shown in (B), the oil filter oil supply port 45 is used as the filter high port 47, the oil filter oil discharge port 46 is used as the filter low port 48, and the oil filter oil discharge passage 46a is used as the filter low port oil passage 48a.

[0129] In this engine, during engine operation, the engine oil 37 passing through the oil filter 44 by the pressure-feeding force of the oil pump 35 descends in the oil filter 44 due to its own weight, thereby reducing the pressure-feeding burden of the oil pump 35 .

[0130] Figure 7 (A) Figure 7 A modified example of the auxiliary equipment mounting base 36 shown in (B) is as follows.

[0131] The oil cooler oil supply passage 40 a and the oil cooler oil discharge passage 41 a of the auxiliary equipment mounting base 36 are both led upward to a height higher than the height of the uppermost portion 19 a of the oil cooler 19 .

[0132] The height above the height of the uppermost portion 19 a in the oil cooler 19 refers to a height that is the same as or higher than the height of the uppermost portion 19 a in the oil cooler 19 .

[0133] In this engine, when the engine is stopped, the engine oil 37 in the oil cooler 19 remains in a state of filling the oil cooler 19. Therefore, when the engine is restarted, the engine oil 37 is supplied to the bearing portion 13a of the crankshaft 13 via the crankshaft oil supply passage 39 in a short time to prevent the bearing portion 13a from burning.

[0134] like Figure 7 (A) Figure 7 As shown in (B), the oil filter oil supply passage 45a and the oil filter oil discharge passage 46a can both be led upward to a height above the height of the uppermost portion 44a of the oil filter 44.

[0135] In this engine, when the engine is stopped, the engine oil 37 in the oil filter 44 remains in a state of being filled in the oil filter 44. Therefore, when the engine is restarted, the engine oil 37 is supplied to the bearing portion 13a of the crankshaft 13 via the crankshaft oil supply passage 39 in a short time to prevent the bearing portion 13a from burning out.

[0136] Figure 7 (A) Figure 7 Other structures and modifications of the auxiliary equipment mounting base 36 shown in (B) Figure 6 The basic example of the auxiliary equipment mounting base 36 shown in (A) to (F) is the same. Figure 7 (A) Figure 7 In (B), Figure 6 The same elements in (A) to (F) are denoted by the same symbols.

[0137] like Figure 5 As shown, in this engine, an auxiliary equipment mounting base 36 is installed at a rear position on the intake end side of the cylinder block 27, as shown in FIG. Fig. 9As shown, there is an oil branch pipe 50 leading out from the rear side of the auxiliary equipment mounting base 36, a rear end wall cross-oil passage 27b crossing the rear end wall 27a of the cylinder body 27, and a supercharger oil supply pipe 51 for supplying the engine oil 37 to the bearing portion 49a of the supercharger 49. The engine oil 37 of the auxiliary equipment mounting base 36 is supplied to the bearing portion 49a of the supercharger 49 via the oil branch pipe 50, the rear end wall cross-oil passage 27b and the supercharger oil supply pipe 51 in sequence.

[0138] In this engine, since the engine oil 37 is supplied from the auxiliary equipment mounting base 36 to the bearing portion 49a of the supercharger 49 via the shortest path, when the engine is started, the engine oil 37 can be supplied to the bearing portion 49a of the supercharger 49 in a short time to prevent the bearing portion 49a from burning out.

[0139] Furthermore, in this engine, when the viscosity of the engine oil 37 increases during cold start of the engine, the engine oil 37 passing through the rear end wall transverse oil path 27b inside the rear end wall 27a of the cylinder body 27 is heated by the combustion heat of the engine immediately after starting, and the engine oil 37 becomes low in viscosity, and the engine oil 37 is supplied to the bearing portion 49a of the supercharger 49 without delay, thereby preventing the bearing portion 49a of the supercharger 49 from burning out during cold start.

[0140] like Figure 8 to Figure 10 As shown, in this engine, a supercharger oil drain pipe 69 is led out from the bearing portion 49 a of the supercharger 49 , and the engine oil 37 that has lubricated the bearing portion 49 a of the supercharger 49 is returned to the oil pan 34 through the supercharger oil drain pipe 69 .

[0141] The oil branch pipe 50, the supercharger oil supply pipe 51 and the supercharger oil drain pipe 69 are all engine external pipes, and the rear end wall crosses the oil passage 27b to form the internal oil passage of the engine.

[0142] like Figure 6 As shown in FIG. 2 (B), the engine oil 37 is branched from the oil cooler drain passage 41 a of the auxiliary equipment mounting base 36 to the oil branch pipe 50 .

[0143] In this engine, the engine oil 37 cooled by the oil cooler 19 is supplied to the bearing 49a of the supercharger 49. Therefore, even when the engine rotates at high speeds, the bearing 49a of the supercharger 49 is prevented from burning out.

[0144] Figure 7 The structure of the modified example of the oil branch pipe 50 shown in (C) is as follows.

[0145] exist Figure 7 The oil branch pipe 50 shown in (C) is equipped with Figure 7The check valve 52 shown in (D) prevents the engine oil 37 from flowing back from the oil branch pipe 50 to the auxiliary equipment mounting base 36.

[0146] In this engine, when the engine is stopped, Fig. 9 The engine oil 37 in the oil branch pipe 50, the rear end wall cross-oil path 27b and the supercharger oil supply pipe 51 shown will not fall off to the side of the auxiliary equipment mounting base 36. Therefore, when the engine is restarted, the engine oil 37 can be supplied to the bearing portion 49a of the supercharger 49 in a short time to prevent the bearing portion 49a of the supercharger 49 from burning out.

[0147] It should be noted that Fig. 9 The oil branch pipe 50 shown is led out from the oil filter drain port 46 on the upstream side of the oil cooler 19 in the flow path.

[0148] Figure 7 The modified example of the oil branch pipe 50 shown in (C) is different from Figure 6 In addition to the basic example combination of the auxiliary equipment mounting base 36 shown in (B), it can also be combined with Figure 7 A modified example combination of the auxiliary equipment mounting base 36 shown in (A).

[0149] Description of Reference Numerals

[0150] 1: cooling water circulation path; 2: water jacket; 2a: cylinder jacket; 2b: cover jacket; 2ba: rear end side jacket portion; 2bb: upper end side portion; 2bc: intake end side portion; 2bd: jacket portion near the rear end; 2c: jacket inlet; 2d: jacket outlet; 7: radiator; 7a: water supply port; 8: water pump; 9: engine cooling water; 16: cylinder; 16a: cylinder center axis; 17: cylinder head; 17a: rear end side cover portion; 18: water floatation port; 18a: rear end side water floatation port; 18b: water floatation port near the rear end; 19: oil cooler; 20: cooler water supply pipe; 21: cooler drain pipe; 22: intake port; 22a: inlet; 22b: lower peripheral wall; 23: upper waterway between cylinder holes; 23a: water floatation port near the rear end; 24: partition wall; 32: exhaust port; 32a: outlet.

Claims

1. A water-cooled engine, characterized in that: The cooling water circulation path (1) of the engine comprises a water jacket (2), a radiator (7) and a water pump (8) in the engine. When the engine is running, the engine cooling water (9) is circulated between the water jacket (2) and the radiator (7) by using the pressure of the water pump (8). The engine is a vertical in-line multi-cylinder engine. The installation direction of the crankshaft (13) is regarded as the front-back direction, one side of the front-back direction is regarded as the front, and the other side is regarded as the rear. The water jacket (2) comprises a cylinder jacket (2a) around the cylinder (16) and a cover jacket (2b) inside the cylinder head (17); the cylinder jacket (2a) comprises a jacket inlet (2c) at the front end, and the cover jacket (2b) comprises a jacket outlet (2d) at the front end; between the cylinder jacket (2a) and the cover jacket (2b), there are a plurality of water floating ports (18) opening on the peripheral side of each cylinder (16); the engine cooling water (9) floats from the cylinder jacket (2a) to the cover jacket (2b) via the plurality of water floating ports (18); the cover jacket (2b) comprises a rear end side jacket portion (2ba) facing the rear end side water floating port (18a) located on the rear end side cover portion (17a) of the cylinder head (17) among the plurality of water floating ports (18); The water-cooled engine comprises: a water-cooled oil cooler (19); a cooler water supply pipe (20) from the cover jacket (2b) to the oil cooler (19); and a cooler drain pipe (21) from the oil cooler (19) to the water pump (8). The cooler water supply pipe (20) is led out from the rear end side jacket portion (2ba).

2. The water-cooled engine according to claim 1, characterized in that: The cooler water supply pipe (20) is led out from the upper end side portion (2bb) of the rear end side jacket portion (2ba).

3. The water-cooled engine according to claim 1, characterized in that: When viewed in a direction parallel to the cylinder center axis (16a), the width direction of the cylinder head (17) orthogonal to the front-rear direction is taken as the lateral direction, the inlet (22a) side of the intake port (22) on both lateral sides is taken as the intake end side, and the outlet (32a) side of the exhaust port (32) is taken as the exhaust end side, and the cooler water supply pipe (20) is led out from the intake end side part (2bc) of the rear end side sleeve part (2ba).

4. The water-cooled engine according to claim 1, characterized in that: The cover sleeve (2b) comprises: a rear end near cylinder bore upper water passage (23a) located in the vicinity of the rear end of the cylinder head (17) among a plurality of cylinder bore upper water passages (23) between cylinder bores; a rear end near water floating port (18b) among a plurality of water floating ports (18) for supplying engine cooling water (9) to the rear end near cylinder bore upper water passage (23a); a rear end near sleeve portion (2bd) facing the rear end near water floating port (18b); and a partition wall (24). The rear end vicinity cover portion (2bd) is arranged on the front side of the rear end side cover portion (2ba), and the partition wall (24) is arranged between the rear end vicinity cover portion (2bd) and the rear end side cover portion (2ba).

5. The water-cooled engine according to claim 4, characterized in that: A partition wall (24) is used to connect a lower peripheral wall (22b) of the intake port (22) and a cover bottom wall (17c) of the cylinder head (17).

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