JP2004132309A - Water-cooled vertical engine and outboard motor loaded with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect the overheat of a water-cooled vertical engine while minimizing the number of cooling water temperature sensors. <P>SOLUTION: A cylinder block cooling water jacket JB and a cylinder head cooling water jacket JH are independently provided among an exhaust guide cooling water jacket JM1, an exhaust manifold cooling water jacket JM2, the cylinder block cooling water jacket JB and the cylinder head cooling water jacket JH. The cylinder block cooling water jacket JB is connected to a downstream side of the exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2, and the cooling water temperature sensors 67, 89 for detecting the overheat are respectively mounted on the exhaust manifold cooling water jacket JM2 and the cylinder head cooling water jacket JH. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a water-cooled vertical engine having an exhaust passage cooling water jacket, a cylinder block cooling water jacket, and a cylinder head cooling water jacket, and an outboard motor equipped with the same.
[0002]
[Prior art]
If the cylinder block and cylinder head of a water-cooled engine are evenly cooled with cooling water, the cylinder block with a relatively small calorific value tends to be overcooled when the cylinder head with a relatively large calorific value is cooled to an appropriate temperature. is there. Therefore, an engine cooling device for cooling both a cylinder head and a cylinder block to an appropriate temperature is known from the following patent documents.
[0003]
What is described in this patent document is that a cylinder block cooling water jacket and a cylinder head cooling water jacket are independently provided, and the cooling water temperatures of both water jackets are detected by corresponding cooling water temperature sensors, and the detected cooling water is detected. The amount of cooling water distributed to both water jackets is controlled based on the temperature.
[0004]
[Patent Document]
Japanese Patent Publication No. 2-3014
[Problems to be solved by the invention]
By the way, in a water-cooled vertical engine having an exhaust passage cooling water jacket in addition to the cylinder block cooling water jacket and the cylinder head cooling water jacket, if a cooling water temperature sensor is provided in each water jacket, a total of three cooling water temperature sensors are provided. Is required.
[0006]
The present invention has been made in view of the above circumstances, and has as its object to reliably detect overheating of a water-cooled vertical engine while minimizing the number of cooling water temperature sensors.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a plurality of combustion chambers arranged along a crankshaft extending substantially vertically, and exhaust gas from the combustion chambers are guided to the outside. An exhaust passage cooling water jacket provided in the exhaust passage means, a cylinder block cooling water jacket provided in a cylinder block for cooling the periphery of the combustion chamber, and a cylinder provided in a cylinder head for cooling the periphery of the combustion chamber A water-cooled vertical engine comprising a head cooling water jacket and a cooling water pump for supplying cooling water to each of the water jackets, wherein the cylinder block cooling water jacket and the cylinder head cooling water jacket are substantially independent, and exhaust passage cooling is performed. Cylinder block cooling downstream of the water jacket Connect the water jacket, water-cooled vertical engine, characterized in that provided respectively a cooling water temperature sensor for detecting overheating in an exhaust passage cooling cooling water jacket and the cylinder head cooling water jacket is proposed.
[0008]
According to the invention described in claim 2, a plurality of combustion chambers are arranged along a crankshaft extending in a substantially vertical direction, and the exhaust passage means for guiding exhaust gas from the combustion chamber to the outside is provided. An exhaust passage cooling water jacket, a cylinder block cooling water jacket provided on a cylinder block for cooling the periphery of the combustion chamber, a cylinder head cooling water jacket provided on a cylinder head for cooling the periphery of the combustion chamber, An outboard motor equipped with a water-cooled vertical engine having a cooling water pump for supplying cooling water to each water jacket, wherein the cylinder block cooling water jacket and the cylinder head cooling water jacket are substantially independent, and an exhaust passage cooling water is provided. Cylinder block cooling water downstream of jacket An outboard motor equipped with a water-cooled vertical engine, characterized in that a cooling water temperature sensor for detecting overheating is provided in the exhaust passage cooling cooling water jacket and cylinder head cooling water jacket, respectively. Is done.
[0009]
According to the above configuration, since the cylinder block cooling water jacket and the cylinder head cooling water jacket are substantially independent, and the cylinder block cooling water jacket is connected to the downstream side of the exhaust passage cooling water jacket, the cylinder head cooling water jacket that is likely to be heated to a high temperature Supplying low-temperature cooling water to the cylinder to prevent overheating and supplying cooling water whose temperature has increased through the exhaust passage cooling water jacket to the cylinder block cooling water jacket, which is likely to be overcooled, to prevent overcooling Can be.
[0010]
In addition, one cooling water temperature sensor is provided for the exhaust passage cooling water jacket and the cylinder block cooling water jacket constituting the first cooling system among the exhaust passage cooling water jacket, the cylinder block cooling water jacket, and the cylinder head cooling water jacket. And one cooling water temperature sensor is provided for the cylinder head cooling water jacket constituting the second cooling system, so that the number of cooling water temperature sensors is minimized to reduce the number of parts and cost. can do. Particularly, of the exhaust passage cooling water jacket and the cylinder block cooling water jacket connected in series, the cooling water temperature sensor is provided on the upstream exhaust passage cooling water jacket, so that the occurrence of overheating can be detected without delay. .
[0011]
The exhaust passage 24 in the engine room of the embodiment corresponds to the exhaust passage means of the present invention, and the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 of the embodiment correspond to the exhaust passage cooling water jacket of the present invention. Corresponding.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.
[0013]
1 to 19 show an embodiment of the present invention. FIG. 1 is an overall side view of an outboard motor, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of FIG. 2, FIG. 4 is an enlarged view of four directions in FIG. 2, FIG. 5 is a view of five directions of FIG. 4, FIG. 6 is an enlarged cross-sectional view of a main part of FIG. FIG. 8 is an enlarged view taken along line -7 (top view of the mount case), FIG. 8 is an enlarged view taken along line 8-8 in FIG. 1 (a bottom view of the pump body), and FIG. 9 is an enlarged view taken along line 9-9 in FIG. 10 (a bottom view of a small assembly such as a block), FIG. 10 is an enlarged view of the exhaust manifold, FIG. 11 is an enlarged view of a connection portion between the exhaust manifold and the exhaust guide, and FIG. 12 is a view taken along line 12-12 of FIG. 13 is a sectional view taken along line 13-13 of FIG. 14, FIG. 14 is an enlarged view taken along line 14-14 of FIG. 1, FIG. 15 is an enlarged view taken along line 15-15 of FIG. FIG. 16-16 cross section taken along line 5, FIG. 17 line 17-17 sectional view of FIG. 16, FIG. 18 line 18-18 sectional view of FIG. 16, FIG. 19 is a circuit diagram of an engine cooling system.
[0014]
As shown in FIGS. 1 to 3, the outboard motor O is attached to the hull so as to perform a steering motion in the left-right direction about the steering shaft 96 and perform a tilt motion in the vertical direction about the tilt shaft 97. The in-line four-cylinder, four-stroke, water-cooled vertical engine E mounted on the upper part of the outboard motor O has a cylinder block 11, a lower block 12 connected to the front surface of the cylinder block 11, and a substantially vertical direction. A journal 13a is supported by the cylinder block 11 and the lower block 12 so as to be sandwiched between the cylinder block 11 and the lower block 12, a crankcase 14 is coupled to a front surface of the lower block 12, and a cylinder head 15 is coupled to a rear surface of the cylinder block 11. And a head cover 16 coupled to a rear surface of the cylinder head 15. Pistons 18 slidably fitted in four sleeve-shaped cylinders 17 formed in the cylinder block 11 are connected to crank pins 13b of the crankshaft 13 via connecting rods 19, respectively. Is done.
[0015]
The combustion chambers 20 formed on the cylinder head 15 so as to face the top surfaces of the pistons 18 are provided on the left side surface of the cylinder head 15, i.e., the intake ports 21 opening on the port side with respect to the traveling direction of the ship. Are connected to an intake manifold 22 via an exhaust port 23 which opens to the right side of the cylinder head 15 and to an exhaust passage 24 in the engine room. An intake valve 25 for opening and closing the downstream end of the intake port 21 and an exhaust valve 26 for opening and closing the upstream end of the exhaust port 23 are opened and closed by a DOHC type valve mechanism 27 housed inside the head cover 16. Driven. The upstream side of the intake manifold 22 is disposed in front of the crankcase 14 and is connected to a throttle valve 29 fixed to the front surface, and is supplied with intake air through a silencer 28. An injector 58 for injecting fuel into the suction ports 21 is provided on an injector base 57 sandwiched between the cylinder head 15 and the intake manifold 22.
[0016]
A chain cover for accommodating a timing chain 30 (see FIG. 14) for transmitting the driving force of the crankshaft 13 to the valve train 27 on the upper surfaces of the cylinder block 11, the lower block 12, the crankcase 14, and the cylinder head 15 of the engine E. 31 (see FIG. 15), an oil pump body 34 is connected to the lower surfaces of the cylinder block 11, the lower block 12 and the crankcase 14, and a mount case 35 and an oil case 36 are further mounted to the lower surface of the oil pump body 34. , Extension case 37 and gear case 38 are sequentially coupled.
[0017]
The oil pump body 34 accommodates the oil pump 33 between the lower surface thereof and the upper surface of the mount case 35. The flywheel 32 is disposed between the oil pump body 34 and the lower surface of the cylinder block 11 and the like on the opposite side. The flywheel chamber and the oil pump chamber are defined by the pump body 34. The periphery of the oil case 36, the mount case 35 and a part of the lower side of the engine E is covered with a synthetic resin under cover 39, and the upper part of the engine E is joined to the upper surface of the under cover 39. It is covered with a cover 40.
[0018]
A drive shaft 41 connected to the lower end of the crankshaft 13 penetrates through the pump body 34, the mount case 35, and the oil case 36, extends downward inside the extension case 37, and has a propeller 43 at the rear end to be connected to the gear case 38. The front end of a propeller shaft 44 supported in the front-rear direction is connected via a forward-reverse switching mechanism 45 operated by a shift rod 52. A lower water supply passage 48 extending upward from a strainer 47 provided in the gear case 38 is connected to a cooling water pump 46 provided on the drive shaft 41, and an upper water supply pipe 49 extending upward from the cooling water pump 46 is connected to the oil case 36. Is connected to the cooling water passage 36b (see FIG. 6).
[0019]
As shown in FIG. 6, a cooling water supply hole 36a to which the upper end of the upper water supply pipe 49 is connected is formed in the lower surface 36L of the oil case 36. On the upper surface 36U of the oil case 36, a cooling water passage 36b connected to the cooling water supply hole 36a is formed so as to surround a part of a periphery of an exhaust pipe portion 36c formed integrally with the oil case. A cooling water passage 35a having the same shape as the cooling water passage 36b of the upper surface 36U of the oil case 36 coupled to the lower surface 35L of the mount case 35 is formed so as to surround a part of the periphery of the exhaust passage 35b penetrating the mount case 35. You.
[0020]
FIG. 7 shows the mount case 35 viewed from above, and an oil case 36 is coupled to the lower surface. A cooling water supply passage 35c... And a cooling water discharge passage 35d surround the outer periphery of the exhaust passage 35b. More specifically, a cooling water supply passage 35c (see FIG. 6) communicating with a cooling water passage 35a formed on the lower surface 35L of the mount case 35 so as to open downward is mounted on the cylinder block of the upper surface 35U of the mount case 35. It is formed so as to open upward on the upper surface outside the area of the surface and along the outer periphery of the cylindrical exhaust passage 35b. In the embodiment, the cooling water supply passages 35c are divided into three arc-shaped cooling water supply passages 35c by walls 35h that are continuous with the outer wall of the exhaust passage 35b. Further, a single arc-shaped cooling water drain passage 35d is formed in a range other than the installation range of the cooling water supply passages 35c on the outer periphery of the cylindrical exhaust passage 35b. Are defined by walls 35i formed on the outer wall.
[0021]
On an upper surface 35U of a mount case 35 coupled to a cylinder block subassembly including an oil pump body 34 described later, a cooling water supply passage 35e extends in the left-right direction of the outboard motor O across the center of the cylinder 17 in plan view, The upper surface 35U is formed in a U-shaped groove having a transverse cross section that opens upward (see FIG. 6). The cooling water passage 35a extends upward and communicates with the cooling water passage 35e. An upper surface 35U of the mount case 35 is provided with a relief valve 51 that opens when the pressure of the cooling water passage 35a becomes equal to or higher than a predetermined value to release the cooling water (see FIGS. 4 and 7).
[0022]
In addition, the cooling water discharge passage 35d is provided with an exhaust 36 formed inside the oil case 36, the extension case 37, and the gear case 38 through an opening 36e (see FIG. 7) formed in the entire lower surface 36L of the oil case 36. It communicates with the chamber 63. Further, the gasket 55 sandwiched between the lower surface 35L of the mount case 35 and the upper surface 36U of the oil case 36 has a punching process through which the cooling water dropped from the cooling water discharge passage 35d of the mount case 35 (see FIG. 7) passes. Holes 55a, and punching holes 55b, which partition a part of the expansion chamber 63 to exhibit a noise reduction effect, are provided (see FIGS. 6 and 7).
[0023]
Next, the structure of the exhaust passage 24 in the engine room will be described with reference to FIGS. 4 to 6 and FIGS.
[0024]
The exhaust passage means is roughly divided into an exhaust passage 24 portion in the engine room and an exhaust chamber portion partitioned from the engine room. The exhaust passage 24 in the engine room is connected to the right side surface of the cylinder head 15 as will be described later, and includes a single pipe portion 61a for introducing exhaust gas from each combustion chamber 20, and a collecting portion 61b which collects in a downstream region thereof. And an exhaust guide 62 connected to the exhaust manifold 61 and guiding exhaust gas to the outside of the engine room.
[0025]
As is clear from FIG. 6, the exhaust guide 62 is connected to the upper surface 35U of the mount case 35 constituting the partition of the engine room, and communicates with the exhaust passage 35b penetrating the mount case 35. The exhaust passage 35b communicates with an exhaust pipe portion 36c formed integrally with the oil case 36, and communicates with the exhaust chamber 63. In the embodiment, the oil case 36 configures the outer wall of the exhaust chamber 63 and also configures the exhaust pipe 36c. However, as another configuration, the exhaust pipe 36c may be a separate passage. The exhaust passage means may have a structure in which a part thereof is integrally continuous. However, by forming the exhaust passage 24 in the engine room and the external passage separately, it is possible to improve the assemblability of each part. It is possible to ensure the sealing performance with respect to the exhaust chamber 63.
[0026]
The upper part of the exhaust chamber 63 communicates with the outside of the under cover 39 via an exhaust outlet pipe 64 provided in the oil case 36, so that the exhaust gas is not discharged into the water when the engine E operates at a low load. The air is discharged to the atmosphere via the outlet pipe 64.
[0027]
The exhaust manifold 61 includes four single pipe portions 61a communicating with the four exhaust ports 23, and a collecting portion 61b in which the single pipe portions 61a collectively come together. Although the portion is in close contact with the side surface of the cylinder head 15, the center line thereof is bent by a distance α in a direction away from the side surface of the cylinder head 15 near the lower end of the collecting portion 61b (see FIG. 10). The exhaust guide 62 is curved in an S-shape, and the inner periphery of the lower end of the exhaust manifold 61 is fitted to the inner periphery of the large-diameter joint portion 62a via a pair of O-rings 53 and 54.
[0028]
As described above, only the lower end portion of the exhaust manifold 61 is bent in a direction away from the side surface of the cylinder head 15, and the other upper half portion of the exhaust manifold 61 is connected along the side surface of the cylinder head 15. In addition, it is possible to prevent the large-diameter coupling portion 62a from interfering with the cylinder head 15 while minimizing the arrangement space of the exhaust passage 24 in the engine room. In particular, since the lower portion of the exhaust manifold 61 is bent below the lowermost combustion chamber 20, the exhaust manifold 61 has an unbalanced effect on the flow of exhaust gas from the plurality of combustion chambers 20 arranged vertically. Is prevented, and a decrease in exhaust efficiency can be minimized.
[0029]
Further, since the connecting portion 62a of the exhaust manifold 61 and the exhaust guide 62 is fitted through the O-rings 53 and 54, the connecting operation of the exhaust manifold 61 and the exhaust guide 62 is not only simple, but also the exhaust in the engine room is easy. The dimensional error in the vertical direction of the passage 24 can be absorbed by the coupling portion 62a to improve the assembling property. In addition, since the upper end of the first exhaust guide cooling water jacket JM1 and the lower end of the exhaust manifold cooling water jacket JM2 are located near the O-rings 53 and 54, deterioration of the O-rings 53 and 54 due to heat is prevented. You.
[0030]
A flange 62b formed at the lower end of the exhaust guide 62 has three bolt holes 62c, three cooling water inlets 62e divided into an arc shape surrounding the exhaust passage 62d, and one cooling water outlet 62f. It is formed. When the flange 62b of the exhaust guide 62 is bolted to the mounting seat 35f (see FIG. 7) of the upper surface 35U of the mount case 35, the cooling water inlets 62e of the exhaust guide 62 communicate with the cooling water supply passages 35c of the mount case 35. At the same time, the cooling water outlet 62f communicates with the cooling water discharge passage 35d of the mount case 35. On the lower surface 35L side of the mounting case 35 of the mounting seat 35f, of the outer wall constituting the cooling water discharge passage 35d, the anti-exhaust passage 35b side is stopped at a position slightly higher than the gasket surface, and from between the lower surface of the outer wall and the gasket surface. Cooling water is drained onto gasket 55.
[0031]
The exhaust guide 62 is formed with a first exhaust guide cooling water jacket JM1 that covers a half circumference on the upper surface side and a second exhaust guide cooling water jacket JM3 that covers a half circumference on the lower surface side so as to surround the exhaust passage 62d. At the upper end of the exhaust guide 62, a part of the first exhaust guide cooling water jacket JM1 in the circumferential direction swells in the radial direction to form a swelling portion 62g.
[0032]
An exhaust manifold cooling water jacket JM2 is formed so as to surround the periphery of the exhaust manifold 61, and a through hole 61c extending in a circumferential direction is formed at a lower end thereof. Therefore, when the lower end of the exhaust manifold 61 is fitted to the inner periphery of the connecting portion 62a of the exhaust guide 62, the exhaust manifold cooling water jacket JM2 of the exhaust manifold 61 and the first exhaust guide cooling water jacket JM1 of the exhaust guide 62 become They communicate with each other via a through hole 61c of the exhaust manifold 61 and a bulging portion 62g of the exhaust guide 62 (see FIG. 13).
[0033]
As is clear from FIGS. 4 and 5, a joint 61d for distributing a part of the cooling water to the cylinder block 11 and a part of the cooling water are provided on the upper part of the exhaust manifold cooling water jacket JM2 of the exhaust manifold 61. A joint 61e for supplying the water to a water detection port 66 (see FIG. 2) via a hose 65 and a cooling water temperature sensor 67 for detecting the temperature of the cooling water are provided.
[0034]
Next, the structure of the cooling system of the cylinder block 11 will be described with reference to FIGS.
[0035]
The cooling water whose temperature has increased by passing through the first exhaust guide cooling water jacket JM1 of the exhaust guide 62 and the exhaust manifold cooling water jacket JM2 of the exhaust manifold 61 and cooling the exhaust passage 24 in the engine room is discharged from the exhaust manifold 61. The water is supplied from the joint 61d provided at the upper end of the manifold cooling water jacket JM2 to the T-shaped three-way joint or the branching member 69 via the water supply pipe 68, and is branched therefrom into two water supply pipes 70 and 71. The cylinder block 11 is formed with a cylinder block cooling water jacket JB surrounding the four cylinders 17. Joints 11a and 11b are provided at a position near the upper end of the cylinder block cooling water jacket JB (the side of the second combustion chamber 20 from the top) and a position near the lower end (the side of the lowest combustion chamber 20). The upper water supply pipe 70 is connected to the upper joint 11a, and the lower water pipe 71 is connected to the lower joint 11b. As described above, since the exhaust manifold cooling water jacket JM2 and the cylinder block cooling water jacket JB are connected by the water supply pipes 68, 70, 71, the cooling water supply passage is formed inside the cylinder block 11 or the cylinder head 15. Processing becomes easier.
[0036]
A slit-shaped cooling water passage 34a (see FIG. 8) formed to penetrate the pump body 34 is connected to a slit-shaped cooling water passage 35e (see FIG. 7) formed to penetrate the mount case 35. A cooling water passage 11c formed on the lower surface of the cylinder block 11 and having the same mating surface shape as the cooling water passage 35e and extending in the left-right direction so as to straddle the center of the cylinder 17 in the left-right width direction (see FIG. 9). ). As shown in FIGS. 3 and 9, the cooling water passage 11c of the cylinder block 11 is a groove having an open lower surface, and is provided with two through holes 11d and 11e penetrating the upper wall of the groove. 11 communicates with the lower end of the cylinder block cooling water jacket JB.
[0037]
As is clear from FIG. 3, the cooling water flowing through the cylinder block cooling water jacket JB of the cylinder block 11 is supplied to a thermostat described later through a cooling water passage 11f formed on the upper left side of the cylinder block 11.
[0038]
Next, the structure of the cooling system of the cylinder head 15 will be described with reference to FIGS.
[0039]
Two short cooling water passages 11g and 11h are branched from the side wall of the slit-shaped cooling water passage 11c formed on the lower surface of the cylinder block 11 toward the cylinder head 15, and the cooling water passages 11g and 11h are connected to the cylinder block. The gasket 56 between the cylinder head 11 and the cylinder head 15 communicates with the cylinder head cooling water jacket JH of the cylinder head 15. The cylinder block cooling water jacket JB surrounding the cylinders 17 of the cylinder block 11 is isolated from the cylinder head cooling water jacket JH of the cylinder head 15 via a gasket 56 interposed on the coupling surface between the cylinder block 11 and the cylinder head 15. (See FIGS. 2 and 6).
[0040]
Next, the thermostat provided in the cooling water circulation system will be described.
[0041]
As shown in FIG. 14, a timing chain 30 is provided between a cam drive sprocket 72 provided at the upper end of the crankshaft 13 and cam driven sprockets 75, 75 provided on a pair of camshafts 73, 74 located at the rear of the cylinder head 15. Can be wrapped around. The hydraulic chain tensioner 76a contacts the slack side of the timing chain 30, and the chain guide 76b contacts the opposite side. The number of teeth of the cam drive sprocket 72 is half the number of teeth of the cam driven sprockets 75, 75, so that the camshafts 73, 74 rotate at half the number of revolutions of the crankshaft.
[0042]
A balancer device 77 is housed in the crankcase 14, and a balancer driven sprocket 80 provided on one of the two balancer shafts 78 and 79 and a balancer drive sprocket 81 provided on the crankshaft 13 are provided with an endless chain 82. Is wrapped around. The chain tensioner 83a contacts the loose side of the endless chain 82, and the chain guide 63b contacts the opposite side. The number of teeth of the balancer driving sprocket 81 is twice the number of teeth of the balancer driven sprocket 80, and therefore, the balancer shafts 78 and 79 rotate at twice the number of rotations of the crankshaft 13.
[0043]
As apparent from FIGS. 15 to 18, the upper surfaces of the cylinder block 11 and the cylinder head 15 are covered with a chain cover 31, and the timing chain 30 is housed inside the chain cover 31. In order to lubricate the timing chain 30, the inside of the chain cover 31 is maintained in an oil atmosphere. The thermostat mounting seat 31a formed on the chain cover 31 so as to straddle the coupling surface of the cylinder block 11 and the cylinder head 15 has a lower surface abutting on the upper surfaces of the cylinder block 11 and the cylinder head 15 and an upper surface thereof having a chain shape. It is one step higher than the upper surface of the main body of the cover 31. The chain cover 31 is provided with an engine speed sensor 59 for detecting the speed of the crankshaft 13 (see FIG. 15).
[0044]
In the thermostat mounting seat 31a of the chain cover 31, cooling water passages 31b and 31c communicating with the cooling water passage 11i branched upward from the cylinder block cooling water jacket JB of the cylinder block 11, and the cylinder head cooling water jacket of the cylinder head 15 are provided. Cooling water passages 31d and 31e communicating with a cooling water passage 15a branched from the JH are formed. A first thermostat 84 on the cylinder block 11 side is attached to the cooling water passage 31c, and a cylinder is provided in the cooling water passage 31e. The second thermostat 85 on the head 15 side is attached. The first thermostat 84 having the valve body 84a and the second thermostat 85 having the valve body 85a are housed in thermostat chambers 94 and 95, respectively, and are fixed to the upper surface of the thermostat mounting seat 31a by three bolts 86. Is covered with a thermostat cover 87. A joint 87a provided on the thermostat cover 87 is connected to the second exhaust guide cooling water jacket JM3 via a drain pipe 88 via a joint 62h provided on the exhaust guide 62.
[0045]
A cooling water temperature sensor 89 is provided in the cooling water passage 31e of the chain cover 31 facing the second thermostat 85 on the cylinder head cooling water jacket JH side.
[0046]
As described above, the combustion gas in the combustion chambers 20 blocked by the intake valves 25 and the exhaust valves 26 is the first heat source, and the exhaust gas flowing to the outside through the exhaust passage 24 in the engine room is used as the first heat source. The second heat source, the cylinder head cooling water jacket JH and the cylinder block cooling water jacket JB are the first cooling means for cooling the first heat source, and exchange heat with the first cooling means. After that, the second cooling means cools the second heat source, and the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 correspond thereto.
[0047]
Next, the structure of the lubrication system of the engine E will be described with reference to FIGS. 3, 4, and 6 to 9. FIG.
[0048]
The oil case 36 is integrally provided with an oil pan 36d, and accommodates a suction pipe 92 having an oil strainer 91 therein. The oil pump 33 is provided with an oil suction passage 33a, an oil discharge passage 33b, and an oil relief passage 33c. The oil suction passage 33a is connected to a suction pipe 92, and the oil discharge passage 33b is formed on the lower surface of the cylinder block 11. The oil relief passage 33c is connected to each lubricated portion of the engine E via an oil supply hole 11m (see FIG. 9), and discharges return oil from the oil pump 33 into an oil pan 36d.
[0049]
Part of the return oil from the valve train 27 provided inside the cylinder head 15 and the head cover 16 is partially returned to the oil return passage 35g (FIG. 7) through the joint 16a, the oil hose 93, and the mount case 35 provided in the head cover 16. The other part of the return oil from the valve mechanism 27 is returned to the oil pan 36d through the oil return passage 15b (see FIG. 9) formed in the cylinder head 15, the cylinder block 11, and the cylinder head 15. An oil return passage 11j (see FIG. 9), an oil return passage 11k (see FIG. 9) penetrating through the cylinder block 11, an oil return passage 34b (see FIG. 8) penetrating through the pump body 34, and a mounting case. The oil pan 36d passes through an oil return passage 35g (see FIG. 7) penetrating through the oil pan 36d. It is. The oil return passage 11j opening in the gasket 56 between the cylinder block 11 and the cylinder head 15 is disposed so as to be sandwiched between the two cooling water passages 11g and 11h opening there (see FIG. 3).
[0050]
The return oil from the crankcase 14 is returned to the oil pan 36d via an oil return passage (not shown) penetrating the pump body 34 and an oil return passage 35g (see FIG. 7) penetrating the mount case 35.
[0051]
Next, the operation of the embodiment of the present invention having the above configuration will be described mainly with reference to the cooling water circuit of FIG.
[0052]
When the drive shaft 41 connected to the crankshaft 13 rotates by the operation of the engine E, the cooling water pump 46 provided on the drive shaft 41 operates, and the cooling water sucked up through the strainer 47 is supplied to the lower water supply passage 48 and the upper water supply passage 48. The oil is supplied to a cooling water supply port 36 a on the lower surface of the oil case 36 via a water supply pipe 49. The cooling water that has passed through the cooling water supply port 36a flows into the cooling water passage 36b on the upper surface 36U of the oil case 36 and the cooling water passage 35a on the lower surface 35L of the mount case 35, and a part of the cooling water branched therefrom is supplied to the engine room. The air is supplied to the first exhaust guide cooling water jacket JM1 formed in the exhaust guide 62 of the inner exhaust passage 24 and the exhaust manifold cooling water jacket JM2 formed in the exhaust manifold 61. The exhaust gas discharged from the combustion chambers 20 of the cylinder head 15 is supplied to the single pipe portions 61a and the collecting portion 61b of the exhaust manifold 61, the exhaust passage 62d of the exhaust guide 62, the exhaust passage 35b of the mount case 35, and the oil case 36. The cooling water discharged into the exhaust chamber 63 through the exhaust pipe portion 36c and flowing through the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 through the exhaust passage 24 in the engine room, which is heated by the exhaust gas at that time. Cool with.
[0053]
The cooling water, which flows upward from the bottom through the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 and has a slightly raised temperature, passes through a water supply pipe 68 and a branch member 69 from a joint 61d provided at the upper end of the exhaust manifold 61. The water is branched into two water supply pipes 70 and 71, and flows into lower and upper sides of the side surface of the cylinder block cooling water jacket JB via joints 11a and 11b provided on the cylinder block 11. At this time, part of the low-temperature cooling water in the cooling water passages 36b and 35a passes through the two through holes 11d and 11e that open to the cooling water passage 11c at the lower end of the cylinder block 11, and is supplied to the cylinder block cooling water jacket JB. It flows into the lower end. A part of the low-temperature cooling water in the cooling water passages 36b and 35a flows from the cooling water passage 11c at the lower end of the cylinder block 11 to the lower end of the cylinder head cooling water jacket JH via the two cooling water passages 11g and 11h. .
[0054]
During the warm-up operation of the engine E, the first thermostat 84 connected to the upper end of the cylinder block cooling water jacket JB and the second thermostat 85 connected to the upper end of the cylinder head cooling water jacket JH are closed, and the first exhaust guide cooling is performed. The cooling water in the water jacket JM1, the exhaust manifold cooling water jacket JM2, the cylinder block cooling water jacket JB, and the cylinder head cooling water jacket JH stays without flowing, and the warm-up of the engine E is promoted. At this time, the cooling water pump 46 continues to rotate, but the cooling water pump 46 substantially idles due to leakage of the cooling water from around the rubber impeller.
[0055]
When the warming-up operation of the engine E is completed and the temperature of the cooling water rises, the first and second thermostats 84 and 85 open, and the cooling water of the cylinder block cooling water jacket JB and the cooling water of the cylinder head cooling water jacket JH become Flows from the common joint 87a of the thermostat cover 87 to the second exhaust guide cooling water jacket JM3 through the drain pipe 88 and the joint 62h of the exhaust guide 62. Then, the cooling water that has cooled the exhaust guide 62 while flowing through the second exhaust guide cooling water jacket JM3 passes through the mount case 35 and the oil case 36 from top to bottom and is discharged to the exhaust chamber 63. When the rotation speed of the engine E increases and the internal pressure of the cooling water passages 36b, 35a becomes equal to or higher than a predetermined value, the relief valve 51 is opened and excess cooling water is discharged to the exhaust chamber 63.
[0056]
Further, a joint 61e provided at an upper end of the exhaust manifold cooling water jacket JM2 of the exhaust manifold 61 is connected to a water detection port 66 via a hose 65, and the water is ejected from the water detection port 66 to check the circulation of the cooling water. can do. Since the joint 61e connected to the water inspection port 66 is provided at the upper end of the exhaust manifold cooling water jacket JM2, the air staying in the exhaust manifold cooling water jacket JM2 can be discharged from the water inspection port 66 together with the cooling water. As described above, since the air in the exhaust manifold cooling water jacket JM2 is discharged by using the water detection port 66, it is not necessary to provide a pipe and an air discharge port for discharging the air. This can contribute to a reduction in man-hours.
[0057]
Moreover, since the exhaust manifold 61 and the water detection port 66 are provided on one side of the outboard motor O and on the other side of the outboard motor O, respectively, even if the water detection port 66 is located lower than the exhaust manifold 61, the exhaust manifold 61 can detect the water. The air in the exhaust manifold 61 can be smoothly pushed out to the water detection port 66 by increasing the distance to the water port 66 and weakening the downward slope.
[0058]
In this embodiment, the exhaust manifold cooling water jacket JM2 communicates with the cylinder block cooling water jacket JB, and the cooling water flowing through the first exhaust guide cooling water jacket JM1, the exhaust manifold cooling water jacket JM2, and the cylinder block cooling water jacket JB. The flow rate is controlled by the first thermostat 84. Assuming that the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 are not in communication with the cylinder block cooling water jacket JB and are at a dead end, the water sampling port 66 is increased in diameter and the exhaust manifold cooling water jacket is made larger. It is necessary to discharge the entire amount of the cooling water discharged from the JM 2 or to provide a cooling water discharge port separate from the water detection port 66 to discharge the cooling water. There is a problem that the load on the device increases. However, according to this embodiment, the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM1 and the exhaust manifold cooling water jacket JM1 are communicated with the cylinder block cooling water jacket JB by connecting the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2. The load on the cooling water pump 46 can be reduced by eliminating the need to wastefully discharge the cooling water that has passed through the jacket JM2.
[0059]
In addition, the cylinder block cooling water jacket JB and the cylinder head cooling water jacket JH are made independent of each other, and low-temperature cooling water is directly supplied to the cylinder head cooling water jacket JH, which tends to overheat during the operation of the engine E, and during the operation of the engine E The cooling water whose temperature has risen through the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2 is supplied to the cylinder block cooling cooling water jacket JB, which tends to be excessively cooled, so that the cylinder head 15 and the cylinder block are cooled. 11 can be cooled to an appropriate temperature to maximize the performance of the engine E. In addition, since the thermostats 84 and 85 are provided on the cylinder block cooling water jacket JB and the cylinder head cooling water jacket JH, respectively, the settings of the thermostats 84 and 85 are changed, so that the cylinder block cooling water jacket JB and the cylinder head cooling water JB. The temperature of the cooling water of the jacket JH can be controlled independently and arbitrarily.
[0060]
By the way, when the cooling water is supplied from the lower end of the cylinder block cooling water jacket JB extending vertically and discharged from the upper end, the distribution of the cooling water temperature becomes lower at the lower part and becomes higher at the upper part. The cooling performance of the water jacket JB may be uneven in the vertical direction. However, according to the present embodiment, the cooling performance of the cylinder block cooling water jacket JB is increased and decreased by supplying the cooling water from the exhaust manifold cooling water jacket JM2 to two vertically separated locations of the cylinder block cooling water jacket JB. It can be made uniform in the direction.
[0061]
Also, even if new cooling water is supplied due to a rapid increase in the engine speed, the cooling water rises in temperature through the first exhaust guide cooling water jacket JM1 and the exhaust manifold cooling water jacket JM2, and the cylinder block cooling water jacket is heated. Since it is supplied to the JB, it is possible to reduce a sudden change in the temperature around the combustion chambers 20.
[0062]
Furthermore, cooling water is supplementarily supplied to the lower end of the cylinder block cooling water jacket JB through the two through holes 11d and 11e to prevent cooling water from remaining in the cylinder block cooling water jacket JB and perform cooling. The uniformity of performance can be further promoted, and since the through holes 11d and 11e are provided at the lower end of the cylinder block cooling water jacket JB, the treatment of residual water when the engine is stopped is easy.
[0063]
Furthermore, the supply of the cooling water from the cooling water passages 36b, 35a to the cylinder head cooling water jacket JH is not performed via the external piping, but between the cooling water passages 11g, 11h formed in the cylinder block 11 and the cylinder head 15. In this case, the cooling water passages 11g and 11h need not be specially assembled, and the number of parts can be reduced by omitting the external piping. Further, since the cooling water passages 11g and 11h can be sealed using the gasket 56 sandwiched between the cylinder block 11 and the cylinder head 15, a special sealing member is not required, and the number of parts is reduced. Moreover, since the cooling water passages 11g and 11h are provided at the lower end of the cylinder head cooling water jacket JH, it is easy to treat residual water when the engine is stopped.
[0064]
In particular, since two cooling water passages 11g and 11h for passing the cooling water from the cylinder block cooling water jacket JB to the cylinder head cooling water jacket JH are separately provided on the left and right sides, the cooling water passages 11g and 11h are provided on the left and right sides of the cylinder head cooling water jacket JH. Cooling water can be evenly supplied to enhance the cooling effect. Further, since the oil return passage 11j for guiding the return oil from the cylinder head 15 is provided between the two cooling water passages 11g and 11h, the flow rate of the cooling water flowing through the two cooling water passages 11g and 11h is unbalanced. , And the oil return passage 11j provided at the lowermost portion of the cam chamber can be compactly arranged in a narrow space.
[0065]
Further, the cooling water is a branch formed inside the cylinder block 11 by forming through holes 11d and 11e communicating with the cylinder block cooling water jacket JB and cooling water passages 11g and 11h communicating with the cylinder head cooling water jacket JH. Since the branch is made in the passage 11c, it is not necessary to provide a special seal member at the branch, and the number of parts is reduced.
[0066]
By the way, if the temperature of the cooling water rises abnormally during the operation of the engine E, a warning is issued that the engine E may be overheated. In this embodiment, a cooling water temperature sensor 67 of a cooling system including the first exhaust guide cooling water jacket JM1, the exhaust manifold cooling water jacket JM2, and the cylinder block cooling water jacket JB is provided at the upper end of the exhaust manifold cooling water jacket JM2. A cooling water temperature sensor 89 for a cooling system including a cylinder head cooling water jacket JH is provided near the second thermostat 85.
[0067]
As described above, a total of four water jackets of the first exhaust guide cooling water jacket JM1, the exhaust manifold cooling water jacket JM2, the cylinder block cooling water jacket JB, and the cylinder head cooling water jacket JH are separated into two systems. One cooling water temperature sensor 67 may be provided for one exhaust guide cooling water jacket JM1, the exhaust manifold cooling water jacket JM2, and the cylinder block cooling water jacket JB, and the cooling water temperature is provided for each of the four water jackets. The number of components can be reduced as compared with the case where a sensor is provided.
[0068]
In particular, of the first exhaust guide cooling water jacket JM1, the exhaust manifold cooling water jacket JM2, and the cylinder block cooling water jacket JB, the cooling water temperature sensor 67 is provided to the exhaust manifold cooling water jacket JM2 upstream of the cylinder block cooling water jacket JB. Is provided, it is possible to quickly detect an abnormal rise in the temperature of the cooling water. Further, since the cooling water temperature sensor 67 of the exhaust manifold cooling water jacket JM2 is provided near the joint 61e connected to the water detecting port 66, the cooling water flows toward the water detecting port 66, so that the cooling water temperature sensor 67 is positioned near the cooling water temperature sensor 67. It is possible to prevent the cooling water from staying, and to improve the temperature detection accuracy of the cooling water.
[0069]
A first thermostat 84 for controlling the discharge of the cooling water from the cylinder block cooling water jacket JB and a second thermostat 85 for controlling the discharge of the cooling water from the cylinder head cooling water jacket JH are provided on a crankshaft on the upper surface of the engine E. Since it is provided on the upper wall of the chain cover 31 that covers the timing chain 30 that connects the camshaft 73 and the camshafts 73 and 74, it is possible to remove the engine cover 40 only by removing the engine cover 40 without disturbing the chain cover 31 and the timing chain 30. First, the second thermostats 84 and 85 can be easily maintained from above.
[0070]
Cooling water passages 31b and 31c connecting the cylinder block cooling water jacket JB to the first thermostat 84 and cooling water passages 31d and 31e connecting the cylinder head cooling water jacket JH to the second thermostat 85 are formed in the chain cover 31. Therefore, the number of components can be reduced as compared with the case where connection is made via external piping. Further, since the outlet sides of the first and second thermostats 84 and 85 are connected to the second exhaust guide cooling water jacket JM3 through the common drain pipe 88, a passage for discharging the cooling water inside the engine E is formed. In addition to eliminating the necessity to perform the processing, the number of drain pipes 88 can be reduced to one and the number of parts can be reduced.
[0071]
A chain in which the first thermostat 84 on the cylinder block 11 side and the second thermostat 85 on the cylinder head 15 side are arranged close to each other, and are connected via a packing surface common to the cylinder block 11 and the cylinder head 15. Since the first and second thermostats 84 and 85 are mounted on the cover 31, the first and second thermostats 84 and 85 can be mounted compactly in a small space. In particular, since the thermostat chambers 94 and 95 for accommodating the first and second thermostats 84 and 85 are disposed above the rotation plane of the timing chain 30, the size of the thermostat chambers 94 and 95 is reduced while avoiding mutual interference. be able to. In addition, since the cooling water passages 31b and 31d connected to the thermostat chambers 94 and 95 are arranged in the loop of the timing chain 30, dead space is effectively used, and it is possible to reduce the size of the cooling chain while avoiding mutual interference and to make it compact. Can be.
[0072]
Further, since the cooling water is led out from the uppermost part of the cylinder block cooling water jacket JB and the uppermost part of the cylinder head cooling water jacket JH, it is easy to derive the cooling water.
[0073]
Further, since the upper joint 11a for supplying the cooling water to the cylinder block cooling water jacket JB is provided not at the side of the uppermost combustion chamber 20 but at the side of the second combustion chamber 20 from the top, It is possible to prevent the cooling water supplied from 11a from acting improperly by acting on the first thermostat 84 at a low temperature. In order to properly operate the first thermostat 84, the position of the joint 11a needs to be arranged at least below the uppermost vertical center position of the uppermost combustion chamber 20.
[0074]
The embodiments of the present invention have been described above. However, various design changes can be made in the present invention without departing from the gist thereof.
[0075]
For example, in the embodiment, the multi-cylinder water-cooled vertical engine E is illustrated, but the present invention can be applied to a single-cylinder water-cooled vertical engine.
[0076]
【The invention's effect】
As described above, according to the first or second aspect of the invention, the cylinder block cooling water jacket and the cylinder head cooling water jacket are made substantially independent, and the cylinder block cooling water jacket is provided downstream of the exhaust passage cooling water jacket. To prevent overheating by supplying low-temperature cooling water to the cylinder head cooling water jacket, which is likely to become hot, and to pass through the exhaust passage cooling water jacket to the cylinder block cooling water jacket, which tends to overcool. The supercooling can be prevented by supplying the raised cooling water.
[0077]
In addition, one cooling water temperature sensor is provided for the exhaust passage cooling water jacket and the cylinder block cooling water jacket constituting the first cooling system among the exhaust passage cooling water jacket, the cylinder block cooling water jacket, and the cylinder head cooling water jacket. And one cooling water temperature sensor is provided for the cylinder head cooling water jacket constituting the second cooling system, so that the number of cooling water temperature sensors is minimized to reduce the number of parts and cost. can do. Particularly, of the exhaust passage cooling water jacket and the cylinder block cooling water jacket connected in series, the cooling water temperature sensor is provided on the upstream exhaust passage cooling water jacket, so that the occurrence of overheating can be detected without delay. .
[Brief description of the drawings]
FIG. 1 is an overall side view of an outboard motor. FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1. FIG. 3 is an enlarged sectional view taken along line 3-3 of FIG. 2. FIG. FIG. 5 is a view in the direction of arrow 5 in FIG. 4 FIG. 6 is an enlarged sectional view of a main part in FIG. 1 FIG. 7 is an enlarged view of arrow 7-7 in FIG. 1 (top view of the mount case)
FIG. 8 is an enlarged view taken along line 8-8 of FIG. 1 (a bottom view of the pump body).
FIG. 9 is an enlarged view taken along line 9-9 of FIG. 1 (a bottom view of a small assembly such as a block).
FIG. 10 is an enlarged view of an exhaust manifold. FIG. 11 is an enlarged view of a connection portion between an exhaust manifold and an exhaust guide. FIG. 12 is a view taken along line 12-12 of FIG. 14 (a plan view of the exhaust guide).
13 is a sectional view taken along line 13-13 of FIG. 14; FIG. 14 is an enlarged view taken along line 14-14 of FIG. 1; FIG. 15 is an enlarged view taken along line 15-15 of FIG. FIG. 17 is a sectional view taken along line 17-17 of FIG. 16; FIG. 18 is a sectional view taken along line 18-18 of FIG. 16; FIG. 19 is a circuit diagram of an engine cooling system.
11 Cylinder block 13 Crankshaft 15 Cylinder head 20 Combustion chamber 24 Exhaust passage in engine room (exhaust passage means)
46 cooling water pump 67 cooling water temperature sensor 89 cooling water temperature sensor JM1 first exhaust guide cooling water jacket (exhaust passage cooling water jacket)
JM2 Exhaust manifold cooling water jacket (Exhaust passage cooling water jacket)
JB Cylinder block cooling water jacket JH Cylinder head cooling water jacket

Claims (2)

A plurality of combustion chambers (20) arranged along a generally vertically extending crankshaft (13);
An exhaust passage cooling water jacket (JM1, JM2) provided in an exhaust passage means (24) for guiding exhaust gas from the combustion chamber (20) to the outside;
A cylinder block cooling water jacket (JB) provided on the cylinder block (11) to cool the periphery of the combustion chamber (20);
A cylinder head cooling water jacket (JH) provided on the cylinder head (15) to cool the periphery of the combustion chamber (20);
A cooling water pump (46) for supplying cooling water to each of the water jackets (JM1, JM2, JB, JH);
A water-cooled vertical engine with
The cylinder block cooling water jacket (JB) and the cylinder head cooling water jacket (JH) are made almost independent, and the cylinder block cooling water jacket (JB) is connected to the downstream side of the exhaust passage cooling water jackets (JM1 and JM2). A water-cooled vertical engine, wherein cooling water temperature sensors (67, 89) for detecting the temperature are provided in the exhaust passage cooling water jackets (JM1, JM2) and the cylinder head cooling water jacket (JH), respectively. A plurality of combustion chambers (20) arranged along a generally vertically extending crankshaft (13);
An exhaust passage cooling water jacket (JM1, JM2) provided in an exhaust passage means (24) for guiding exhaust gas from the combustion chamber (20) to the outside;
A cylinder block cooling water jacket (JB) provided on the cylinder block (11) to cool the periphery of the combustion chamber (20);
A cylinder head cooling water jacket (JH) provided on the cylinder head (15) to cool the periphery of the combustion chamber (20);
A cooling water pump (46) for supplying cooling water to each of the water jackets (JM1, JM2, JB, JH);
An outboard motor equipped with a water-cooled vertical engine having
The cylinder block cooling water jacket (JB) and the cylinder head cooling water jacket (JH) are made almost independent, and the cylinder block cooling water jacket (JB) is connected to the downstream side of the exhaust passage cooling water jackets (JM1 and JM2). A water-cooled vertical engine is provided, characterized in that cooling water temperature sensors (67, 89) for detecting pressure are provided on the exhaust passage cooling water jackets (JM1, JM2) and the cylinder head cooling water jacket (JH), respectively. Outboard motor.

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