JPS61167115A - Cooling device of engine - Google Patents

Abstract

PURPOSE:To keep optimum temperature by separating cooling water temperature control systems of a cylinder head and a cylinder block in an engine in which a crank shaft is disposed in the longitudinal direction. CONSTITUTION:In an engine in which a crank shaft of an outboard unit in the longitudinal direction, a cooling water path 17a flowing in a cooling jacket in a cylinder head 17 and a cooling water path 19a flowing in a cooling jacket in a cylinder block 19 are provided separately, and cooling water from a cooling water pump 28 is flowed. And valves T1, T2 controlling flow rate recording to the temperature are provided on outlets of respective paths, and the setting temperature T2 of the valve T1 is lowered to keep the temperature of the cooling water of the cylinder head working to cool the intake air low and the setting temperature t3 of the valve T2 is raised to keep the temperature of the cooling path of the cylinder block working to control the temperature in a combustion chamber high.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a cooling device for an engine used, for example, in an outboard motor.

(Prior Art) Generally, an outboard motor draws in seawater as cooling water, and the engine is directly cooled by the drawn seawater. For this reason, there is a tendency that the cylinder block portion, which generates relatively little heat M, becomes overcooled.

Incidentally, in recent years, diesel engine outboard motors using diesel engines have been developed. When the above-mentioned direct seawater cooling structure is applied to this diesel engine outboard motor, the following problems occur. 1- That is, diesel fuel contains sulfur, and when the sulfur is burned, sulfur dioxide gas is generated. If a diesel engine, which is filled with sulfur dioxide gas, is directly cooled with relatively low-temperature seawater, the cylinder liner, etc., will become extremely low temperature, avoiding condensation of the sulfur dioxide gas and producing sulfuric acid, causing so-called sulfuric acid corrosion. A problem occurs. This problem is especially noticeable at low loads when the amount of heat generated from the diesel engine is small.When using a diesel engine outboard motor for work, it is often used at low load conditions, so sulfur Fl! 2. There is a problem that the wear of the cylinder liner due to corrosion increases.

It is also well known that keeping the cylinder head temperature low increases volumetric efficiency due to the low intake air temperature, and keeping the cylinder block at an appropriate humidity reduces mechanical loss, resulting in an engine with low fuel consumption and alpine horns. There is a need for a cooling device that can sufficiently cool the cylinder head and prevent overcooling of the cylinder block.

(Object of the Invention) An object of the present invention is to provide an engine cooling device that can sufficiently cool a cylinder head that generates a large amount of heat and can prevent overcooling of a cylinder block.

(Structure of the Invention) The present invention provides an engine in which a crank 11 is arranged vertically and a cylinder head and a cylinder block are arranged horizontally in parallel. This is an engine cooling device characterized in that it is formed by H and is provided with a mostat for individually controlling the cooling water temperature of each cooling water jacket.

(Example) In FIG. 1 showing the case where the present invention is applied to a diesel engine and installed in an outboard motor, 10 is a hull, and the rearmost part of the hull 10 is connected to a diesel engine boat through brackets 1 to 12. An external engine 14 is attached. The diesel engine outboard IN1/I has a structure in which a diesel engine 16 and drive units 1 to 18 are combined, the diesel engine 16 is covered with a cowling 20, and the drive unit 18 is provided with a propeller 22.

The diesel engine outboard 114 is rotatably mounted around the axis 2/I of the bracket 12 via an arm 23 stacked on the bracket 12, and is used for tilting the propeller 22 out of the water or as a drive unit. If the diesel engine outboard motor 18 collides with an obstacle such as a rock, the diesel engine outboard motor 14 can rotate about the shaft 24.

The diesel engine 16 is fixed with the crankshaft 15 arranged vertically, and the diesel engine 16
The cylinder head 17 and cylinder block 19 are arranged in parallel in the lateral direction. The cooling water jacket 17a of the cylinder head 17 is formed to allow cooling water to flow in the vertical direction, and the cooling water jacket 19a of one cylinder block is similarly formed.

The seawater supplied to the cooling water jackets 17a, 19a is pumped by a seawater pump 28 in the drive unit 18, and after cooling is discharged into the water through a passage 30 in the drive unit 18. An exhaust pipe 32 of the diesel engine 16 also opens into the passage 30.

A first embodiment of the cooling system for the diesel engine 16 will be described with reference to FIG. In this embodiment, the temperature of the seawater flowing through the cooling water jacket 17a is controlled to t2, and the temperature of the seawater flowing through the cooling water jacket l-19a is controlled to t3 (t2<
t3).

The seawater pumped up by the seawater pump 28 has a low temperature, tQ (t2>tO). cylinder head 17
A cooling water population 17b is formed in the upper part of the cylinder head 17, and a cooling water outlet 17C is formed in the lower part of the cylinder head 17.
The seawater pump 28 and the cooling water population 17b are connected to the passage 1!1. O
connected with. A thermostat T1 is provided near the cooling water outlet 17c, and the valve opening temperature of the thermostat T1 is set to t2. Thermostat T1
and the cooling water population 19b of the cooling water jacket 19a is the passage 4.
2, and a cooling water port 19b is provided at the bottom of the cylinder block 19. Cooling water jacket 1
An auxiliary cooling water outlet 19G and a main cooling water outlet 19d are provided at the upper end of 9a, and a thermostat T2 is arranged near the auxiliary cooling water outlet 19c. In addition, the main cold I
Install Mostat T1 near JI water outlet 19d
No is fine.

Therefore, cooling water di(r kerato cylinder head 1 fa has cold 2J) water ["+ 17 b to cold III water [-
Sea water flows downward towards 1170, cold JJl water 1? The shells 1 to 19a have a structure in which seawater flows upward from the cooling head D19b to the main cold IJ water outlet 19d.

The valve opening temperature of the thermostat T2 is 3, one end of the passage 44 is connected to the thermostats 1 to T2, and the passage/I
The other end of 4 is connected to a passage 30 (FIG. 1).

When a thermostat T1 (valve opening temperature 1'2) is provided near the main cooling water outlet 19d, one end of the passage 46 is connected to the thermostat T1, and the other end of the passage 16 is connected to the passage 46.
/I is connected in the middle. A switching valve 48 is interposed in the middle of the passage 46, and when the cylinder block 19 generates a large amount of heat under high load, the switching valve 48 is opened to supply seawater with a humidity of 1-2 to the cooling water jacket 19a. When the load is low, such as during idling, when the amount of heat generated by one cylinder block is small, the switching valve 48 is closed to allow seawater at a temperature of 13 to flow into the cooling water jacket 19a.

The switching valve 48 is opened and closed manually or automatically.

Normally, the thermostat T1 is installed at the cooling water inlet 17b (in the case of a standalone system, the thermostat T1 is not installed at the main cooling water outlet 19d, and the thermostat T1 is installed at either the cooling water inlet 17b1 or the main cooling water outlet 19d). Set up.

Passage 4. /I and passageway/1. 0 are communicated through a bypass passage 50, and the end of the bypass passage 50 is connected to a water test hole (not shown) for confirming normal operation of the cooling water pump.

The lower end of the passage 52 is connected to the upper part of the cooling water jacket 17a, and the upper end of the passage 52 is connected to the middle of the passage 44. A float valve 54 for air removal is interposed in the middle of the passage 52, and the air remaining in the cooling water jacket 17a is discharged from the float valve 54.

Further, the upper end of a drain passage 58 having a throttle 56 is connected to the lower part of the cooling water jacket 17a, and the lower end of the drain passage 58 is connected to the middle of the passage 42.

The lower end of a passage 62 having a float valve 60 for air bleeding is also connected to the upper part of the cooling water jacket 19a.
The upper end of the passage 62 is connected to the middle of the passage 44. A passage 66 having a check valve 64 is also connected between the passage 42 and the bypass passage 50. A throttle 68 is interposed near the left side in the figure of the connection point p between the passage 66 and the bypass passage 50, and the switching valve 48 is in the closed state and the thermostat +-
Even when T1 is open and thermostat T2 is closed, the pressure of seawater from the cooling water jacket 17a closes the check valve 6.
4 does not open, and the seawater in the cooling water jackets 1 to 17a stays in the cooling water jacket 17a until the temperature reaches T3, at which the thermostat T2 opens.

Also, when cooling water jacket 17 is stopped, cooling water jacket 17
It is common for outboard motors to discharge the seawater in the a1 cooling water jack 19a, but the Diekel engine 16
When the system stops, the check valve 64 opens due to the weight of the seawater, and the passage 3
It is designed to be discharged to 0.

Next, the effect will be explained. First, if the throttle 68 is provided on the left side, when the switching valve 48 is closed, for example during idling,
The temperature of the cooling water jacket 19a is controlled at T3. That is, at a temperature of 10, the cooling water population 17b from the seawater pump 28
The seawater that has flowed into the cooling water jacket 17a mixes with the relatively high temperature seawater that has gathered at the upper part due to the convection phenomenon in the cooling water jacket 17a, and reaches a temperature of tl. The temperature of the seawater that has flowed into the cooling water jacket 17a rises from tl to 12 with a relatively small temperature gradient, and at the temperature of T2, the thermostat T1 of the cylinder head 17 opens, but the check valve 64 : The valve remains closed, and the thermostats 1 to T2 of the cylinder block 19 also remain closed, and the seawater remains stagnant. As it cools down, the temperature of the jacket 19a rises, reaching the temperature T3, and the thermostat T2 opens.
Cooling water-]O- The seawater from Jakera I-17a is cooled and flows from the inlet 19b toward the auxiliary cooling water outlet 19C, and is discharged from the passage /I/4 to the passage 30 II.

Therefore, during idle time 1, that is, when the switching valve 48 is closed, the seawater temperature stone enters the thermostat T2, and the relatively high temperature 1
3, and there is no risk of the aforementioned sulfur MO corrosion occurring on the cylinder liner of the cylinder block 19.

On the other hand, when the load is high when sailing at full power, the switching valve/I8 is opened and the seawater in the cooling water jacket 19a is transferred to the cold 731 water inlet 19b.
The water flows from the main cooling water outlet 19d toward the main cooling water outlet 19d, and is discharged from the passage 46 to the passage 30 (A).

Therefore, at idle, that is, when the switching valve 48 is closed,
The seawater temperature is set to relatively high temperature 1 on thermostat T2.
3, and there is no risk of the above-mentioned sulfuric acid corrosion occurring on the cylinder liner of the cylinder tub [19].

On the other hand, during full power cruising, the switching valve 48 is opened for cooling, and the seawater in the jacket 19a flows from the cooling water volume 19b toward the main cooling water outlet 19d, and is discharged from the passage 46 to the passage 30.

Therefore, when the switching valve 48 is open, the temperature is controlled by the four-normostat T1. Since the heat generated from the cylinder block 19 increases during this high load, there is no risk of sulfuric acid corrosion occurring even if the temperature is controlled at a relatively low temperature t2.

On the other hand, the cylinder head 17a is cooled to a low temperature t2, and the intake boat (U' not shown) of the cylinder head 17 is cooled to a low temperature to improve the filling efficiency of the intake air. The heat load such as ヂ) is also reduced.

Another embodiment will be described in which the diaphragm 68 is arranged on the right side of the connection point p as indicated by the broken line in the figure. When the switching valve 48 is closed, the thermostat T1 is opened, and when the thermostats 1-T2 are closed, the seawater from the cooling water jacket 17a is sequentially routed through the passage 42, the passage 66, the bypass passage 50, and the passage /I4. It is designed to pass through to 30 meters and discharge at 30 meters. That is, the temperature of the cooling water jacket 17a is controlled by the thermostat hT1, and the temperature of the cooling water jackets 1 to 198 is controlled by the thermostat 72.

On the other hand, when the switching valve/I8 is closed during idle, etc., the cooling water jackets 1 to 17a are t2, and the cooling water jacket 17a is t2.
The temperature of a is controlled by r3. That is, the seawater flowing into the cooling water population 17b from the seawater pump 28 at a temperature of 1-0 mixes with the relatively high temperature seawater gathered at the upper part due to the convection phenomenon in the cooling water jacket 17a, and reaches a temperature of tl. . The seawater that has flowed into the cooling water jacket 17a has a relatively small temperature gradient from tl to 12, and when the thermostat l-T1 of the cylinder head 17 listens to the humidity at t2, the pressure of the tlli water causes the check valve to close. Listen to 64, passage 4
2, passage 66 and bypass passage 50 to be discharged to passage 30.

On the other hand, if the thermostat T1 is installed near the main cooling water outlet 19d and the thermostat T1 near the cold water outlet 17c is removed, the passage 42 will be connected to the adjacent cooling water outlet 17.
Since it is only necessary to connect C and the cooling water population 19b, the passage 42
Since the length of the cylinder is short, it can be integrally cast into the rad 17 and the cylinder block 19 by casting.

Eventually, when the temperature of the seawater in the cooling water jacket 19a reaches from t2 to t3, the thermostat]-2 opens, and the seawater from the cooling water jacket 17a reaches the cooling water population 19.
b flows toward the auxiliary cooling water outlet 19c, and is discharged from the passage 44 to the passage 3o.

Therefore, the temperature of the cylinder block 19 is controlled at a relatively high temperature t3, and there is no fear that the cylinder liner of the cylinder block 19 will suffer the aforementioned sulfuric acid corrosion.

Furthermore, when the thermostat T2 opens, the seawater flowing into the cooling water jacket 19a has a relatively small temperature gradient from tl to 12 in the cooling water jacket 17a of the cylinder head 17. The temperature of the water flowing into the cooling water jacket 19a from the auxiliary cooling water port 19c becomes uniform, and the temperature of the preparation of the cylinder block 19, especially the part where the cylinder head 17 and the adjacent piston rings I to Tubring come in sliding contact, becomes uniform. will be maintained.

On the other hand, during high loads such as when cruising at full power, even if the switching valve 48 is opened and the temperature of the cylinder block 19 is controlled at 12, the heat generated from the cylinder block 19 is still high! 1 hair, so there is no risk of sulfuric acid corrosion occurring.

On the other hand, the cylinder head 17 is cooled to a low temperature t2, and the intake bow 1 (not shown) of the cylinder head 17a is cooled to a low temperature to improve the filling efficiency of intake air. The heat load between the valves (not shown) etc. is reduced.

Regarding the materials of the cylinder head 17 and one cylinder block, the cylinder head 17 and the cylinder block 19 are not limited to being made of aluminum alloy and the cylinder block 19 is not limited to being made of plow iron, but both the cylinder head 17 and the cylinder block 19 may be made of aluminum alloy. In this case as well, since the temperature is controlled by the cylinder block 19t thermostat T2 during idle, the problem of overcooling does not occur.

Furthermore, the cylinder head 17 and cylinder block 19 are integrally molded, and the cooling water jackets 1 to 178 for cooling the cylinder head 17 and the cooling water jackets 11 and 11 for cooling the cylinder block 19 are installed inside! Even if it is formed
:stomach. In this case, the position of the partition wall between the cooling water jacket 17a and the cooling water jacket 19a can be freely shifted, so it is possible to strictly control the partial temperature of the cylinder head 17 and cylinder block 19. can.

Next, a modification of the first embodiment in which the cold III water inlet to the cylinder rad 17 is provided above will be described with reference to FIGS. 2A to 2C. In the case of FIG. 2a, a thermostat 1-T1 is installed at the bottom of the cylinder head 17 to control the temperature at the outlet of the cooling water pipe I7a. In addition, in the case of Fig. 2b, a T2 is provided at the top of the cylinder block 19 and a T2 is provided to the top 1 of the cooling water jacket 1.
The outlet temperature of 9a is controlled. Furthermore, the second C
The figure shows seawater flowing from top to bottom through the cooling water jacket 17a of the cylinder head 17, and seawater flowing from top to bottom through the cooling water jacket 19a of the cylinder block 19. .

Further, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 3, parts marked with the same reference numerals as those in FIG. 2 indicate the same or equivalent parts.

FIG. 3 shows a case where the cooling water inlet of the cooling water jacket 17a is set downward, and the seawater flow direction is upward from the bottom to the top. This J: Uni cooling water jacket 1
If the seawater flow direction of the cooling water jacket 17a1 and the cooling water jacket 19a are both directed upward, there is no possibility that air will stay in the middle of the cooling water jacket 17a1 and the water jacket 19a.
It is advantageous in terms of air removal.

3a shows a case where a thermostat T1 is installed at the top of the cylinder head 17, and FIG. 3b shows a case where a thermostat T2 is installed at the top of the cylinder block 19.

Furthermore, in FIG. 3C, the cooling water is made to flow through the cooling water jacket 17a from the bottom to the top, and the cooling water discharged from the cooling water jacket 17a is made to flow from the top to the bottom of the cooling water jacket 19a. This shows the case where it is done like this.

Another embodiment will be described with reference to FIGS. 1a and 1b. 1a and 1b, cooling water is distributed between the cylinder head 17a and the cylinder block 19a, and
In this embodiment, the cooling water that cooled the cylinder head 17 is controlled at a temperature of t2 by a su-mostat T1, and the temperature of the cooling water that cooled the cylinder block is controlled at a temperature of t3 by a thermostat T2. In this case, cooling water of the same temperature is circulated through the cooling water populations 17b and 19b of the cylinder head and cylinder block, and is maintained at appropriate temperatures t2 and t3, respectively.

Figure 1a shows the cylinder head 17 and cylinder block 19.
Since the cooling water population 17b and 119b are provided above, there is no fear that 8 liters of air will remain in the cooling water jacket, and the structure is simple. Also, in Fig. 1b, the positions of the cooling water populations 17b, 19b and the cooling water outlets 17G, 19G are reversed from those in Fig. 1a, and the cooling water at the inlet and outlet is transferred by convection within the cooling water jacket 17a119a. This reduces temperature differences and prevents uneven parts of the engine.

(Effects of the Invention) As explained above, the engine cooling device according to the present invention provides cooling water for the cylinder head in an engine in which the crankshaft is arranged vertically and the cylinder head and cylinder block are arranged horizontally in parallel. When the jacket and the cooling water jacket of the cylinder block are formed separately and a thermostat is provided to separately control the cooling water temperature of each cooling water jacket 1~, the cylinder head 17 can be adjusted as shown in Fig. 1a. Cooling water jacket 17 for cooling
a and the cooling water jacket 19a are separated and heated individually by thermostat i-T 1 and thermostat T2, and the cylinder head 17 to be cooled to a low temperature is heated to a low temperature t.
On the other hand, if the cylinder block 19 is supercooled, adverse effects such as an increase in horsepower loss due to a drop in lubricating oil temperature, poor combustion due to combustion flame cooling, and sulfuric acid corrosion occur. It can be cooled at a temperature of 7 J]1-.

Therefore, the temperature of the intake bow 1 of the cylinder head 17 becomes low, and the filling efficiency of the intake air improves.
Since the cylinder liner of No. 9 is kept at a high temperature, engine performance is improved and the amount of wear on the cylinder liner, which determines the engine's performance, is reduced.

There is a problem that uneven parts occur in various parts of the engine because the cooling water inlet has low humidity and the outlet has high temperature. Examples to solve this problem are shown in Figures 1b, 2, and 3. This is an example. In the case of Fig. 1b, the convection phenomenon is used, and in the case of Figs. 2 and 3, cooling water is passed through the cooling water jacket of the cylinder head in one vertical direction to cool the cylinder block. When the cooling water after cooling the cylinder head is not passed through the water jacket, the cylinder head 17 is cooled by the low-temperature cooling water, and the cooling water warmed by the cylinder head 17 flows into one cylinder block, keeping the cylinder liner at an appropriate temperature. The above-mentioned effects can be further enhanced by maintaining the Therefore, this embodiment is effective in increasing the cylinder temperature when the amount of heat radiation is small, such as during idle operation.

When cooling water is made to flow from above to below the cooling water jacket h17a of the cylinder head 17 as shown in FIGS. 1b and 2, convection occurs inside the cylinder head 17a.
The heated and warm cooling water remaining at 811 rises toward the cooling water population 17b at the top of the jacket, and the temperature at the cooling water population 17b is higher than tQ despite the entrance. tQ+α, which reduces the temperature difference with the cooling water outlet 17G, which has the advantage of uniformly cooling all parts of the engine. Furthermore, the same applies to the cylinder block side, and FIGS. 1B, 2C, and 3C are examples that exhibit this advantage.

If the cooling water is made to flow through the cooling water jacket of the cylinder head from the bottom to the top, and the cooling water after cooling the cylinder head is made to flow from the bottom to the top through the cooling water jacket of the cylinder block, This has the advantage that there is no risk of air remaining in the middle of both cooling water jacks, making it easier to bleed air.

(Another Embodiment) (1) The present invention is not limited to the case where it is applied to the diesel engine outboard motor as described above.
5 is applicable to an engine such as a gasoline engine that is used in a longitudinally arranged position. However, when applied to a diesel engine outboard motor, problems such as the aforementioned sulfuric acid corrosion can be solved, making it optimal.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of a diesel engine outboard motor equipped with a diesel engine to which the present invention is applied, Figs. 1a and 1b are structural diagrams showing the basic structure of the cooling system of the present invention, and Fig. Fig. 2a, Fig. 2b, and Fig. 2C are structural schematic diagrams showing a modification of the first embodiment of Fig. 2, and Fig. 3 is a structural diagram showing a first embodiment of the cooling system of the Geru engine. Structural diagram showing the second embodiment of the system, Figure 3a, Figure 3
FIG. b and FIG. 3C are structural diagrams showing modifications of the second embodiment shown in FIG. 3, respectively. 16...Diesel engine, 1
7... Cylinder head, 19... Cylinder block, 17a... Cooling water jacket, 19a... Cooling water jacket, 17b... Cooling water inlet, 17G... Cooling water outlet, 19b. ...Cooling water inlet, 19C...Auxiliary cooling water outlet, T1, T2...Thermostat Fig. 3b

Claims (3)

[Claims] (1) In an engine in which the crankshaft is arranged vertically and the cylinder head and cylinder block are arranged horizontally in parallel, the cooling water jacket of the cylinder head and the cooling water jacket of the cylinder block are formed separately, and each An engine cooling device characterized by being provided with a thermostat that individually controls the cooling water temperature of the cooling water jacket. (2) Cooling water is made to flow from above to below through the cooling water jacket of the cylinder head, and cooling water after cooling the cylinder head is made to flow through the cooling water jacket of the cylinder block. Cooling system for the engine described in Section 1. (3) Cooling water flows through the cooling water jacket of the cylinder head from the bottom to the top, and cooling water after cooling the cylinder head flows through the cooling water jacket of the cylinder block. Cooling system for the engine described in Section 1.