JPH0452441Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a cooling device for a water-cooled turbocharged engine.

(Prior Art) In recent years, turbochargers that use the energy of exhaust gas to supercharge intake air have been put into practical use in automobile engines and the like in order to improve intake air filling efficiency or engine output.
However, since this turbocharger is configured to drive a turbine using high-temperature exhaust gas discharged from the engine, the temperature of the turbine section increases significantly due to the heat of the exhaust gas, which causes damage to the bearing section, etc. The lubricating oil deteriorates prematurely, causing problems such as seizure between the turbine shaft and the bearings and reduced durability.

Therefore, in order to deal with such problems, for example, as shown in Japanese Utility Model Application Laid-Open No. 58-152528, a cooling water passage (water jacket) is formed in the turbine housing of the above-mentioned turbocharger, and the above-mentioned There is one in which the cooling water that circulates through the engine cooling system is supplied to the cooling water passage. According to this, the turbocharger is actively cooled by the cooling water, and the above-mentioned deterioration of lubricating oil and decrease in durability in the turbocharger are prevented.

However, when such a water-cooled turbocharger is provided, the following problems occur when the engine is stopped. In other words, when the engine is stopped, the water pump that circulates the cooling water that was being driven by the engine is also immediately stopped, cutting off the supply of cooling water to the turbocharger. The cooling water that remains in the cooling water passage in the turbocharger boils due to the heat of the turbocharger, generating water vapor bubbles, which flow into the radiator through the engine cooling system, causing water vapor inside the radiator to boil. cooling water starts to overflow.

By the way, in the engine cooling system as mentioned above,
For example, as shown in Japanese Utility Model Application Publication No. 57-180114, a reserve tank is connected to the radiator through a communication path, and overflowing cooling water is introduced into the reserve tank as described above. One end of the communication passage is disposed at the bottom of the tank because it is necessary to return the cooling water from the reserve tank to the radiator when the amount of cooling water decreases. Therefore, when the air bubbles generated in the cooling passage in the turbocharger as described above overflow from the radiator with cooling water and are introduced into the reserve tank when the engine is stopped, the air bubbles are introduced from the bottom of the reserve tank. Become,
In that case, since supplementary cooling water is stored in the tank, the bubbles will be discharged into this cooling water. Then, when it floats up in the cooling water and reaches the liquid level, it disappears, but at this time,
An abnormal noise (so-called gurgling noise) occurs. There is a problem in that this abnormal noise is propagated from the reserve tank through the vehicle body into the vehicle interior, causing discomfort to the occupants.

(Means for Solving the Problems) The present invention was made with the aim of solving the above problems, and includes a radiator to which cooling water from the engine and turbocharger is supplied,
A reserve tank in which a portion of the cooling water overflowing from the radiator is stored, and a suction pipe communicating the radiator and the reserve tank and introducing the engine cooling water overflowing from the radiator into the reserve tank. In a cooling system for a water-cooled turbocharged engine, the introduction end of the suction pipe introduced into the reserve tank is bent into a U shape to open into the space above the stored water filling position, and A one-way valve that opens only to the inside of the passage is provided near the bend.

(Function) According to the above means, the other end of the suction pipe introduced into the reserve tank is bent into a U shape and opened above the stored water filling position in the reserve tank, while the cooling The lower opening for water return is opened and closed by a one-way valve that can only be opened inside the passage, so when overflow cooling water from the radiator is supplied into the reserve tank, the one-way valve is When closed, the stored water is discharged into the space above, but when the cooling water returns from the reserve tank to the radiator, the one-way valve opens and the stored water can be taken in from the bottom of the reserve tank.

(Example) Hereinafter, an example of this invention will be described in detail with reference to the drawings.

First, FIG. 1 is a schematic diagram showing a cooling system for a water-cooled turbocharged engine. In FIG. 1, the cooling system 1 of this embodiment includes a radiator 2 provided at the front end of the engine room, and a system formed from the bottom of the radiator 2 around each cylinder, intake port, exhaust port, etc. of the engine 3. It has a main introduction passage 4 that leads cooling water to a water jacket or the like, and a main return passage 5 that returns the cooling water from the water jacket of the engine 3 to the upper part of the radiator 2. Heat is exchanged with outside air within the radiator 2 by the operation of a water pump 7 that is attached to one side of the engine 3 and driven by the crankshaft (not shown) of the engine 3 via a belt 6. Cooling water that has been brought to a low temperature state is introduced into the water jacket from the main introduction passage 4, is brought to a high temperature state by cooling the surroundings of each cylinder, etc., and is then passed through the main return passage 5. It is designed to be fed back into the radiator 2. Further, this cooling system 1 is provided with a bypass passage 8 that directly communicates the main introduction passage 4 and the main return passage 5, and a thermostatic A tat valve 9 is provided to form a circulation path that does not pass through the radiator 2, which is comprised of the bypass passage 8 and the water jacket of the engine 3, when the engine 3 is warmed up.

Furthermore, in this cooling system 1, an intake manifold 1 that guides intake air to each cylinder of the engine 3 is provided.
A passage for circulating cooling water is also formed inside the engine 3, and entrances 10a, 10a of this passage are connected to the engine 3.
It is connected to two outlets 3a, 3a formed in the main body of the main body. Cooling water that has reached a high temperature within the water jacket of the engine is introduced into the passage within the intake manifold 10, thereby heating the intake air passing through the intake manifold 10, thereby increasing the temperature within each cylinder. The vaporization and atomization of the fuel mixture supplied to the fuel mixture is promoted. Further, the outlet 10b of the passage in the intake manifold 10 is communicated with the bypass passage 8 via a heater unit 11 for raising the temperature inside the vehicle interior.

On the other hand, the engine 3 is equipped with a water-cooled turbocharger 12, and a cooling passage (not shown) is formed inside a turbine housing 12a of the water-cooled turbocharger 12. ing. A sub-introduction passage 13 led from the lower part of the main body of the engine 3 and a sub-return passage 14 communicating with the bypass passage 8 are communicated with this cooling passage. Then, from the main return passage 5 to the engine 3
Cooling water that has been introduced into the water jacket and has not reached a high temperature state is guided from the sub-introduction passage 13 to the cooling passage in the turbine housing 12a of the turbocharger 12, thereby cooling the turbocharger 12. The cooling water that has reached a high temperature by cooling the turbocharger 12 in this manner is returned to the end of the main introduction passage 4 on the engine 3 side via the sub-return passage 14 and the bypass passage 8. ing.

Furthermore, in addition to the above configuration, this cooling system 1
is equipped with a reserve tank 15 for storing cooling water overflowing from the radiator 2,
In addition, a cooling water introduction passage (also serving as a return passage) 16 is provided that communicates the reserve tank 15 and the radiator 2. As shown in FIG. 2, the end of the cooling water introduction passage 16 on the radiator 2 side is formed in a protruding manner on the upper part of the body member 2a of the radiator 2, and a radiator cap 17 is crowned at the upper end. The attached cylindrical member 2
A first valve 18 and a second valve 19 are provided inside the cylindrical member 2b, which are connected to the side surface of the body member 2b and which communicate and cut off the introduction passage 16 and the inside of the body member 2a. Here, the first valve 18 is urged downward by a coil spring 20, and is normally seated as shown by the solid line in the figure, but the cooling water in the body member 2a is When an overflow condition occurs, body member 2
As the pressure within a increases, the cooling water is moved upward to the position shown by the chain line, and the overflowing cooling water flows into the cooling water introduction passage 16 through the path shown by arrow A. Further, the second valve 19 is
It is urged upward by a conical coil spring 21, and is normally seated as shown by the solid line in the figure, but when the cooling water temperature or pressure within the body member 2a decreases, the position changes as shown by the chain line. The cooling water that has been moved downward as shown in FIG. There is.

Further, as shown in FIG. 3, an upper end 22a of a suction pipe 22 is connected to the end of the cooling water introduction passage 16 on the reserve tank 15 side. The suction pipe 22 passes through a reserve tank cap 23 that covers the upper part of the reserve tank 15 and hangs down into the reserve tank 15.
By further bending the hanging end portion upward into a U shape, the open end portion 24 is connected to the reserve tank 1.
5 is opened above the stored water FULL position Fu. On the other hand, a return port 25 for recirculating the stored water is formed on the side of the hanging end (bent portion), and a one-way valve 26 that opens only inside the passage is installed in the return port 25. Further, the bottom portion 27 is provided with a small-diameter cooling water flow hole 28 . The one-way valve 26 is closed when the overflow cooling water from the radiator 2 side flows into the reserve tank 15, and is opened when the radiator 2 side becomes negative pressure and the water stored in the reserve tank 15 flows back. It's becoming like that.

In addition, the reserve tank cap 23 has
A pipe 29 for air venting is attached.

Next, the operation of the above embodiment will be explained.

First, when the engine 3 is in operation, the water pump 7 shown in FIG. 1 is driven.
The cooling water brought to a low temperature in the radiator 2 first passes through the main introduction passage 4 as shown by arrow a, and then is guided into the water jacket of the engine 3 as shown by arrow b, and the cooling water is Most of the heat cools the surroundings of each cylinder, which is in a high temperature state, and then returns to the radiator 2 through the main return passage 5 as shown by arrow c. In that case,
A portion of the cooling water introduced into the water jacket as described above flows into the sub-introduction passage 3 from the bottom of the engine 3 as shown by the arrow d before cooling the surroundings of each cylinder, etc. The cooling water that has passed through this passage 13 is guided to a cooling passage (water jacket) formed in the turbine housing 12a of the turbocharger 12, and cools the turbocharger 12 which is in a high temperature state.
Thereafter, it flows out into the sub-return passage 14 as shown by arrow e, and then returns to the main introduction passage 4 through the bypass passage 8 as shown by arrow f.

By the way, when the engine 3 is stopped after operating while cooling the cylinders, turbocharger 12, etc. which are in a high temperature state as described above, the drive of the water pump 7 is also immediately stopped and the cooling water is no longer circulated. In particular, the cooling water staying in the cooling passage in the turbocharger 12, which is in a high temperature state, is boiled by the heat of the turbocharger 12, and steam bubbles are generated in the cooling passage. These water vapor bubbles flow from the cooling passage in the turbocharger 12 into the radiator 2 via, for example, the sub-return passage 14, the bypass passage 8, and the main introduction passage 4, and along with this, the cooling inside the radiator 2 The water overflows and pushes up against the spring force of the coil spring 20 of the first valve 18 shown in FIG. 2 to the position shown by the chain line in the same figure.
will be pushed up as well). As a result, the overflowing cooling water flows into the cooling water introduction passage 16 through the path shown by arrow A inside the cylindrical member 2b of the radiator 2, passes through this passage 16, and enters the third
It is introduced into the reserve tank 15 via the suction pipe 22 shown in the figure. At this time, the suction pipe 22 disposed inside the reserve tank 15 as described above is bent into a U shape, and its open end 24 is opened above the stored water FULL position Fu. Since the one-way valve 26 is also closed, the water vapor bubbles introduced into the reserve tank 15 are discharged not into the stored water but into the space above the stored water (see FIG. 4A). Therefore, unlike the conventional case where the water is discharged into the stored water, no abnormal noise is generated.

Further, when the temperature of the cooling water in the engine cooling system 1 decreases, the second valve 19 in FIG. 2 is moved down as described above. As a result, negative pressure is generated toward the reserve tank 15 side, the one-way valve 26 opens, and the cooling water in the reserve tank 15 shown in FIG. The cooling water is returned to the radiator 2 through the cooling water, and the cooling water is thus replenished into the radiator 2 (see FIG. 4B).

(Effects of the Invention) As explained above, the present invention includes a radiator to which cooling water from the engine and turbocharger is supplied, a reserve tank in which a portion of the cooling water overflowing from the radiator is stored, and A cooling device for a water-cooled turbocharged engine, comprising a suction pipe that communicates a radiator with a reserve tank and introduces engine cooling water overflowing from the radiator into the reserve tank, wherein the suction pipe is arranged to be introduced into the reserve tank. The introduction end of the suction pipe is bent into a U shape to open into the space above the stored water filling position, and a one-way valve that opens only to the inside of the passage is provided near the lower bent part. It is something to do.

That is, according to the present invention, the other end of the suction pipe introduced into the reserve tank is bent into a U shape and opened above the filled position of the stored water in the reserve tank, while the suction pipe for returning cooling water The lower opening of the radiator is opened and closed by a one-way valve that can only be opened inside the passage, so when overflow cooling water from the radiator is supplied to the reserve tank, the one-way valve is closed and the water is removed from the reservoir tank. On the other hand, when the cooling water returns from the reserve tank to the radiator, the one-way valve opens and the stored water can be taken in from the bottom of the reserve tank.

Therefore, unlike the conventional case where the overflow cooling water from the radiator is directly returned to the stored water, no abnormal noise is generated.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of a cooling device for a water-cooled turbocharged engine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the cooling water introduction passage on the radiator side of the device, and FIG. 3 is the same. FIGS. 4A and 4B, which are schematic configuration diagrams of the main parts of the apparatus, are cross-sectional views for explaining the operating state of the apparatus. 1...Cooling system, 2...Radiator, 3...Engine, 12...Water-cooled turbocharger, 15
... Reserve tank, 16 ... Cooling water introduction path, 2
2... Suction pipe, 24... Open end, 2
5...Cooling water return port, 26...One-way valve.

Claims (1)

[Scope of utility model registration request] A radiator to which cooling water from the engine and turbocharger is supplied, a reserve tank in which a portion of the cooling water that overflowed from the radiator is stored, and an engine cooling water that overflowed from the radiator by communicating with the radiator and the reserve tank. A cooling system for a water-cooled turbocharged engine, comprising: a suction pipe for introducing the water into the reserve tank;
The introduction end of the suction pipe introduced into the reserve tank is bent into a U shape to open into the space above the stored water filling position, and a pipe is opened only to the inside of the passage near the lower bent part. A cooling device for a water-cooled turbocharged engine characterized by being equipped with a directional valve.