JPS6214346Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a water-cooled turbocharger equipped with a water jacket.

Most turbochargers used in internal combustion engines are exhaust supercharging turbochargers driven by engine exhaust gas, and the oil that lubricates the bearings deteriorates quickly due to the influence of exhaust temperature, and the oil used beyond the oil change interval is often used. With oil that has undergone severe deterioration, there have been problems such as oil carbide depositing on bearings and oil passages. To this end, it has been devised to provide a water jacket in the turbine housing and center housing of the turbocharger to cool it, but when the engine is stopped, the supply of cooling water to the turbocharger stops, and the turbocharger is exposed to high temperatures again. There was a problem.

JP-A No. 53-68309 discloses an invention in which the cooling water inlet of the water jacket of the turbocharger is provided at a low position, and the cooling water outlet is provided at a high position so that the cooling water flows through the turbocharger by convection when the engine is stopped. is listed. However, in the invention described in this publication, since the convection of the cooling water occurs through the engine, turbocharger, and radiator, the convection path becomes long and passes through the engine, resulting in large convection resistance and insufficient flow. The cooling efficiency was unsatisfactory. In addition, ``Japan Institute of Invention and Innovation Publication Technical Report'' Publication No. 82-2582 describes an idea to provide a water cooling passage in the housing of a turbocharger and to supply cooling water through a passage bypassing the engine cooling water passage. In the idea described in this technical report, the coolant inlet located at a high position is connected to the lower tank side of the radiator, and the outlet located at a low position is connected to the upper tank side of the radiator. There is no way that convection can occur, and the
Similar to Publication No. 53-68309, it was necessary to arrange a pump or the like to act as a resistance when the turbocharger stopped in the cooling water passage. Furthermore, these proposals did not take engine warm-up performance into consideration, and in particular, no consideration was given to the use of a thermostatic valve device in conjunction with turbocharger cooling.

The present invention was devised in view of the above problems and aims to provide a turbocharger that allows some cooling water to flow even after the engine is stopped. Another objective is to shorten engine warm-up time by improving the connection of the turbocharger to the engine cooling water system.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of the turbocharger 1.
It is well known that the turbocharger 1 is composed of three main parts: a turbine housing 2, a center housing 3, and a compressor housing 4. A turbine 5 is rotatably housed in the turbine housing 2, and the turbine 5 is driven by engine exhaust gas introduced in the circumferential direction shown by arrow a in FIG. 1 and discharged in the axial direction shown by arrow a'. It receives rotational force. On the other hand, compressor housing 4
An impeller 6 is rotatably housed in the housing, and the impeller 6 is connected to the turbine 5 by a turbine shaft 7, and thus rotates with the rotation of the turbine 5 to direct air taken in from an air cleaner (not shown). Inhale from the axial direction shown by arrow b in Figure 1.
The pressurized air is sent in the circumferential direction indicated by b' to supercharge the engine. A bearing 8 that supports the turbine shaft 7 is arranged in the center housing 3 . Although not shown in FIG. 1, the center housing 3 is provided with an oil hole for lubricating the bearing 8, and oil is supplied under pressure to the bearing 8 from above, for example, in FIG. It is collected in a trough and returned to the oil pan. The center housing 3 is further provided with a water jacket 9. This water jacket 9 is formed in various shapes along the center housing wall so as not to overlap the aforementioned oil holes and troughs. This water jacket 9
Alternatively, it can be formed not only in the center housing 3 but also in the turbine housing 2.

As shown in FIG. 1, the cooling water inlet 10 of the water jacket 9 when the engine is stopped is provided on its lower wall, and the cooling water outlet 11 when the engine is stopped is provided on its upper wall. Cooling water enters from the lower cooling water inlet 10, traverses the water jacket 9 in an annular manner, and exits from the upper cooling water outlet 11. When the cooling water inlet 10 and outlet 11 cannot be provided on the lower wall and the upper wall as described above due to the positional relationship with the oil passage,
These inlets and outlets can also be provided in the side walls. It should be noted that the cooling water inlet and outlet are arranged in a vertical relationship with each other. As a result, when the water temperature in the water jacket 9 rises after the engine is stopped, this convection flows from the upper outlet into the cooling water circulation system, and the cooling water whose temperature has not been raised by the turbocharger flows from the lower inlet into the water jacket 9. It flows into the interior by convection. Such a configuration that causes convection becomes more effective by arranging the cooling water inlet and outlet so that they have a vertical relationship with each other when the engine is stopped. Further, in order to circulate cooling water while the engine is running, a cooling water inlet 10' during operation is provided in the water jacket 9 adjacent to a cooling water inlet 10' when the engine is stopped, and a cooling water outlet 11 is provided in the water jacket 9.
is used while the engine is running and when the engine is stopped.

FIG. 2 is a diagram of the cooling water system for the engine and turbocharger of the vehicle. 12 is an engine, and 13 is a radiator. 13' and 13'' are the radiator upper and lower tanks.The cap 14 of the radiator 13 normally incorporates a regulating valve mechanism for pressurizing and regulating the pressure of the cooling water to increase cooling efficiency. An expansion adjustment reserve tank 15 is provided, and the cap 14 and reserve tank 15 are connected by a hose 16.

The engine 12 and the radiator 13 are connected to the hose 17,
Connected at 17', 18, 18', radiator 13
The engine is cooled by circulating cooling water through the hoses 18, 18', the engine 12, and the hoses 17', 17. A turbocharger 1 connected to a thermostat housing 20 by a hose 21 is installed in this engine cooling water circulation path. That is, the hose 21 is connected to the cooling water inlet 10 when the engine is stopped as shown in FIG.
7' is connected to the cooling water inlet 10' during operation, and a hose 17 is connected to the cooling water outlet 11. Therefore,
Engine cooling water is circulated through the water jacket 9 of the turbocharger 1.

In the embodiment shown in FIG. 2, a water pump 19 is disposed at the cooling water inlet of the engine 12, and a thermostat housing 20 is disposed upstream thereof. The above-mentioned hose 17' is bypassed to the thermostat housing 20 via the hose 21. From hose 21 to hose 18, hose 2
2 is bypassed, and a solenoid valve 23 is placed therein. Therefore, the hoses 18 and 18' form a first conduit from the lower tank 13'' of the radiator 13 to the engine 12, and the hoses 17' and 17 form a first conduit from the engine 12 to the upper tank 1 of the radiator 13.
3', and the hose 21 forms a third conduit connecting the thermostat housing 20 and the second conduit. The hose 22 is an auxiliary passage when the flow from the thermostat housing 20 to the hose 21 is small when the engine is stopped, and as shown in FIGS. The hose 22 can be omitted if the flow through it is sufficient. Note that the thermostat housing 20 normally connects the hose 18 when the engine is stopped.
This acts to shut off the hose 21 (see explanation in Figure 3), but in reality there is some leakage, so a flow from the thermostat housing 20 through the hose 21 occurs when the engine is stopped. be.

Figure 3 shows the thermostat housing 2 in Figure 2.
0, which shows the three inlets 24, 2
5, 26, and the above-mentioned hoses 18, 18', 21 are connected to these inlet portions, respectively. Approximately in the center of the housing is a valve body 27 which contains wax and is movable in the axial direction due to its thermal expansion, and when this valve element 27 engages with and separates from the valve seat 28,
Passages between the opening 24 and the other openings 25 and 26 are opened and closed. On the other hand, the valve body 27 has a second valve body 29
is secured to engage a valve seat 30 formed in the opening 26. These valve bodies 27 and 29 are connected so that they mutually move in the same direction in response to expansion and contraction of the wax. Therefore, when the temperature of the wax is low, that is, during warm-up, the valve body 27
and 29 are located on the left in FIG.
The passage from 4 is closed and the openings 25 and 26, ie the hoses 21 and 18', are brought into communication. When the temperature of the wax increases, the valve bodies 27 and 29 move to the right, opening the passage from the opening 24 and closing the passage from the opening 26. Therefore, at this time, the hoses 18 and 18' are in communication with each other.

Therefore, in the cooling water system shown in FIG. 2, the engine 12 and hose 1 are
7', part of turbocharger 1, hose 21,
thermostat housing 20, hose 18',
Cooling water is circulated through the water pump 19. When warm-up is completed, the hoses 18 and 18' will be in communication within the thermostat housing 20, so the engine 12, hose 17', turbocharger 1, hose 17, radiator 13, hose 18, hose 18', and water pump 19 A circulation occurs through. Note that while the engine is operating, the solenoid valve 23 is closed and there is no flow through the hose 22. When the engine is stopped, the water pump 19 is stopped and at the same time the solenoid valve 23 is opened. Therefore, the flow of cooling water through the radiator 13, hose 18, hose 22, hose 21, turbocharger 1, and hose 17 is not forced, but is free. The turbocharger 1 has the highest temperature in this system, and its cooling water inlets and outlets 10 and 11 are arranged in a vertical relationship with each other when the engine is stopped, so that hotter cooling water flows from the outlet 11 located above. Cooling water at a lower temperature flows toward the radiator 13.
Heat convection into the inlet 10 below takes place as indicated by the arrows.

Figure 4 shows a second example of the cooling water circulation system.
Hoses 31 and 32 are added to the first example shown in the figure. This eliminates the need for the entire amount of engine cooling water to pass through the turbocharger 1; instead, a portion of the engine cooling water flows through the turbocharger, and the rest returns directly to the radiator 13 through the hoses 31 and 17. Cooling water is circulated from hose 17' and hoses 31 and 32 to turbocharger 1, hose 21, thermostat housing 20, hose 18', water pump 19, and engine 12. After warming up, the hose 18 is connected from the radiator 13, the thermostat housing 20, the hose 18', the water pump 19, the engine 12, and the turbocharger 1 is connected from the hose 17'.
Cooling water is circulated from the hoses 32, 17 and the hose 31 to the hose 17. After the engine is stopped, the cooling water is circulated from the radiator 13 to the hose 18, hose 22 (the solenoid valve 23 is opened), hose 21, turbocharger 1, hose 32, and hose 17 by convection as shown by the arrows. .

FIG. 5 similarly shows a third example of the cooling water system, in which the hose 22 and solenoid valve 2 of FIG.
3 is omitted. The movements of the valve bodies 27 and 29 of the thermostat housing 20 are not instantaneous, but gradually move in response to changes in temperature. Therefore, the hoses 18 and 21 are in communication for a certain period of time after the engine is stopped, and the above-mentioned Cooling water circulation is performed along the arrows as in the example. Further, as shown by the broken line, it is also possible to provide the hose 33 from the hose 21 to the hose 17 by bypassing the turbocharger 1, thereby connecting the hose 18 and the hose 21.
The amount of water flowing through the radiator 13 is increased, and after the engine is stopped, the cooled water in the radiator 13 is transferred to the turbocharger 1.
This makes it easier to introduce. FIG. 6 similarly shows a fourth example, in which the hose 22 and electromagnetic valve 23 in FIG. 4 are omitted, and hoses 31 and 32 are added as in FIG. 4. The circulation of cooling water is the same as in the above example.

FIG. 7 is a graph showing the temperature change of the turbocharger, where the curve X relates to the conventional turbocharger and the curve Y relates to the turbocharger according to the present invention. It can be seen that by providing a water jacket in the turbocharger, the temperature rise during engine operation can be reduced, and the temperature rise after the engine is stopped, as indicated by _t0 , is also considerably reduced. In particular, when the engine is stopped, cooling water convection occurs from the lower inlet 10 of the turbocharger, through the upper outlet 11, and from the upper tank 13' of the radiator 13 to the lower tank 13'', and this convection path does not pass through the engine, so it is relatively Since the convection path is short and has low resistance, and there is nothing in this convection path that creates resistance when the pump or the like is stopped, the convection can flow smoothly.

As explained above, according to the present invention, the deterioration of the oil for lubricating the bearings is prevented, and as a result, the oil change interval can be extended, and the accumulation of oil carbon on the bearings, the inner wall of the center housing, and the oil passages can be prevented. Furthermore, since the extreme temperature rise of the housing after the engine is stopped can be prevented, the thermal strain of the turbocharger can be prevented, and since the turbine clearance can be reduced, a turbocharger with excellent performance can be obtained, and it is possible to prevent interference between the turbine and components and cracks in the housing due to thermal strain, and the durability and reliability of the turbocharger can be improved. And since it is configured to shorten the engine warm-up time, it has the effects of saving fuel and improving exhaust gas purification.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a turbocharger according to the present invention, FIG. 2 is a schematic diagram showing a first example of a cooling water circulation system for an engine and a turbocharger, and FIG.
The figures are a detailed view of the thermostat housing in Figure 2, Figure 4 is a schematic diagram of the second example, Figure 5 is a schematic diagram of the third example, and Figure 6 is a schematic diagram of the fourth example.
FIG. 7 is a graph showing the temperature change of the turbocharger. 1...Turbo charger, 3...Center housing, 9...Water jacket, 10...Cooling water inlet, 11...Cooling water outlet, 12...Engine, 1
3...Radiator.

Claims (1)

[Scope of utility model registration request] A water jacket having at least two ports disposed in vertical relation to the housing of the turbocharger is provided, the turbocharger having a first conduit extending from the lower tank of the radiator to the engine and having a thermostatic valve device disposed therebetween; The second heading towards the radiator's Atsupata tank.
and a third conduit connecting the thermostat valve device and the second conduit, the opening being disposed at the intersection of the second conduit and the third conduit of the engine cooling water system and located at least at a low position. is connected to a third conduit, and a high-positioned mouth is connected to a radiator side of the second conduit.