JP7082037B2 - Internal combustion engine for automobiles - Google Patents

Description

The present invention relates to an internal combustion engine for an automobile provided with an exhaust turbocharger.

In recent years, it has become common to install an exhaust turbocharger in an internal combustion engine for an automobile. The exhaust gas inlet of the exhaust turbocharger is connected to the cylinder head or the exhaust manifold, and the exhaust gas outlet is generally connected to a catalyst case containing a catalyst. The catalyst case tends to become larger due to the tightening of exhaust gas regulations in recent years. Then, in order to secure the space for arranging the catalyst case, the exhaust turbocharger and the turbine scroll chamber are used for the exhaust gas inflow passage. In some cases, it may have to be placed in the form of an upper winding located on top of it.

This aspect is disclosed in Patent Document 1. In Patent Document 1, the exhaust turbocharger is a water-cooled type, and cooling water is sent from the water jacket of the engine to the water jacket of the exhaust turbocharger. The cooling water that has passed through the water jacket is sent to the sub-tank of the radiator via the air-water separation tank.

Further, in Patent Document 1, in the basic mode in which the cooling water that has passed through the water jacket of the engine flows through the radiator to the water pump, a thermo valve is provided in the radiator return passage, and the thermo valve is closed during warm-up operation. In this state, the cooling water that has passed through the water jacket of the engine returns to the water pump via the bypass passage.

Japanese Patent Application Laid-Open No. 2003-56352

In many conventional internal combustion engines such as Patent Document 1, a cooling water distribution control unit is provided at one end of a cylinder head, and water is supplied from this distribution control unit to a radiator, a heater core, or the like. However, in this structure, when the exhaust turbocharger is arranged in the upper winding mode, the cooling water distribution control unit is lower than the exhaust turbocharger, so that the cooling water injection port is located higher than the cylinder head. Must be placed (otherwise a sufficient amount of cooling water cannot be injected into the cooling system).

Therefore, when the exhaust turbocharger is arranged in the upper winding system, the water injection tank whose water injection port is closed with a cap (radiator cap) is arranged at a position higher than the exhaust turbocharger to inject water. The tank and the water jacket of the exhaust turbocharger are connected, but this has the problem that the number of parts increases, the cost does not increase, the piping becomes complicated, and the design becomes troublesome.

The invention of the present application was made in the wake of such a situation, and while reducing the number of members to reduce weight and cost, ensuring water injection into a cooling system having an exhaust turbocharger, a radiator, or the like. It is an invention.

The internal combustion engine of the present invention is
"It is equipped with a head cover fixed to the upper surface of the cylinder head, a water-cooled exhaust turbocharger, and a radiator that cools the cooling water.
The head cover is formed with a cooling water tank having a water injection port that is opened and closed by a cap, and the cooling water tank has at least a cooling water return passage or a feed passage of the water jacket of the exhaust turbocharger. It is connected to the feed passage to the radiator,
The exhaust turbocharger is located below the upper end of the cooling water tank. "
It is configured as.

Equipment that can connect the feed passage or the return passage to the cooling water tank includes a heater core, a CVT warmer, a throttle warmer, an EGR cooler, an oil cooler, an intercooler, and the like, in addition to the exhaust turbocharger and the radiator.

In the present invention, the cooling water tank provided on the head cover functions as a control unit for distributing the cooling water and as a receiving container for injecting the cooling water. Therefore, the number of members can be suppressed and the cost can be suppressed. In addition, since the cooling water passage can be formed in the head cover, the piping can be simplified and the freedom of design can be improved.

The head cover is placed at the highest position of the engine body, and the members and appliances through which the cooling water flows are usually placed at a position lower than the head cover. Even in the case of the above configuration, the required amount of cooling water can be injected so that the water jacket of the exhaust turbocharger is filled with the cooling water.

It is a rear view (rear view) of an embodiment. It is a side view of II-II of FIG. (A) is a partial front view, and (B) is a partial plan view. It is the IV-IV view of FIG. 1 in the state which the exhaust turbocharger is simply displayed.

(1). Basic configuration Next, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the front-back and left-right directions are used to specify the direction, but the front-back and left-right directions are the front-back direction and the horizontal direction orthogonal to the crank axis direction as the left-right direction.

As shown in FIG. 1, the internal combustion engine includes a cylinder block 1, a cylinder head 2 fixed to the upper surface thereof, and a head cover 3 fixed to the upper surface of the cylinder head 2. Further, as shown in FIG. 4, a front cover 4 fixed to the front surface of the cylinder head 2 and the cylinder block 1 is provided, and these form the main members of the engine body. The head cover 3 is a molded resin product, an aluminum die-cast product, or an aluminum cast product.

As shown in FIGS. 2 and 3, the internal combustion engine includes an exhaust turbocharger 5. The exhaust turbocharger 5 is provided on a turbine housing 7 fixed to the exhaust side surface of the cylinder head 2 via a flange 6, a bearing housing 8 integrally formed on the rear surface of the turbine housing 7, and a rear surface of the bearing housing 8. It has a fixed compressor housing 9. An exhaust gas outlet 10 is open on the front surface of the turbine housing 7, and a catalyst case 12 is connected to the front flange 11 of the turbine housing 7.

Although not shown, a water jacket for cooling the turbine scroll chamber, the exhaust gas inflow passage, and the like is formed inside the turbine housing 7, and cooling water is supplied to the water jacket at the lower end of the turbine housing 7. A cooling water inlet port 13 for sending is formed, and an elbow type cooling water outlet port 14 for discharging the cooling water that has passed through the water jacket is formed at the upper end of the turbine housing 7. In FIG. 3A, reference numeral 15 indicates a wastegate passage, and FIG. 2A, reference numeral 16 indicates a valve holding hole into which a valve shaft fixed to the wastegate valve is rotatably fitted. ..

Needless to say, a turbine blade driven by exhaust gas is arranged inside the turbine housing 7, and a compressor blade is arranged inside the compressor housing 9, and both are integrally connected by a rotating shaft. Has been done. In the compressor housing 9, the intake air flows in from the axial direction and is discharged in the circumferential direction (tangential direction).

In the present embodiment, the exhaust turbocharger 5 is arranged in an upper winding system in which exhaust gas flows upward. Therefore, the upper end of the catalyst case 12 is located next to the cylinder head 2.

(2). Cooling structure As shown in FIG. 4, a cooling water tank 19 is formed at the rear end of the head cover 3 and at a portion closer to the intake side, and a cap 20 is formed on the upper surface of the cooling water tank 19. The water injection port 21 that is opened and closed by is projected upward. The cooling water tank 19 may be arranged in the left and right middle portions of the head cover 3 or may be arranged closer to the exhaust side.

The cam shaft 22 is rotatably held inside the cylinder head 2 via the cam cap 23, but the cooling water tank 19 is naturally arranged at a height that does not hit the cam shaft 22 or the cam cap 23. ing. Since the cooling water tank 19 has a certain height, it is possible to project only the portion of the cooling water tank 19 upward from the other portions of the head cover 3.

As shown in FIG. 4, a water jacket 24 is formed in the cylinder head 2, and cooling water flows into the water jacket 24 of the cylinder head 2 from the water jacket 25 formed in the cylinder block 1 through the communication hole 26. .. A relay passage 29 communicating with the water jacket 24 of the cylinder head 2 and the cooling water tank 19 is formed on the rear end wall 27 of the cylinder head 2 and the rear end wall 28 of the head cover 3. The relay passage 29 is formed in a boss portion that protrudes inward from the rear end walls 27 and 28 of the cylinder head 2 and the head cover 3. That is, the rear end walls 27 and 28 are partially thickened to form the relay passage 29.

As shown in FIG. 1, the cooling water outlet port 14 of the exhaust turbocharger 5 is connected to the cooling water tank 19 via a hose 30 and a pipe 31, and the turbocharger is connected by the hose 30 and the pipe 31. The return passage 32 is formed. The pipe 31 may be formed separately from the head cover 3 and fitted to the head cover 3, or may be integrally formed by using a slide pin when the head cover 3 is manufactured by injection molding or the like. good. As shown in FIG. 4, the turbocharger feed passage 33 that sends cooling water to the exhaust turbocharger 5 is connected to the rear end portion (downstream portion) of the water jacket 24 in the cylinder head 2.

Further, as schematically shown in FIG. 1, a radiator 34 is mounted as an accessory device of an internal combustion engine in the engine room of an automobile, and a radiator feed passage 35 for sending cooling water to the radiator 34 is provided in the cooling water tank 19. It is connected.

As shown in FIG. 4, a water pump 36 driven by a crank shaft is arranged at the front portion of the engine body, and cooling water is supplied from the discharge port 37 of the water pump 36 to the water jacket 25 of the cylinder block 1. It is being pumped. Further, the main return passage 38 is connected to the inflow port of the water pump 36, and the radiator return passage 39 is connected to the main return passage 38.

The water supply to the radiator 34 is controlled by a thermo valve (not shown). The thermo valve may be connected to the radiator feed passage 35 or may be connected to the radiator return passage 39. If a thermo valve is provided in the cooling water tank 19 and the radiator feed passage 35 is connected via the thermo valve, the space can be effectively used, which is preferable.

The cooling water tank 19 and the main return passage 38 are connected by a bypass passage 41 having a differential pressure valve 40. When the thermo valve is closed, the differential pressure valve 40 is opened, and the cooling water that has cooled at each site is sucked into the water pump 36 via the bypass passage 41. In the figure, the differential pressure valve 40 is drawn in a state of being separated from the cooling water tank 19, but it is rational to incorporate the differential pressure valve 40 into the cooling water tank 19.

As schematically shown in FIG. 4, the automobile is provided with a heater core 42 for heating the inside of the vehicle, and the heater feed passage 43 is connected to the water jacket 24 or the relay passage 29 of the cylinder head 2 and is connected to the heater return passage 44. Is connected to the cooling water tank 19. In addition, a CVT warmer return passage, an intercooler return passage, and the like can be connected to the cooling water tank 19.

In the above configuration, since the cooling water tank 19 is provided on the head cover 3 constituting the upper end of the engine body, the cooling water tank 19 can be arranged at a position higher than the equipment / devices through which the cooling water passes. Therefore, when the cooling water is injected into the cooling water tank 19, each device / device and the cooling water passage can be filled with the cooling water. Therefore, even if the height of the exhaust turbocharger 5 is increased due to the increase in size of the catalyst case 12, the water jacket of the exhaust turbocharger 5 can be filled with the cooling water.

Since the cooling water tank 19 has a cooling water distribution function and a cooling water control unit function that is often provided in the cylinder head 2, it is only necessary to increase the height of the water injection port. The structure as a whole can be simplified as compared with the case where the tank is provided for the purpose of.

Further, when the cooling water control unit is provided on the cylinder head 2, the placement location is limited to the rear portion of the cylinder head 2 due to space limitations, and it can be said that there is no option for arranging the cooling water control unit in other parts. Since the choice of where to provide the cooling water tank 19 in the head cover 3 is wide, the freedom of design can be improved.

In the illustrated embodiment, the supercharger return passage 32 is connected to the cooling water tank 19, but the supercharger feed passage 33 is connected to the cooling water tank 19, and the supercharger return passage 32 is the bypass passage 41 or the main. It may be connected to the return passage 38.

The invention of the present application can be embodied in an internal combustion engine equipped with an exhaust turbocharger. Therefore, it can be used industrially.

1 Cylinder block 2 Cylinder head 3 Head cover 5 Exhaust turbocharger 12 Catalyst case 19 Cooling water tank 20 Cap 21 Water injection port 24 Cylinder head water jacket 25 Cylinder block water jacket 32 Supercharger return passage 33 Supercharger feed passage 34 Radiator 35 Radiator feed passage 36 Water pump 38 Main return passage 39 Radiator return passage 41 Bypass passage

Claims (1)

It is equipped with a head cover fixed to the upper surface of the cylinder head, a water-cooled exhaust turbocharger, and a radiator that cools the cooling water.
The head cover is formed with a cooling water tank having a water injection port that is opened and closed by a cap, and the cooling water tank has at least a cooling water return passage or a feed passage of the water jacket of the exhaust turbocharger. It is connected to the feed passage to the radiator,
The exhaust turbocharger is located below the upper end of the cooling water tank.
Internal combustion engine for automobiles.

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