JP2822707B2 - Cooling device for V-type internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled type cooling apparatus for a V-type internal combustion engine, and more particularly to an improvement of a cooling apparatus in which cooling water is individually passed through a cylinder block and a cylinder head.

[0002]

2. Description of the Related Art In many water-cooled cooling systems for internal combustion engines, cooling water is introduced from one end of a water jacket on the cylinder block side, passes through a water jacket on the cylinder head side inside the engine, and then is moved to the end on the cylinder head side. Although it is configured to be taken out from the part etc., in such a configuration,
Active cooling of the cylinder head side, which is important for preventing knocking, cannot be achieved, and overcooling of the cylinder block side cannot be sufficiently prevented. Therefore, Tokuhei 1-56251
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-264, a so-called two-system cooling system cooling device has been proposed in which cooling water is caused to flow individually to a cylinder block side and a cylinder head side.

In this two-system cooling system, cooling water is introduced from a water pump at the front end of the engine to both the front end of the water jacket on the cylinder block and the front end of the water jacket on the cylinder head. Each is taken out from the rear end. Therefore, the cooling water flows through each water jacket individually along the front-rear direction of the engine. By appropriately setting the respective water flow rates, the cooling water is suitable for the cylinder block side and the cylinder head side. Cooling can be performed. Also, for example, if an on-off valve is provided in the water passage to the cylinder block side water jacket, the cooling performance of the cylinder block side can be changed by opening and closing the valve, for example, by increasing the cylinder wall temperature during steady operation. Fuel efficiency can be improved.

[0004]

By the way, assuming that the above-mentioned two-system cooling system cooling device is applied to a V-type internal combustion engine, cooling water is individually passed through the water jackets of the left and right banks also in the cylinder block. must must Yara Remove the cooling water from the end after each. However, if cooling water outlets are provided in the left and right banks of the V-shaped cylinder block, respectively,
The structure of the rear end of the engine becomes complicated, and the overall length of the engine increases. In addition, when the above-described on-off valve is provided on the outlet side, it is necessary to provide each of the cooling water outlets of the left and right banks, resulting in a complicated configuration and an increase in the number of parts.
There is a problem that.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a cooling water distribution chamber communicating with a discharge side of a water pump attached to a front end of a cylinder block at a position between banks at the front end of the cylinder block. In a cooling device for a V-type internal combustion engine, cooling water is introduced from a water distribution chamber into a water jacket on a cylinder block side and a water jacket on a cylinder head side of left and right banks, and flows from a front end to a rear. A cooling water outlet is provided at the rear end of the head, and a cooling water outlet communicating with the water jacket on the cylinder block side of the left and right banks is formed upward on the upper surface of the interbank connection part at the rear end of the cylinder block. It is characterized by doing. Further, in the invention of claim 2, the cylinder
A cooling water outlet on the block side is
The switching valve is connected and this switching valve
It is housed in the space below the intake system parts located between
It is characterized by having.

[0006]

The cooling water introduced from the cooling water distribution chamber at the front end of the cylinder block into the water jacket on the cylinder head side flows in the water jacket on the cylinder head side in the front-rear direction, and is taken out from each cooling water outlet.

The cooling water introduced into the water jackets on the cylinder block side of the left and right banks flows in the water jackets in the front-rear direction, and then joins each other near the cooling water outlet at the rear end to form a single cooling water. It is taken out from the exit. Since the cooling water outlet is formed upward at the position between the banks, the cooling water outlet between the banks as in claim 2 is provided.
Use a space to place a switching valve or connect external piping.
It is possible to continue.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 3 is an explanatory view showing the overall structure of a cooling device for a V-type internal combustion engine according to the present invention.

In this V-type internal combustion engine, as shown in FIG. 1, cylinder heads 2 are fixed to upper surfaces of left and right banks of a cylinder block 1, respectively. A pair of cylinder block side water jackets 3 are formed along the cylinder row. This water jacket 3 on the cylinder block side
Is formed so as to surround the upper half of the cylinder 4 as shown in FIG. In the cylinder head 2, an intake port 6 is formed inside the bank with the combustion chamber 5 interposed therebetween, and an exhaust port 7 is formed outside the bank.
The cylinder head side water jacket 8 is formed so as to surround the exhaust port 7 and the like. Note that the water jacket 3 on the cylinder block side and the water jacket 8 on the cylinder head side are partially connected similarly to a general water-cooled cooling device.

Further, between the cylinder heads 2 of both banks,
As shown in FIG. 1, an intake manifold drawer 9a forming a part of the intake manifold 9 is arranged, and a branch portion thereof is connected to the intake port 6 of each cylinder. An intake manifold upper 9b is connected to the intake manifold drawer 9a, and communicates with a collector 9c located above one bank.

As shown in FIG. 3, a water pump 11 is provided on the front surface of the cylinder block 1, specifically, on the front surface of one bank. A cooling water distribution chamber 12 is formed at a position between the banks at the front end of the cylinder block 1 so as to communicate with the discharge port 11a of the water pump 11. The cooling water distribution chamber 12 has a cooling water inlet 13,
The cooling water is introduced into the water jackets 3 on the cylinder block side of the left and right banks through the respective 14. Cooling water is also introduced into the water jacket 8 on the cylinder head side of each bank via cooling water inlets 15 and 16 opened on the bottom surface of the cylinder head 2. The water pump 11 includes a chain chamber 1 defined by a chain case rear 17 and a chain case front 18.
9 are driven simultaneously by a timing chain for driving a valve operating mechanism.

A thermostat housing 21 is provided at the front end of one of the cylinder heads 2. The inside of the thermostat housing 21 and the water pump 1 are provided.
The first pump chamber communicates with the first pump chamber via the cooling water introduction chamber 22 of the cylinder block 1. A known thermostat valve 23 is inserted into the thermostat housing 21 and an inlet tube 24 is attached. A heater outlet passage 25 and a thermostat valve 23 are provided in a side flange portion of the thermostat housing 21.
Is connected to a bypass passage 26 that is opened and closed.

On the other hand, the position between the banks at the rear end of the cylinder block 1 , more specifically, the bank connecting the left and right banks
As shown in FIG. 4, a cooling water outlet 28 having an upwardly facing flange surface 27 is formed on the upper surface of the inter-connecting portion . The cooling water outlet 28 is concavely formed in a circular shape facing upward, and a pair of communication holes 29 and 30 are formed obliquely so as to partially overlap the cooling water outlet 28. Each communication hole 29, 30 extends toward the center of the cylinder 4 at the rear end of the left and right banks, and communicates with the cylinder block side water jacket 3 of each bank as shown in FIG. That is, the cooling water outlet 28 communicates with the left and right cylinder block side water jackets 3 via the respective communication holes 29 and 30.

A switching valve 31 also serving as a water outlet is provided on the flange surface 27 where the cooling water outlet 28 is opened.
Is attached. This switching valve 31 is shown in FIGS.
As shown in FIG. 1, a main body includes a flange portion 32, a cylindrical portion 33 having one end opened, and a butterfly valve type valve body 35 for opening and closing a cooling water passage 34 formed in the cylindrical portion 33. In addition, a diaphragm type actuator 36 for driving the valve body 35 is attached to a side portion, and a solenoid valve 38 for opening and closing a negative pressure passage 37 (see FIG. 2) from a vacuum tank (not shown) to the actuator 36 is provided. It is attached to the end of the cylindrical part 33.
As shown in FIG. 2, this switching valve 31 is fixed with the opening side of the cylindrical portion 33 facing the rear of the engine, and as shown in FIG. The passage 39 is connected.

At the rear end of each cylinder head 2,
Each of the cooling water outlets 40 is formed, and these cooling water outlets 40 are also connected to the radiator inlet passage 39. A heater inlet passage 41 branches off from the vicinity of the cooling water outlet 40 of one cylinder head 2, and a heater core 42 is interposed between the heater inlet passage 41 and the above-described heater outlet passage 25. Also radiator entrance passage 3
The bypass passage 26 described above branches off from the middle of the line 9. A radiator 44 is interposed between the radiator outlet passage 43 connected to the inlet tube 24 and the radiator inlet passage 39. In addition, FIG.
1 shows a piping layout in a case where a V-type internal combustion engine is mounted on a vehicle in a so-called horizontal configuration.

The flow of the cooling water in this embodiment will be described with reference to FIG. 3. The cooling water pumped by the water pump 11 once flows into the cooling water distribution chamber 12, from which the left and right sides of the cylinder block 1 side are moved. The water flows into the water jacket 3 and the left and right water jackets 8 on the cylinder head 2 side from the front end side. These cooling waters flow inside the water jackets 3 and 8 toward the rear of the engine.
The cooling water flowing through the water jacket 8 on the cylinder head side is taken out from the cooling water outlet 40 at the rear end, and is guided to the radiator 44 via the radiator inlet passage 39.
The cooling water flowing through each cylinder block side water jacket 3 is taken out from the cooling water outlet 28 via the switching valve 31 and is also guided to the radiator 44 via the radiator inlet passage 39. The cooling water exchanged by the radiator 44 returns to the thermostat housing 21 through the radiator outlet passage 43, and circulates again to the water pump 11 via the thermostat valve 23. A part of the cooling water is guided to the heater core 42. When the thermostat valve 23 is closed and the water temperature is low, the water flows from the radiator inlet passage 39 to the bypass passage 26 and returns from the thermostat housing 21 to the water pump 11.

On the other hand, when the load of the engine is low, the valve 3 of the switching valve 31 is controlled by a control signal of a control unit (not shown).
5 is closed. In this state, the cooling water hardly flows through the water jacket 3 on the cylinder block side, and the cooling water circulates only in the water jacket 8 on the cylinder head side. Therefore, the temperature on the side of the cylinder block 1 is kept high, and particularly, the wall temperature of the cylinder 4 becomes high, and the friction loss is reduced.

Here, in the above configuration, the cylinder block 1
The cooling water outlet 28 on the side is provided at a position between the banks at the rear end of the cylinder block 1, so that the amount of protrusion from the rear end of the cylinder block 1 to the rear is reduced, and the overall size of the engine can be reduced. As is clear from FIGS. 1 and 2, the switching valve 31 can be accommodated in an empty space between the intake manifold 9 and the external piping interferes with the intake manifold 9 and a transmission (not shown). Therefore, the configuration of the rear end of the engine can be very compactly assembled. As is apparent from FIG. 4, the cooling water outlet 28 communicates with the water jackets 3 of the left and right banks at the same position with respect to the cylinder bore, so that there is no imbalance in the flow rates of the left and right banks. .

[0020]

As is apparent from the above description, according to the cooling device for a V-type internal combustion engine according to the present invention, in a cooling device of a so-called two-system cooling system, The cooling water outlet communicating with the water jacket on the cylinder block side of the left and right banks is opened upward, so that cooling water can be taken out using the empty space between the banks, and the overall length of the engine can be shortened. The configuration can be simplified as compared with the case where the cooling water outlets are provided for each of the left and right banks. Further, in the case where a switching valve for changing the flow rate of the two systems is provided, the installation space thereof can be easily secured, and the size of the entire engine can be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rear end portion of a V-type internal combustion engine according to the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1;

FIG. 3 is an explanatory diagram showing the configuration of the entire cooling system.

FIG. 4 is a plan view of a single cylinder block.

FIG. 5 is a sectional view showing only a switching valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Cylinder head 3 ... Water jacket on cylinder block side 8 ... Water jacket on cylinder head side 28 ... Cooling water outlet 31 ... Switching valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01P 3/02 F01P 3/20 F02B 75/22

Claims (2)

(57) [Claims] 1. A cooling water distribution chamber communicating with a discharge side of a water pump attached to a front end portion of a cylinder block is formed at a position between banks at a front end portion of the cylinder block. In a cooling device for a V-type internal combustion engine configured to introduce cooling water into the water jacket and the water jacket on the cylinder head side and to flow backward from the front end, respectively.
A cooling water outlet is provided at the rear end of each cylinder head, and the interbank connection at the rear end of the cylinder block
A cooling device for a V-type internal combustion engine, characterized in that cooling water outlets communicating with the water jackets of the left and right banks on the cylinder block side are formed on the upper surface of the upper surface of the upper surface . 2. A cooling water outlet on the cylinder block side.
Is connected to a switching valve that opens and closes the cooling water outlet.
In both cases, this switching valve is an intake system component located between banks.
Contracted in the space below
The cooling device for a V-type internal combustion engine according to claim 1.