JPH0140217B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cooling device for a V-type engine, and in particular to an installation structure for a cooling water circulation system.

(Prior Art) A V-type engine in which a cylinder block is provided with left and right cylinder heads requires a passage for circulating cooling water flowing into the left and right cylinder heads to a radiator.

In addition, an intake manifold will be installed between the left and right cylinder heads to supply intake air from the air cleaner to each cylinder of the left and right cylinder heads.
A known technique is to heat the intake air by joining an intake manifold to the upper surface of the cylinder block and connecting the cooling water jacket of the cylinder block to the radiator through the intake manifold.

As in the above-mentioned known technology, connecting the cooling water that has passed through the cylinder block or cylinder head to the radiator through the intake manifold located between the left and right cylinder heads simplifies the cooling water circulation system. Although it has the advantage of being able to
Passing the cooling water passage through the intake manifold heats the intake air. As in this known example, engines equipped with a carburetor can actively heat the intake air to promote vaporization of the air-fuel mixture. In an engine with a conventional engine, heating the intake air has the problem that the density of the air decreases, resulting in a decrease in charging efficiency and, on the contrary, a decrease in output.

However, separating the cooling water passage from the intake manifold and installing it separately requires the installation of pipes, etc., resulting in space constraints or complicating the engine structure and layout.

(Object of the Invention) In view of the above circumstances, the present invention forms a cooling water passage in the intake manifold in order to ensure the simplification of the cooling water circulation system, and at the same time suppresses intake air heating by this cooling water passage to improve charging efficiency. It is an object of the present invention to provide a cooling device for a V-type engine that prevents a decrease in output due to power reduction.

(Structure of the Invention) The cooling device for a V-type engine of the present invention is a V-type engine in which a cylinder block is provided with left and right cylinder heads, and an intake manifold has a distribution chamber for introducing intake air from an air cleaner, and a distribution chamber for introducing intake air from an air cleaner. It has a branch passage that distributes intake air introduced into the left and right cylinder heads to each cylinder of the left and right cylinder heads, and two water chambers are formed independently before and after the intake manifold. The cooling water jackets are connected to each other, and one water chamber is connected to a radiator, and the other water chamber is connected to a heat exchanger such as a heater.

(Effects of the invention) By connecting the cooling water that has passed through the left and right cylinder heads to a heat exchanger such as a radiator or heater via an intake manifold,
It is possible to enjoy the advantage of arranging the cooling water circulation system in the intake manifold and simplify its configuration, and also to suppress the heat exchange between the cooling water and the intake air to prevent a decrease in output due to an increase in the intake air temperature. Can be done.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the V-type engine 1 has a left cylinder head 3A and a right cylinder head 3B arranged at an angle on a cylinder block 2, each having a cylinder C at an angle to the other. A left bank 1A and a right bank 1B are formed.

An intake manifold 5 is disposed between the left and right cylinder heads 3A and 3B in the left and right banks 1A and 1B. This intake manifold 5 has a distribution chamber 5a that introduces intake air from the air cleaner 6.
(surge tank), and branch passages 5b for distributing the intake air introduced into the distribution chamber 5a to each cylinder C of the left and right cylinder heads 3A, 3B.

The cooling device for the V-type engine 1 has two water chambers 7 and 8 that are independently formed before and after the intake manifold 5. The front and rear water chambers 7, 8 are communicated with cooling water jackets 9, 9 of the left and right cylinder heads 3A, 3B, respectively, and water is supplied to the left and right cylinder blocks 2 from a water pump 10 to the water chambers 7, 8. It is provided so that the cooling water that has passed through the cylinder heads 3A and 3B flows into it.

The front water chamber 7 is connected to the radiator 12 via the thermostat 11 and to the suction side of the water pump 10.
The cooling water that has passed through is connected by a thermostat 11 to be circulated to a water pump 10 when the temperature is low and to a radiator 12 when the temperature is high.
The outflow side of the water pump 2 is connected to the suction side of the water pump 10.

In addition, the rear water chamber 8 is equipped with a heater 13 for indoor heating.
(heat exchanger), and is connected to the suction side of the water pump 10 via the heater 13.

Note that 14 indicates a throttle installed in the cooling water passage from the cooling water jackets 9, 9 of the cylinder heads 3A, 3B to the water chamber 8 at the rear. This is for adjusting the flow rate ratio of cooling water to 13).

Specific structural examples are shown in FIGS. 2 to 5. In this specific example, in a V-type engine 1, a low-speed intake port 14, a high-speed intake port 15, and an exhaust port 16 are opened in each cylinder C, and
A low-speed intake passage 17, a high-speed intake passage 18, and an exhaust passage 19 are connected to each port, and each port 14 to 16 is operated at a predetermined timing by a low-speed intake valve 20, a high-speed intake valve 21, and an exhaust valve 22. This is an example of a 3-port type that opens and closes at .

The intake manifold 5 is formed with a low-speed intake passage 17 and a high-speed intake passage 18 corresponding to the three-port type. The low-speed intake passage 17 introduces intake air from the air cleaner 6 into the distribution chamber 17b via the introduction passage 17a, and from both lower sides of the distribution chamber 17b, which has a large volume common to each cylinder C, passes through branch passages 17c to the left and right banks 1A. , 1B, and a fuel injection nozzle 23 for each cylinder C is arranged in this low-speed intake passage 17.

The high-speed intake passage 18 (not shown) introduces and distributes the intake air from the air cleaner 6 through the introduction passage 18a, and distributes it to the side of the distribution chamber 17b of the low-speed intake passage 17. The provided high-speed branch intake passages 18b are connected to the high-speed intake ports 15 of each cylinder C of the left and right banks 1A and 1B, respectively.

Furthermore, the front and rear water chambers 7 and 8 formed in the intake manifold 5 are formed as independent chambers at the front and rear so as to project into the interior of the distribution chamber 17b of the low-speed intake passage 17, and the front and rear water chambers Outflow ports 9a, 9a of cooling water jackets 9, 9 formed in the left and right cylinder heads 3A, 3B are connected to inflow ports 7a, 8a provided on the left and right sides below the water chambers 7, 8, respectively. Cooling water flows into 8.

An outlet 7b provided at the front end of the front water chamber 7 is connected to a radiator 12 and a water pump 10 via a thermostat 11, while an outlet 8b provided at the rear end of the rear water chamber 8 is connected to a radiator 12 and a water pump 10 via a thermostat 11. Heater 1
Connected to 3.

In the structure of the intake manifold 5, the front and rear water chambers 7, 8 are designed so that there is almost no contact (heat exchange) with the low-speed intake passage 17 and the high-speed intake passage 18, which is greatly affected by fluctuations in intake air temperature. The heat transfer area relative to the volume is set to be as small as possible.

As a result, the water chambers 7 and 8 for cooling water circulation are formed integrally with the intake manifold 5, thereby simplifying the structure of the cooling water circulation system. High speed intake passage 1
7 and 18, thereby suppressing the heating and temperature increase of the intake air, thereby preventing a decrease in output.

[Brief explanation of drawings]

FIG. 1 is an overall schematic configuration diagram of a V-type engine according to an embodiment of the present invention, FIG. 2 is a central sectional side view of the main part of the V-type engine showing a specific structural example, and FIG. 3 is a - 4 is a partially sectional plan view of the intake manifold, and FIG. 5 is a sectional front view of the intake manifold and cylinder head taken along line - in FIG. 4. 1...V-type engine, 1A, 1B...bank,
2... Cylinder block, 3A, 3B... Cylinder head, 5... Intake manifold, 5a, 17
b... Distribution chamber, 5b, 17c, 18b... Branch passage, 6... Air cleaner, 7, 8... Water chamber, 9...
...Cooling water jacket, 10...Water pump,
12...Radiator, 13...Heater, C...Cylinder.

Claims (1)

[Claims] 1 In a V-type engine in which a cylinder block is provided with left and right cylinder heads, the intake manifold has a distribution chamber that introduces intake air from the air cleaner and distributes the intake air introduced into the distribution chamber to each cylinder of the left and right cylinder heads. Two water chambers are formed independently before and after the intake manifold, each water chamber is communicated with the cooling water jackets of the left and right cylinder heads, and one water chamber is A cooling device for a V-type engine, characterized in that a radiator is connected to the other water chamber, and the other water chamber is connected to a heat exchanger such as a heater.