JPH0763054A - Water cooler of multicylinder engine - Google Patents

Abstract

PURPOSE:To achieve just enough cooling at each cylinder in equalizing a quantity of cooling water passing in and around each spot of respective cylinders by setting up each of both cooling water return and outlet ports as being sorted to both front and rear opposite sides of this multicylinder engine. CONSTITUTION:A water pump house 12 and a cooling water return port 5 both are formed in a cylinder jacket 1. In addition, a lower tank 13b of a radiator 4 is interconnected to the cooling water return port 5 via a cooling water inlet pipe 14 and the water pump house 12 in order. Likewise, a cooling water outlet 6 is formed in a head jacket 2. In succession, this cooling water outlet 6 is interconnected to an upper tank 13a of the radiator 4 via a cooling water outlet pipe 15. With this constitution, cooling water taken in from the cooling water return port 5 passes through the cylinder jacket 1, a water port 3 and the head jacket 2 in order toward the cooling water outlet 6 at the longitudinal opposite side. Therefore, a quantity of cooling water passing in and around each cylinder is equalized, so that neither-more-nor-less cooling is thus realizable at each cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water cooling device for a multi-cylinder engine, and more particularly to a device for equalizing the amount of cooling water passing around each cylinder so as to perform proper cooling without excess or deficiency in each cylinder.

[0002]

BACKGROUND OF THE INVENTION The basic structure of a water cooling system for a multi-cylinder engine, which is the subject of the present invention, is as follows, as shown in FIG. 1 or FIG. That is, the cylinder jacket 1 and the head jacket 2 of a multi-cylinder engine E having a plurality of cylinders arranged in the front-rear direction are communicated with each other through a plurality of water passages 3 arranged in the front-rear direction, and the cooling water outlet of the head jacket 2 is connected. 6 is connected to the cooling water return port 5 of the cylinder jacket 1 via the radiator 4, and the cooling water flowing from the cooling water return port 5 is
Cylinder jacket 1, water passage 3, head jacket 2
Through the cooling water outlet 6, and the radiator 4 radiates heat.

[0003]

2. Description of the Related Art As a conventional technique of this type, as shown in FIG. 3, a cooling water return port 5 is provided on the front side of a cylinder jacket 1 of a vertical multi-cylinder water-cooled engine E, and cooling is performed on the front side of a head jacket 2. A water outlet 6 is generally provided.

[0004]

In the above prior art, most of the cooling water that has flowed into the front portion of the cylinder jacket 1 from the cooling water return port 5 flows to the front portion of the head jacket 2 through the front water passage port 3. It is short-circuited and tends to pass around the front cylinder. Therefore, while the amount of cooling water passing around the front cylinder is excessive, the amount of cooling water passing around the rear cylinder is insufficient, and proper cooling is not performed in each cylinder, causing various inconveniences. .

That is, in the front cylinder, due to supercooling, the degree of thermal expansion of the cylinder head is smaller than that of the piston head, and the piston ring and the cylinder liner are pressed against each other with excessive pressure, and these are worn. easy. In addition, in the cylinder closer to the rear, seizure easily occurs between the piston ring and the cylinder liner due to insufficient cooling. Also,
Since the heat drop between the front and rear portions of the cylinder block and the cylinder head becomes large, the thermal strain of these becomes large, and cooling water leakage and gas leakage easily occur from the joint sealing surfaces of these.

It is an object of the present invention to provide a water cooling device for a multi-cylinder engine, which equalizes the amount of cooling water passing around each cylinder and can perform proper cooling without excess or deficiency in each cylinder.

[0007]

[Means for Solving the Problems]

(First Invention) As shown in FIG. 1, a first invention is a water cooling device for a multi-cylinder engine having the basic structure, in which the cooling water return port 5 and the cooling water outlet 6 are provided before and after the multi-cylinder engine E. The feature is that they are distributed to the opposite side and arranged respectively.

(Second Invention) As shown in FIG. 2, the second invention is such that, in the first invention, the outlet side water passage 7 is led out from the cooling water outlet 6 along the outer wall surface 11a of the cylinder head 11. The exhaust port 8 projecting from the outer wall surface 11a is traversed in the outlet side water channel 7.

[0009]

[Operation and effect of the invention]

(First Invention) As illustrated in FIG. 1, the cooling water flowing in from the cooling water return port 5 flows toward the cooling water outlet 6 on the opposite side in the front-rear direction through the cylinder jacket 1, the water passage port 3, and the head jacket 2. Pass in order. For this reason, the amount of cooling water passing around each cylinder is equalized, cooling is performed in each cylinder without excess and deficiency, and various inconveniences due to insufficient cooling can be avoided.

That is, the piston ring and the cylinder liner are less likely to wear due to supercooling. Further, seizure between the piston ring and the cylinder liner due to insufficient cooling hardly occurs. Further, since the heat drop between the front and rear portions of the cylinder block 10 and the cylinder head 11 is small, the thermal strain of these is also small, and cooling water leakage and gas leakage from these joint sealing surfaces are unlikely to occur.

(Second invention) The second invention has the following effects in addition to the effects of the first invention. That is, as illustrated in FIG. 2, the exhaust gas in the exhaust port 8 cooled by the cooling water in the head jacket 2 is recooled by the cooling water flowing in the outlet side water passage 7. Therefore, the temperature of the exhaust gas discharged from the end of the exhaust muffler is low and the expansion coefficient is small, so that the exhaust noise due to the expansion of the exhaust gas is low. Also, since the volume of exhaust gas in the exhaust path is small and the back pressure is low,
High scavenging efficiency of the combustion chamber and high output performance.

[0012]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a vertical side surface of a vertical four-cylinder engine according to a first embodiment of the present invention.

The structure of this engine E is as follows.
That is, four cylinders are internally provided in the cylinder block 10, and these cylinders are arranged in the front-rear direction. The cylinder head 11 is assembled on the upper side of the cylinder block 10, and the radiator 4 is arranged on the front side of these.
A cylinder jacket 1 is provided inside the cylinder block 10, and a head jacket 2 is provided inside the cylinder head 11. A plurality of water passages 3 are provided on the joint surface between the cylinder block 10 and the cylinder head 11, and the cylinder jacket 1 and the head jacket 2 communicate with each other through the water passages 3. The plurality of water passage holes 3 are arranged in the front-rear direction.

A water pump chamber 12 and a cooling water return port 5 are formed in the cylinder jacket 1. The lower tank 13b of the radiator 4 is connected to the cooling water inlet pipe 1
4, cooling water return port 5 through the water pump chamber 12 in order
Is in communication with. A cooling water outlet 6 is formed in the head jacket 2. The cooling water outlet 6 communicates with the upper tank 13a of the radiator 4 via the cooling water outlet pipe 15.

In this engine E, the cooling water flowing from the cooling water return port 5 is supplied to the cylinder jacket 1, the water passage port 3,
After passing through the head jacket 2 in order, it flows out from the cooling water outlet 6 and is radiated by the radiator 4.

In this engine E, the following structure is adopted in order to equalize the amount of cooling water passing around each cylinder and perform proper cooling in each cylinder without excess or deficiency. That is, the water pump chamber 12 and the cooling water return port 5 are formed in the front part of the cylinder jacket 1, and the cooling water return port 6 is provided in the rear part of the head jacket 1. A thermostat valve 16 is provided at the cooling water outlet 6.
Is provided, and a detour 17 to the water pump chamber 12 is formed in the front portion of the head jacket 2.

Therefore, when the temperature of the cooling water exceeds the opening temperature setting temperature of the thermostat valve 16, the thermostat valve 16 is open, so that the cooling water returns from the cooling water return port 5 by the action of the water pump. The cooling water thus passed sequentially passes through the cylinder jacket 1, the water passage 3, and the head jacket 2 toward the cooling water outlet 6 on the opposite side in the front-rear direction. Therefore, the amount of cooling water passing around each cylinder is equalized.

If the temperature of the cooling water is lower than the set temperature for opening the thermostat valve 16, the thermostat valve 1
Since 6 is closed, the cooling water of the cylinder jacket 1 is
It circulates by passing through the communication port 6, the head jacket 2, the detour 17, and the water pump chamber 12 in order, and does not flow to the radiator 4, and warm-up operation is performed.

Next, a second embodiment of the present invention will be described. FIG. 2 is a cross-sectional plan view of a cylinder head used in a multi-cylinder engine according to the second embodiment of the present invention. The cylinder head 11 used in the second embodiment differs from the cylinder head 11 of the first embodiment shown in FIG. 1 only in the following points. That is, the outlet side water passage 7 is led out from the cooling water outlet 6 along the outer wall surface 11a of the rear portion and the lateral portion of the cylinder head 11, and the exhaust port 8 protruding from the outer wall surface 11a traverses in the outlet side water passage 7. ing. Therefore, the exhaust gas in the exhaust port 8 cooled by the cooling water in the head jacket 2 is recooled by the cooling water flowing in the outlet side water passage 7. Further, the thermostat valve 16 is arranged in the outlet side water passage 7.

Since the present invention is characterized in that the cooling water return port 5 and the cooling water outlet 6 are distributed to the front and rear opposite sides of the multi-cylinder engine, contrary to the above embodiment, the cooling water return port 5 is provided.
To the rear side and the cooling water outlet 6 to the front side.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vertical side surface of a vertical four-cylinder engine according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of a cylinder head used in a vertical four-cylinder engine according to a second embodiment of the present invention.

FIG. 3 is a view corresponding to FIG. 1 of the prior art.

[Explanation of symbols]

1 ... Cylinder jacket, 2 ... Head jacket, 3 ...
Water passage port, 4 ... Radiator, 5 ... Cooling water return port, 6 ... Cooling water outlet, 7 ... Exit side water channel, 8 ... Exhaust port, 11 ... Cylinder head, 11a ... 11 outer wall surface, E ... Multi-cylinder engine.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuyuki Nakamura 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Co., Ltd. (72) Kozo Yoshida 64, Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Plant

Claims (2)

[Claims] 1. A cylinder jacket (1) and a head jacket (2) of a multi-cylinder engine (E) having a plurality of cylinders arranged in the front-rear direction, through a plurality of water passages (3) arranged in parallel in the front-rear direction. Cooling water outlet (6) of the head jacket (2)
Communicates with the cooling water return port (5) of the cylinder jacket (1) through the radiator (4), and the cooling water flowing from the cooling water return port (5) is connected to the cylinder jacket (1) and the water passage port (3). In the water cooling device of the multi-cylinder engine, which is configured to pass through the head jacket (2) in order, flow out from the cooling water outlet (6), and dissipate heat by the radiator (4), the cooling water return port (5) and A water cooling device for a multi-cylinder engine, characterized in that the cooling water outlet (6) is arranged on the front and rear opposite sides of the multi-cylinder engine (E), respectively. 2. The water cooling device for a multi-cylinder engine according to claim 1, wherein the cylinder head is provided from the cooling water outlet (6).
The outlet side water channel (7) was led out along the outer wall surface (11a) of (11), and the exhaust port (8) protruding from the outer wall surface (11a) was made to traverse in the outlet side water channel (7). A water cooling device for a multi-cylinder engine characterized by the above.