JP2000087741A - Engine cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reduce the duration of warm-up time in cold starting of the engine. SOLUTION: An engine cylinder block 3 is provided with integrally formed water jackets 5, 6 extending in the longitudinal direction thereof and a coolant passage 9. During the cold starting of the engine, the coolant circulation is such that the coolant discharged from the coolant pump flows through the water jackets 5, 6 and into the water jackets formed in the cylinder head from left to right in the figure shown. The coolant then flows from the other end 13 of the coolant passage 9 into the coolant passage 9 from right to left in the figure shown, and finally flows into the coolant pump.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a water-cooled engine, and more particularly to a structure for shortening a warm-up time of an engine at a cold start.

[0002]

2. Description of the Related Art Reducing the warm-up time at the cold start of an engine can promote the temperature rise of an exhaust purification catalyst and improve the heating performance using cooling water. For example, in a conventional cross-flow engine that supplies cooling water to the engine from the front and discharges cooling water from the other side of the engine, for example, from the rear,
As exemplified in Japanese Utility Model Publication No. 6-14030,
The cooling water discharged from the rear end face of the cylinder head is led to the radiator on the front side of the engine by a cooling water outlet pipe installed along the longitudinal direction of the engine away from the engine body, or by bypassing the radiator from the thermostat It is configured to guide to the cooling water pump,
In this case, the cooling water radiates heat while flowing through the relatively long cooling water outlet pipe, so that the rise of the cooling water temperature is suppressed,
There was a problem that engine warm-up was delayed.

Further, the cooling water jacket in the cylinder block is made relatively shallow, the amount of circulating cooling water is reduced by reducing the volume of the cooling water jacket, and the temperature rise of the cooling water at the time of cold start of the engine is accelerated. Although it is conceivable, reducing the capacity of the cooling water jacket reduces the heat receiving area of the cooling water, and the effect of increasing the temperature of the cooling water is not always good. Was inadequate.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to easily shorten the warm-up time when the engine is cold started.

[0005]

Therefore, an engine cooling structure according to the present invention includes a cooling water pump disposed at one end of an engine body, and a cooling water pump formed in the engine body and discharged from the cooling water pump. A cooling water jacket for guiding water from the one end side to the other end side of the engine body, and cooling water formed integrally with a cylinder block of the engine body and discharged from the other end side of the engine body. A cooling water passage leading to the cooling water pump.

That is, the cooling water discharged from the cooling water pump disposed at one end of the engine main body is guided from one end side to the other end side of the engine main body by a cooling water jacket formed on the engine main body. The cooling water discharged from the other end of the engine body is guided to the cooling water pump by the cooling water passage, but flows through the cooling water passage because the cooling water passage is formed integrally with the cylinder block of the engine body. As a result, the cooling water is suppressed from radiating heat as in the conventional device. As a result, the temperature of the cooling water can be increased relatively quickly during the cold start of the engine, and the warm-up time can be easily reduced. .

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described by assigning the same reference numerals to the same parts. 1 to 6, a water-cooled horizontal in-line four-cylinder engine 2 mounted on a vehicle 1 includes an engine body including a cylinder block 3 and a cylinder head 4, the cylinder block 3 being adjacent to the cylinder head 4. The cooling water jackets 5, 6 extending in the longitudinal direction are integrally formed. In this case, the cooling water jackets 5,
Numeral 6 is relatively shallow, for example, so that the lower ends of the cooling water jackets 5, 6 are arranged above the position of the piston ring at the time of the bottom dead center of the piston (not shown).

A plurality of communication passages 7 formed in the cylinder block 3 at appropriate intervals in the longitudinal direction of the cooling water jackets 5, 6 to form a cooling water jacket integrally formed with the cylinder head 4 and extending in the longitudinal direction. 8 and the cooling water jackets 5 and 6 communicate with each other.

Further, a cooling water passage 9 is formed integrally below the cylinder block 3 along the cooling water jacket 5, and a suction port of a cooling water pump 10 disposed in front of the cylinder block 3. The other end 13 of the cooling water passage 9 is connected to a thermostat 12 disposed on the rear side of the cylinder block 3.
The thermostat 12 is connected to the rear end side of the cooling water jacket 8 in the cylinder head 4, and is connected to the upper tank of the radiator 14, and the lower tank of the radiator 14 is connected to the other end 13 of the cooling water passage 9. The outlet of the cooling water pump 10 is connected to the front ends of the cooling water jackets 5 and 6.

Accordingly, as indicated by the arrow in the figure, the cooling water discharged from the cooling water pump 10 when the engine 2 is operating flows through the cooling water jackets 5 and 6 of the cylinder block 3 in the longitudinal direction. At the same time as flowing to the rear side of the cylinder block 3, flows into the cooling water jacket 8 of the cylinder head 4 through each communication passage 7, and further flows through the cooling water jacket 8 along the longitudinal direction of the cylinder head 4. Although flowing toward the rear side, when the engine 2 is cold started, the flow to the radiator 14 is blocked by the thermostat 12, so that the cooling water flows from the other end 13 of the cooling water passage 9 through the cooling water passage 9 to the cooling water. The cooling water is returned to the suction port of the pump 10 and circulates.

That is, since the cooling water passage 9 is formed integrally with the cylinder block 3, the heat radiation of the cooling water when the cooling water flows through the cooling water passage 9 is suppressed to a minimum. As a result, the temperature rise of the cooling water at the time of the cold start is effectively promoted, and the warming-up of the engine 2 is easily accelerated. In addition, there is an advantage that heating performance using cooling water can be improved.

The cooling water jackets 5, 6 are formed relatively shallow, and the amount of cooling water circulating through the cooling water jackets 5, 6 is relatively small. Can be promoted, and the weight of the engine 2 can be reduced.

Further, even if the cooling water jackets 5 and 6 are formed relatively shallow, since the cooling water passage 9 is formed integrally with the cylinder block 3 below the cooling water jacket 5, the cylinder block 3 The cooling water passage 9 is formed integrally with the cylinder block 3, so that the cooling water return passage is provided outside the cylinder block. Compared to the above-described conventional device, there is an advantage that the entire engine 2 is configured to be compact and mounting on the vehicle 1 becomes easy.

As shown in FIG. 6, the inner wall surface 9a of the cooling water passage 9 which enters between the respective cylinder bores is formed.
Since the curvature in the horizontal plane is set to be relatively large, there is no danger that the cooling water stagnates between the cylinder bores and the temperature distribution of the cylinder liner becomes uneven.

In the embodiment shown in FIGS. 7 and 8, a relatively shallow cooling water jacket 6 is formed integrally with the cylinder block 3 and is adjacent to the cylinder head 4 and extends in the longitudinal direction thereof. A plurality of communication passages 7 formed in the cylinder block 3 at appropriate intervals in the longitudinal direction of the jacket 6 form a cooling water jacket 8 and a cooling water jacket 6 integrally formed with the cylinder head 4 and extending in the longitudinal direction. Further, a cooling water passage 9 extending in the longitudinal direction of the cylinder block 3 and adjacent to the cylinder head 4 is formed integrally with the cylinder block 3, and a cooling water pump disposed on the front surface of the cylinder block 3. 10
The other end 13 of the cooling water passage 9 is connected to a thermostat 12 disposed on the rear surface side of the cylinder block 3, and the thermostat 12 is connected to the cylinder head 4. Is connected to the rear end side of the cooling water jacket 8 in the first embodiment, and other structures are not particularly different from those in the above-described embodiment.

Therefore, as indicated by the arrows in the figure, the cooling water discharged from the cooling water pump 10 when the engine 2 is operating is supplied to the cooling water jacket 6 of the cylinder block 3 and the cooling water of the cylinder head 4. The cooling water is supplied into the jacket 8 and flows in the cooling water jacket 6 along the longitudinal direction to the rear side of the cylinder block 3, and at the same time, flows into the cooling water jacket 8 of the cylinder head 4 through each communication path 7. Further, the coolant flows through the cooling water jacket 8 along the longitudinal direction to the rear side of the cylinder head 4, but when the engine 2 is started in a cold state, the cooling water is entirely discharged from the other end 13 of the cooling water passage 9 by the thermostat 12. The cooling water passage 9 is returned to the suction port of the cooling water pump 10 through the inside of the cylinder 9 and the cooling water passage 9 is formed integrally with the cylinder block 3 as in the above-described embodiment. Because, it is possible to obtain the same effect as the above embodiment.

[0017]

In the engine cooling structure according to the present invention, the cooling water discharged from the other end of the engine body is guided to the cooling water pump through a cooling water passage formed integrally with the cylinder block. Since the cooling water flowing through the cooling water passage is suppressed from radiating heat as in the conventional device, the temperature of the cooling water can be raised relatively quickly during cold start of the engine, and the warm-up time can be easily reduced. In addition, the exhaust gas purifying function of the catalyst can be surely enhanced, and the heating performance using the cooling water can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic top view in an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the embodiment.

FIG. 3 is a vertical sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a conceptual explanatory view of a cooling water passage in the embodiment.

FIG. 5 is a perspective view of a cooling water passage in the embodiment.

FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 3;

FIG. 7 is a longitudinal sectional view corresponding to FIG. 3 in another embodiment of the present invention.

FIG. 8 is a conceptual explanatory view of a cooling water passage in the other embodiment.

[Explanation of symbols]

 2 Engine 3 Cylinder block 4 Cylinder head 5, 6, 8 Cooling water jacket 9 Cooling water passage 10 Cooling water pump 12 Thermostat

Claims (1)

[Claims] 1. A cooling water pump disposed at one end of an engine body and cooling water formed in the engine body and discharged from the cooling water pump from the one end to the other end of the engine body. An engine cooling structure comprising: a cooling water jacket for leading; and a cooling water passage formed integrally with a cylinder block of the engine body and leading cooling water discharged from the other end of the engine body to the cooling water pump.