JPH04347327A - Water cooler of engine - Google Patents

Abstract

PURPOSE:To prevent any overheating from occurring by cooling a thrust side higher in the heat load of a cylinder strongly before an engine is not approximated to an abnormal high temperature as well as increasing the extent of circulation of cooling water when it is approximated to the abnormal temperature after checking any heat strain in the cylinder. CONSTITUTION:A thrust side water hole 4c, leading to a head jacket 5 from a cylinder jacket 3, and a counter thrust side water hole 4d are installed parallelly, and a passage expanding thermosensitive working valve 7 is installed in this counter thrust side water hole 4d. This working valve 7 is operated at a time when a temperature of cooling water goes up to a passage expanding working temperature T1 a little lower than an abnormal high temperature area Th, expanding a passage sectional area S of the water hole 4d up to an expanded sectional area S1 from the reference sectional area Sb. In this connection, the passage sectional area S of the water hole 4c is set to be larger in value than that of the reference sectional area Sb of the water hole 4d.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water cooling system for an engine.

0002

[Prerequisite Structure] The engine water cooling system of the present invention is predicated on having the following prerequisite structure, as shown in FIG. 4, for example. That is, the cooling water of the engine 1 is pumped from the cylinder jacket 3 to the water hole 4 and the head jacket 5 by the water pump 2.
- It is constructed so that the radiator 6 and the cylinder jacket 3 are fed and circulated in this order. The water hole 4 includes a thrust side water hole 4c located on the thrust side 10 of the cylinder 25, and a thrust side water hole 4c located on the anti-thrust side 11 of the cylinder 25.
The anti-thrust side water holes 4d are arranged in parallel.

0003

[Prior art] In the above-mentioned premise structure, in the prior art,
The water hole 4 was formed to have a standard cross-sectional area Sb.

0004

[Problems to be Solved by the Invention] The above-mentioned prior art has the following problems. Since the water hole 4 is formed to have a standard cross-sectional area Sb, when the load output does not exceed the rating of the engine 1, the circulating amount of cooling water does not become excessive, and a reduction in combustion performance due to overcooling is prevented. ing. However, engine 1
During operation, thermal distortion occurs between the thrust side 10 of the cylinder 25, which is susceptible to heat from the piston 26 and has a high thermal load, and the anti-thrust side 11, which is less so, and in severe cases, the piston 26 may seize. be. Furthermore, during overload output, the amount of heat generated increases but the amount of circulating cooling water does not increase, so the engine 1 may overheat. An object of the present invention is to suppress thermal distortion in the cylinder 25 and seizure of the piston 26 and overheating of the engine 1 during overload.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention adds the following improved structure to the above-mentioned premise structure, as shown in FIGS. 1 and 2, for example. That is, the passage expansion temperature-sensitive operation valve 7 is provided in the anti-thrust side water hole 4d, and the passage expansion operation temperature T1 of this temperature-sensor operation valve 7 is set to a temperature slightly lower than the abnormally high temperature region Th of the cooling water. . This temperature-sensitive operation valve 7 is temperature-sensing activated when the temperature of the cooling water passing through the anti-thrust side water hole 4d rises to the passage expansion operating temperature T1, and the temperature-sensitive operation valve 7 is activated when the temperature of the cooling water passing through the anti-thrust side water hole 4d rises to the passage expansion operating temperature T1. The passage cross-sectional area S is configured to be expanded from the reference cross-sectional area Sb to the enlarged cross-sectional area S1. And, from the reference cross-sectional area Sb of this anti-thrust side water hole 4d,
The passage cross-sectional area S of the thrust side water hole 4c is set to a large value.

[0006]

[Operation] The present invention operates as follows. When the load output does not exceed the rating of the engine 1, the temperature of the cooling water passing through the water holes 4 is lower than the passage expansion operating temperature T1. At this time, since the passage cross-sectional area S of the thrust-side water hole 4c is set to a larger value than the reference cross-sectional area Sb of the anti-thrust side water hole 4d, the cylinder 25 is more likely to receive heat from the piston 26, thereby causing a thermal load on the cylinder 25. High thrust side water hole 4
Cooling water easily flows into the water hole opening 22f of c.
By powerfully cooling the cylinder 25, the cylinder 25 is evenly cooled and the occurrence of thermal distortion is suppressed. Also, temperature-sensitive valve 7
is the passage cross-sectional area S of the anti-thrust side water hole 4d as the reference cross-sectional area S
Since the amount of cooling water is maintained at b, the circulating amount of cooling water does not become excessive, and combustion performance is prevented from deteriorating due to overcooling. On the other hand, when the engine 1 outputs an overload, the temperature of the cooling water passing through the water holes 4 becomes higher than the passage expansion operating temperature T1 due to an increase in the amount of heat generated. Therefore, the temperature-sensitive operating valve 7 is temperature-sensing operated to expand the passage cross-sectional area S of the anti-thrust side water hole 4d from the standard cross-sectional area Sb to the enlarged cross-sectional area S1. As a result, the amount of circulating water increases, the cooling capacity increases, and overheating of the engine 1 is suppressed.

[0007]

[Effects of the Invention] Since the present invention is constructed and operates as described above, it has the following effects. Cooling water flows more easily into the thrust side than the anti-thrust side, and by powerfully cooling this, the cylinder is evenly cooled, suppressing the occurrence of thermal distortion and preventing piston seizure. In addition, while the amount of heat generated increases when the engine outputs an overload, the temperature-sensitive operation of the temperature-sensitive valve increases the passage cross-sectional area of the water hole, increasing the amount of circulating water, thereby suppressing engine overheating. can do.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Figure 1(A) is a plan view of the main parts of the engine head gasket.
1(B) is a sectional view taken along the line X-X in FIG. 1(A), FIG. 2 is a diagram showing the relationship between the cross-sectional area of water holes and cooling water temperature, FIG. 3 is a plan view of the head gasket, and FIG. is a schematic vertical cross-sectional view of the engine. In FIG. 4, the engine 1 includes a cylinder block 21 integrally formed above a crankcase 20, and a cylinder head 23 and a head cover 24 placed and fixed in order on the upper surface of the cylinder block 21 via a head gasket 22. , forming the engine body. Inside the cylinder block 21, there are a piston 26 that slides inside the cylinder 25, a connecting rod 28 that connects the piston 26 to a crankshaft 27, and others. Water holes 4 are provided in the inner walls of the cylinder block 21 and the cylinder head 23 to allow cooling water to flow from the cylinder jacket 3 to the head jacket 5.
It is connected through 2. The water hole 4 is connected to the cylinder 25
The anti-thrust side water hole 4d located on the anti-thrust side 11 of the cylinder 25 and the thrust side water hole 4c located on the thrust side 10 of the cylinder 25 are provided in parallel. engine 1
The cooling water flows from the crankshaft 27 to the belt 29 and pulley 30.
A water pump 2 driven through
and the cylinder jacket 3 are configured to be pumped and circulated in this order. Further, a thermostat 31 for detecting the temperature of the cooling water is provided in the middle of the cooling water circulation path, and the radiator 6 uses a radiator fan 32 to cool the high temperature cooling water. As shown in FIG. 3, the head gasket 22 includes each cylinder opening 22a, each push rod opening 22b, and each water hole opening 22c, 22d, and 22.
f and the required number of openings 22e for each mounting bolt are provided.

(First Embodiment) In the first embodiment of the present invention,
Among the water holes 4 that connect the cylinder jacket 3 and the head jacket 5, a water hole opening 22c of the head gasket 22 located in the middle of the anti-thrust side water hole 4d has a shape, for example, as shown in FIG. A temperature-sensitive operating valve 7 for expanding the passage is provided, which is made of a memory alloy. The temperature-sensitive valve 7 is not formed in the water hole opening 22f of the head gasket 22 facing the thrust side water hole 4c, and the standard disconnection of the water hole opening 22c of the anti-thrust side water hole 4d is Area S
b, the water hole opening portion 22 of the thrust side water hole 4c
The passage cross-sectional area S of f is set to a large value. The passage expansion operating temperature T1 of the temperature-sensitive operating valve 7 is set to a temperature slightly lower than the abnormally high temperature region Th of the cooling water. As shown in FIG. 2(A), this temperature-sensitive valve 7 has a temperature of 100, for example, the cooling water passing through the anti-thrust side water hole 4d.
Cooling water temperature T1 just before the valve starts to open and overheats at ℃
(for example, 110° C.), it is fully opened and the passage cross-sectional area S of the anti-thrust side water hole 4d is expanded from the standard cross-sectional area Sb to the enlarged cross-sectional area S1. Therefore, the amount of circulating water increases, the cooling capacity increases, and overheating of the engine 1 is suppressed. Note that the temperature-sensitive operating valve 7 is not formed in the water hole opening 22d between the cylinders of the head gasket 22, and cooling water is constantly allowed to flow to promote cooling between the thermally severe cylinders.

(Second Embodiment) In the second embodiment of the present invention,
The temperature-sensitive valve 7 is formed as shown in FIG. 5, for example. Figure 2
As shown in (B), the temperature T of the cooling water passing through the water hole 4 is 1 higher than the valve opening temperature T2 (for example, 82°C) of the thermostat 31.
When the temperature rises to ~2° C. higher, the upper operating valve 7a is temperature-sensing operated to expand the passage cross-sectional area S of the water hole 4 from the reduced cross-sectional area S2 to the enlarged cross-sectional area S1. Immediately after starting, the cooling water temperature T reaches the valve opening temperature T2 of the thermostat 31.
If the temperature is 1 to 2 degrees Celsius higher than the upper operating valve 7a,
does not operate temperature-sensingly, and the passage cross-sectional area S of the water hole 4 is narrowed down to the reduced cross-sectional area S2, so the amount of circulating water is small.
The cooling water temperature inside the engine rapidly rises and becomes uniform. As a result, it is no longer necessary to close the thermostat 31 and bypass the radiator 6 through the bypass passage 33 as in the conventional case, and the thermostat 31 can also be abolished. Furthermore, when the thermostat 31 opens, a large amount of low-temperature cooling water in the radiator 6 flows into the cylinder jacket 3, which may overcool a part of the otherwise homogenized engine interior, resulting in cooling loss. thermostat 3
By abolishing 1, engine overcooling in such cases can be eliminated, resulting in less cooling loss at room temperature. Then, the cooling water temperature T is 1 higher than the valve opening temperature T2 of the thermostat 31.
When the temperature is higher than ~2° C., the upper operating valve 7a is operated by temperature sensing, and the passage cross-sectional area S of the water hole 4 becomes the reference cross-sectional area Sb. Further, when the cooling water temperature T rises to the passage expansion operating temperature T1, the lower operating valve 7b is temperature-sensing operated.
The passage cross-sectional area S of the water hole 4 is expanded from the standard cross-sectional area Sb to the enlarged cross-sectional area S1. Therefore, the amount of circulating water increases, the cooling capacity increases, and overheating of the engine 1 is suppressed. The upper operating valve 7a and the lower operating valve 7b in this embodiment can be constructed by changing their positions.

The temperature-sensitive valve 7 has a head gasket 2.
Instead of forming it in the water hole opening 22c of No. 2, it may be formed in the cylinder jacket 3 or the head jacket 5. Furthermore, the temperature-sensitive operating valve 7 may be made of bimetal instead of being made of a shape memory alloy.

[Brief explanation of drawings]

1 shows an embodiment of the present invention, FIG. 1(A) is a plan view of the main part of an engine head gasket, and FIG. 1(B) is a plan view of main parts of an engine head gasket;
) is a sectional view taken along line X-X.

FIG. 2 is a diagram showing an example of the present invention and showing the relationship between water hole cross-sectional area and cooling water temperature.

FIG. 3 shows an embodiment of the present invention and is a plan view of a head gasket.

4 shows an embodiment of the present invention, FIG. 4(A) is a schematic vertical cross-sectional view of an engine, and FIG. 4(B) is a cross-sectional view taken along the line U-U in FIG. 4(A).

FIG. 5 shows another embodiment of the present invention, and FIG. 5(A) shows FIG.
A diagram corresponding to (A), Figure 5 (B) is Y-Y of Figure 5 (A)
It is a sectional view along the arrow line.

6 shows a conventional example, FIG. 6(A) is a diagram corresponding to FIG. 1(A), and FIG. 6(B) is a sectional view taken along the line Z-Z in FIG. 6(A).

[Explanation of symbols]

1...Engine, 2...Water pump, 3...Cylinder jacket, 4...Water hole, 4c...Thrust side water hole, 4d...Anti-thrust side water hole, 5...Head jacket, 6...Radiator, 7...
Temperature-sensitive operating valve, 10... Thrust side, 11... Anti-thrust side,
25... Cylinder, T1... Operating temperature for passage expansion, Th... Abnormally high temperature region, S... Passage cross-sectional area, S1... Expanded cross-sectional area, Sb
...Reference cross-sectional area.

Claims (1)

[Claims] Claim 1: A water pump (
2) from the cylinder jacket (3) to the water hole (4).
The head jacket (5), radiator (6) and cylinder jacket (3) are configured to be pumped and circulated in this order, and the water hole (4) is located on the thrust side (25) of the cylinder (25).
The thrust side water hole (4c) located at 10) and the anti-thrust side water hole (4d) located at the anti-thrust side (11) of the cylinder (25) are arranged in parallel. In the water cooling system for the engine, a temperature-sensitive operating valve (7) for passage expansion is provided in the anti-thrust side water hole (4d), and the operating temperature for passage expansion (T1) of the temperature-sensitive operation valve (7) is
) is set to a temperature slightly lower than the abnormally high temperature region (Th) of the cooling water, and this temperature-sensitive operating valve (7) is set so that the temperature of the cooling water passing through the anti-thrust side water hole (4d) is set to the above temperature. When the passage expansion operating temperature (T1) is reached, temperature-sensing operation is performed to increase the passage cross-sectional area (S) of the water hole (4d) on the anti-thrust side.
is expanded from the standard cross-sectional area (Sb) to the enlarged cross-sectional area (S1), and the thrust-side water hole (4c) is larger than the standard cross-sectional area (Sb) of the anti-thrust side water hole (4d).
) A water cooling device for an engine, characterized in that the passage cross-sectional area (S) of the engine is configured to be set to a large value.