JPH06147003A - Structure of cylinder head in intake advance cooling slant type internal combustion engine - Google Patents

Abstract

PURPOSE:To respectively prevent air stagnation and boiling of cooling water by drilling an air vent hole for releasing air on a partitioning plate which divides the cooling jacket of a cylinder head into plural sections from the jacket in low position to that in high position out of respective cooling water jackets. CONSTITUTION:The cylinder bore axial line 3 of each cylinder viewed from the direction of a crank shaft 2 is inclined by appropriate angle theta in relation to a horizontal surface 4 in a slant type multiple cylinder internal combustion engine 1. A cooling jacket inside a cylinder head 6 is divided into respective cooling jackets 18, 19 extended in the cylindrical direction respectively on the intake part 8 side and the exhaust part 10 side, by partitioning plate giving connection among the respective cylinders. By this constitution, an air vent hole 20 for releasing air from one side 19 of the respective cooling jackets to the other side 18 is drilled on the partitioning plate. Consequently, air stagnation inside the cooling jacket 19 in the low position is eliminated, and boiling of cooling of cooling water in its state of stagnation is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In order to improve the cooling performance for a cylinder head, the present invention first cools a portion of the cylinder head on the intake port side with cooling water from a radiator, and then cools it. The present invention relates to the structure of a so-called intake preceding cooling type internal combustion engine in which a portion of the cylinder head on the exhaust port side is cooled by cooling water from a cooling water jacket of a cylinder block.

[0002]

2. Description of the Related Art In recent internal combustion engines, in order to achieve a high compression ratio by suppressing knocking, a cooling water jacket in the cylinder head and a first cooling water jacket extending in the intake port side in the cylinder row direction are provided. The exhaust port side is divided into a second cooling water jacket extending in the direction of the cylinder row, and cooling water from the radiator is first introduced into one end of the first cooling water jacket, and then the first cooling water jacket is provided. It is proposed that the cooling water pump feeds the cooling water pump from the other end to the cooling water jacket in the cylinder block, then introduces it from the cooling water jacket in the cylinder block into the second cooling water jacket in the cylinder head, and then sends it to the radiator. Yes (Actual Kaihei 2
-6302).

Since this cooling device cools the intake port side of the cylinder head in advance, it is called a so-called intake preceding cooling system.

[0004]

Among the vehicles, in a cab-over type vehicle in which an internal combustion engine is mounted under a cabin having a driver's seat, in order to make the height of the internal combustion engine as low as possible, A slant type internal combustion engine in which the cylinder bore axis is inclined at an appropriate angle with respect to the horizontal plane when viewed from the direction of the crankshaft in a posture in which the longitudinal side surface on the intake port side of the cylinder head faces upward is applied.

When the intake pre-cooling method is applied to this slant type internal combustion engine, the second cooling water jacket in the cylinder head is located at a position lower than the first cooling water jacket. As a result, air accumulates in the portion between the cylinders of the second cooling water jacket, and boiling of the cooling water occurs in this accumulation of air, so that the cooling performance for the entire internal combustion engine decreases significantly. There was a problem to say.

It is a technical object of the present invention to provide a structure of a cylinder head capable of solving this problem, that is, the problem that occurs when the intake precooling system is applied to a slant type internal combustion engine. It is what

[0007]

In order to achieve this technical object, the present invention provides a cooling water jacket in a cylinder head fastened to the upper surface of a cylinder block with a first cooling water extending on the intake port side in the cylinder row direction. The jacket and the exhaust port side are divided into a second cooling water jacket extending in the direction of the cylinder row, and the cylinder bore axis is viewed from the crankshaft direction with the longitudinal side surface of the cylinder head on the intake port side facing upward. In a slant type internal combustion engine of an intake pre-cooling type which is inclined at an appropriate angle with respect to a horizontal plane, among the partition plates that divide the cooling water jacket in the cylinder head into a first cooling water jacket and a second cooling water jacket. In the part between each cylinder, the second
An air vent hole is formed from the cooling water jacket to the first cooling water jacket.

[0008]

[Operation] In this way, in the part between the cylinders of the partition plate that divides the cooling water jacket in the cylinder head into the first cooling water jacket and the second cooling water jacket,
By slanting the internal combustion engine by forming the air vent holes, the air clogging the portion between the cylinders in the second cooling water jacket, which is lower than the first cooling water jacket, from the air vent holes Since the air can be successively released to the first cooling water jacket, it is possible to reliably prevent the occurrence of an air pool in the second cooling water jacket.

[0009]

Therefore, according to the present invention, when the intake pre-cooling method is applied to the slant type internal combustion engine, it is possible to prevent the cooling performance of the entire internal combustion engine from being deteriorated, and the slant type internal combustion engine can be prevented. There is an effect that a high compression ratio can be reliably achieved by the intake pre-cooling method.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. In the figure, reference numeral 1 indicates the cylinder bore axis 3 of each cylinder when viewed from the direction of the crankshaft 2 and the horizontal plane 4
A slant type multi-cylinder internal combustion engine inclined by an angle θ with respect to the cylinder block 5 is shown.
And a cylinder head 6 fastened by a plurality of head bolts 7 arranged on both sides of the cylinder row to the upper surface of the cylinder block 5, and The internal combustion engine 1 is mounted so as to be inclined so that the output side at one end in the longitudinal direction is low and the front end side at the other end opposite to this one end is high.

The cylinder head 6 is formed with an intake port 8 with an intake valve 9 for each of the cylinders so as to open to one longitudinal side surface 6a of the cylinder head 6, and for each of the cylinders. Exhaust valve 1 for
The exhaust port 10 with 1 is formed so as to open to the other longitudinal side surface 6b of the cylinder head 6. Further, in the cylinder head 6, a portion of the head bolt 7 outside the one head bolt 7 located on the intake port 8 side is provided with the valve mechanism chamber 12 on the upper surface of the cylinder head 6 and the cylinder block 5. A blow-by gas passage 13, which also serves as an oil remover, is formed to communicate with the inside of the crankcase.

Further, the intake port 8 in each of the cylinders is provided on one longitudinal side surface 6a of the cylinder head 6.
The intake pipe lines 14 are connected to each other by fastening a integrally formed flange portion 15 between the tips of the intake pipe lines 14 with a plurality of bolts 16. The cooling water jacket inside the cylinder head 6 is formed by a partition plate 17 which is formed so as to connect the cylinders to each other, and a first cooling water jacket 18 extending in the cylinder row direction on the intake port 8 side and an exhaust port 10 are provided. The side is divided into a second cooling water jacket 19 extending in the cylinder row direction. In this case, the partition plate 17 is provided with a small-diameter air vent hole 20 for allowing the air in the second cooling water jacket 19 to escape to the first cooling water jacket 18, from the one longitudinal side surface 6 a of the cylinder head 6. It is drilled by drilling with a drill tool. Further, the second cooling water jacket 19 and the cooling water jacket 22 in the cylinder block 5 communicate with each other through a through hole 21 provided outside each cylinder.

A thermostat valve chamber 23 communicating with one end of the first cooling water jacket 18 is formed in a recess at one end portion on the output side of both longitudinal ends of the cylinder head 6, and the second cooling water is formed. A cooling water outlet pipe 25 from the jacket 19 to the radiator 24 is provided. The cooling water inlet pipe 26 from the radiator 24 is connected to the thermostat valve chamber 23, and in the thermostat valve chamber 23, when the temperature of the cooling water is low, the second cooling water jacket 19 to the first cooling water jacket 18 are provided. The bypass passage 27 is opened, but when the temperature of the cooling water rises to a predetermined temperature, the bypass passage 27 is closed,
Thermostat valve 2 which operates so that all the cooling water from the radiator 24 flows into the first cooling water jacket 18.
8 is provided.

Furthermore, the first end is provided at the other end of the cylinder head 6 on the front end side of the both ends in the longitudinal direction.
A cooling water outlet 29 from the cooling water jacket 18 is provided so that the cooling water outlet 29 opens to the lower surface of the cylinder head 6, and a peripheral surface 29 a of the cooling water outlet 29 is provided.
Are formed on the same plane as the lower surface of the cylinder head 6.

On the other hand, a cooling water pump 30 having an impeller 30a rotatably driven by power transmission from the crankshaft 2 is provided on the side surface of the other end portion on the front end side of the cylinder block 5 in the longitudinal direction. The cooling water pump 30 is attached by fastening with a plurality of bolts 31 so that the discharge port 30b of the cooling water pump 30 communicates with the cooling water jacket 32 of the cylinder block 5.

The suction port 30c of the cooling water pump 30 is extended toward the cooling water outlet 29 of the first cooling water jacket 18 of the cylinder head 6, and the peripheral surface 30c 'of the suction port 30c is formed into the first cooling water outlet 29c. 1 Peripheral surface 29 of the cooling water outlet 29 in the cooling water jacket 18
At the same time as mounting the cylinder head 6 to the cylinder block 5 by the head bolt 7 with respect to a, a sealing material such as an O-ring 32 is sandwiched and pressed therebetween to join the suction port 30c and the cooling water outlet 29. To configure.

Furthermore, in the portion corresponding to the blow-by gas passage 13 on one longitudinal side surface 6a of the cylinder head 6, the opening 1 is formed in the first cooling water jacket 18.
8a is bored, and the opening 18a is made into the intake pipe line 1
4 is closed by the lid 15a integrally formed with the connecting flange portion 15 in FIG. 4, the cross-sectional area of the passage in the first cooling water jacket 18 along the longitudinal direction is reduced at the blow-by gas passage 13. In this case, the lid 1 is
By providing the recess 15a 'on the back surface of 5a, the passage cross-sectional area of the blow-by gas passage 13 in the first cooling water jacket 18 can be further increased.

In this configuration, in the warm-up operation in which the temperature of the cooling water has not risen to the predetermined temperature, the thermostat valve 28 closes the passage from the radiator 24 while opening the bypass passage 27, so that the cylinder block is opened. 5
The cooling water in the cooling water jacket 22 in
After flowing out to the second cooling water jacket 19 of the cylinder head 6 via the bypass passage 27, the current flows into the first cooling water jacket 18, and from the first cooling water jacket 18 to the cooling water pump 30 by the cylinder block 5
The cooling water jacket 22 is circulated.

When the temperature of the cooling water rises to a predetermined temperature, the thermostat valve 28 causes the radiator 2
By opening the passage from 4 and closing the bypass passage 27, the cooling water cooled by the radiator 24 first flows into the first cooling water jacket 18 of the cylinder head 6, and the cylinder After cooling the portion of the head 6 on the intake port 8 side, the cooling water pump 3
0, it is sent to the cooling water jacket 22 in the cylinder block 5, then flows from the cooling water jacket 22 in the cylinder block 5 into the second cooling water jacket 19 in the cylinder head 6 through the through hole 21, and then to the radiator 24. The entire cycle is carried out.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional plan view taken along the line II-II of FIG.

3 is an enlarged sectional view taken along line III-III of FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

[Explanation of Codes] 1 Internal Combustion Engine 5 Cylinder Block 6 Cylinder Head 6a Longitudinal Side of Intake Port Side of Cylinder Head 7 Head Bolt 8 Intake Port 14 Intake Pipe Line 17 Partition Plate 18 First Cooling Water Jacket in Cylinder Head 19 In Cylinder Head Second cooling water jacket 24 Radiator 27 Bypass passage 28 Thermostat valve 30 Cooling water pump 20 Air vent hole

Claims (1)

[Claims] 1. A cooling water jacket in a cylinder head fastened to the upper surface of a cylinder block, a first cooling water jacket extending on the intake port side in the cylinder row direction and a second cooling water extending on the exhaust port side in the cylinder row direction. An intake pre-cooling method in which the cylinder bore axis is tilted at an appropriate angle with respect to the horizontal plane when viewed from the direction of the crankshaft, while the cylinder bore axis line is oriented with the long side surface on the intake port side of the cylinder head facing up In the slant type internal combustion engine, the second cooling water jacket is provided between the cylinders of the partition plate partitioning the cooling water jacket in the cylinder head into the first cooling water jacket and the second cooling water jacket. The slant type internal combustion engine of the intake pre-cooling type is characterized in that an air vent hole is provided in the cooling water jacket. The structure of the cylinder head that.