JPH0437228Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cylinder head cooling device for an internal combustion engine used in vehicles such as automobiles, and particularly relates to a cylinder head cooling device for a spark ignition internal combustion engine having a spark plug. .

Prior Art In a spark-ignition internal combustion engine, in order to suppress the occurrence of knocking and improve the mechanical octane number, it is necessary to strongly cool the head wall of the combustion chamber, which is made up of the cylinder head. In view of this, it is recommended to provide a guide wall around the spark plug so that the cooling water actively flows at a relatively high flow rate, to provide an individual cooling water passage near the spark plug, or to install a cooling water jet nozzle. It has been proposed to install a cooling water jet nozzle to spray cooling water onto the head wall of the combustion chamber.
It is shown in each publication of Utility Model Application Publication No. 126828/1983.

Problems to be Solved by the Invention In the conventional cylinder head cooling system as described above, even if the intended purpose is achieved, the guide wall prevents the spark plug from overheating at low temperatures during the warm-up process. If the spark plug is cooled and has a risk of smoldering, and is provided with a separate cooling water passage or cooling water jet nozzle, the flow rate of the cooling water supplied to these must flow within the cooling chamber of the cylinder head. By being controlled separately from the flow rate of the cooling water, no supercooling phenomenon occurs, but the combustion chamber head wall cannot be adequately cooled over a wide range.

The object of the present invention is to provide an improved cylinder head cooling system for an internal combustion engine that solves the above-mentioned problems.

Means for Solving the Problems According to the present invention, the object as described above is such that the spark plug is provided in the cooling water chamber of the cylinder head of an internal combustion engine, extends around the spark plug, and has one end directed toward the head wall of the combustion chamber. a cylindrical fixed cooling water guide member with an open opening; and a fixed cooling water guide member that is fitted into the fixed cooling water guide member so as to be movable in the axial direction thereof, and selectively extends from the open end of the fixed cooling water guide member to the head wall of the combustion chamber. Achieved by a cylinder head cooling device for an internal combustion engine having a cylindrical movable cooling water guide member extending toward the fixed cooling water guide member and a cooling water supply means for selectively supplying cooling water to the inside of the fixed cooling water guide member. be done.

Effects and Effects of the Invention According to the configuration as described above, the cooling water supplied inside the fixed cooling water guide member flows from around the spark plug toward the combustion chamber head wall, so that the combustion chamber head wall is widened. The movable cooling water guiding member selectively extends from the open end of the fixed cooling water guiding member toward the head wall of the combustion chamber. This makes it possible to both cool the head wall of the combustion chamber and promote warm-up of the spark plug, and the cooling water supply means for supplying cooling water to the inside of the fixed cooling water guide member is connected to the fixed cooling water guide member. Since cooling water is selectively supplied to the inside, the occurrence of smoldering phenomenon due to overcooling of the spark plug is avoided.

Embodiments Hereinafter, the present invention will be described in detail by way of embodiments with reference to the accompanying drawings.

FIG. 1 shows one embodiment of a cylinder head cooling device for an internal combustion engine according to the present invention. In FIG. 1, numeral 10 indicates a cylinder block and numeral 12 indicates a cylinder head.

The cylinder block 10 receives a piston 16 in a cylinder bore 14 and defines the side circumference of the combustion chamber, and the cylinder head 12 has a combustion chamber recess 18 and defines the head of the combustion chamber. . The cylinder head 12 has a threaded hole 22 for mounting a spark plug in each combustion chamber in the head wall 20 of the combustion chamber, and a threaded spark plug 24 is screwed into the threaded hole 22 for mounting the spark plug. Further, a cylinder head cover 26 is attached to the cylinder head 12.

The cylinder block 10 is provided with a cooling water chamber 30 that extends around the side peripheral wall of the combustion chamber, and the cylinder head 12 is provided with a cooling water chamber 32 that extends and surrounds the combustion chamber head wall 20. These cooling water chambers communicate with each other through communication holes 34 and 36.

A relatively large through hole 40 is provided in the upper wall 38 of the cylinder head 12 for each combustion chamber and is concentric with the spark plug mounting screw hole 22, and a fixed cooling water guide member 42 is installed in each of the through holes 40. It is installed in a fixed state. Fixed cooling water guide member 42
is a cylindrical outer cylinder 42 that internally fits into the through hole 40.
a and the combustion chamber head wall 20 extending around the spark plug 24 and sandwiching the packing 44 at the lower end in the figure.
A cylindrical inner cylinder 42b that is airtightly joined to define a storage hole 46 for the spark plug 24 inside, and an annular upper part that joins the upper ends of the outer cylinder 42a and the inner cylinder 42b to each other in the respective figures. It has an end wall 42c, and opens toward the combustion chamber head wall 20 at the lower end in the figure,
A cooling water passage 48 is provided between the outer cylinder 42a and the inner cylinder 42b.
is defined. The respective cooling water passages 48 of the fixed cooling water guide member 42 communicate with each other via a cooling water communication passage 50, and are supplied with cooling water from the cooling water communication passage. Storage hall 46
As shown in the figure, the spark plug cap 28 is open at the upper end and a spark plug cap 28 is inserted therein.

A cylinder chamber configuring cylindrical member 52 is fixed inside the outer cylinder 42a of the fixed cooling water guide member 42 provided for each combustion chamber, and is defined by the cylinder chamber member and the outer cylinder 42a. A piston 56 is provided in a fixed cylinder chamber 54 so as to be movable in the vertical direction as shown in the figure. The upper end of a cylindrical movable cooling water guide member 58 is fixedly connected to the piston 56 . The movable cooling water guide member 58 extends from the lower end of the cylindrical member 52 toward the combustion chamber head wall 20 .

The cylinder chamber 54 is provided with a compression coil spring 60 that urges the piston 56 downward in the figure, that is, the movable cooling water guide member 58 in the projecting direction. The cylinder chamber 54 communicates through a port 62 with a negative pressure supply hole 64 provided in the cylinder head 12, through which intake manifold negative pressure can be applied.

The cooling water chamber 30 of the cylinder block 10 is connected to a pump 72 through a cooling water passage 70, and is supplied with cooling water from the pump 72. After passing through the cooling water chamber 30, the cooling water supplied to the cooling water chamber 30 flows through the communication holes 34 and 36 to the cooling water chamber 32 of the cylinder head 12, and from there, the cooling water provided in the cylinder block 12 is supplied to the cooling water chamber 30. The water flows out from the outlet 33 and is returned to the pump 32 by a general cooling water circulation device (not shown).

The cooling water communication passage 50 is connected to the pump 72 via a cooling water passage 74, a flow rate control valve 78, and a cooling water passage 76, and is supplied with cooling water from the pump 72 while the flow rate is controlled by the flow rate control valve 78. It's like that.

The flow rate control valve 78 is of a diaphragm type, and includes a valve element 80 for flow rate control, a compression coil spring 82 that biases the valve element 80 in the valve opening direction, and a diaphragm chamber 84 that is supplied with intake manifold negative pressure. When the negative pressure supplied to the diaphragm chamber 84 is equal to or higher than a predetermined value, that is, during low load operation, the valve element 80 is located at the closed position as shown in the figure, The valve is opened by the spring force of the compression coil spring 82 as the negative pressure decreases.

According to the above-described configuration, the cooling water discharged by the pump 72 always flows through the cooling water chamber 30 of the cylinder block 10 and the cooling water chamber 32 of the cylinder head 12 regardless of the load of the internal combustion engine. Cooling is carried out according to the normal state of the engine.

Apart from the flow of cooling water as described above, the pump 72
The cooling water discharged is selectively supplied to the cooling water passage 48 of the fixed cooling water guide member 42 provided for each cylinder, with its flow rate being controlled by the flow rate control valve 78. During low load operation, the intake manifold negative pressure is large, so at this time the flow control valve 7
8 is closed, so that the cooling water passage 4 is closed at this time.
8 is not supplied with cooling water. This prevents the ignition plug 24 from being overcooled, thereby avoiding the occurrence of a smoldering phenomenon. At this time, a relatively large intake manifold negative pressure is also supplied to the cylinder chamber 54, so that the movable cooling water guide member 58 is pulled upward in the figure against the spring force of the compression coil spring 60, thereby causing combustion. The amount of extension to the chamber head wall 20 is reduced. As a result, the inner cylinder 42b of the fixed cooling water guide member 42 is directly exposed to the cooling water chamber 32, and the inner cylinder 42b is heated by the cooling water flowing through the cooling water chamber 32, and the spark plug 24 is warmed up. will be promoted.

When the load on the internal combustion engine increases beyond a predetermined value,
When the intake manifold negative pressure decreases beyond a predetermined value, the flow rate control valve 78 opens and a portion of the cooling water discharged by the pump 72 flows into the fixed cooling water guide member 42.
This cooling water is guided by the fixed cooling water guide member 42 and further by the movable cooling water guide member 58, and is directed toward the combustion chamber head wall 50 from the lower end thereof. It flows out and cools the combustion chamber head wall 20 over its entirety. As the negative pressure in the cylinder chamber 54 decreases as the load of the internal combustion engine increases, the movable cooling water guide member 58 moves downward in the figure by the spring force of the compression coil spring 60, and its extension amount increases. The opening end, ie, the cooling water outlet, is brought closer to the combustion chamber head wall 20. As a result, the opening amount of the flow rate control valve 78 increases in accordance with an increase in the load of the internal combustion engine, and the flow rate of cooling water supplied to the cooling water passage 48 increases. cooling becomes even more powerful, and the mechanical octane number of the internal combustion engine improves.

2 and 3 each show another embodiment of the cylinder head cooling device for an internal combustion engine according to the present invention. In FIGS. 2 and 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. 1.

In the embodiment shown in FIG. 2, a pressure receiving surface portion 58a exposed to the cooling water passage 48 is provided at the upper end portion of the movable cooling water guide member 58. In response to an increase in the water pressure acting on 58b, it moves downward in the figure against the spring force of the compression coil spring 66, increasing the amount of extension.

In the embodiment shown in FIG.
2a, and a pressure receiving surface portion 58b which also functions as a nozzle is provided at the lower end, and the movable cooling water guide member 58 responds to the spring force of the compression coil spring 66 in response to an increase in the water pressure acting on the pressure receiving surface portion 58b. The extension amount is increased by moving downward in the figure against the pressure.

In both embodiments shown in FIGS. 2 and 3, the movable cooling water guide member 58 has a pressure receiving surface portion 58.
a or 58b The extension amount increases in accordance with an increase in the water pressure acting on it, in other words, an increase in the flow rate of cooling water supplied to the cooling water passage 48, thereby increasing the cooling water supplied to the cooling water passage 48. In combination with an increase in the flow rate of water, the combustion chamber head wall 20 is cooled more powerfully as the engine load increases, similar to the above-described embodiment.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of the drawing]

1 to 3 are longitudinal sectional views showing an embodiment of a cylinder head cooling device for an internal combustion engine according to the present invention. 10... Cylinder block, 12... Cylinder head, 14... Cylinder bore, 16... Piston, 18... Combustion chamber recess, 20... Combustion chamber head wall, 22... Screw hole for installing spark plug, 24 ……
Spark plug, 26... Cylinder head cover, 2
8...Spark plug cap, 30, 32...Cooling water chamber, 33...Cooling water outlet, 34, 36...Communication hole, 38...Top wall, 40...Through hole, 42...
Fixed cooling water guide member, 44... Packing, 46
...Storage hall, 50...Cooling water communication path, 52...
... Cylindrical member for cylinder chamber configuration, 54 ... Cylinder chamber, 56 ... Piston, 58 ... Movable cooling water guide member, 60 ... Compression coil spring, 62 ... Port, 64 ... Negative pressure supply hole, 66 ... Compression coil spring, 70 ... Cooling water passage, 72 ... Pump, 7
4, 76...cooling water passage, 78...flow control valve,
80...Valve element, 82...Compression coil spring, 84
...Diaphragm chamber.

Claims (1)

[Scope of utility model registration request] A cylindrical fixed cooling water guide member extending around a spark plug provided in a cooling water chamber of a cylinder head of an internal combustion engine and having one end opened toward a combustion chamber head wall; a cylindrical movable cooling water guide member fitted movably in the axial direction and selectively extending from the open end of the fixed cooling water guide member toward the head wall of the combustion chamber; and the fixed cooling water guide member. A cylinder head cooling device for an internal combustion engine, comprising cooling water supply means for selectively supplying cooling water to the inside of a member.