JP3355635B2 - Cylinder block for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine, and more particularly to a cylinder block having a cooling water passage formed therein.

[0002]

2. Description of the Related Art Conventionally, as this kind of technology, there is a cylinder block disclosed in Japanese Utility Model Laid-Open No. 58-96033, for example. As shown in FIG. 11, in the cylinder block 26, in between the two bolt holes 27 between the respective bores, grooves (slits) 29 of the circular arc cross sectional shape of the cooling water passage to the deck surface 2 8 is formed ing. During the operation of the internal combustion engine (engine), the roundness of the bore may be deteriorated because the temperature in the cylinder block 26 becomes particularly high between the bores as compared with other parts. The above slit 29
In order to cope with such a problem, the cooling device was formed with a special aim for cooling between the bores.

[0003]

However, in the above-mentioned prior art, the width of the slit 29 is inevitably narrowed when the space between the bores is reduced to make the engine compact. Therefore, not only does the amount of cooling water in the slit 29 decrease, but also the flow of the cooling water in the slit 29 deteriorates, and there is a problem that the cooling performance between the bores is reduced.

[0004] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a cylinder block of an internal combustion engine that can further improve the cooling performance between bores by slits.

[0005]

In order to achieve the above object, according to the present invention, a plurality of bores are arranged in series, and an opening is formed on a deck surface between the bores and both of them are opened.
In the cylinder block of the internal combustion engine, the end of which forms a slit communicating with the water jacket, between the bores
The water jacket diagonally from one side to the other
Two communication holes as cooling water passages
The intersection of the two communication holes is located at the center of the bottom wall of the slit .

[0006]

According to the above arrangement, each link as a cooling water passage is provided.
By supplying the cooling water to the slit through the through hole , the flow of the cooling water in the slit is improved, and the flow rate of the cooling water passing through the slit is increased. In addition, as the cooling water passage
Since the intersection of the communication holes is located at the center of the bottom wall of the slit, the flow of the cooling water is concentrated at the center where the heat load is highest between the bores.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a cylinder block of an internal combustion engine according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows an internal combustion engine (engine) of this embodiment.
FIG. 2 is a plan view showing a part of the cylinder block 1 adopted in FIG. 2, and FIG. 2 is a sectional view taken along line AA of FIG. The cylinder block 1 is of a siamese type in which a plurality of bores 2 are arranged in series, and the space between the bores 2 is narrowed to reduce the size and weight of the engine. Inside the cylinder block 1, a water jacket 3 of a closed deck type as a cooling water passage continuously surrounding each bore 2 is formed. Further, at the position corresponding to the center of each of the bores 2, a pair of cooling water outlets 5 opening to the deck surface 4 of the cylinder block 1 are formed on the water jacket 3 at right and left sides. Further, in the water jacket 3 at positions corresponding to between the respective bores 2, a pair of left and right cooling water outlets 6 similarly opening to the deck surface 4 are formed. Outside the outlet 6, a pair of left and right bolt holes 7 for assembling a cylinder head (not shown) to the cylinder block 1 is formed.

[0009] and slits 8 as cold <br/>却水passage which opens to the deck surface 4 is formed between each bore 2. In this embodiment, the slit 8 has an arc-shaped cross section, and both ends thereof communicate with the water jacket 3 near both the outlets 6. The slits 8 are formed for the purpose of cooling between the bores 2 which become hotter than other parts during operation of the engine. Moreover, since the cylinder block 1 is of the Siamese type in which the space between the bores 2 is narrow, the width of the slit 8 is relatively narrow.

In this embodiment, in order to supply cooling water from the water jacket 3 to the center of the bottom wall of the slit 8, a cooling water passage extending obliquely from one side of the water jacket 3 to the other side is provided. Two communication holes 9.1
0 are formed crossing each other. In this embodiment, the slit 8 is cut after the communication holes 9 and 10 are cut in the cylinder block 1 with a drill. These intersections 11 of the two communication holes 9 and 10 are formed so as to be positioned on the bottom wall central portion of the slit 8. The diameter of each of the communication holes 9 and 10 is set slightly larger than the width of the slit 8.

Accordingly, when the cooling water flows through the water jacket 3, the cooling water is positively supplied to the slit 8 through the communication holes 9 and 10. By this action, the flow of the cooling water in the slit 8 is improved, and the flow rate of the cooling water passing through the slit 8 is increased. In addition, each communication hole 9,
Since the ten intersections 11 communicate with the center of the bottom wall of the slit 8, the flow of the cooling water is concentrated at the center where the heat load is highest between the bores 2.

Therefore, the flow of the cooling water is improved even in the slit 8 having a relatively small width, and the cooling water between the slits 8 can further improve the cooling performance between the bores 2. In addition, since the flow of the cooling water is concentrated at the center of the bottom wall of the slit 8, the cooling effect at that portion can be particularly enhanced.

As a result, during the operation of the engine, the cooling performance between the respective bores 2 is improved, and the temperature between the respective bores 2 can be made closer to the temperature of a part other than between the respective bores 2. For this reason, the roundness of each bore 2 is improved, and the rise of oil into the combustion chamber is reduced, so that the consumption of engine oil can be improved. Further, friction between each bore 2 and the piston can be reduced, and as a result, improvement in engine performance can be expected.

In this embodiment, the slit 8 is cut after the communication holes 9 and 10 are cut with a drill. Therefore, by using the coolant at the time of cutting the slit 8, the coolant easily flows from each of the communication holes 9 and 10 into the processing portion of the slit 8, and the coolant can effectively act, and the processing of the slit 8 can be performed. Can be improved.

[0015] The above embodiments may also be other specific forms suitably carried out as reference example shown in the following. In the above embodiment, two communication holes 9, 1 passing through the slit 8 between the water jackets 3 in the cylinder block 1 are provided.
0 is formed so as to cross the X-shape, and the crossing portion 11 is located at the center of the bottom wall of the slit 8, whereas the water jacket 3 is formed in the cylinder block 1 as shown in FIG. A single communication hole 12 passing through the slit 8 may be formed diagonally between them, and a part of the communication hole 12 may be located near the center of the bottom wall of the slit 8.

As shown in FIG. 4, a V-shaped communication hole 13 passing through the slit 8 is formed between the water jackets 3 in the cylinder block 1, and the bent portion 13a is located at the center of the bottom wall of the slit 8. You may make it.

Further, as shown in FIG. 5, two communication holes 14, 15 passing through the slit 8 between the water jackets 3 in the cylinder block 1 are formed so as to intersect in a Y-shape, and the intersection 16 is formed. The slit 8 may be located at the center of the bottom wall.

In addition, as shown in FIG. 6, a slit 8 is formed between the water jackets 3 in the cylinder block 1.
May be formed so as to intersect in an X-shape, and the intersection 19 may be located slightly above the center of the bottom wall of the slit 8. Also, as shown in FIG. 7, two communication holes 17, 18 passing through the slit 8 between the water jackets 3 in the cylinder block 1.
May be formed so as to intersect in an X shape, and the intersection 19 may be located slightly below the center of the bottom wall of the slit 8. Alternatively, as shown in FIG. 8, the communication holes 17, 18, 20, 21 of FIGS. When the communication holes 17, 18, 20, 21 are combined in this manner, the flow of the cooling water in the slit 8 can be further improved.

In addition, as shown in FIG. 9, a slit 8 is provided between the water jackets 3 in the cylinder block 1.
May be formed horizontally so as to communicate with the center of the bottom wall of the slit 8. Alternatively, as shown in FIG. 10, in addition to the horizontal communication holes 23, communication holes 24 obliquely intersecting the communication holes 23 from the water jacket 3.
25 may be formed. Note that the horizontal communication hole 23 in FIGS. 9 and 10 may be set at a position that avoids interference with a bolt hole (not shown).

In the above-described embodiment, the slit 8 is formed in an arcuate cross section. However, a slit having a flat bottom surface may be formed, or a slit having another shape may be used. Further, in the above embodiment, the cylinder block 1 having the closed deck type water jacket 3 is embodied.
It may be embodied in a cylinder block having an open deck type water jacket.

In addition, in the above-described embodiment, the outflow ports 6 communicating with the water jacket 3 are opened on both sides between the bores 2 and the slits 8 communicating with the water jacket 3 are formed. A slit communicating with the water jacket may be formed in a cylinder block having no outlet on both sides.

In addition, in the above-described embodiment, each communication hole 9, 1
Although 0 was cut with a drill, the drilling of the communication holes 9 and 10 may be performed at any angle.

[0023]

As described in detail above, according to the present invention,
A plurality of bores are arranged in series, with openings on the deck surface between each bore and both ends in a water jacket.
In a cylinder block formed with a communicating slit , one side of the water jacket is provided between each bore.
As cooling water passages extending obliquely to the other side
Are formed so as to intersect with each other.
Since the and is positioned in the bottom wall central portion of the slit, flow of cooling water in between the bore with the flow of cooling water in the slit becomes better focused, further improving the cooling performance between the bore by the slit The effect is excellent.

[Brief description of the drawings]

FIG. 1 is a plan view showing a part of a cylinder block according to an embodiment of the present invention.

FIG. 2 shows a cross section taken along line AA of FIG. 1 in one embodiment;
In particular, it is a diagram showing a type in which communication holes intersect in an X shape.

FIG. 3 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which one communication hole is formed obliquely.

FIG. 4 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which a communication hole is formed in a V-shape.

FIG. 5 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which communication holes intersect in a Y-shape.

FIG. 6 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which communication holes intersect in an X-shape and the intersection position is arranged above the slit bottom wall. is there.

FIG. 7 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which communication holes intersect in an X-shape and the intersection position is disposed below a slit bottom wall. is there.

FIG. 8 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which two sets of communication holes intersecting in an X-shape are formed.

FIG. 9 is a view showing a partial cross section of a cylinder block in another embodiment (reference example) , particularly showing a type in which one communication hole is formed horizontally.

FIG. 10 shows a partial cross section of a cylinder block in another embodiment (reference example) , in particular, a type in which one communication hole is formed horizontally and another communication hole obliquely intersects the communication hole. FIG.

FIG. 11 is a partial sectional view of a cylinder block having a slit in a conventional example.

[Description of Signs] 2 ... Bore, 3 ... Water jacket as cooling water passage, 4 ... Deck surface, 8 ... Slit, 9,10,12-1
5, 17, 18, 20, 21, 23 to 25 ... communication holes as other cooling water passages.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-159111 (JP, A) JP-A-62-652 (JP, A) JP-A-61-209763 (JP, A) JP-A-4-1992 27710 (JP, A) JP-A-4-350348 (JP, A) JP-A-63-147521 (JP, U) JP-A-2-54348 (JP, U) JP-A-59-127852 (JP, U) Japanese Utility Model Showa 58-96033 (JP, U) Japanese Utility Model Showa 59-175649 (JP, U) Japanese Utility Model 1-145965 (JP, U) Japanese Utility Model Showa 61-113944 (JP, U) Japanese Utility Model Showa 60-149848 (JP, U) Japanese Utility Model 58-96032 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02F 1/00-1/42 F01P 3/02

Claims (1)

(57) [Claims] A plurality of bores are arranged in series, and an opening is formed in a deck surface between the respective bores, and both ends of the bores are recessed.
In a cylinder block of an internal combustion engine having a slit communicating with the water jacket, a space between each bore is provided from one side of the water jacket to another.
Two lines as cooling water passages extending obliquely to the sides
Is through hole is formed to cross the cylinder block of the intersection of these two communication holes <br/> internal combustion engine, characterized in that is positioned in the bottom wall central portion of the slit.