JP2897523B2 - Multi-cylinder engine crankcase - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crankcase for a multi-cylinder engine.

[0002]

2. Description of the Related Art In a multi-cylinder engine for a vehicle such as an automobile,
In order to reduce the overall length of the engine to reduce its weight and to improve its mountability on the vehicle, parts of the outer peripheral walls that limit the cylinder bores of adjacent cylinders are joined together to form a common wall portion (hereinafter referred to as Siamese wall). The so-called siamese type crankcase forming the section is widely used. In this type of multi-cylinder engine, it is extremely important to sufficiently cool the siamese wall between the cylinder bores. For this reason, conventionally, the siamese wall has a plurality of cylinders extending in a direction perpendicular to the crank axis. Cooling water holes are provided.

Now, the structure of a siamese wall portion in a conventional multi-cylinder engine will be described with reference to an enlarged sectional view of FIG. 4. Reference numeral 1 in the drawing denotes a siamese wall portion formed between cylinder bores of a multi-cylinder engine, 2a and 2b. The upper and lower two cooling water holes 3a and 3b penetrate the siamese wall portion 1 at right angles to the crank axis, and are the drilling start ends of the cooling water holes 2a and 2b when the cooling water holes 2a and 2b are drilled. The large-diameter shallow dishing portions 4a and 4b are drill chuck portions of a drilling device.

As shown in the figure, in a conventional engine, an opening serving as a punching device insertion hole is provided in one crankcase side wall in an extension of the siamese wall portion 1 in a direction perpendicular to the crank axis, and a hole is drilled in the opening. The drill chuck portions 4a and 4b of the apparatus were inserted side by side in the same direction, and the cooling water holes 2a and 2b were formed.

Accordingly, the distance B between the center lines of the cooling water holes 2a and 2b is restricted by the large outer diameter of the drill chucks 4a and 4b. There is a problem that the cooling effect cannot be improved by disposing the water holes 2a and 2b close to each other.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a structure in which two or more cooling water holes are penetrated closer to a required portion of a siamese wall of a multi-cylinder engine than before. The purpose of this is to improve the cooling effect of the siamese wall.

[0007] To achieve the above object, the present invention is the siamese wall between adjacent cylinder bores, the made to penetrate through a plurality of cooling water holes in a substantially perpendicular direction to the crank axis, the cooling water The crankcase side walls on both sides of the extension of the hole are provided with openings that can be used as drilling device insertion holes, and the drilling device is inserted from each opening in the facing direction so that at least two holes close to the center line distance are provided. Drill the cooling water hole, and remove the dished part when drilling the cooling water hole.
Adjacent cooling water holes are set to be on different sides.
The present invention proposes a crankcase for a multi-cylinder engine, which is characterized in that the crankcase is provided with a crankcase.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS. In the figure, reference numeral 10 denotes a crankcase of a multi-cylinder engine (four-cylinder engine in the case shown), 1
2 is a cylinder bore arranged in line in the crankcase 10, 14 is an outer peripheral wall which limits the cylinder bore 12, 16 is a siamese wall formed by connecting the outer peripheral walls 14 of adjacent cylinder bores 12 to each other. Numerals 18a and 18b denote crankcase side walls formed substantially parallel to the crank axis OO on both sides of the 12 rows of cylinder bores, and 20 denotes an extension of the siamese wall 16 in a direction substantially perpendicular to the crank axis OO. Similarly, a plurality of first openings 22, which are punching device insertion holes disposed in the crankcase side wall 18a, are formed in the extension of the siamese wall 16 in a direction substantially perpendicular to the crank axis OO. A plurality of second openings 24a and 24b serving as punching device insertion holes disposed at 18b are provided on the outer peripheral wall of the cylinder bore. 4 and a cooling water chamber which is respectively formed between the crankcase side walls 18a and 18b.

The siamese wall 16 has a plurality (two in the illustrated case) extending substantially perpendicular to the crank axis OO in order to communicate the cooling water chambers 24a and 24b on both sides thereof. Water holes 26a and 26b are formed.

As shown in the enlarged sectional view of FIG. 3, the cooling water hole 26a is formed by a drill gripped by a drill chuck 28a of a drilling device inserted through the first opening 20. You. The cooling water hole 26b is
The cooling water hole 26a is drilled in a direction opposite to the cooling water hole 26a by a drill gripped by the drill chuck portion 28b of the drilling device inserted from the second opening 22. The cooling water hole 26a
Before the drilling operation, large-diameter dish fir portions 30a and 30b are formed at the drilling start ends of the drill holes 26a and 26b . Therefore, on
The plate fir portions 30a, 30b are adjacent to the cooling water holes 26a,
26b are provided on different sides.

As described above, the cooling water holes 26a and 26b
Are drilled from opposite directions, so that
The distance A between the center lines of the cooling water holes 26a and 26b is shown in FIG. 4 in a range where the required strength is secured despite the inevitable decrease in the strength of the siamese wall 16 due to a and 30b. Distance B between the center lines of conventional cooling water holes
Therefore, the cooling effect of a desired portion of the siamese wall portion 16 which needs to be cooled can be significantly improved.

In the cross sectional view of the crankcase shown in FIG.
A cooling water inlet 34 is provided at one end wall 32 of the crankcase 10.
The cooling water discharged from a water pump (not shown) is supplied to the inlet 34. The first opening 20
Is closed by a plate plug (not shown) after the cooling water holes 26a and 26b are formed. Further, the second opening 22 is formed as shown in FIG.
As shown by a dashed line in FIG. 3, the oil chamber 36 communicates with a water chamber 38 of an oil cooler 36 attached to the crankcase side wall 18b, and the water chamber 38 communicates with the cooling water inlet 34.

As best shown in FIG. 2, the cooling water chambers 24a and 24a are separated from the upper end surface 40 of the crankcase 10.
Vertical cooling water holes 42a and 42 reaching the top of 4b
b is drilled. In the same figure, reference numeral 44 denotes a main oil gallery that is bored in the crankcase 10 so as to extend in the direction of the crank axis, 46 denotes a bearing portion that supports a journal portion of a crankshaft (not shown), and 48 denotes the main oil gallery. An oil passage 50 in the crankcase 10 for supplying the oil in 44 to the bearing portion 46 is a sand vent hole provided in one end wall of the crankcase 10, and is formed by a plate plug similarly to the first opening 20. Closed.

In the above configuration, the cooling water supplied from the water pump to the cooling water inlet 34 passes through the water chamber 38 of the oil cooler 36 to cool the oil as shown by the arrow in FIG. 2 into the cooling water chamber 24b in the crankcase 10 through the opening 22, and further flow through the cooling water holes 26a and 26b in the siamese wall 16 to flow through the cooling water chamber 2b.
4a to cool the siamese wall. The cooling water in the cooling water chambers 24a and 24b is
a and 42b and a large number of water holes (not shown) flow into the cylinder head to cool the portions of the cylinder head that require cooling. Note that the above cooling water flow path is merely an example, and any other cooling water flow path can be appropriately adopted.

According to the above configuration, as described above,
A perforation device is inserted into the siamese wall portion 16 from the first and second openings 20 and 22 provided in the crankcase side walls 18a and 18b on both sides thereof so as to form cooling water holes 26a and 26b. Thereby, the distance A between the center lines of the cooling water holes 26a and 26b can be reduced as compared with the conventional art, and the portion of the siamese wall portion 16 where cooling is particularly desirable can be effectively cooled, and the engine durability and There is an advantage that reliability can be improved.

The cooling water holes 26a and 26b are
Usually drilled at the same time, but due to the engine manufacturing process,
After first forming one of the cooling water holes, the other cooling water hole can be machined. Further, FIG. 3 illustrates an example in which two cooling water holes 26a and 26b are formed in the siamese wall portion 16. However, if necessary, the cooling water holes 26a are provided in the same direction as the cooling water holes 26b. It is clear that the third cooling water hole can be additionally drilled and that four or more cooling water holes can be drilled in the same manner as described above. In this case, the large-diameter dish fir portion 30a,
Since 30b are dispersedly arranged on both sides of the siamese wall portion 16, the distance between the center lines of the plurality of cooling water holes is reduced while suppressing the decrease in strength of the siamese wall portion, thereby effectively improving the cooling performance. be able to.

[0017]

According to the present invention as the ordination crankcase of a multi-cylinder engine according to the present invention, the siamese wall between adjacent cylinder bores, a plurality of cooling water holes in a substantially perpendicular direction to the crank axis penetrated In each of the crankcase side walls on both sides of the extension of the cooling water hole, openings that can be used as drilling device insertion holes are provided, and the drilling device is inserted from each of the openings in the opposite direction, so that the center line is removed. Forming at least two cooling water holes which are close to each other , and
When the water hole is drilled, the dished part is used between adjacent cooling water holes.
It is characterized by being provided on different sides, so that the cooling of the siamese wall portion of the crankcase can be effectively improved, and thus the durability and reliability of the engine can be improved. Is beneficial.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (in a cross section taken along line II of FIG. 2) of a crankcase showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the crankcase shown in FIG. 1, taken along the line II-II.

FIG. 3 is an enlarged partial cross-sectional view of a main part of FIG. 2;

FIG. 4 is a partial sectional view similar to FIG. 3, showing a siamese wall in a conventional multi-cylinder engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Crankcase 12 Cylinder bore 16 Siamese wall 18a and 18b Crankcase side wall 20 1st opening 22 2nd opening 26a and 26b Cooling water hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01P 3/02 F02F 1/14 F02F 7/00

Claims (1)

(57) [Claims] [Claim 1] A siamese wall between adjacent cylinder bores, the made to penetrate through a plurality of cooling water holes in a substantially perpendicular direction to the crankshaft axis, a crankcase side wall in an extension on both sides of the coolant hole In each, an opening that can be used as a perforation device insertion hole is provided, and a perforation device is inserted from each opening in a facing direction, and at least two cooling water holes whose center line distances are close to each other are formed ; Drilling the cooling water hole
When the dishing part is used, the cooling water holes adjacent to each other
Crankcase of a multi-cylinder engine, characterized by comprising providing so that that side.