JPH03260358A - Cylinder block structure for multicylinder engine - Google Patents

Abstract

PURPOSE:To improve cooling performance for the upper part of a cylinder wall especially for the wall upper part between respective cylinders by providing a wave-shaped cooling water guide wall, waved so as to form the side of the cylinder low and the side between the cylinders high, in a water jacket on an exhaust side. CONSTITUTION:Intake and exhaust side water jackets 30, 34 are respectively provided between an internal wall formed on the inner side part of each bank 14 and the inner side part of each cylinder wall and between an external wall formed in the outer side part of the bank 14 and the outer side part of each cylinder wall, in a cylinder block A of a 6-cylinder V-engine. Here the wall surface lower part on the side of the exhaust side water jacket 34 in the external wall of each bank 14 is protruded to the side of the exhaust side water jacket 34, and an exhaust side guide wall 46, which is the upper surface of this protruding part, is formed in a wave shape waved so as to provide a low sideward part 46a of each cylinder 22 and a high sideward part 46b between the cylinders 22.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in the cylinder block structure of a multi-cylinder engine.

(Prior art) In the cylinder block of a multi-cylinder engine, which has cylinders arranged in parallel in the direction of the crankshaft, in order to cool the cylinder walls with cooling water, there are two cranks on the intake side and the exhaust side of the cylinder. A structure is known in which a water jacket is provided that extends in the axial direction, and an introduction part for introducing cooling water is provided at one end in the crankshaft direction.

However, the temperature distribution in the cylinder during combustion is not uniform and has various characteristics, for example, the exhaust side of the cylinder wall has a characteristic that the temperature is higher than the intake side of the cylinder wall.

Therefore, as shown in Japanese Utility Model Application No. 61-1641, the outer water jacket in each bank of a V-type engine, that is, the bottom of the water jacket on the exhaust side, is lower than other parts, such as the bottom of the water jacket on the intake side. Cylinder block structures for multi-cylinder engines have been proposed that are formed in a downward position.

This cylinder block structure allows a larger amount of cooling water to flow through the exhaust side water jacket than the intake side water jacket by making the capacity of the exhaust side water jacket larger than the intake side water jacket. This is particularly intended to prevent high temperatures on the sides.

(Problems to be Solved by the Invention) Incidentally, in a cylinder block, in addition to the characteristic that the exhaust side of the cylinder wall becomes hotter than the intake side,
Because the combustion chamber is located at the head of the cylinder, the upper part of the cylinder wall is hotter than the lower part of the cylinder wall, and because adjacent cylinders are usually placed close to each other, the walls between the cylinders are It has the characteristic that it becomes hotter than the side walls of the cylinder. Therefore, in the cylinder block, there is a problem in that the upper part of the wall between the cylinders becomes significantly hotter than other parts.

However, in the conventional cylinder block structure, as is clear from the vector diagram of the cooling water velocity shown in FIG. It has the characteristic of being fast.

For this reason, in the conventional cylinder block structure, there was a problem in that the upper part of the wall between the cylinders of the cylinder block was difficult to cool down compared to other parts, even though the upper part of the wall between the cylinders became high temperature.

In view of the above, an object of the present invention is to improve the cooling performance for the upper part of the cylinder wall in a cylinder block, particularly for the upper part of the wall between the cylinders.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a system in which the flow of cooling water flowing through the water jacket on the exhaust side becomes faster at the upper part, and the cooling water actively moves toward the upper part between the cylinders. A guide wall will be provided to guide you.

Specifically, the solution taken by the present invention is that a water jacket extending in the crankshaft direction is provided on each of the intake side and exhaust side of the cylinders that are parallel in the crankshaft direction, and a water jacket is provided at one end in the crankshaft direction. It is assumed that the cylinder block structure of a multi-cylinder engine is provided with an introduction part for introducing cooling water, and at least the water jacket on the exhaust side extends in the crankshaft direction, and is low on the side of the cylinder and is placed on the side between the cylinders. In this case, a cooling water guide wall having a corrugated shape that increases in height is provided.

(Function) With the above configuration, the water jacket on the exhaust side
Cooling water flowing through the water jacket on the exhaust side is
The upper part of the cylinder wall is particularly cooled because the flow at the upper part is faster than at the lower part.

In addition, the shape of the cooling water guide wall is wavy so that the side of the cylinder is low and the side between the cylinders is high, so the cooling water flowing through the exhaust side water jacket is directed to the upper part between each cylinder. Since the heat is guided to the cylinder wall, the wall soil between the cylinders in the upper part of the cylinder wall is particularly cooled.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIGS. 1 and 2 show a longitudinal cross-sectional side structure of an A1 alloy cylinder block A of a V-type 6-cylinder engine according to an embodiment of the present invention, and FIGS. 3 to 5 respectively show a longitudinal cross-sectional front view of the cylinder block A. FIG. 6 shows the planar structure of the cylinder block A, which includes skirt portions 10 and 10 provided on both sides of the lower part, and a crank provided between the skirt portions 10. It consists of a case part 12 and two banks 14, 14 extending in a V-shape above the crankcase part 12.

The crankcase portion 12 is provided in the crankshaft direction (Fig. 1,
End walls 16, 16 are provided parallel to each other in the front and rear parts (in the left-right direction in FIG. 2, and in the up-down direction in FIG. A semicircular bearing portion 20 is provided inside the partition wall 18 to support a crankshaft (not shown) via a bearing journal (not shown).

As shown in FIG. 6, each bank 14 has three cylinders 22, 22.22 arranged in series in the direction of the crankshaft, and the axis of each cylinder 22 is aligned with the axis of the crankshaft. extending towards. Also, each cylinder 2
The cylindrical cylinder walls 24, 24.24 forming the cylinders 2 are continuous with each other, and extend in the crankshaft direction on both the inside and outside sides of each cylinder 22.

In this embodiment, a cast iron cylinder liner 26 is cast inside each cylinder wall 24.

An intake side water jacket 30 is provided between the inner wall 28 formed on the inner side of each bank 14 and the inner side of each cylinder wall 24, extending in the crankshaft direction and for circulating cooling water. In addition, an exhaust side water jacket 34 is provided between the outer wall 32 formed on the outer side of the bank 14 and the outer side of each cylinder wall 24, extending in the crankshaft direction and for circulating cooling water. It is being Also, between the front wall 36 formed at the front end of each bank 14 (lower side in FIG. 6) and the front part of the cylinder wall 24 on the near side, cooling water supplied by a water pump (not shown) is provided. An introduction section 38 is provided for inflow and branches into an intake side water jacket 30 and an exhaust side water jacket 34, and a rear wall 40 formed at the rear end (upper side in FIG. 6) of each bank 14 is provided. A merging portion 42 is provided between the rear cylinder wall 24 and the rear portion of the rear cylinder wall 24, where the cooling water flowing through the intake water jacket 30 and the exhaust water jacket 34 join together.

The cylinder head (not shown) incorporated in the cylinder block A is provided with a total of eight cooling water inlets 44, for example, at the positions indicated by the dashed line in FIG. The cooling water supplied to the introduction section 38 is supplied to the intake side and exhaust side water jackets 3.
0.34, and flows through the inlet 44 of the cylinder head from the introduction section 38, between the cylinders 22 in the intake and exhaust side water jackets 30.34, and from the confluence section 42. and flows into the water jacket of the cylinder head.

In the cylinder block A as described above, the present embodiment is characterized in that the lower part of the wall surface on the exhaust side water jacket 34 side of the outer wall 32 of each bank 14 protrudes toward the exhaust side water jacket 34 side, and the upper surface of the protruding portion A certain exhaust side guide wall 46 extends from the side portion 46 of each cylinder 22.
It is formed in a wavy shape so that a is low and the side portions 46b between the cylinders 22 are high. In this embodiment, the exhaust side guide wall 46 extends in the crankshaft direction while waving at a position approximately at the heightwise center of the exhaust side water jacket 34.

In this embodiment, since the exhaust side guide wall 46 having the above structure is provided, the following effects can be obtained.

■ The cooling water flowing through the exhaust side water jacket 34 from the introduction part 38 toward the confluence part 42 flows quickly at the upper part and slowly at the lower part, as shown in the flow velocity vector diagram in Fig. 8. Therefore, the upper part of each cylinder wall 24 is particularly cooled.

■ The exhaust side guide wall 46 is located at the side portion 46a of the cylinder 22.
Since the cooling water flowing through the exhaust side water jacket 34 is formed in a wavy wave shape so that the side portions 46b between the cylinders 22 are high and the side portions 46b between the cylinders 22 are low, the cooling water flowing through the exhaust side water jacket 34 is
Since the water is led to the upper part between the cylinders 22 in a polarized manner, the upper part of the wall between each cylinder 22 is particularly cooled, and it is easy to flow into the water jacket of the cylinder head from the inlet 44 of the cylinder head.

■ In this embodiment, since the cylinder liner 26 is cast inside each cylinder wall 24 as described above, each cylinder
Since it is not possible to provide a through hole between each cylinder 22 to communicate with the water jackets 30 and 34 on the intake side and exhaust side,
There is a problem in that the upper part of the wall between the cylinders 22 becomes particularly hot (7) and tends to cause thermal distortion in the cylinder liner 26, but since the exhaust side guide wall 46 of the shape described above is provided, the upper part of the wall between the cylinders The above-mentioned problem is solved because the upper part of the wall in between can be particularly cooled.

Further, as a feature of this embodiment, the inner wall 28 of each bank 14
The center and lower part of the wall surface on the intake side water jacket 30 side protrudes toward the intake side water jacket 30 side, and the intake side guide wall 48, which is the upper surface of the protrusion, has a lower side portion 48a of the cylinder 22, so that the cylinder The side portions 48b between 22 are formed in a wavy shape so that the side portions 48b are higher.

In this embodiment, the intake side guide wall 48 extends in the crankshaft direction while waving at the upper part of the intake side water jacket 30 in the height direction.

Since the intake side guide wall 48 having the above-described structure is provided, the upper part of the cylinder wall 24 is particularly cooled, similar to the exhaust side guide wall 46, and the cooling water easily flows into the water jacket from the inlet 44 of the cylinder head. Furthermore, thermal distortion of the cylinder liner 26 is prevented.

Further, as described above, since the exhaust side guide wall 46 is provided at a lower position than the intake side guide wall 48, the cooling water flows through the exhaust side water jacket 34 more than the intake side water jacket 30, so that the temperature easily increases. The cylinder wall 24 on the exhaust side is effectively cooled.

Further, as is clear from a comparison between FIG. 1 and FIG. 2, the waveform shape of the exhaust side guide wall 46 is set to have a larger undulation than the waveform shape of the intake side guide wall 48. For this reason, u
In the 1st air side water jacket 34, the cooling water can be more effectively led to the upper part between the cylinders 22,
The exhaust side in the upper part of the wall between the cylinders 22 can be particularly cooled.

In the above embodiment, the exhaust side and intake side guide walls 4
6.48 was provided protruding from the outer wall 32 and inner wall 28 of each bank 14, but instead of this, by making the bottom surfaces of the exhaust side and intake side water jackets 34.30 waveform, the exhaust side water jacket 34. and intake side guide wall 46.4
8 may be formed.

Furthermore, as a feature of this embodiment, the rear wall 40 of the bank 14
The wall surface on the side of the merging part 42 in the merging part 42 side protrudes toward the merging part 42 side.
is formed into a high chevron shape.

Thereby, the cooling water that has passed through the exhaust side water jacket 34 and reached the confluence section 42 is guided by the confluence section indoor wall 50 and directed upward, so that it is difficult to flow into the intake side water jacket 30 side.

Therefore, the cooling water flowing through the exhaust side water jacket 34 flows into the intake side water jacket 30 and stagnation of the cooling water at the confluence section 42 is eliminated, so that the cooling performance for the rear wall 22a of the rear cylinder 22 is improved. improves.

(Effects of the Invention) As explained above, according to the cylinder block structure of the multi-cylinder engine according to the present invention, the water jacket on the exhaust side has a wave pattern that is low on the side of the cylinder and high on the side between the cylinders. By providing a shaped cooling water guide wall, the cooling water flowing through the water jacket on the exhaust side can flow faster at the upper part and can be actively guided to the upper part between each cylinder. In particular, the cooling performance for the upper part of the wall between each cylinder can be improved.

In addition, when providing an inlet for cooling water to flow in from the water jacket of the cylinder block between the cylinders of the cylinder head assembled in the cylinder block, cooling water can easily flow in from the inlet, so that Cooling water can be introduced approximately evenly and smoothly.

[Brief explanation of drawings]

1 to 6 show the cylinder block structure of a multi-cylinder engine according to an embodiment of the present invention, FIG. 1 is a cross-sectional view taken along lines I to I in FIG. ~■ line sectional view, Figure 3 is m~■ line sectional view in Figure 6, Figure 4
The figure is a sectional view taken along the line ■ to ■ in Fig. 6, Fig. 5 is a sectional view taken along the line V-V in Fig. 6, Fig. 6 is a plan view, and Figs. 7 and 8 are velocity vector diagrams of cooling water. 7 shows the case of the conventional structure, and FIG. 8 shows the case of the above embodiment. A...Cylinder block 22...Cylinder 24...Cylinder wall 30...Intake side water jacket 34...Exhaust side water jacket 38...Introduction part 46...Exhaust side guide wall (cooling water Guide wall) 46a...
Side part 46b between the cylinders... side part b of the cylinder

Claims (1)

[Claims] (1) A water jacket extending in the crankshaft direction is provided on each of the intake side and exhaust side of the cylinders arranged in parallel in the crankshaft direction, and an introduction part for introducing cooling water into the water jacket at one end in the crankshaft direction. In the cylinder block structure of a multi-cylinder engine, at least the water jacket on the exhaust side has a wavy cooling water guide that extends in the crankshaft direction and is low on the sides of the cylinders and high on the sides between the cylinders. A multi-cylinder engine cylinder block structure characterized by a wall.