JPH0218298Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cylinder block structure for an engine.

(Prior Art) As a cylinder block structure for a multi-cylinder engine, a water-cooled cylinder block structure in which a water jacket is formed around a liner is generally known, as disclosed in, for example, Japanese Utility Model Application Publication No. 57-54638. ing. However, since a normal water jacket is formed over a wide area around the liner from the upper part to the lower part, the amount of cooling water is large, which is disadvantageous in terms of warming up and reducing the weight of the engine.

On the other hand, in Utility Model Application Publication No. 58-62140,
The water jacket is formed to be wide vertically between the liners, and narrow in other parts (both end face parts and both side face parts in the longitudinal direction of the engine) by positioning the lower end of the water jacket higher than the part between the liners, In other words, a technique has been disclosed in which the liner is formed only in the upper part where the thermal load is large around the liner.

(Problem to be solved by the invention) However, as mentioned above, if the water jacket is formed only in the upper part around the liner on both end faces and both side faces in the longitudinal direction of the engine, it is difficult to warm up the engine and reduce the weight. Although this is advantageous in terms of speed reduction, it is disadvantageous in terms of suppressing vibration and noise generated from the engine.

In other words, vibration and noise are generated from the engine as it operates, but since there is no water jacket formed at the bottom around the liner at both ends and side surfaces of the engine in the longitudinal direction, there is no noise from the bottom. There are problems in that noise tends to leak outside the engine and vibrations cannot be suppressed.

The present invention is based on the fact that the water jacket contributes to suppressing the vibration and noise of the engine.
While taking advantage of the vibration and noise suppressing effects of the water jacket, the amount of cooling water can be reduced to improve warm-up performance and reduce the weight of the engine.

(Means for Solving the Problem) The present invention solves this problem by reducing the amount of vibration and noise that leaks to the outside because the area exposed to the outside of both end faces in the longitudinal direction of the engine is smaller than that of the side parts. Focusing on the fact that the engine is small and that auxiliary equipment is generally provided, which suppresses the vibration and noise mentioned above, the water jacket is formed only on the upper part around the liner at both end faces in the longitudinal direction of the engine. However, the side portions in the longitudinal direction of the engine are formed to be wide vertically in order to sufficiently obtain the vibration and noise suppression effect of the water jacket.

That is, a specific means for this purpose is as follows: In a cylinder block of a multi-cylinder engine in which a water jacket is arranged around the liner, the water jacket is located at the upper part of the periphery of the liner at both end faces in the longitudinal direction of the engine. The engine is characterized in that the lower end of the water jacket is set at a lower position than the both end face parts in the side part in the longitudinal direction of the engine, and the water jacket is formed from the upper part to the lower part around the liner. It has a cylinder block structure.

(Function) In the cylinder block structure described above, the side surface in the longitudinal direction of the engine has a large area exposed to the outside, but since the water jacket is formed wide at the top and bottom, engine noise leaks to the outside due to this water jacket. This can be prevented, and vibrations can also be suppressed.

On the other hand, at both end faces in the longitudinal direction of the engine, the lower part around the liner, where the thermal load is small, is not covered with a water jacket, but the upper part, where the thermal load is large, is covered with a water jacket. There are no problems in terms of surface area. Although the effect of suppressing vibration and noise by this water jacket is small, the area exposed to the outside of both end faces is small, and therefore the amount of vibration and noise leaking from these end faces is small. Moreover, there are few problems with vibration and noise because the separately provided auxiliary equipment can be expected to have a vibration and noise isolation effect. Rather, since the water jacket was formed only on the upper part of these end faces,
The amount of cooling water can be reduced, which makes it easier to improve engine warm-up performance, and
This makes it possible to reduce the weight of the engine.

(Effect of the invention) Therefore, according to the invention, the water jacket is formed only at the upper part of both end faces in the longitudinal direction of the engine, and is formed widely from the upper part to the lower part of the side part of the engine in the longitudinal direction. Therefore, it is possible to reduce the amount of cooling water, improve warm-up performance, and reduce the weight of the engine without impairing engine cooling performance and the effect of suppressing engine vibration and noise.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The cylinder block 1 is for a four-cylinder engine in which liners 2a to 2d are arranged in series, and a water jacket 3 is formed between the cylinder block outer wall 4 and each liner 2a to 2d and between adjacent liners. .

The upper end position of the water jacket 3 is set near the upper ends of the liners 2a to 2d by the upper wall 5 over the entire water jacket 3. On the other hand, the lower end position of the water jacket 3 is
In the portions between the liners and on both side surfaces in the longitudinal direction of the engine, the lower wall 6a is set near the lower end of the liners 2a to 2d, and in the end portions 3a and 3a in the longitudinal direction of the engine, it is set at a higher position than the lower wall 6a. That is, the intermediate wall 6b provided near the upper end of the piston 7 at the bottom dead center position shown by the chain line in FIG. 2 is set at a higher position than the lower end of the liners 2a to 2d.

That is, the water jacket 3 has the liner 2 at both end surfaces 3a, 3a in the longitudinal direction of the engine.
It is formed only in the upper part around a and 2d, and in both side parts in the longitudinal direction of the engine and the part between the liners,
Connect the lower end of the water jacket 3 to the above-mentioned both end surfaces 3.
It is set at a lower position than that of lines a and 3a, and is formed broadly from the upper part to the lower part around the liner.

Note that 8 is a cooling water inlet opening in the cylinder block outer wall 4 at the front end in the longitudinal direction of the engine to introduce cooling water into the water jacket 3;
It is connected to a discharge port of a water pump (not shown).

When an engine is configured with the cylinder block 1 configured in this way, the water jacket 3
Each liner 2a to 2d is cooled by the cooling water flowing therethrough.

Therefore, at both ends in the longitudinal direction of the engine, the water jacket 3 is formed wide vertically, that is, the water jacket 3 covers not only the upper part but also the lower part of the liners 2a to 2d, so that this water The jacket 3 blocks engine noise from leaking to the outside, and also effectively suppresses engine vibration.

On the other hand, at both end faces in the longitudinal direction of the engine, the lower parts of the liners 2a and 2d, where the thermal load is small, are not covered with the water jacket 3, but the upper parts, where the thermal load is large, are covered with the water jacket 3. Therefore, there is no problem in terms of cooling the engine. Although the vibration and noise suppression effect of the water jacket 3 cannot be obtained at the lower part of both end face parts, the amount of vibration and noise leaking from these both end face parts itself is small, and the amount of vibration and noise that leaks from these end face parts is small, and the amount of vibration and noise suppressed by separately provided auxiliary equipment is small. Since vibration and noise isolation effects can be expected, there are fewer problems with vibration and noise. Therefore, quiet engine operation can be achieved, which is not much different from the conventional case in which a water jacket is formed over a wide range from the upper end to the lower end of the liner.

Since the water jacket 3 is formed only in the upper part of both end faces, the amount of cooling water can be reduced, which makes it easier to improve engine warm-up performance and reduce the weight of the engine. It is something that can be done.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a horizontal sectional view of a cylinder block, and FIG. 2 is a cross-sectional view of the cylinder block shown in FIG.
3 is a sectional view taken along the - line in FIG. 1. 1... Cylinder block, 2a to 2d... Liner, 3... Water jacket, 3a... Both end surfaces of the water jacket in the engine longitudinal direction.

Claims (1)

[Scope of utility model registration request] In a cylinder block of a multi-cylinder engine in which a water jacket is arranged around the liner, the water jacket is formed only at the upper part around the liner at both end faces in the longitudinal direction of the engine. A cylinder block structure for an engine, characterized in that the lower end of the water jacket is set at a lower position than the both end face parts in the side part, and the cylinder block is formed wider from the upper part to the lower part around the liner.