JP6527363B2 - Cylinder block - Google Patents

Description

  The present invention relates to a cylinder block of an engine.

  As described in Patent Documents 1 and 2, the cylinder block of the engine is provided with a water jacket through which cooling water flows. Further, by forming a rib around the cylinder liner to increase rigidity, deformation of the cylinder bore due to stress is suppressed.

JP-A-58-74851 JP 2005-337140 A

  By the way, development has been advanced to reduce the weight of the cylinder block by recessing a part of the outer wall of the cylinder block to the vicinity of the water jacket on the inner side of the cylinder block. In such a configuration, thermal stress is generated inside the cylinder block by receiving combustion heat, and as a result, the stress that pulls the cylinder liner radially outward of the depressed portion is weaker than that of the periphery of the depressed portion. There was a problem that the degree decreased.

  Then, this invention aims at providing the cylinder block which can suppress the fall of the roundness of a cylinder bore, achieving weight reduction of a cylinder block.

In order to solve the above problems, the cylinder block of the present invention is formed on a cylinder block body, a cylinder liner housed inside the cylinder block body, and an outer wall of the cylinder block body, and a depressed portion recessed on the cylinder liner side And a water jacket provided in the cylinder block body between the cylinder liner and the outer wall of the cylinder block, avoiding the hollow portion and supplied with cooling water, the hollow portion being the cylinder liner Protrusions extending in a circumferential direction from both sides to a depth to be sandwiched by the water jacket and having a protrusion extending in a direction parallel to the central axis of the cylinder liner are arranged, and the water jacket extends from the recess to the cylinder liner side vinegar Rukoto and features.

  Among the gaps constituting the water jacket, portions on both sides of the depression may be communicated with each other at a position shifted in a direction parallel to the central axis than the depression.

  According to the present invention, it is possible to suppress the decrease in the roundness of the cylinder bore while achieving the weight reduction of the cylinder block.

It is an external view of a cylinder block of an engine. It is an explanatory view for explaining the depth (depth of a slot) of a water jacket. It is an explanatory view for explaining a communicating part of a water jacket.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values and the like shown in this embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the specification and the drawings, elements having substantially the same functions and configurations will be denoted by the same reference numerals to omit repeated description, and elements not directly related to the present invention will not be illustrated. Do.

  FIG. 1 is an external view of a cylinder block 1 of an engine, and FIG. 1 (a) shows a top view of the cylinder block 1, and FIG. 1 (b) shows the cylinder block 1 in FIG. The right side view is shown. As shown in FIG. 1, the cylinder block 1 has a cylinder block main body 2 formed by casting an aluminum alloy, for example.

  Inside the cylinder block body 2, a cylinder liner 3 (sleeve) is disposed. The cylinder liner 3 is an annular member, and is fixed to the cylinder block body 2 by being cast into the cylinder block body 2 or press-fitting into the cylinder block body 2. Alternatively, the cylinder liner 3 may not be provided as a separate member from the cylinder block body 2, and the inner wall of an annular hole formed in the cylinder block body 2 may be coated with plating or the like to form the cylinder liner 3.

  And in FIG.1 (b), the crankshaft not shown is distribute | arranged to the concave part 2a below the cylinder block main body 2. As shown in FIG. As shown in FIG. 1A, a connecting rod (not shown) is inserted through an opening 2b formed on the bottom surface side of the cylinder liner 3 (in FIG. 1B, on the side of the recessed portion 2a). A piston (not shown) accommodated in the cylinder liner 3 is connected to a crankshaft via a connecting rod.

  Further, by fastening a cylinder head (not shown) to the upper surface 2c side of the cylinder block main body 2, the upper surface 2c side of the cylinder block main body 2 in the cylinder liner 3 is closed, and a combustion chamber is formed inside. The combustion of the fuel in the combustion chamber causes the piston to reciprocate in the cylinder liner 3, and the power of the piston's reciprocation is converted to the rotational movement of the crankshaft via the connecting rod and output.

  As described above, since fuel is burned in the combustion chamber to generate combustion heat, the vicinity of the cylinder liner 3 is heated to a high temperature by the combustion heat. Therefore, a water jacket 4 (shown by cross hatching in FIG. 1A) is provided to cool the high temperature portion.

  The water jacket 4 is an air gap S formed around the cylinder liner 3 in the cylinder block body 2 and serves as a cooling water channel to which cooling water is supplied. Here, the water jacket 4 is a groove recessed from the top surface 2 c side of the cylinder block main body 2 toward the bottom surface side.

  In other words, the water jacket 4 is provided in the cylinder block body 2 between the cylinder liner 3 and the outer wall 2 d of the cylinder block body 2. The water jacket 4 is formed on the radially outer side of the cylinder liner 3 in the cylinder block main body 2 substantially over the entire circumference, and cools the entire circumference of the cylinder liner 3.

  Thus, when the water jacket 4 is provided, the outer wall 2 d and the inner wall 2 e for housing the cylinder liner 3 are formed in the cylinder block body 2. Then, in order to secure the strength of both the outer wall 2d and the inner wall 2e, it is necessary to make each of the outer wall 2d and the inner wall 2e have a certain thickness, and the weight increases as the thickness increases.

  So, in the cylinder block 1, as shown to FIG. 1B, the hollow part 2f is formed in the outer wall 2d of the cylinder block main body 2. As shown in FIG. The recess 2 f is a portion recessed from the outer wall 2 d of the cylinder block body 2 toward the cylinder liner 3. In FIG. 1 (b), the bottom surface of the depression 2 f is indicated by hatching. And the water jacket 4 is provided avoiding the hollow part 2f.

  FIG. 2 is an explanatory view for explaining the depth (depth of the groove) of the water jacket 4. In FIG. 2 (a), a line II (a)-II (a) in FIG. 1 (b) FIG. 2 (b) shows a cross section taken along line II (b) -II (b) of FIG. 1 (b), and FIG. 2 (c) shows a cross section II (c) of FIG. 1 (b). -II (c) line cross section is shown.

  2 (a) is a sectional view taken along the line II (a) of FIG. 1 (a), and FIG. 2 (b) is a cross section taken along the dashed line b of FIG. 1 (a). Fig. 2 (c) is a view taken along line II (c) of Fig. 1 (a).

  As shown in FIG. 2C, the water jacket 4 extends to a depth of half or more of the length in the central axis direction of the cylinder liner 3 in the cross section of the portion without the recess 2f in the outer wall 2d of the cylinder block body 2. It exists.

  On the other hand, as shown in FIG. 2 (b), in the cross section of the portion where the recess 2f is formed, the water jacket 4 is not interposed between the recess 2f and the cylinder liner 3, and the water jacket 4 is recessed It extends only from the portion 2 f to the upper surface 2 c side of the cylinder block main body 2 and is shallow.

  In the portion of water jacket 4 having a predetermined depth L (see FIGS. 1 (b) and 2 (a), 2 (b)) or more, continuity of cylinder liner 3 in the circumferential direction is obtained by recess 2f. It has been refused. In other words, the recess 2 f extends from both sides in the circumferential direction of the cylinder liner 3 to a depth to be sandwiched by the water jacket 4. And the water jacket 4 is provided avoiding the hollow part 2f.

  Therefore, in the portion where the recessed portion 2f is formed, the cylinder block body 2 is integrated without dividing the inner wall 2e from the outer wall 2d, as shown in FIG. 2 (c), the water jacket 4 is interposed therebetween. Compared with the part which intervenes and is divided into the outer wall 2d and the inner wall 2e, it becomes possible to reduce the overall thickness and to reduce the weight of the cylinder block body 2.

  As described above, although the weight reduction can be achieved by providing the recess 2f, a new problem arises. That is, simply by providing the recess 2f, the overall thickness of the portion where the recess 2f is formed becomes thin, and when the cylinder block body 2 is heated by the combustion heat (at the time of hot), the recess The amount of thermal deformation of the outer wall 2 d located at the bottom of the portion 2 f is smaller than that of the surroundings.

  As a result, in the cylinder liner, the load pulled in the direction shown by the hatching arrow becomes smaller than the load pulled in the direction shown by the white arrow in FIG. Roundness will decrease.

  So, in this embodiment, as shown in Drawing 1 (b) and Drawing 2 (a), projection 5 is provided in crevice 2f. The projection 5 protrudes outward in the radial direction of the cylinder liner 3 from the bottom surface of the recess 2 f and is parallel (parallel) to the central axis of the cylinder liner 3 (vertical direction in FIG. 1 (b)) Extends to

  Thus, when the projection 5 is provided, the thermal deformation of the projection 5 at the time of hot deformation increases the total amount of thermal deformation of the portion where the recessed portion 2 f is formed, and the amount of thermal deformation with the periphery of the recessed portion 2 f It is possible to reduce the difference of As a result, when hot, the imbalance in the circumferential direction of the load that pulls the cylinder liner 3 radially outward is improved, and it is possible to maintain high roundness of the cylinder bore 3a on the inner peripheral surface of the cylinder liner 3. Become.

  FIG. 3 is an explanatory view for explaining the communicating portion of the water jacket 4. FIG. 3 (a) extracts and shows the vicinity of the outer wall 2d on the right side in FIG. Further, in FIG. 3B, the cylinder block main body 2 and the cylinder liner 3 shown in FIG. 3A are cut at a position where the recess 2f and the protrusion 5 are formed in a plane parallel to the upper surface 2c. It shows a cross section.

  In the cross section shown in FIG. 3B, the portions Sa and Sb on both sides of the air gap S across the depression 2f are separated by the depression 2f. And as for space S of water jacket 4, both sides Sa and Sb which pinched this hollow part 2f are upper surface 2c side in a direction parallel to a central axis rather than hollow part 2f, as shown in Drawing 2 (a). It communicates in the position which shifted to. Therefore, since the cooling water circulates around the entire circumference of the cylinder liner 3, it is possible to suppress a decrease in the cooling performance due to the provision of the depressions 2 f and the projections 5.

  While the preferred embodiments of the present invention have been described with reference to the accompanying drawings, it is a matter of course that the present invention is not limited to the above-described embodiments, and various modifications in the scope described in the claims. It goes without saying that the modifications also fall within the technical scope of the present invention.

  The present invention is applicable to a cylinder block of an engine.

S Air gap Sa, Sb Part 1 Cylinder block 2 Cylinder block main body 2 f Recessed part 3 Cylinder liner 4 Water jacket 5 Protrusion

Claims (2)

Cylinder block body,
A cylinder liner housed inside the cylinder block body;
A recess formed on the outer wall of the cylinder block body and recessed toward the cylinder liner side;
A water jacket which is provided in the cylinder block main body between the cylinder liner and the outer wall of the cylinder block main body so as to avoid the recess and to which cooling water is supplied;
Equipped with
The recess extends from both sides in the circumferential direction of the cylinder liner to a depth sandwiched by the water jacket, and a protrusion extending in a direction parallel to a central axis of the cylinder liner is disposed .
The water jacket, the cylinder block to extend Mashimasu wherein Rukoto to said cylinder liner side of the recess.   The part on both sides which pinched | interposed the said hollow part among the space | gaps which comprise the said water jacket are connected in the position which shifted in the direction parallel to the said central axis rather than this hollow part. Cylinder block.

Images