JP2011080420A - Cylinder block for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in which lubricating oil bubbles since the lubricating oil passing through an oil drop passage hits a balance weight of a crankshaft and there is a great possibility that a lot of bubbles are mixed in the lubricating oil stored in an oil pan, if the oil drop passage is provided along a cylinder arrangement direction. <P>SOLUTION: This cylinder block for an internal combustion engine includes lubricating oil return space communicating to lubricating oil return passages provided at a plurality of sections of a cylinder head of the internal combustion engine and communicating to the oil pan. The lubricating oil return space is equipped with: a first space extending from the cylinder head side toward the oil pan and communicating to an inside of the oil pan at one end; a second space provided at a section opposing to the cylinder head along the cylinder arrangement direction, constituted of single recess part, communicating to all of the plurality of lubricating oil return passages, and communicating to the first space; and an intermediate space including a curved space of a small curvature and providing communication between the first space and the second space. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cylinder block of an internal combustion engine mounted on an automobile or the like, and more particularly to a structure for returning lubricating oil in a cylinder head to an oil pan.

  Conventionally, an engine is designed to store lubricating oil in an oil pan and supply the lubricating oil to each operating part. In order to circulate such lubricating oil, the cylinder head and the cylinder block constituting the engine are provided with a structure called an oil return passage or an oil dropping passage for returning the lubricating oil in the cylinder head to the oil pan.

  For example, in Patent Document 1, a block wall is formed on the outer side of a water jacket outer wall along the cylinder arrangement direction, and a space between one water jacket outer wall and the block outer wall serves as a cooling water passage space to the water jacket. A cylinder block is described in which an oil drop passage for returning the lubricating oil of the cylinder head is provided between the outer wall of the water jacket and the outer wall of the block.

JP 11-280537 A

  However, with such a configuration, since the oil dropping passage is provided along the cylinder arrangement direction, the lubricating oil that has passed through the oil dropping passage drops onto the balance weight of the crankshaft. That is, the lubricating oil drops from the lower end of the oil dropping passage and strikes the balance weight. For this reason, the lubricating oil is foamed, and there is a high possibility that a large amount of bubbles are mixed with the lubricating oil stored in the oil pan.

  Therefore, the present invention aims to eliminate such problems.

  That is, the cylinder block of the internal combustion engine of the present invention includes a lubricating oil return space that communicates with a lubricating oil return passage provided at a plurality of locations of a cylinder head of the internal combustion engine and that communicates with an oil pan. The lubricating oil return space is a block that extends from the cylinder head side toward the oil pan, and has one end communicating with the inside of the oil pan and a portion facing the cylinder head along the cylinder arrangement direction. The second space is configured by a single recess and communicates with all of the plurality of lubricant return passages and communicates with the first space, and the first space and the second space have a curved surface with a small curvature. An intermediate space is provided.

  According to such a configuration, since the intermediate space has a curved surface with a small curvature, it is possible to smoothly move the lubricating oil from the second space to the first space. Therefore, it is possible to suppress the generation of bubbles when the lubricating oil moves from the first space to the oil pan.

  In order to further suppress the generation of bubbles, it is preferable that the first space is formed in a corner near the end in the longitudinal direction to guide the lubricating oil in the second space to the corner of the oil pan. Specifically, the first space is preferably one in which lubricating oil is dropped in the vicinity of an oil strainer disposed in the oil pan.

  The present invention is configured as described above, and since the intermediate space has a curved surface with a small curvature, the lubricating oil can be smoothly moved from the second space to the first space. It is possible to suppress the generation of bubbles when the lubricating oil moves from one space to the oil pan.

The perspective view seen from the side of the engine which uses the cylinder block of the embodiment of the present invention. The perspective view seen from the front side of the engine of the embodiment. The perspective view of the cylinder block of the embodiment. The perspective view of the cylinder block main body of the embodiment. The top view (a) of the cylinder block main body of the embodiment, and the bottom view (b) of a cylinder head. The longitudinal cross-sectional view in the intermediate | middle wall part of the embodiment. The front view of the cylinder block main body of the embodiment. The longitudinal cross-sectional view in the front side end wall of the embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  The cylinder block 1 of the engine 100 of this embodiment is that of a two-cylinder engine. The whole engine 100 using the cylinder block 1 of this embodiment is shown in FIG. The cylinder block 1 includes a cylinder bore 2 forming a cylinder, a water jacket 3 provided around the cylinder bore 2, a cylinder block body 5 having a lubricating oil return space 4, which will be described later, and a front end cover 6 attached to the cylinder block body 5. It consists of. The cylinder block 1 has a cylinder head 7 attached to its upper surface 1a via a gasket (not shown) and an oil pan 8 attached to its lower side. The cylinder head 7 is provided with lubricating oil return passages 9 at a plurality of locations. Since the lubricating oil return passage 9 provided in the cylinder head 7 may be the same as that widely known in this field, description and illustration are omitted. A strainer 10 is disposed at a position near the lower side of the front end cover 6 of the oil reservoir 8 a of the oil pan 8.

  The cylinder block 1 includes a lubricant return space 4 that communicates with each of the plurality of lubricant return passages 9 of the cylinder head 7. The lubricating oil return space 4 extends toward the oil pan 8 from the cylinder head 7 side, that is, a first space 11 whose lower end communicates with the inside of the oil pan 8 in this embodiment, and a portion facing the cylinder head 7. And the second space 13 which is provided along the arrangement direction of the cylinder bores 2 and is configured by a single recess 13a and communicates with all of the plurality of lubricating oil return passages 9 and communicates with the first space 11. An intermediate space 14 having a curved surface 14 a and communicating the first space 11 and the second space 13 is provided. In this embodiment, the lubricating oil return space 4 is formed on the intake side of the engine 100 to which the intake manifold 15 is attached.

  The first space 11 is formed by the front end wall 16 and the front end cover 6 in the arrangement direction of the cylinder bores 2 of the cylinder block body 5. The first space 11 is formed by covering the groove 11 a provided on the front end wall 16 side of the cylinder block 1 exposed with the front end cover 6 removed with the front end cover 6. The groove 11 a is formed in a shape along the side surface of the cylinder block body 5 in a state of being recessed from the surface of the front end wall 16 toward the cylinder bore 2, that is, the inside of the cylinder block body 5. By providing the first space 11 at the corner in the longitudinal direction of the cylinder block main body 5, that is, in the vicinity of the end in the arrangement direction of the cylinder bores 2, the lower end is a position in the vicinity of the strainer 10 arranged in the oil pan 8. It will be located above.

  The second space 13 includes the concave portion 13a that opens upward as described above, and is located outside the water jacket 3 formed around the cylinder bore 2 with the intermediate wall 17 interposed therebetween. The second space 13 is formed in a flange portion 5 a that protrudes outward from the side surface of the upper portion of the cylinder block body 5 in order to correspond to the lubricant return passage 9 provided in the cylinder head 7. When the cylinder block body 5 is viewed from above, the second space 13 is formed along the respective cylinder bores 2, and thus over substantially the entire length in the arrangement direction of the cylinder bores 2 on the upper surface of the cylinder block body 5. Therefore, the opening area of the recess 13a constituting the second space 13 is substantially the maximum between the cylinder bore 2 and the side surface of the flange portion 5a. The recess 13a is deeper on the intermediate space 14 side than on the opposite side, and therefore the bottom surface of the recess 13a is slightly inclined toward the intermediate space 14.

  The intermediate space 14 is provided continuously to the second space 13 and communicates with the first space 11 via the through hole 18. The intermediate space 14 is provided in an intermediate wall portion 5b formed so as to bulge below the flange portion 5a of the cylinder block body 5 in which the second space 13 is formed. The intermediate wall portion 5b is formed from approximately the center of the flange portion 5a to the front end wall 16. The intermediate space 14 includes a curved surface 14 a that is continuous with the bottom surface of the second space 13. The curved surface 14 a has a small radius of curvature and therefore a large radius, and is bent at approximately 90 degrees from the bottom surface of the second space 13 and is continuous with the inner surface of the lower side of the intermediate space 14.

  The cylinder block body 5 of this embodiment is provided with another front lubricating oil return space 19 on the upper surface of the cylinder block body 5 located above the front end wall 16. The front lubricating oil return space 19 is formed in a wall portion of the front end wall 16 adjacent to the intermediate wall portion 5b in which the intermediate space 14 is formed, and is formed through a communication hole 20 provided in the front end wall 16. It communicates with one space 11.

  The engine 100 of this embodiment is of a so-called horizontal type that is mounted with the crankshaft parallel to the axle, and is mounted on the front exhaust side with the exhaust side facing the front side of the vehicle and the intake side facing the rear side. It is called an engine. When the engine 100 is mounted in this manner, the lubricant return space 4 is located on the rear side of the engine room. In addition, in the case of this engine 100, in the state mounted in the motor vehicle, it inclines back.

  In such a configuration, the second space 13 and the intermediate space 14 continuing to the second space 13 are open toward the upper side of the cylinder block body 5, so that when the cylinder block body 5 is cast, Since the second space 13 and the intermediate space 14 can be formed by the upper mold, it is not necessary to use a core. Therefore, the manufacture of the cylinder block body 5 can be simplified.

  When the engine 100 is operated, the lubricating oil in the oil pan 8 is supplied to each part of the engine 100 and returned from the cylinder head 7 to the second space 13 of the lubricating oil return space 4 through the lubricating oil return passage 9. By returning the lubricating oil in this way, the lubricating oil from the cylinder head 7 is collected. The lubricating oil accumulated in the second space 13 passes through the curved surface 14 a of the intermediate space 14 and flows into the first space 11. In this case, since the curved surface 14a of the intermediate space 14 is gentle, the lubricating oil can smoothly flow into the first space 11 and foaming can be suppressed.

  Similarly, the lubricating oil that has moved to the front lubricating oil return space 19 also flows into the first space 11. Therefore, in the first space 11, the amount of lubricating oil further increases.

  The lubricating oil that has flowed into the first space 11 falls into the oil pan 8. In this case, since the lower end of the first space 11 is positioned above the vicinity of the strainer 10 in the oil pan 8, the lubricating oil is hit by the balance weight of the crankshaft and the balance weight of the balance shaft for vibration reduction. There is nothing. And since there is much oil quantity of the lubricating oil which falls, it can suppress that lubricating oil foams in the oil pan 8. FIG. Moreover, since a large amount of lubricating oil is returned to the strainer 10 vicinity, the fluctuation | variation of the oil level in the oil pan 8 can be suppressed, and a mechanical loss can be reduced. Therefore, engine 100 can be operated at a high rotational speed.

  Further, between the cylinder bore 2 and the side wall of the cylinder block body 5, there are two walls, a wall forming the cylinder bore 2 and a wall between the water jacket 3 and the oil return space 4. Can effectively block noise and vibration.

  In the above-described embodiment, the lower end of the first space 11 is disposed above the vicinity of the strainer 10 built in the oil pan 8. However, each of the balance weights described above after the lubricating oil has left the first space 11. What is necessary is just the corner of the oil pan 8 that does not almost directly contact with the oil pan. In other words, the lower end of the first space 11 may be arranged so that the lubricating oil returns to the oil pan 8 through a portion excluding the vicinity of the space where the balance weights of the legs are rotating.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  As an application example of the present invention, an engine mounted on an automobile can be cited. In particular, it is preferable to apply to an engine in which the engine is of a horizontal type and is disposed at the front exhaust.

DESCRIPTION OF SYMBOLS 1 ... Cylinder block 2 ... Cylinder bore 4 ... Lubricant return space 7 ... Cylinder head 8 ... Oil pan 9 ... Lubricant return passage 11 ... First space 13 ... Second space 14 ... Intermediate space 14a ... Curved surface

Claims (3)

A cylinder block of an internal combustion engine comprising a lubricating oil return space communicating with a lubricating oil return passage provided at a plurality of locations of a cylinder head of the internal combustion engine and communicating with an oil pan,
The lubricating oil return space extends from the cylinder head side toward the oil pan, a first space whose one end communicates with the inside of the oil pan, and a single recess provided in a portion facing the cylinder head along the cylinder arrangement direction. A second space that communicates with all of the plurality of lubricant return passages and communicates with the first space, and an intermediate space that has a curved surface with a small curvature and communicates the first space and the second space. A cylinder block for an internal combustion engine.   The cylinder block of an internal combustion engine according to claim 1, wherein the first space is formed at a corner near the end in the longitudinal direction, and guides the lubricating oil in the second space to the corner of the oil pan.   The cylinder block of the internal combustion engine according to claim 2, wherein the first space has the lubricating oil dropped in the vicinity of an oil strainer disposed in the oil pan.

Images