JP2016191320A - Stiffening structure of cylinder block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stiffen a space having low rigidity and surrounded by a cylinder block and an oil pan, and improve rigidity to torsional vibration of the cylinder block thereby to reduce in-vehicle sound.SOLUTION: A stiffening structure 10 of a cylinder block 12 includes: a cylinder block 12 pivotally supporting a crank shaft 14; an oil pan 11 positioned vertically below the cylinder block, and configured to collect engine oil; and stiffening members 17 intersecting with each other so as to connect the paired apexes of a substantially rectangular shape in an opening area in which the horizontal cross section of a cylinder block lower part or oil pan upper part is formed into the substantially rectangular shape.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cylinder block stiffening structure, and more specifically, to stiffen a space enclosed by a cylinder block and an oil pan to improve rigidity against torsional vibration to the cylinder block. Concerning structure.

  2. Description of the Related Art Conventionally, in an automobile engine or the like, engine oil is stored in an oil pan provided below a cylinder block, and engine oil is driven by an oil pump using a rotation of a crankshaft or the like to drive a piston sliding part or the like. The engine was pumped to various parts of the engine, such as the rotating part of the crankshaft, and each part was lubricated and cooled, and then was transferred to the oil pan as oil droplets along the wall. The engine oil circulates in the engine by being sucked up again by the oil pump.

  The space surrounded by the cylinder block and the oil pan is secured widely for smooth recovery of engine oil, but its rigidity is relatively low due to its size. Therefore, for example, in prior art document 1, a technique for disposing a damping material that connects the centers of opposite sides of the bottom wall of the oil pan is disclosed. Moreover, in the example of the prior art document 2, a reinforcing structure including a lattice-shaped partition wall portion having a plurality of openings and a baffle plate formed by extending a part thereof downward is shown in the lower part of the cylinder block.

Japanese Unexamined Patent Publication No. Sho 63-8010 Japanese Utility Model Publication No. 3-104151

  By the way, in a reciprocating internal combustion engine in which a reciprocating linear motion of a piston is converted into a rotational motion by a crank mechanism to rotate the crankshaft, the crankshaft receiving the in-cylinder pressure is deformed into a bow shape by an inertial force, and the crankshaft There is a case where vibration and noise occur in contact with the bearing (journal). Due to the vibration caused by the contact between the crankshaft and the bearing, torsional deformation around the Y-axis appears in many modes in the engine (cylinder block), which is transmitted to the vehicle body through the engine mount, causing the interior noise. Become.

  Therefore, the present invention can reduce the noise in the vehicle by stiffening the space surrounded by the cylinder block and the oil pan, which has low rigidity, and improving the rigidity against torsional vibration of the cylinder block. It is an object to provide a rigid stiffening structure for a cylinder block.

  In order to solve the above-mentioned problems, the cylinder block stiffening structure of the present invention is located vertically below the cylinder block, and has an oil pan for storing engine oil, and a horizontal section at the bottom of the cylinder block or at the top of the oil pan is substantially rectangular. And a stiffening member that intersects with a pair of substantially rectangular vertices in the opening region.

  The stiffening member may have a T-shaped cross section perpendicular to the longitudinal direction.

  Of the stiffening members, one width that receives tension in the longitudinal direction due to the torsion of the engine may be formed wider than the other.

  According to the present invention, it is possible to reduce vehicle interior noise by suppressing torsional vibration of the engine.

It is the longitudinal cross-sectional view which looked at the 4-cylinder horizontally opposed engine which is a reciprocating engine in this embodiment from the Y direction, ie, a side surface. It is explanatory drawing for demonstrating the torsional vibration which an engine receives. It is explanatory drawing which showed the outline of the stiffening member in the stiffening structure of a cylinder block. It is explanatory drawing for demonstrating the shape of a stiffening member. It is a longitudinal cross-sectional view for showing the shape of a stiffening member.

  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 shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Cylinder block stiffening structure 10)
FIG. 1 is a longitudinal sectional view of a four-cylinder horizontally opposed engine (hereinafter simply referred to as an engine 1), which is a reciprocating engine in the present embodiment, as viewed from the Y direction, that is, from the side. In the description of the present embodiment, the X, Y, and Z axes are defined as shown in FIG.

  As shown in FIG. 1, the oil pan 11 is attached to the lower bottom surface of the cylinder block 12 with a bolt 13a, and is attached so as to cover the oil pan upper 11a having an opening at the bottom and the opening of the oil pan upper 11a from below. The oil pan lower 11b is divided into two parts (two-stage type) and stores engine oil. The engine oil is driven by an oil pump (not shown) utilizing the rotation of the crankshaft 14 pivotally supported by the cylinder block 12 and various parts of the engine such as the sliding portion of the piston 15 and the rotating portion of the crankshaft 14. After the parts are lubricated and cooled, they are transferred as oil droplets through the wall and dropped onto the oil pan 11. The engine oil circulates in the engine 1 by being sucked up again by the oil pump.

  The oil pan upper 11a is made of a cast product made of an aluminum alloy. A baffle plate (not shown) having a wave-dissipating function is integrally formed, and components such as a water pump and a thermostat are also assembled.

  The oil pan lower 11b is connected to the oil pan upper 11a with bolts 13b and is made of sheet metal obtained by pressing a steel plate. An oil strainer 16 is placed in the space inside the oil pan lower 11b.

  FIG. 2 is an explanatory diagram for explaining the torsional vibration that the cylinder block 12 receives. The crankshaft 14 that has received the in-cylinder pressure with respect to the engine 1 may be deformed into a bow shape due to an inertial force, and may come into contact with a bearing (journal) of the crankshaft 14 to generate vibration or noise. Due to the vibration caused by the contact between the crankshaft 14 and the bearing, the cylinder block 12 (engine 1) has torsional deformation around the Y axis in many modes, as indicated by arrows in FIG. It is transmitted to the vehicle body through an engine mount (not shown), which causes in-vehicle noise. In view of this, a space surrounded by the cylinder block 12 and the oil pan 11, specifically, an oil pan upper 11a, is provided with a stiffening member 17 having a cross-shaped rib in a plan view and having a T-shaped cross section. By improving the torsional rigidity of the block 12, vibrations and abnormal noises transmitted to the vehicle are reduced.

(Height position of the stiffening member 17)
FIG. 3 is an explanatory view showing an outline of the stiffening member 17 in the stiffening structure 10 of the cylinder block. Here, a structure surrounding the space 22 formed in the cylinder block 12, that is, a structure in which the side surface is the wall surface of the cylinder block 12, the upper surface is the crankshaft 14, and the lower surface is the stiffening member 17, is assumed to be a cube. In the case of a cube, when the surface areas are equal, the closer to a regular hexahedron, the higher the rigidity. Therefore, the position of the stiffening member 17 is positioned in an opening region having a substantially rectangular horizontal section in the oil pan upper 11a. In this way, the rigidity can be increased by effectively utilizing the cylinder block 12 as a side surface.

(Shape of stiffening member 17)
As described above, by positioning the stiffening member 17 on the oil pan upper 11a, it is possible to increase the rigidity of the structure that looks like a cube. At this time, the rigidity of each face of the cube is higher when it does not have a missing part. Therefore, it is desirable to form the stiffening member 17 with a flat plate. However, such a position hits vertically below a cylinder (not shown) or the crankshaft 14 and serves as an engine oil path. Therefore, if the stiffening member 17 is simply formed of a flat plate, the circulation performance of the stiffening structure 10 of the cylinder block may be affected.

  FIG. 4 is an explanatory diagram for explaining the shape of the stiffening member 17. Suppose that a flat plate as shown in FIG. 4A is arranged in the horizontal direction (XY plane) as a stiffening member at the height shown in FIG. Then, the torsion of the cylinder block 12 shown in FIG. 2 applies stress to the flat plate as shown in FIG. In FIG. 4, the engine 1 is viewed from below and is displayed in black as the stress is high.

  As can be understood with reference to FIG. 4A, the portion where the stress is high is concentrated at the opposite vertex when the flat plate is rectangular and extends in the diagonal direction. Therefore, in the present embodiment, as shown in FIG. 4B, the stiffening member 17 is formed to cross in a cross shape so as to connect the paired vertices, and other portions are cut out.

  With such a configuration, it is possible to secure a path for engine oil while effectively suppressing stress.

  4 (a) and 4 (b), in particular, the stress in the direction C extending from the left paired vertex A in front of the cylinder block 12 to the right paired vertex B behind the cylinder block 12 is high. Can understand. This is because the twist indicated by the arrow in FIG. 2 applies a tension in the direction C and a pressure in the direction D with respect to the stiffening member 17. In this case, the stress due to the torsion of the cylinder block 12 is dominated by the tension in the direction C, and the stretching amount in the direction C is larger than the compression amount in the direction D. Therefore, in this embodiment, the width of the stiffening member 17 extending in the direction C receiving the tension in the longitudinal direction due to the twist of the cylinder block 12 is formed wider than the stiffening member 17 extending in the direction D.

  With this configuration, it is possible to increase the rigidity more effectively while minimizing the occupied volume of the member.

  In addition, although the example which forms the stiffening member 17 integrally was given here, it is not restricted to such a case, The stiffening member 17 which connects a pair vertex can be provided in a different body, respectively. The former can reduce the assembly load, and the latter can cancel the influence of each other's stress.

  FIG. 5 is a longitudinal sectional view for illustrating the shape of the stiffening member 17. As shown in FIG. 5, the stiffening member 17 of this embodiment has a T-shaped cross section perpendicular to the longitudinal direction. Therefore, the rigidity can be increased with respect to torsion around the longitudinal direction of the stiffening member 17.

  As described above, in the cylinder block stiffening structure 10 provided with the stiffening member 17 of the present embodiment, the space surrounded by the cylinder block 12 and the oil pan 11 with low rigidity is stiffened. Thus, it is possible to improve the rigidity against the torsional vibration of the cylinder block 12 and, in turn, vibration and noise associated with the deformation of the cylinder block 12 can be suppressed.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications within the scope described in the claims. Needless to say, the modified examples also belong to the technical scope of the present invention.

  For example, in the above-described embodiment, the example in which the stiffening member 17 is provided on the upper side of the oil pan 11, more specifically, the oil pan upper 11 a, has been described. You may provide in a bottom face, ie, the oil pan 11 side opening area | region.

  The present invention relates to a cylinder block stiffening structure, and more specifically, to stiffen a space enclosed by a cylinder block and an oil pan to improve rigidity against torsional vibration to the cylinder block. Available for construction.

1 Engine 10 Cylinder Block Stiffening Structure 11 Oil Pan 11a Oil Pan Upper 11b Oil Pan Lower 12 Cylinder Block 17 Stiffening Member

Claims (3)

A cylinder block that supports the crankshaft;
An oil pan located vertically below the cylinder block for storing engine oil;
A stiffening member that crosses the apexes of the substantially quadrangular quadrilateral in a horizontal quadrilateral opening section of the cylinder block lower part or the oil pan upper part,
A cylinder block stiffening structure comprising:   The cylinder block stiffening structure according to claim 1, wherein the stiffening member has a T-shaped cross section perpendicular to the longitudinal direction.   3. The cylinder block stiffening structure according to claim 1, wherein one of the stiffening members that receives tension in a longitudinal direction due to engine twist is formed wider than the other. 4.