JP2018105401A - Bearing cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing cap which hardly transmits the vibration of a shaft to a bolt for fixing the bearing cap to an object to be fixed.SOLUTION: A bearing cap 1A rotatably supports a crankshaft 11 via a bearing. The bearing cap 1A comprises an insertion hole 23, a notch 24 and an elastic member 3. The insertion hole 23 is formed along a direction intersecting with an axial direction of the crankshaft 11, and inserted with a bolt 13 for fixing the bearing cap 1A to an object to be fixed. The notch 24 is formed at a periphery of the insertion hole 23 so as to be connected to the insertion hole 23. The elastic member 3 has a penetration hole 31 penetrated with the bolt 13, is fit into the notch 24, and suppresses the transmission of the vibration of the crankshaft 11 to the bolt 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bearing cap structure. In particular, the present invention relates to a bearing cap in which vibration of a shaft is difficult to be transmitted to a bolt that fixes the bearing cap to a fixing target.

  As a structure for suppressing vibration of a bearing cap that rotatably supports an engine crankshaft or camshaft via a bearing, an engine vibration noise prevention device of Patent Document 1 is known. This vibration and noise prevention device for an engine includes a bearing cap and a bolt for fixing the bearing cap to a fixing target. The vibration noise prevention device further includes a damper mass provided on the opposite side of the bearing cap from the crankshaft so that its own weight is transmitted to the bearing cap, and a rubber plate interposed between the bearing cap and the damper mass. And a bolt for fixing the damper mass and the rubber plate to the bearing cap, and a spring provided around the bolt and constituting the damper together with the damper mass. In this configuration, when the vibration of the crankshaft is transmitted to the bearing cap and the damper mass vibrates due to the vibration of the bearing cap, the vibration of the bearing cap is attenuated by causing a phase shift by the spring.

Japanese Utility Model Publication No. 60-32441

  It is difficult to completely suppress the vibration of the bearing cap. Therefore, when the bearing cap vibrates due to the vibration of the crankshaft, the vibration is transmitted to the fixed object via the bolt that fixes the bearing cap to the fixed object, and the fixed object vibrates to generate noise.

  One of the objects of the present invention is to provide a bearing cap in which the vibration of the shaft is difficult to be transmitted to a bolt that fixes the bearing cap to an object to be fixed.

The bearing cap according to one aspect of the present invention is:
A bearing cap that rotatably supports the shaft via a bearing,
An insertion hole formed along a direction intersecting the axial direction of the shaft, through which a bolt for fixing the bearing cap to a fixed object is inserted;
A notch formed around the insertion hole so as to be connected to the insertion hole;
And an elastic member that has a through-hole through which the bolt penetrates and that is fitted into the notch to suppress transmission of vibration of the shaft to the bolt.

  The bearing cap includes a notch formed around the insertion hole and connected to the insertion hole, and an elastic member fitted into the notch, so that the elastic member can be disposed around the bolt that fixes the bearing cap to the fixing target. . Since this elastic member absorbs the vibration of the shaft, the vibration is difficult to be transmitted to the bolt. Therefore, the vibration of the shaft is not easily transmitted to the fixed object via the bolt, and the noise accompanying the vibration of the fixed object can be easily reduced.

1 is a cross-sectional view illustrating an outline of a bearing cap according to a first embodiment. FIG. 6 is a cross-sectional view illustrating an outline of a bearing cap according to a second embodiment.

  Embodiments 1 and 2 of the bearing cap of the present invention will be described below with reference to FIGS. 1 and 2, respectively. The same reference numerals in the figure indicate the same names. In the following first and second embodiments, the bearing caps 1 </ b> A and 1 </ b> B will be described by taking a crankshaft bearing cap that supports the crankshaft 11 as an example to be fixed to the cylinder block 12 of the engine. The arrows in the figure indicate the rotation direction of the crankshaft 11, and FIGS. 1 and 2 show views viewed from the direction in which the rotation direction of the crankshaft 11 is clockwise. That is, the left side of the paper is the thrust side, and the right side of the paper is the anti-thrust side. In the combustion / expansion stroke, when a combustion pressure is applied, a force pressed against the inner wall of the bore acts on the piston connected to the connecting rod (both not shown). This pressing force is called a lateral pressure, and the side of the piston where the lateral pressure acts immediately after top dead center is called the thrust side, and the side facing the thrust side in the radial direction of the piston is called the anti-thrust side. In FIG. 1 and FIG. 2, hatching of the crankshaft 11 is omitted for convenience of explanation. Here, the thrust side is on the left, the anti-thrust side is on the right, the axial direction of the crankshaft 11 is the front-rear direction, the direction orthogonal to both the left-right direction and the front-rear direction, that is, the crankshaft 11 (cylinder block 12) and the bearing cap 1A. 1B is the vertical direction.

Embodiment 1
[Bearing cap]
The bearing cap 1A according to the first embodiment rotatably supports the crankshaft 11 via a bearing (not shown) (FIG. 1). One feature of the bearing cap 1A is that an insertion hole 23 through which a bolt 13 for fixing the bearing cap 1A to the cylinder block 12 to be fixed is inserted, and an insertion hole 23 around the insertion hole 23. It is in the point provided with the notch 24 formed and the elastic member 3 fitted in the notch 24. Hereinafter, each configuration will be described in detail.

[Main unit]
The bearing cap 1 </ b> A has a main body portion 2 formed of a U-shaped block body in which a semicircular concave portion is formed. The concave portion of the main body 2 has a bearing surface 21 on which a bearing is mounted. As the bearing, a half-type slide bearing can be used. The crank journal 111 of the crankshaft 11 is disposed on the bearing surface 21 via a bearing. Below the bearing surface 21 in the main body 2, there is a central portion 22 that divides left and right cutouts 24 described later to form the bottoms of the cutouts 24. The central portion 22 makes it easy to prevent an excessive load from being applied to the left and right elastic members 3 (described later) due to vibration (bending vibration or torsional vibration) of the crankshaft 11 while ensuring the strength of the main body 2. The center portion 22 has the same lengths BL and BR from the imaginary line C to the bottom of the left and right notches 24 when the imaginary line C is taken along the vertical direction through the center of the crankshaft 11. is there.

[Insertion hole]
The insertion hole 23 is inserted with a bolt 13 that fixes the bearing cap 1 </ b> A to a fixing target. The insertion hole 23 is formed along a direction intersecting the axial direction of the crankshaft 11. Here, the insertion holes 23 are formed along the direction (vertical direction) perpendicular to the axial direction of the crankshaft 11 at two positions on the left and right sides of the bearing surface 21 of the main body 2. The axes of the left and right insertion holes 23 are symmetric with respect to the virtual line C.

[Notch]
The cutout 24 is fitted with an elastic member 3 to be described later. The notch 24 is formed around the insertion hole 23 so as to be connected to the insertion hole 23. Here, the notches 24 are formed at two locations around each of the left and right insertion holes 23. The left and right cutouts 24 open to the left and right side surfaces of the main body 2 and the front and rear surfaces of the main body 2, respectively. The left and right cutouts 24 do not communicate with each other, and a part (the center portion 22) of the main body 2 is provided between them.

  The contour shape of each notch 24 is a shape that follows the shape of the elastic member 3, and is a flat rectangular block here. The width (length along the left-right direction) and thickness (length along the up-down direction) of each notch 24 can be appropriately selected according to the desired width and thickness of the elastic member 3. Here, the left and right cutouts 24 have the same width and thickness as each other.

  The formation location along the vertical direction of the notch 24 can be selected as appropriate. For example, in the combustion / expansion stroke, a location located on an extension line in the longitudinal direction of the connecting rod when the side pressure is maximum is preferable. If it does so, it will be easy to suppress the transmission of the vibration of the crankshaft 11 to the volt | bolt 13 effectively. Here, the formation location along the vertical direction of the left and right cutouts 24 is set to the approximate center of the main body 2 in the vertical direction.

[Elastic member]
The elastic member 3 is fitted into the notch 24 and suppresses transmission of vibration of the crankshaft 11 to the bolt 13. The elastic member 3 is fitted in each of the left and right cutouts 24. The elastic members 3 can be fitted into the cutouts 24 by press-fitting from the left and right outer sides of the main body 2. Each elastic member 3 is formed with a through hole 31 through which the bolt 13 passes. The diameter of each through hole 31 can be the same as the outer diameter of the bolt 13.

  The materials of the left and right elastic members 3 may be the same material, but are preferably different materials, specifically, materials having different hardnesses. In the case of materials having different hardnesses, it is preferable that the material of the elastic member 3 on the anti-thrust side is made of a material having higher hardness than the material of the elastic member 3 on the thrust side. Then, while making it difficult to transmit the vibration of the crankshaft 11 to the bolt 13, it is easy to equalize the degree of wear of the left and right elastic members 3 due to the influence of the vibration of the crankshaft 11, so that the elastic member 3 on the anti-thrust side is thrust. It is easy to suppress that it becomes easier to wear out than the elastic member 3 on the side. This is because the load caused by the vibration of the crankshaft 11 is larger in the elastic member 3 on the anti-thrust side than in the elastic member 3 on the thrust side. Examples of the material of the elastic member 3 include rubber.

  The shape of each elastic member 3 can be selected as appropriate, and here is a flat rectangular block shape. The widths EL and ER of the left and right elastic members 3 are the same as each other, but may be different from each other as described in the second embodiment described later. The left and right elastic members 3 have the same thickness, but may be different from each other. For example, the thickness of the elastic member 3 on the anti-thrust side may be larger than the thickness of the elastic member 3 on the thrust side.

  The bearing cap 1A is attached to a crank pulley (not shown) on the other end of the crankshaft 11 from the flywheel (not shown) side of the crankshaft 11 in the crank journal 111 of the crankshaft 11. It is preferable to use a crank journal (not shown). This is because the crankshaft 11 vibration (bending vibration or torsional vibration) is larger on the crank pulley side than on the flywheel side, which is effective in suppressing transmission of vibration to the bolt 13. If the mounting location of the bearing cap 1A is the crank journal closest to the crank pulley (the first journal), it is particularly effective in suppressing vibration transmission to the bolt 13. Of course, all the crank journal bearing caps may be used as the bearing cap 1A of the first embodiment.

[Function and effect]
According to the bearing cap 1A of the first embodiment, the bearing cap 1A is provided with the cylinder block by including the notch 24 formed around the insertion hole 23 and connected to the insertion hole 23 and the elastic member 3 fitted into the notch 24. An elastic member 3 is provided around a bolt 13 that is fixed to 12. Since the elastic member 3 absorbs the vibration of the crankshaft 11 through the main body 2, the vibration is hardly transmitted to the bolt 13. Therefore, the vibration of the crankshaft 11 is hardly transmitted to the cylinder block 12 via the bolt 13. Thereby, the vibration of the cylinder block 12 can be reduced, and hence the vibration of the entire engine can be reduced, and noise can be easily reduced.

<< Embodiment 2 >>
[Bearing cap]
The bearing cap 1B of the second embodiment is mainly different from the bearing cap 1A of the first embodiment in that the left and right cutouts 24 have different widths and the left and right elastic members 3 have different widths. The following description will focus on the differences, and the description of the same configuration and the same effect will be omitted.

  Of the left and right cutouts 24, the width of the cutout 24 on the anti-thrust side (right side in FIG. 2) is smaller than the width of the cutout 24 on the thrust side (left side in the figure). The width of the elastic member 3 on the anti-thrust side is smaller than the width of the elastic member 3 on the thrust side. The left and right elastic members 3 are made of rubber having the same hardness. The central portion 22 of the main body 2 has different lengths BL and BR from the imaginary line C to the bottoms of the left and right cutouts 24. Specifically, in the central portion 22, the length BR from the virtual line C to the bottom of the right notch 24 is longer than the length BL from the virtual line C to the left notch 24. Therefore, even if the materials of the left and right elastic members 3 are made of the same hardness, the length BR of the central portion 22 is longer than the length BL, thereby increasing the hardness of the elastic member 3 on the anti-thrust side. As in the case of No. 1, it is easy to equalize the degree of wear of the left and right elastic members 3 due to the influence of the vibration of the crankshaft 11, and prevent the elastic member 3 on the anti-thrust side from being more easily consumed than the elastic member 3 on the thrust side. Easy to do.

  The present invention is not limited to these exemplifications, is shown by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. For example, the notch may be a through hole that opens on both the left and right side surfaces of the main body. That is, the notch is closed without opening the front and back surfaces and the top and bottom surfaces of the main body. In that case, the elastic member may be fitted over the entire length of the through hole, or may be fitted only around the left and right bolts, and a gap may be formed between the left and right elastic members. Further, the main body portion of the bearing cap may be composed of two upper and lower independent members with the central portion as a boundary. The two upper and lower members are preferably connected together with a bolt that fixes the bearing cap to the object to be fixed. At least one of the two upper and lower members has a convex portion extending to the other side. That is, by connecting the two members together so that the convex portion is in contact with the other member, notches that are independent of each other are formed on the left and right sides of the main body portion. As in the first embodiment, an elastic member is fitted in each notch. Further, the bearing cap may be used as a camshaft bearing cap that is fixed to the cylinder head and supports the camshaft.

  The bearing cap of the present invention can be suitably used for a crankshaft bearing cap that supports a crankshaft of an automobile engine and a camshaft bearing cap that supports a camshaft.

1A, 1B Bearing cap 2 Body part 21 Bearing surface 22 Center part 23 Insertion hole 24 Notch 3 Elastic member 31 Through hole 11 Crankshaft 111 Crank journal 12 Cylinder block 13 Bolt

Claims (1)

A bearing cap that rotatably supports the shaft via a bearing,
An insertion hole formed along a direction intersecting the axial direction of the shaft, through which a bolt for fixing the bearing cap to a fixed object is inserted;
A notch formed so as to be connected to the insertion hole around the insertion hole;
A bearing cap comprising a through-hole through which the bolt passes, and an elastic member that is fitted into the notch and suppresses transmission of vibration of the shaft to the bolt.

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