JP6901957B2 - Bearing cap and internal combustion engine equipped with it - Google Patents

Description

The present invention relates to a bearing cap that is fastened to a cylinder block and configured to rotatably support a crankshaft together with the cylinder block, and an internal combustion engine including the same.

Japanese Patent Application Laid-Open No. 2013-113337 (Patent Document 1) describes a shaft support portion configured to rotatably support a crankshaft via a half-split type spur bearing, and both sides of the shaft support portion. Described is a bearing cap comprising a pair of fastening bosses provided in the sword and configured to be fastened to a cylinder block by bolts.

The bearing cap has a structure in which the corners of the fastening boss portion are shaved and lightened to suppress stress concentration caused by input from the crankshaft around the bolt holes formed in the fastening boss portion.

Japanese Unexamined Patent Publication No. 2013-113337

By the way, in recent years, cast parts such as automobile parts may be provided with characters or symbols for identifying the parts such as manufacturing lot information by engraving or casting from the viewpoint of traceability. It is desirable that such identification characters and identification symbols be provided in places that are easily visible not only in the individual parts but also in the assembled state. When such identification characters and identification codes are provided on the bearing cap by engraving or casting, from the viewpoint of visibility, the back side of the shaft support portion, that is, the inner peripheral surface side on which the bearing surface of the shaft support portion is provided is defined. It is desirable to provide it on the outer peripheral surface on the opposite side.

However, if identification characters or identification symbols are provided by engraving or casting, irregularities due to the identification characters or identification symbols are formed on the outer peripheral surface of the shaft support portion of the bearing cap, and the corners or corners of the irregularities are formed from the crankshaft. Stress concentration occurs due to the input of. The bearing cap described in the above-mentioned publication does not mention the suppression of stress concentration when the identification character or the identification code is provided, and it is said that the visibility of the identification character or the identification code is ensured without causing the stress concentration. In that respect, there is still room for improvement.

The present invention has been made in view of the above, and one of the objects of the present invention is to provide a bearing cap capable of ensuring the visibility of the identification code without causing stress concentration and an internal combustion engine provided with the bearing cap.

The bearing cap of the present invention and the internal combustion engine provided with the bearing cap have adopted the following means in order to achieve the above-mentioned object.

According to a preferred embodiment of the bearing cap according to the present invention, a bearing cap is configured which is fastened to a cylinder block and is configured to rotatably support a crankshaft together with the cylinder block. The bearing cap has a pair of fastening portions that are fastened to the cylinder block by a fastening member, and a bearing surface that is provided between the pair of fastening portions so as to connect the pair of fastening portions and supports the crankshaft. It is equipped with a connecting part. The connecting portion is provided on the bearing surface configured to pivotally support the crankshaft and the outer peripheral surface side of the connecting portion opposite to the inner peripheral surface side where the bearing surface is provided, and specifies information on the bearing cap. It has an identification symbol installation portion in which an identification symbol is provided in a protruding or concave shape, and a recess in which a part of the outer peripheral surface of the connecting portion is recessed toward the bearing surface side. It has an adjacent portion. The identification symbol installing portion is provided on both sides of the recess so as to sandwich the recess.

Here, the "information about the bearing cap" in the present invention corresponds to the information for identifying the bearing cap including the production history such as the production lot information of the bearing cap. Further, the "identification code" in the present invention is a concept including characters, numbers, symbols and the like. Further, "provided in a protruding or concave shape" in the present invention typically corresponds to a mode in which an identification code is provided by engraving or casting, but the identification code is provided by cutting such as laser machining. It preferably includes the aspects provided.

According to the present invention, since the identification code is provided on the outer peripheral surface side of the connecting portion opposite to the inner peripheral surface side where the bearing surface is provided, the visibility of the identification code is ensured. In addition, since the structure is such that the rigidity is lower than that of other parts of the connecting portion adjacent to the identification symbol installation portion provided with the identification symbol, the periphery of the identification symbol (the corner portion of the unevenness of the identification symbol or The stress, which tends to be concentrated in the corners), can be dispersed in the adjacent portions formed in a shape having low rigidity. As a result, it is possible to realize a configuration in which the visibility of the identification code is ensured without causing stress concentration in the bearing cap. Since only a part of the outer peripheral surface of the connecting portion is recessed toward the bearing surface side, a shape having lower rigidity than other portions can be easily realized. In addition, since the identification code installation part is provided on both sides of the recess, it is possible to understand.
A wide area for providing another symbol can be secured. Further, the stress concentrated on the identification code provided on both sides of the recess can be dispersed by one recess. As a result, it is possible to prevent the bearing cap from being unnecessarily reduced in rigidity.

According to a further form of the bearing cap according to the present invention, the pair of fastening portions has a contact surface that abuts on the cylinder block. The recess is formed in an asymmetrical shape with respect to a straight line passing through the center of the bearing surface and orthogonal to a plane including the contact surface.

The input acting from the crankshaft to the connecting portion of the bearing cap via the bearing surface acts so as to show a maximum value in a direction inclined with respect to a straight line passing through the center of the bearing surface and orthogonal to the contact surface. According to this embodiment, the recess is formed so as to be orthogonal to the plane including the contact surface and to have an asymmetric shape with respect to the plane including the axis of the bearing surface. Therefore, for example, the input from the crankshaft is the maximum value. The curvature of the recess in the direction indicating the maximum value can be set larger than the curvature of the recess in the direction other than the direction in which the input from the crankshaft indicates the maximum value, and the stress concentration can be efficiently dispersed while suppressing the decrease in rigidity. It is possible to realize a rational shape that can be achieved.

According to a preferred embodiment of the internal combustion engine according to the present invention, the present invention of any of the above-described embodiments configured to be fastened to a cylinder block having a cylinder bore, a cylinder head fastened to the cylinder block, and a cylinder block. A bearing cap according to the above, a crankshaft rotatably supported between the cylinder block and the bearing cap, and a piston connected to the crankshaft and configured to slide in the cylinder bore. There is. The combustion chamber is composed of a cylinder bore, a cylinder head and a piston. Then, the piston is reciprocated by the combustion pressure generated in the combustion chamber, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft to output power.

According to the present invention, since the configuration includes the bearing cap according to the present invention in any of the above-described aspects, the same effect as that of the bearing cap of the present invention, for example, the identification code without causing a decrease in rigidity. It is possible to achieve an effect that can ensure visibility. This makes it possible to improve the reliability of the internal combustion engine.

According to the present invention, the visibility of identification characters and identification symbols can be ensured without causing a decrease in rigidity.

It is a block diagram which shows the outline of the structure of the internal combustion engine 1 which concerns on embodiment of this invention. It is a block diagram which shows the outline of the structure of the internal combustion engine 1 which concerns on embodiment of this invention. It is a perspective view which shows the appearance of a cylinder block 6. It is a back view which looked at the cylinder block 6 from the bottom surface side (the fastening side of an oil pan 8). It is a front view which looked at the cylinder block 6 from the front wall 22c side. It is a perspective view which shows the appearance of a bearing cap 50. It is a four-sided view which shows the outline of the structure of the bearing cap 50. It is an enlarged view of the main part which shows the main part of a bearing cap 50 in an enlarged manner. It is explanatory drawing which shows the state of the force Fb acting on the bearing cap 50. It is a front view of the bearing cap 50A of the conventional shape of the comparative example seen from the direction along the axis CL of the bearing surface 54a. It is a front view of the bearing cap 50B of the comparative example seen from the direction along the axis CL of the bearing surface 54a. It is explanatory drawing which shows the representative part a to e which evaluated the stress value acting on the connecting part 54 of a bearing cap 50. It is an enlarged view of the main part which shows the main part of the bearing cap 50 of the modified example in an enlarged manner.

Next, the best mode for carrying out the present invention will be described with reference to Examples.

As shown in FIG. 1, the internal combustion engine 1 according to the embodiment of the present invention includes a cylinder head 2, a rocker cover 4 attached to the upper part of the cylinder head 2, and a cylinder attached to the lower part of the cylinder head 2. It includes a block 6, an oil pan 8 attached to the lower part of the cylinder block 6, and a crankshaft 10 rotatably supported by the cylinder block 6.

In the present embodiment, the internal combustion engine 1 is configured as an in-line 3-cylinder engine in which three cylinders are arranged in series as shown in FIG. 2, and is composed of a cylinder head 2, a cylinder bore 24a described later, and a piston 12. The piston 12 is reciprocated in the cylinder bore 24a by the combustion pressure generated in the combustion chamber CC, and the reciprocating motion of the piston 12 is converted into the rotary motion of the crankshaft 10 to output power.

As shown in FIGS. 3 and 4, the cylinder block 6 rotates an outer wall portion 22 constituting the outer shell of the cylinder block 6, a cylinder bore wall portion 24 having three cylinder bores 24a (see FIG. 3), and a crankshaft 10. A support wall portion 26 that can support the engine is provided, and a block water jacket BWJ is formed between the outer wall portion 22 and the cylinder bore wall portion 24.

As shown in FIG. 3, the cylinder bore wall portion 24 constitutes a Saiyan cylinder in which three cylinder bores 24a are arranged in series and the cylinder bore wall portions 24 adjacent to each other are connected to each other. As shown in FIG. 2, the piston 12 slides in the cylinder bore 24a.

As shown in FIG. 4, the support wall portion 26 is configured to connect both side walls 22a and 22b extending along the arrangement direction of the cylinder bores 24a (horizontal direction in FIG. 4) among the outer wall portions 22. , Four crank chambers CR are provided in the arrangement direction of the cylinder bores 24a so as to partition each cylinder bore 24a. The two support wall portions 26 located at both ends of the support wall portion 26 in the arrangement direction of the cylinder bores 24a are the front wall 22c and the rear wall extending in the direction intersecting the arrangement direction of the cylinder bores 24a of the outer wall portions 22. It is integrally formed on 22d.

As shown in FIGS. 3 to 5, a substantially semi-cylindrical bearing surface 26a for rotatably supporting the crankshaft 10 is formed on the bottom surface of each support wall portion 26. Further, as shown in FIGS. 4 and 5, fastening bolts BLT (see FIG. 2) for fastening the bearing cap 50, which will be described later, are screwed on both sides of the bearing surface 26a at the bottom of each support wall portion 26. A pair of female screw holes 26b, 26b to be engaged are formed.

As shown in FIGS. 6 and 7, the bearing cap 50 to be fastened to the bottom surface of each support wall portion 26 is a pair of boss portions 52 in which an insertion hole 52a through which a fastening bolt BLT (see FIG. 2) is inserted is formed. , 52 and a connecting portion 54 for connecting the pair of boss portions 52, 52, which is substantially front view (viewed from the direction along the axis CL (see FIG. 7) of the bearing surface 54a described later). It is configured in an inverted U shape. The fastening bolt BLT is an example of an implementation configuration corresponding to the "fastening member" in the present invention.

As shown in FIGS. 6 and 7, one surface of the pair of boss portions 52, 52 through which the insertion holes 52a are opened is configured as an abutting surface 52b with which the seat surface of the fastening bolt BLT (see FIG. 2) abuts. The other surface through which the insertion holes 52a of the pair of boss portions 52 and 52 are opened is configured as a contact surface 52c that abuts on the bottom surface of the support wall portion 26 of the cylinder block 6. The contact surface 52b and the contact surface 52c are configured to be parallel to each other. The pair of boss portions 52, 52 is an example of an implementation configuration corresponding to the "fastening portion" in the present invention.

As shown in FIGS. 6 and 7, the connecting portion 54 includes a bearing surface 54a for rotatably supporting the crankshaft 10 and a pair of identification symbol installation portions 54b and 54b on which the identification symbol 55 is provided. It has a stress concentration dispersion portion 54c provided between the pair of identification symbol installation portions 54b, 54b.

The bearing surface 54a is formed in a semi-cylindrical shape as shown in FIGS. 6 and 7. By fastening the bearing cap 50 to the support wall portion 26 of the cylinder block 6 by the fastening bolt BLT, the bearing surfaces 54a and the bearing surfaces 26a of the semi-cylindrical shapes are aligned to form the cylindrical bearing portion 30. (See FIG. 9). A half-split metal bearing (not shown) is mounted on the inner peripheral surface of the bearing portion 30, and the crank journal portion of the crankshaft 10 is attached to the bearing portion 30 via the metal bearing. It is rotatably supported.

As shown in FIGS. 6 and 7, the pair of identification code installation portions 54b, 54b are planes continuous with the contact surfaces 52b, 52b of the pair of boss portions 52, 52, and the contact surfaces 52b, 52b. It is configured as an inclined surface having an ascending inclination toward a direction away from, in other words, a direction approaching each other. In this embodiment, the pair of identification code installation portions 54b and 54b are connected to the contact surfaces 52b and 52b with curved surfaces (corners R).

By providing the pair of identification code installation portions 54b and 54b on the outer peripheral surface side of the bearing cap 50 in this way, the identification code is provided even after the bearing cap 50 is assembled to the support wall portion 26 of the cylinder block 6. Since the confirmation of the 55 can be easily performed, the visibility of the identification code 55 can be ensured. Further, by configuring the pair of identification symbol installation portions 54b, 54b as inclined surfaces having an upward inclination in the direction of approaching each other, the cross-sectional area (diameter of the bearing surface 54a) with respect to the identification symbol installation portions 54b, 54b in the connecting portion 54 is formed. It is possible to suppress the reduction of the plane along the direction (the area in the cross section cut by the two-dot chain line arrow in FIG. 7), and thereby the decrease in the rigidity of the identification symbol installation portions 54b and 54b can be suppressed.

In the present embodiment, the identification code 55 is configured as a cast character provided by casting, and is provided so as to project with respect to the identification code installation portions 54b and 54b. Further, the identification symbol 55 is for confirming information about the bearing cap 50 including production history such as production lot information of the bearing cap 50, and is composed of symbols, letters, numbers, codes, or a combination thereof. Has been done.

As shown in FIG. 8, the stress concentration dispersion portion 54c is a concave curved surface connecting the pair of identification code installation portions 54b, 54b as an inclined surface in succession to the pair of identification code installation portions 54b, 54b. Specifically, it is configured as a concave curved surface that is recessed toward the bearing surface 54a side. Here, in the present embodiment, the stress concentration dispersion portion 54c is configured to be orthogonal to the plane VP1 including the pair of contact surfaces 52c and 52c and to have a symmetrical shape with respect to the plane VP2 including the axis CL of the bearing surface 54a. Has been done. The stress concentration dispersion portion 54c is an example of an implementation configuration corresponding to the “adjacent portion” and the “recess” in the present invention.

Next, the state of stress generated in the bearing cap 50 due to the operation of the internal combustion engine 1 configured in this way will be described. When the internal combustion engine 1 according to the embodiment of the present invention is operated, a combustion explosion occurs due to ignition of a mixture of air and fuel in the combustion chamber CC, and the piston 12 makes a reciprocating linear motion in the cylinder bore 24a. The reciprocating linear motion of the piston 12 is converted into a rotary motion by the crankshaft 10.

Here, the combustion pressure Fcc (see FIG. 9) due to the combustion explosion in the combustion chamber CC acts on the bearing cap 50 from the piston 12 via the connecting rod 14 (see FIG. 9) and the crankshaft 10. As shown in FIG. 9, the force Fb acting on the bearing cap 50 does not reach the maximum value on the plane VP2, but shows the maximum value at a position shifted to the right side of FIG. 9 with respect to the plane VP2. This is because the connecting rod 14 is attached to the crank pin portion provided at a position offset from the crank journal portion of the crankshaft 10.

Here, since the identification code 55 provided in the pair of identification code installation portions 54b, 54b is provided so as to protrude from the pair of identification code installation portions 54b, 54b, the rising portion (root) of the identification code 55 is provided. Stress concentration due to the force Fb occurs in the portions and corners). However, in the present embodiment, the stress concentration distribution portion 54c is provided so as to connect the identification symbol installation portions 54b, 54b, that is, the outer peripheral surface of the bearing cap 50 is provided at a position adjacent to the identification symbol installation portions 54b, 54b. Since a portion having a lower rigidity than other portions is provided by denting toward the bearing surface 54a, the stress concentrated on the rising portion (root portion, corner portion) of the identification symbol 55 is concentrated on the stress. It can be dispersed in the dispersion unit 54c. As a result, the bearing cap 50 can be configured to ensure the visibility of the identification code 55 without causing stress concentration.

Next, the analysis result of the distribution of stress generated in the connecting portion 54 due to the force Fb will be described in comparison with the bearing caps 50A and 50B of the comparative examples shown in FIGS. 10 and 11. In this embodiment, the evaluation was performed using the stress values at the representative locations a to e shown in FIG. Table 1 shows the analysis results of the distribution of stress generated in the connecting portion 54 due to the force Fb.

As shown in FIG. 10, the bearing cap 50A has an arc whose outer peripheral surface shape (including a pair of identification symbol installation portions 54Ab and 54Ab) of the connecting portion 54A is radially outwardly convex following the shape of the bearing surface 54a. It is formed in a shape, and an identification symbol 55 is provided on a pair of identification symbol installation portions 54Ab and 54Ab by casting. In other words, the bearing cap 50A is a conventional bearing cap 50A that does not have the stress concentration distribution portion 54c. Further, as shown in FIG. 11, the bearing cap 50B has a pair of contact surfaces 52Bb, 52Bb having an outer peripheral surface shape of the connecting portion 54B (including a pair of identification symbol installation portions 54Bb, 54Bb and a stress concentration distribution portion 54Bc). It is formed on a plane that is substantially parallel, and an identification symbol 55 is provided on a pair of identification symbol installation portions 54Bb and 54Bb by casting.

As shown in Table 1, the distribution of stress generated in the connecting portion 54 due to the force Fb is as follows. While the stress value exceeding the threshold value of 50 MPa was shown at the rising portion (root portion, corner portion) of the identification symbol 55 of 54Bb, in the bearing cap 50 according to the present embodiment, the force Fb indicates the maximum value. The stress value is also less than the threshold value of 50 MPa at the rising portion (root portion, corner portion) of the identification symbol 55 of the provided identification symbol installation portion 54b, and the rising portion (root portion) of the identification symbol 55 is provided by the stress concentration distribution portion 54c. , Corner) It was confirmed that stress concentration was suppressed.

According to the bearing cap 50 according to the present embodiment described above, the identification symbol 55 is on the outer peripheral surface of the connecting portion 54 of the bearing cap 50 on the side opposite to the side (inner peripheral surface side) where the bearing surface 54a is formed. Since the pair of identification symbol installation portions 54b and 54b are provided so as to project the bearing cap 50, the identification symbol 55 can be easily confirmed even after the bearing cap 50 is assembled to the support wall portion 26 of the cylinder block 6. Therefore, the visibility of the identification symbol 55 can be ensured. Further, since the stress concentration distribution portion 54c having a concave curved surface recessed toward the bearing surface 54a side is provided between the pair of identification symbol installation portions 54b and 54b, the connecting rod 14 and the crankshaft 10 are separated from the piston 12. The stress concentrated around the identification symbol 55 (the rising portion (root portion, corner portion) of the identification symbol 55) due to the force Fb acting on the bearing cap 50 via the bearing cap 50 is distributed to the stress concentration distribution portion 54c (concave curved surface). Can be made to. As a result, in the bearing cap 50, the visibility of the identification code 55 can be ensured without causing stress concentration.

In the present embodiment, the stress concentration dispersion portion 54c is configured to be orthogonal to the plane VP1 including the pair of contact surfaces 52c and 52c and to have a symmetrical shape with respect to the plane VP2 including the axis CL of the bearing surface 54a. Not limited to this. For example, the stress concentration dispersion portion 54c may be configured to be orthogonal to the plane VP1 including the pair of contact surfaces 52c and 52c and to have an asymmetric shape with respect to the plane VP2 including the axis CL of the bearing surface 54a.

In this case, of the pair of identification symbol installation portions 54b, 54b, the radius of curvature R1 of the curved surface of the stress concentration distribution portion 54c connected to the identification symbol installation portion 54b provided in the direction in which the force Fb due to the combustion pressure Fcc indicates the maximum value. Is smaller than the radius of curvature R2 of the curved surface of the stress concentration distribution portion 54c connected to the identification symbol installation portion 54b arranged on the opposite side of the identification symbol installation portion 54b provided in the direction in which the force Fb indicates the maximum value. Can be set to be. According to this configuration, the stress concentrated on the rising portion (root portion, corner portion) of the identification symbol 55 of the identification symbol installation portion 54b provided in the direction in which the force Fb indicates the maximum value is the stress configured in the radius of curvature R1. It can be effectively dispersed in the centralized dispersion portion 54c. Further, the radius of curvature R1 can be set to be larger than the radius of curvature R2. According to this configuration, the stress concentrated on the rising portion (root portion, corner portion) of the identification symbol 55 of the identification symbol installation portion 54b provided in the direction in which the force Fb indicates the maximum value is stressfully applied to the radius of curvature R1 portion. Since it can be dispersed in the radius of curvature R2 portion with a margin, it is possible to satisfactorily concentrate the stress on the rising portion (root portion, corner portion) of the identification symbol 55 of the identification symbol installation portion 54b while suppressing the decrease in rigidity. Can be prevented.

In the present embodiment, the identification code 55 is cast so as to project from the identification code installation portions 54b and 54b, but the present invention is not limited to this. For example, the identification code 55 may be projected from the identification code installation portions 54b and 54b by engraving or laser processing. Further, the identification code 55 may be recessed in the identification code installation portions 54b and 54b by casting, engraving, laser processing, or the like.

In the bear rig cap 50 of the present embodiment and the modified example, the stress concentration dispersion portion 54c is configured as a concave curved surface, but the rising portion (root portion, corner portion) of the identification symbol 55 provided in the identification symbol installation portions 54b, 54b). It does not have to be a concave curved surface as long as the stress concentrated on the surface can be dispersed. For example, the stress concentration dispersion portion 54c may be configured as a concave plane composed of a plurality of planes, or may be composed of a plurality of recesses. Alternatively, the stress concentration dispersion portion 54c is not provided on the outer peripheral surface of the connecting portion 54 (the side opposite to the side on which the bearing surface 54a is formed), but the side surface of the connecting portion 54 (the surface orthogonal to the axis CL of the bearing surface 54a). ) May be provided with a stress concentration dispersion portion 54c (recess or hole).

The present embodiment shows an example of the embodiment for carrying out the present invention. Therefore, the present invention is not limited to the configuration of the present embodiment. The correspondence between each component of the present embodiment and each component of the present invention is shown below.

1 Internal combustion engine (internal combustion engine)
2 Cylinder head 4 Rocker cover 6 Cylinder block (cylinder block)
8 Oil pan 10 Crankshaft (crankshaft)
12 Piston (Piston)
14 Connecting rod 22 Outer wall 22a Side wall 22b Side wall 22c Front wall 22d Rear wall 24 Cylinder bore Wall 24a Cylinder bore (cylinder bore)
26 Support wall part 26a Bearing surface 26b Female screw hole 30 Bearing part (bearing part)
50 Bearing cap (bearing cap)
50A bearing cap (bearing cap)
50B bearing cap (bearing cap)
52 Boss part (fastening part)
52a Insertion hole 52b Contact surface 52c Contact surface (contact surface)
54 Connecting part (connecting part)
54a Bearing surface (bearing surface)
54b Identification code installation part (Identification code installation part)
54Ab identification code installation part (identification code installation part)
54Bb Identification code installation part (Identification code installation part)
54c Stress concentration dispersion part (adjacent part, concave part)
55 Identification code (identification code)
CC combustion chamber (combustion chamber)
Water jacket for BWJ block CR crank chamber CL axis (axis)
BLT fastening bolt (fastening member)
VP1 plane (plane including contact surface)
VP2 plane (plane including axis)
Fcc combustion pressure Fb force

Claims (3)

A bearing cap that is fastened to a cylinder block and configured to rotatably support a crankshaft together with the cylinder block.
A pair of fastening portions to be fastened to the cylinder block by a fastening member,
A connecting portion provided between the pair of fastening portions so as to connect the pair of fastening portions,
With
The connecting portion is provided on a bearing surface configured to pivotally support the crankshaft and an outer peripheral surface side of the connecting portion opposite to the inner peripheral surface side on which the bearing surface is provided. An identification symbol installation portion in which an identification symbol for specifying information regarding the above is provided in a protruding or concave shape, and a part of the outer peripheral surface of the connection portion arranged adjacent to the identification symbol installation portion toward the bearing surface side. It has an adjacent portion with a recessed recess and
The identification mark installing unit may have a bearing cap provided on both sides of the recess so as to sandwich the recess. The pair of fastening portions has a contact surface that abuts on the cylinder block.
The bearing cap according to claim 1 , wherein the recess is orthogonal to a plane including the contact surface and is formed in an asymmetric shape with respect to the plane including the axis of the bearing surface. A cylinder block with a cylinder bore and
A cylinder head fastened to the cylinder block and
The bearing cap according to claim 1 or 2 , which is fastened to the cylinder block.
A crankshaft rotatably supported between the cylinder block and the bearing cap,
A piston that is connected to the crankshaft and is configured to slide in the cylinder bore.
With
A combustion chamber is composed of the cylinder bore, the cylinder head, and the piston.
An internal combustion engine configured to reciprocate the piston by the combustion pressure generated in the combustion chamber and convert the reciprocating motion of the piston into the rotational motion of the crankshaft to output power.

Images