JP4586035B2 - Cylinder block of internal combustion engine and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cylinder block of an internal combustion engine and a manufacturing method thereof.

Conventionally, as disclosed in Patent Document 1, in order to relieve pressure fluctuation in the crankcase due to the reciprocating motion of the piston, it extends parallel to the axis of the crankshaft and a part thereof is opened to the inner periphery of the cylinder bore. There is a cylinder block having a communication hole.
JP 2003-74408 A

In the structure disclosed in Patent Document 1, since the communication hole is opened from the outside of the crankcase by drilling, unnecessary communication holes are formed on the outer wall of the crankcase, and the strength of the cylinder block is reduced. was there.
In addition, because of machining with a tool, it is not possible to form communication holes only between arbitrary cylinders or to form communication holes of different sizes, and it is possible to form communication holes that are effective in reducing pressure fluctuations. There was a problem that it was difficult.

The present invention has been devised in view of the above-described conventional problems, and a cylinder block of an internal combustion engine in which a vent hole for reducing pressure fluctuation in a crankcase can be formed by a simple method and a method for manufacturing the same. And providing a cylinder block for an internal combustion engine and a method of manufacturing the same, in which vent holes for reducing pressure fluctuations in the crankcase can be arranged in an effective shape and position. the purpose of 1 Tsutoshi that its first aspect, the crankshaft side of a plurality of cylinder bores arranged in a row, the cylinder block the vent hole is opening communicating between sheet Rindaboa,
A cylinder liner in which adjacent cylinder bores are connected and a notch communicating between the cylinder bores is formed;
A lid that forms part of the cylinder bore;
With
The vent hole is formed by covering the lid portion on the opening side of the notch portion .

A method of manufacturing a cylinder block of an internal combustion engine according to claim 2, the crank shaft side between a plurality of cylinder bores arranged in a line, the vent holes communicating between sheets Rindaboa is in the manufacturing method of the apertured cylinder block, A notch portion that communicates between the cylinder bores is formed in a cylinder liner that connects the adjacent cylinder bores, and a vent member that covers a lid member that forms a part of the cylinder bore is provided on the opening side of the notch portion. Forming the cylinder liner and the lid member on the mold of the cylinder block to form a cast-in.

The present invention, on the crankshaft side of a plurality of cylinder bores arranged in a row, the cylinder block the vent hole is opening communicating between shea Rindaboa, together between the adjacent cylinder bores are connected, between the cylinder bores A cylinder liner having a notch communicating therewith, and a lid forming a part of the cylinder bore, and the vent is formed by covering the lid on the opening side of the notch As a result, the structure of the vent hole is divided into two parts, the notch part and the lid part of the cylinder liner, so there is no need for machining or casting , and the vent hole is formed only by the mold design of the cylinder liner. Will be able to. In addition, since the vent hole is formed of a mold, the vent hole can be easily formed at different sizes and positions between arbitrary cylinder bores.

A method of manufacturing a cylinder block, a crankshaft side among the plurality of cylinder bores arranged in a row, in the manufacturing method for a cylinder block ventilation holes communicating between sheet Rindaboa is opened, between the adjacent cylinder bores A notch portion that communicates between the cylinder bores is formed in the connected cylinder liner, and a cover member that forms a part of the cylinder bore is formed on the opening side of the notch portion to form a vent hole, and the cylinder liner and Since the lid member is arranged in the cylinder block mold to form a cast hole, there is no need for casting or machining, and the cylinder block can be easily formed with a vent by simply designing the cylinder liner mold. Will be able to.

A first embodiment of the present invention will be described below with reference to the drawings.
1 is a longitudinal sectional view of a cylinder block of an internal combustion engine, and FIG. 2 is a sectional view taken along line AA of FIG. In the following description, the top dead center side in the piston sliding direction in the cylinder block is the top.

In the figure, in a cylinder portion 2 of a cylinder block 1, a connection type (Siamese type) cylinder liner 10 in which adjacent cylinder bores are connected is cast-in, and the first cylinder is configured in the cylinder liner 10. Cylinder bore 2a, a cylinder bore 2b constituting the second cylinder, a cylinder bore 2c constituting the third cylinder, and a cylinder bore 2d constituting the fourth cylinder are formed in each cylinder bore 2a, 2b, 2c, 2d. The piston 3 moves up and down, and the crankshaft 6 provided with the counterweight 5 can be rotated via the connecting rod 4.
Further, a skirt portion 8 of the cylinder block 1 cast integrally with the cylinder portion 2 is provided in a crankcase 7 connected to the lower portion of the cylinder block 1, and the skirt portion 8 is provided in each cylinder bore. The partition walls 8a, 8b, 8c, 8d, and 8e correspond to 2a, 2b, 2c, and 2d, and each of the partition walls 8a, 8b, 8c, 8d, and 8e has a shaft that can rotate the crankshaft 6. The bearing part 9 to support is formed concentrically.

As shown in FIG. 3, the cylinder liner 10 is connected to each other between adjacent cylinder bores 2 a and cylinder bores 2 b, between adjacent cylinder bores 2 b and cylinder bores 2 c, and between adjacent cylinder bores 2 c and cylinder bores 2 d ( A notch 20 for communicating the cylinder bore 2a and the cylinder bore 2b in advance with the lower end of the cylinder liner 10, and a notch 20 for communicating the cylinder bore 2b and the cylinder bore 2c. And the notch part 20 which connects between the cylinder bore 2c and the cylinder bore 2d can be formed.
Also, a lid member 11 as shown in FIG. 4 is manufactured separately, and this lid member 11 is joined and integrated with the lower end of the cylinder liner 10 to open the lower ends of the notches 20, 20, 20. Is closed with the lid member 11, and the vent holes H1, H2, and H3 can be formed as shown in FIG.

  4 forms part of a cylinder bore, and includes a ring-shaped first cylinder portion 11a joined to the lower end of the cylinder bore 2a and a ring-shaped second cylinder joined to the lower end of the cylinder bore 2b. A part 11b, a ring-shaped third cylinder part 11c joined to the lower end of the cylinder bore 2c, and a ring-like fourth cylinder part 11d joined to the lower end of the cylinder bore 2d are connected and integrally formed. is there.

As shown in FIG. 5, when the lid member 11 is assembled to the lower end of the cylinder liner 10, the first cylinder part 11a, the second cylinder part 11b, the third cylinder part 11c, and the fourth cylinder part 11d are respectively provided with notches. 20 abuts on the lower end of each notch 20 and closes the opening side at the lower end of each notch 20, thereby forming the air holes H1, H2, H3 during assembly.
That is, the vent hole H1 communicates between the cylinder bore 2a and the cylinder bore 2b, the vent hole H2 communicates between the cylinder bore 2b and the cylinder bore 2c, and the vent hole H3 communicates between the cylinder bore 2c and the cylinder bore 2d. It communicates.

  In this way, the cylinder liner 10 having the notch 20 on the lower end side is manufactured in advance, and the lid member 11 is assembled to the lower end of the cylinder liner 10, thereby forming the vent holes H1, H2, and H3 in advance. The cylinder liner 10 and the lid member 11 in which the pores H1, H2, and H3 are formed are placed in a mold for casting the cylinder block 1, and the cylinder liner 10 and the lid member 11 are cast to cast the cylinder block 1. It is something that can be done.

  In the method of forming the cast liner by disposing the cylinder liner 10 and the lid member 11 in FIG. 5 on the mold of the cylinder block 1, it is not necessary to use a core and it is not necessary to perform machining, and the cylinder block 1 can be easily formed. Ventilation holes H1, H2, and H3 can be formed in the cylinder liner 10 and the cutout portion 20 is formed in the cylinder liner 10. Therefore, the size of each cutout portion 20 is determined by the design of the cylinder liner 10 manufacturing mold. It is easy to make the lengths different between the cylinder bores, it is easy to provide notches 20 only between necessary cylinder bores, and the size and number of the vent holes H1, H2, H3 are also easy. Can be designed to It is also easy to set the notches 20 at different positions and set the vent holes H1, H2, H3 at different positions.

In the case where the core is used, since it is necessary to provide a draft angle, the size of the air holes is different between the cylinder bores. In this example, the air holes H1, H2 having the same size are used. , H3 can be easily formed.
Further, in the conventional method of forming the vent hole by machining, it is necessary to penetrate the tool from the outside. However, in this example, such a through hole is eliminated, and the strength of the cylinder block 1 can be increased accordingly. It will be a thing.
In addition, each vent hole H1, H2, H3 can relieve | moderate well the pressure fluctuation in the crankcase 7 by the reciprocating motion of piston 3. FIG.

6 is a longitudinal sectional view of a cylinder block according to the second embodiment, and FIG. 7 is a sectional view taken along line AA in FIG.
In the figure, a cylinder portion 2 of a cylinder block 1 includes a cylinder bore 2a constituting a first cylinder, a cylinder bore 2b constituting a second cylinder, a cylinder bore 2c constituting a third cylinder, and a cylinder bore constituting a fourth cylinder. 2d is formed, and the piston 3 moves up and down in each cylinder bore so that the crankshaft 6 provided with the counterweight 5 can be rotated via the connecting rod 4.
Further, in the crankcase 7 connected to the lower part of the cylinder block 1, a skirt portion 8 of the cylinder block 1 cast separately from the cylinder portion 2 is provided. A plurality of partition walls 8a, 8b, 8c, 8d, and 8e corresponding to the respective cylinder bores 2a, 2b, 2c, and 2d are configured, and the crankshaft 6 can be rotated on each of the partition walls 8a, 8b, 8c, 8d, and 8e. A bearing portion 9 that pivotally supports the shaft is formed concentrically.

In the cylinder block 1 of this example, the cylinder part 2 and the skirt part 8 are cast in separate molds, and the separate skirt part 8 is joined to the cylinder part 2 with bolts or the like.
When casting the cylinder part 2 with a mold, the notch part 20 can be formed at the lower end of the cylinder part 2 by the mold. That is, the notch 20 that communicates between the cylinder bore 2a and the cylinder bore 2b of the cylinder part 2, the notch 20 that communicates between the cylinder bore 2b and the cylinder bore 2c, and the notch 20 that communicates between the cylinder bore 2c and the cylinder bore 2d, When the cylinder part 2 is cast, it is formed at the lower end of the cylinder part 2 respectively.

When the skirt portion 8 cast as a separate body is joined to the cast cylinder portion 2 with bolts or the like and integrally assembled, a lid portion 80 (the upper end of the partition wall 8b and the upper end of the partition wall 8c) of the skirt portion 8 is illustrated. And the upper end of the partition wall 8d are in contact with the lower ends of the respective cutout portions 20, and the opening side of the lower end of each cutout portion 20 is closed, whereby the vent holes H1, H2, H3 are formed during assembly. It becomes.
That is, the vent hole H1 communicates between the cylinder bore 2a and the cylinder bore 2b, the vent hole H2 communicates between the cylinder bore 2b and the cylinder bore 2c, and the vent hole H3 communicates between the cylinder bore 2c and the cylinder bore 2d. It communicates. By these vent holes H1, H2, H3, the pressure fluctuation in the crankcase 7 due to the reciprocating motion of the piston 3 can be satisfactorily reduced.

Therefore, in this example, the cylinder part 2 and the skirt part 8 constituting the cylinder block are separately cast from a mold, and these are connected and assembled to form the air holes H1, H2, and H3. In order to form a vent hole as in the prior art, it is not necessary to perform machining with a tool from the outside of the crankcase 7, and it is not necessary to form a vent hole using a core. The notches 20 can be easily formed only by designing the mold of the cylinder portion 2 constituting the air holes H1, H2, and H3 can be easily formed by assembling.
In addition, it is easy to make the size of each notch part 20 different by the mold design of the cylinder part 2, and each notch part 20 is formed at a different position by the mold design of the cylinder part 2, It is also easy to set the air holes H1, H2, and H3 at different positions.

When such a cylinder block 1 is divided into the cylinder part 2 and the skirt part 8, the air holes H1, H2, H3 can be easily formed even in the linerless cylinder block 1 in which no cylinder liner is present. it can.
Further, in the case of the cylinder block 1 having cylinder liners arranged for each cylinder bore without being connected between the cylinder bores 2a, 2b, 2c, 2d, a notch is provided at the lower end between the cylinder bores of the adjacent cylinder liners. It is easy to form and form the cylinder part 2 by casting each cylinder liner in the mold so that the notch part and the notch part 20 of the cylinder part 2 communicate with each other. Ventilation holes H1, H2, and H3 can be formed on the surface.

It is a longitudinal cross-sectional block diagram of the cylinder block of Example 1. FIG. It is the sectional view on the AA line of FIG. It is the perspective block diagram which formed the notch part beforehand in the cylinder liner. It is a perspective view of a separate lid member assembled to a cylinder liner. FIG. 5 is a perspective configuration diagram in a state where the lid member of FIG. 4 is assembled to the cylinder liner of FIG. 3. It is a longitudinal cross-sectional block diagram of the cylinder block of Example 2. FIG. It is the sectional view on the AA line of FIG.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder part 2a, 2b, 2c, 2d Cylinder bore 3 Piston 6 Crankshaft 7 Crankcase 8 Skirt part 8a, 8b, 8c, 8d, 8e Partition 10 Cylinder liner 11 Cover member 20 Notch part H1, H2, H3 through Pores

Claims (2)

The crank shaft side of the plurality of cylinder bores arranged in a row, the cylinder block the vent hole is opening communicating between sheet Rindaboa,
A cylinder liner in which adjacent cylinder bores are connected and a notch communicating between the cylinder bores is formed;
A lid that forms part of the cylinder bore;
With
The vent hole is a cylinder block of an internal combustion engine formed by covering the lid portion on the opening side of the notch portion . The crank shaft side of the plurality of cylinder bores arranged in a line, the vent holes communicating between sheets Rindaboa is in the manufacturing method of the apertured cylinder block,
Forming a notch communicating between the cylinder bores in a cylinder liner connected between adjacent cylinder bores;
A vent member is formed by covering a cover member that forms part of the cylinder bore on the opening side of the notch,
A method of manufacturing a cylinder block of an internal combustion engine, wherein the cylinder liner and the lid member are disposed in a mold of the cylinder block to form a cast hole.

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