JP2011069236A - Engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine preventing engine oil from leaking from a bolt through-hole of a bearing case cover during engine operation. <P>SOLUTION: In this engine having a bearing case 3 fixed on a cylinder block rear end wall 5 by putting a case mounting bolt 12 through a bolt through-hole 10 of the bearing case cover 8 and a bolt through-hole 13 of a case gasket 7 from a rear outside of the bearing case cover 8, a locking part 5b is provided on a cylinder head side section 5a of the cylinder block rear end wall 5, a locked part 3b is provided on a cylinder head side section 3a of the bearing case 3, and the cylinder head side section 3a of the bearing 3 which tends to fall down to a front side by explosion pressure in a combustion chamber is locked with the locking part 5b of the cylinder block end wall 5 by making the locking part 5b abut on the locked part 3b from a front side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an engine, and more particularly, to an engine capable of preventing engine oil from leaking from a bolt through hole of a bearing case cover during engine operation.

  As illustrated in FIG. 1, the engine which is a premise of the present invention is such that a bearing case (3) supporting a bearing is externally fitted to a rear end journal portion (2) of a crankshaft (1). The case (3) is fitted in the end bearing hole (6) of the cylinder block rear end wall (5), and the bearing case (3) is bearing from the rear outer side of the cylinder block (20) through the case gasket (7). Cover the case cover (8), attach the bearing case cover (8) to the rear end wall (5) of the cylinder block with cover mounting bolts (9), and insert the crankshaft into the crankshaft through hole (8a) of the bearing case cover (8). Penetrate (1),

As illustrated in FIG. 2, the bearing case cover (8) is provided with a plurality of bolt through holes (10) while maintaining a predetermined interval in the circumferential direction, and as illustrated in FIG. 3 (A), the bearing case (3 ) Is provided with a screw hole (11) at a predetermined interval in the circumferential direction at the outer peripheral edge of the bearing case cover, and as shown in FIG. 1, the bolt through hole of the bearing case cover (8) is formed from the outside of the bearing case cover (8). The case mounting bolt (12) is passed through the bolt through hole (13) of (10) and the case gasket (7), and this case mounting bolt (12) is screwed into the screw hole (11) of the bearing case (3). By doing so, the bearing case (3) is fixed to the cylinder block end wall (5) (see Patent Document 1).
This type of engine has an advantage that the bearing case (3) can be easily attached to the cylinder block end wall (5).

    However, in the conventional engine, engine oil may leak from the bolt through hole (10) of the bearing case cover (8) during engine operation.

Japanese Patent Laying-Open No. 2006-219999 (see FIGS. 3 and 4)

In the above-described prior art, engine oil may leak from the bolt through hole (10) of the bearing case cover (8) during engine operation, which may contaminate the engine and its surroundings.
The inventor of the present invention has discovered that the cause of engine oil leakage during engine operation is as follows, leading to the present invention.
While the engine is running, the cylinder head closer portion (3a) of the bearing case (3) falls forward due to the explosion pressure in the combustion chamber, and a gap is created before and after the cylinder head closer portion (7a) of the case gasket (7). Engine oil leaks from the bolt through hole (10) of the bearing case cover (8) through the gap.

  An object of the present invention is to provide an engine capable of preventing engine oil from leaking from a bolt through hole of a bearing case cover during engine operation.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 1, a bearing case (3) supporting a bearing is fitted on the rear end journal portion (2) of the crankshaft (1), and the bearing case (3) is attached to the rear end of the cylinder block. It fits in the end bearing hole (6) of the wall (5), covers the bearing case (3) from the rear outer side of the cylinder block (20) with a bearing case cover (8) via a case gasket (7), The case cover (8) is attached to the rear end wall (5) of the cylinder block with a cover mounting bolt (9), and the crankshaft (1) is passed through the crankshaft through hole (8a) of the bearing case cover (8).

As illustrated in FIG. 2, the bearing case cover (8) is provided with a plurality of bolt through holes (10) while maintaining a predetermined interval in the circumferential direction, and as illustrated in FIG. 3 (A), the bearing case (3 ) Is provided with a screw hole (11) at a predetermined interval in the circumferential direction at the outer peripheral edge of the bearing case cover, and as shown in FIG. 1, the bolt through hole of the bearing case cover (8) is formed from the outside of the bearing case cover (8). The case mounting bolt (12) is passed through the bolt through hole (13) of (10) and the case gasket (7), and this case mounting bolt (12) is screwed into the screw hole (11) of the bearing case (3). In the engine in which the bearing case (3) is fixed to the cylinder block end wall (5),
As illustrated in FIG. 1, a locking portion (5b) is provided on the cylinder head end portion (5a) of the cylinder block end wall (5), and the cylinder head end portion (3a) of the bearing case (3) is locked. By providing the portion (3b) and contacting the latched portion (3b) from the front side with the latched portion (5b),
The cylinder head end portion (3a) of the bearing case (3) that is about to fall forward due to the explosion pressure in the combustion chamber can be locked by the locking portion (5b) of the cylinder block end wall (5). An engine characterized by that.

The invention according to claim 1 has the following effects.
<Effect> It is possible to prevent engine oil from leaking from the bolt through hole of the bearing case cover during engine operation.
As illustrated in FIG. 1, the cylinder head end portion (3 a) of the bearing case (3) tends to fall forward due to the explosion pressure in the combustion chamber. ) So that there is no gap before and after the cylinder head portion (7a) of the case gasket (7), and the bolt through hole ( It is possible to prevent engine oil from leaking from 10).

It is a vertical side view of the bearing case of the engine which concerns on embodiment of this invention, and its peripheral part. It is a disassembled perspective view explaining the attachment state of the bearing case of the engine which concerns on embodiment of this invention. FIG. 3A is a front view of the bearing case, FIG. 3B is a front view of the case gasket, and FIG. 3C is a view for explaining the bearing case and the case gasket used in the engine according to the embodiment of the present invention. ) Is a diagram in which a bearing case and a case gasket are overlapped. It is a vertical side view of the engine which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are diagrams for explaining an engine according to an embodiment of the present invention. In this embodiment, a vertical two-cylinder diesel engine will be described.

The outline of the engine according to the embodiment of the present invention is as follows.
As shown in FIG. 4, the cylinder head (21) is assembled to the upper part of the cylinder block (20), and the head cover (22) is assembled to the upper part of the cylinder head (21). An oil pan (23) is assembled to the lower part of the cylinder block (20). A gear case (24) is assembled to the front portion of the cylinder block (20). The crankshaft (1) is accommodated in the lower part of the cylinder block (20). With the intermediate bearing case (26) assembled to the intermediate journal part (25) of the crankshaft (1) and the end bearing case (3) assembled to the end journal part (2), the rear cylinder block The crankshaft (1) is inserted into the cylinder block (20) from the end bearing hole (6) of the end wall (5), and the bearing case (26) is fitted into the intermediate bearing hole (27). A tunnel type bearing structure is adopted in which the bearing case (3) at the end is fitted into the partial bearing hole (6). A flywheel (29) is attached to the rear end of the crankshaft (1).

The bearing structure at the end is as follows.
As illustrated in FIG. 1, a bearing case (3) supporting a bearing (4) is fitted on the rear end journal portion (2) of the crankshaft (1), and a bearing ( 4) is mounted, this bearing case (3) is fitted into the end bearing hole (6) of the cylinder block rear end wall (5), and the bearing case (3) is bearing from the outside via the case gasket (7). The case cover (8) is covered, and the bearing case cover (8) is attached to the cylinder block rear end wall (5) with a cover mounting bolt (9). The crankshaft (1) is passed through the crankshaft through hole (8a) of the bearing case cover (8), an oil seal (8b) is fitted into the crankshaft through hole (8a), and the oil seal (8b) is cranked. It is brought into pressure contact with the peripheral surface of the shaft (1). The bearing (4) is composed of a radial metal (4a) and a thrust metal (4b). The bearing case (3) has a vertically divided structure and is assembled to the rear end journal (2) from above and below. A case cover gasket (28) is sandwiched between the bearing case cover (8) and the cylinder block rear end wall (5).

  As illustrated in FIG. 2, the bearing case cover (8) is provided with a plurality of bolt through holes (10) while maintaining a predetermined interval in the circumferential direction. As shown in FIG. 1 (A), the bearing case (3) A screw hole (11) is provided in the outer peripheral edge of the bearing case with a predetermined interval in the circumferential direction. As shown in FIG. ) And the bolt through hole (13) of the case gasket (7), the case mounting bolt (12) is passed through, and the case mounting bolt (12) is screwed into the screw hole (11) of the bearing case (3). Thus, the bearing case (3) is fixed to the cylinder block rear end wall (5), and the case gasket (7) is sandwiched between the bearing case cover (8) and the bearing case (3). The case gasket (7) is a copper thin plate.

The idea of the bearing structure at the end is as follows.
As shown in FIG. 1, a locking portion (5b) is provided on the cylinder head rear portion (5a) of the cylinder block rear end wall (5), and the cylinder head closer portion (3a) of the bearing case (3) is locked. A portion (3b) is provided, and a locking portion (5b) is brought into contact with the locked portion (3b) from the front side, whereby the cylinder head side portion (3a) of the bearing case (3) due to the explosion pressure of the combustion chamber Can be locked by the locking portion (5b) of the cylinder block end wall (5).
The locked portion (3b) is integrally formed with the cylinder block rear end wall (5) and extends from the peripheral surface of the end bearing hole (6) of the cylinder block rear end wall (5) to the end bearing hole (6). It protrudes toward the center. The locking portion (5b) is formed by recessing a portion (3a) closer to the cylinder head of the bearing case (3) from the rear side to the front side and a wall at the back end.

As illustrated in FIG. 3 (A), a plurality of bosses (14) and an arcuate connection portion (15) are provided on the outer peripheral portion of the bearing case (3), and the plurality of bosses (14) are connected to the bearing case (3). Are provided at predetermined intervals in the circumferential direction of the outer periphery of each of the adjacent bosses (14), and the adjacent bosses (14) are connected to each other by an arcuate connecting part (15), and each boss (14) is connected to the inner part of the arcuate connecting part (15). The screw holes (11) of the bearing case (3) are provided in each boss (14) so as to protrude inward from the periphery. The screw hole (11) has a dead end dead end bag-like structure.
As illustrated in FIG. 3B, the case gasket (7) is composed of an annular connecting portion (16) and a plurality of semicircular protrusions (17), and the plurality of semicircular protrusions (17) are formed. A plurality of semicircular protrusions (17) are provided to protrude outward from the outer peripheral edge of the annular connecting portion (16), and are provided on the outer peripheral edge of the annular connecting portion (16). A bolt through hole (13) of the case gasket (7) is provided across the protruding portion (17) and the annular connecting portion (16).

As illustrated in FIG. 3 (C), the boss (14) of the bearing case (3) and the bolt insertion hole (13) of the case gasket (7) when viewed in a direction parallel to the installation direction of the crankshaft (1). ) And a circular connection portion (15) that connects adjacent bosses (14) of the bearing case (3) and an annular connection of the case gasket (7). The remaining part (19) of the part (16) other than the surrounding annular part (18) is displaced inward and outward so as not to overlap each other.
As illustrated in FIG. 3 (C), the peripheral ring portion (18) of the bolt insertion hole (13) of the case gasket (7) is connected to the boss (14) of the bearing case (3) and the bearing case cover (8). The remaining portion (19) other than the peripheral annular portion (18) of the annular coupling portion (16) of the case gasket (7) is sandwiched between the bearing case (3) and the bearing case cover ( 8) so that it cannot be pinched.

(1) Crankshaft
(2) Rear end journal section
(3) Bearing case
(3a) Cylinder head side portion of bearing case
(3b) Locked part
(4) Bearing
(5) Cylinder block rear end wall
(5a) Cylinder head side portion of the cylinder block rear end wall
(5b) Locking part
(6) End bearing hole
(7) Case gasket
(9) Cover mounting bolt
(10) Bolt through hole of bearing case cover
(11) Screw hole
(12) Case mounting bolt
(13) Bolt through hole of case gasket

Claims (1)

A bearing case (3) supporting a bearing is fitted on the rear end journal portion (2) of the crankshaft (1), and this bearing case (3) is attached to the end bearing of the cylinder block rear end wall (5). Fit in the hole (6), cover the bearing case (3) from the rear outside of the cylinder block (20) with the case case cover (8) through the case gasket (7), and the bearing case cover (8) to the cylinder block. It is attached to the rear end wall (5) with a cover mounting bolt (9), the crankshaft (1) is passed through the crankshaft through hole (8a) of the bearing case cover (8),
A plurality of bolt through holes (10) are provided in the bearing case cover (8) with a predetermined interval in the circumferential direction, and screw holes (11) are provided in the outer peripheral edge of the bearing case (3) with a predetermined interval in the circumferential direction. ) And from the rear outer side of the bearing case cover (8), the case mounting bolt (12) is passed through the bolt through hole (10) of the bearing case cover (8) and the bolt through hole (13) of the case gasket (7). In the engine in which the bearing case (3) is fixed to the cylinder block rear end wall (5) by screwing the case mounting bolt (12) into the screw hole (11) of the bearing case (3).
A locking portion (5b) is provided on the cylinder head portion (5a) of the cylinder block rear end wall (5), and a locked portion (3b) is provided on the cylinder head portion (3a) of the bearing case (3). By bringing the locking portion (5b) into contact with the locked portion (3b) from the front side,
The locking portion (5b) of the cylinder block end wall (5) can catch the cylinder head side portion (3a) of the bearing case (3) that is about to fall forward due to the explosion pressure in the combustion chamber. An engine characterized by that.

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