JP2009197780A - Cover body for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize a cover body of an internal combustion engine, and to control the oscillation of a wall in the axial direction while forming a breather passage capable of smoothly introducing blow-by gas in an internal space, in the cover body covering the end of the engine body of an internal combustion engine from the axial direction and having a wall forming an internal space in conjunction with the end. <P>SOLUTION: A wall 50 of a chain cover 40 forming a chain chamber 25 has a lower wall 53a facing the end of the engine body in the axial direction of a crankshaft 6, and a higher wall 53b facing the end of the engine body and more apart from the end than the lower wall 53a, and formed so as to be in a different level from the lower wall 53a through a different level part 51 in a first bank 40a. The higher wall 53b covers the end from the lower part of the cylinder block to the cylinder head, and forms a breather passage 54 for introducing blow-by gas in the crank chamber to an operation valve chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cover body that covers an end portion of an engine main body side member of an internal combustion engine from the axial direction of a crankshaft and forms an inner space in cooperation with the end portion. The cover body is, for example, a transmission cover that forms a transmission chamber in which a transmission mechanism for rotationally driving the camshaft of the valve gear is disposed.

The internal combustion engine is provided with a cover body (for example, a chain cover that forms a chain chamber in which a chain transmission mechanism for valve trains is disposed) that covers the end of the engine body in the axial direction of the crankshaft. The cover body includes an outer edge portion coupled to an end portion of the engine body, covers the end portion from the crankcase to the cylinder head from the axial direction of the crankshaft, and cooperates with the end portion to form an inner space (for example, a chain). And a wall forming a chamber. And this wall part has many ribs for raising the rigidity and improving the vibration proofing effect.
In such a cover body, a part of the many ribs described above is used to collect the oil scattered in the inner space and form a guide path for returning to the oil pan. (See, for example, Patent Document 1).
JP-A-8-200089

In the cover body that covers the end portion of the internal combustion engine from the axial direction of the crankshaft, the inner space formed by the wall portion of the cover body is a head side space (for example, a valve operating valve) in which the blow-by gas in the crank chamber is formed by the cylinder head. When the air is also used as a breather passage that leads to the chamber, the flow of blow-by gas is obstructed by the parts (for example, the transmission mechanism for the valve train) arranged in the inner space itself or the chain running of the winding transmission mechanism. May be.
Therefore, in order to facilitate the flow of the blow-by gas in the inner space, it is conceivable to increase the axial distance between the wall portion and the end portion. Larger in the axial direction. Further, when the passage is formed using the rib of the cover body as in Patent Document 1, the width of the passage in the axial direction (hereinafter referred to as “axial width”) is determined by the height of the rib. In order to increase the axial width of the passage, it is necessary to increase the height of the rib, so that the entire cover body is also enlarged in the axial direction.
In addition, when the internal space is an oil atmosphere space where oil is present, if the mixing of oil into the blow-by gas increases in the internal space, the gas-liquid separator is increased in size. Therefore, it becomes necessary to increase the amount of oil separated, which leads to an increase in size and cost of the internal combustion engine. For this reason, it is desirable to suppress the mixing of oil into the blow-by gas as much as possible in the inner space.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 to 7 covers the end portion of the engine body side member of the internal combustion engine from the axial direction and cooperates with the end portion. In the cover body having a wall portion that forms the inner space, the cover body can be reduced in size in the axial direction and the wall portion vibration while forming a breather passage capable of smoothly guiding the blow-by gas in the inner space. The purpose is to control the above. The invention described in claims 2 and 3 further aims to smoothly guide the blow-by gas in the inner space by devising the formation position of the breather passage. The invention described in claim 5 further includes An object of the present invention is to reduce the oil in the blow-by gas flowing through the breather passage in the inner space, and the invention according to claim 6 further utilizes an axial space formed by the low wall portion of the wall portion. In order to arrange the winding transmission mechanism arranged outside the cover body in a compact manner in the axial direction, the invention according to claim 7 further utilizes a passage wall of an oil passage formed in the cover body. Then, it aims at suppressing the vibration of the wall part which has the high wall part formed of the level | step-difference part in an axial direction.

The invention according to claim 1 is a cover body (40) coupled to the end (1e, 2e, 102e, 3e, 4e, 5e) of the engine body side member (Ea) of the internal combustion engine (E), An outer edge portion (43) coupled to the end portion and the end portions (1e, 2e, 102e, 3e, 4e, 5e) are connected to the cylinder head (2) from the crankcase (1c) to the crankshaft (6). In the cover body (40) having a wall portion (50) which covers from the axial direction (A) and forms an inner space (25) in cooperation with the end portions (1e, 2e, 102e, 3e, 5e) The wall portion (50) includes a low wall portion (53a) facing the end portions (1e, 2e) in the axial direction (A) and the end portions (1e, 2e) in the axial direction (A). And spaced apart from the end portions (1e, 2e) in the axial direction (A) relative to the low wall portion (53a), and in the axial direction (A) The lower wall portion (53a) and the higher wall portion (53b) formed in a step difference are provided through the step portion (51) at the upper portion, and the higher wall portion (53b) has the end portions (1e, 2e). ) From the crankcase (1c) to the cylinder head (2), and the blow-by gas in the crank chamber formed by the crankcase (1c) is blown to the head side formed by the cylinder head (2). A cover body (40) forming a breather passage (54) leading to the space.
According to a second aspect of the present invention, in the cover body (40) according to the first aspect, the high wall portion (53b) is formed adjacent to the outer edge portion (43i) and along the outer edge portion (43i). Is.
According to a third aspect of the present invention, in the cover body (40) according to the first or second aspect, the internal combustion engine (E) includes a pair of banks (b1, b2) and the pair of banks (b1, b2). ) And an exhaust device (H) disposed outside the pair of banks (b1, b2), and the high wall portion ( 53b) is located closer to the inside of the pair of banks (b1, b2) in the wall portion (50).
According to a fourth aspect of the present invention, in the cover body (40) according to any one of the first to third aspects, the low wall portion (53a) is a window portion (60) that opens to the low wall portion (50). ) And a peripheral wall (61) coupled to the end (2e).
According to a fifth aspect of the present invention, in the cover body (40) according to any one of the first to fourth aspects, the high wall portion (53b) is connected to the end portion (1e) in the axial direction (A). A protrusion (59) formed on the opposing inner surface (41c), and the protrusion (59) intersects the cylinder axial direction of the internal combustion engine (E) when viewed from the axial direction (A). And a weir crossing the breather passage (54), and connecting the step portion (51) and the outer edge portion (43).
The invention according to claim 6 is the cover body (40) according to any one of claims 1 to 5, wherein the inner space (25) is sandwiched between the wall portion (50) in the axial direction (A). In the outer space on the opposite side, a winding transmission mechanism (T3) including a tensioner (36) for applying tension to the endless transmission band (35) is disposed, and the low wall portion (53a) in the axial direction (A). The tensioner (36) is disposed on the opposite side of the end (1e) across the gap, and the step (51) is formed outside the swing range of the tensioner (36).
According to a seventh aspect of the present invention, in the cover body (40) according to any one of the first to sixth aspects, the passage walls (Wa1, Wa2) forming the oil passages (Pa1, Pa2) are the step portions (51). ), And the passage walls (Wa1, Wa2) are provided integrally over the low wall portion (53a) and the high wall portion (53b).

According to the first aspect of the present invention, in the cover body coupled to the end portion of the engine body side member, the wall portion that covers the end portion from the axial direction of the crankshaft to form the inner space is the low wall portion. A high wall portion spaced apart from the end portion in the axial direction than the low wall portion through a step portion in the axial direction, and the high wall portion locally protruding outward in the axial direction at the wall portion A space portion that protrudes outward in the axial direction locally in the inner space is formed, and a breather passage having a larger axial width is formed by the space portion. As a result, the blow-by gas smoothly flows in the breather passage formed by expanding the inner space in the axial direction, so that the blow-by gas can be smoothly guided to the head side space in the inner space.
Moreover, since the low wall portion, which is a portion of the wall portion other than the high wall portion forming the breather passage, is positioned closer to the end portion in the axial direction than the high wall portion, the cover body is axially moved by the low wall portion. Can be downsized.
Further, the wall portion is formed with a step portion composed of a low wall portion, a step portion, and a high wall portion, so that the rigidity of the wall portion is enhanced by the step portion and a wall caused by vibration of the internal combustion engine. The film surface vibration of the part is suppressed.
According to the second aspect of the present invention, since the breather passage is formed by the outer edge portion, the blow-by gas flows in the breather passage while the disturbance is restricted by the outer edge portion, so that the blow-by gas flows from the breather passage in the inner space. Diffusion is suppressed and blow-by gas can be smoothly guided to the head side space.
According to the third aspect of the present invention, since the breather passage is formed at a position farther from the exhaust device in the cover body, the breather gas flows into the blow-by gas due to the high heat of the exhaust device arranged outside the pair of banks. The occurrence of turbulence is suppressed, and blow-by gas can be smoothly guided to the head side space.
According to the fourth aspect of the present invention, since the low wall portion is joined to the end portion by the peripheral wall forming the window portion that opens to the wall portion, the rigidity of the low wall portion is increased, and the low wall portion Membrane vibration is suppressed. In addition, the peripheral wall that forms the window portion is provided in the low wall portion that is closer to the end portion in the axial direction than the high wall portion, so when the peripheral wall that forms the window portion is provided in the high wall portion. Compared to the height of the peripheral wall in the axial direction, the cover body having the peripheral wall can be reduced in weight.
According to the fifth aspect of the present invention, since the ridge constitutes a weir crossing the breather passage extending in the cylinder axial direction from the crankcase to the cylinder head, the blow-by gas collides with the ridge. As a result, the oil mixed in the blow-by gas adheres to the protrusions and is separated, so that the oil in the blow-by gas flowing through the breather passage can be reduced.
Moreover, since the protrusion has connected the outer edge part and the level | step-difference part, the rigidity of a high wall part and a level | step-difference part is improved with a protrusion, and the vibration of a wall part is suppressed.
According to the sixth aspect of the present invention, the tensioner is disposed using the space in the axial direction formed by the low wall portion that is a portion close to the end portion in the axial direction in the wall portion. Since the tensioner can be disposed at a position close to the end, the winding transmission mechanism including the tensioner can be disposed compactly in the axial direction.
According to the seventh aspect of the present invention, the rigidity of the wall portion is increased in the direction crossing the step portion by using the passage wall that forms the oil passage provided in the cover body. Bending vibration generated so that the wall portion bends around the portion can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIG. 1, an internal combustion engine E is a V-type multi-cylinder four-stroke internal combustion engine mounted on a vehicle, and one of an engine body Ea as an engine body side member and an engine body Ea in the axial direction A. And a chain cover 40 that covers the end of each. The chain cover 40 as a transmission cover is a cover body that is detachably coupled to the engine body Ea.

The engine body Ea has a cylinder block having a plurality of cylinders (one cylinder 26 of the bank b1 is shown in FIG. 3) arranged to form a pair of V-shaped banks b1 and b2. 1 and a pair of cylinder heads 2,102 coupled to the upper end of the cylinder 26 in each of the first and second banks b1, b2 and a pair of cylinders coupled to the upper end of each cylinder head 2,102 The head cover 5 includes a lower block 3 coupled to the lower end portion of the cylinder block 1, and an oil pan 4 coupled to the lower end portion of the lower block 3.
The lower part 1c of the cylinder block 1, the lower block 3 and the oil pan 4 constitute a crankcase forming a crank chamber in which a crankshaft 6 as a rotating shaft provided in the internal combustion engine E is disposed. The crankshaft 6 is a cylinder. The lower part 1c of the block 1 and the lower block 3 are rotatably supported. Here, the lower portion 1c is a portion closer to the crankshaft 6 than the cylinder bore 26a (see FIG. 3) of each cylinder 26 in the cylinder axial direction.

In the specification and claims, the axial direction A (see FIG. 2) of the crankshaft 6 is the direction of the rotation center line LC of the crankshaft 6. In the embodiment, the vertical direction is a vertical direction when the rotation center line LC of the crankshaft 6 is included in the horizontal plane.
The lateral direction is assumed to be a direction orthogonal to the direction of the cylinder axis of the cylinder (hereinafter referred to as “cylinder axis direction”) when viewed from the axial direction A.

Referring also to FIG. 3, a piston 27 is slidably fitted in the cylinder bore 26a of each cylinder 26. The cylinder heads 2 and 102 of the banks b1 and b2 respectively include an intake valve and an exhaust valve that open and close an intake port and an exhaust port communicating with the combustion chamber 28 formed between the piston 27 in the cylinder axial direction, A valve operating device that opens and closes the intake valve and the exhaust valve according to the rotational position of the crankshaft 6 is provided.
In each cylinder head 2, 102, an intake device N having an intake manifold Na that guides intake air to the intake port is connected to a side wall where the intake port of the intake port is open, and an outlet of the exhaust port is open to the side wall of the cylinder head 2, 102. Is connected to an exhaust device H having an exhaust manifold Ha through which exhaust gas discharged from the combustion chamber 28 through the exhaust port is guided. Therefore, when viewed from the axial direction A, the intake device N arranged in the bank space 8 formed by the pair of banks b1 and b2 is arranged inside the pair of banks b1 and b2, and the exhaust device H is 1 Arranged outside the pair of banks b1 and b2. In each of the banks b1 and b2, when viewed from the axial direction A, the intake device N and the exhaust device H arranged with the cylinder axis Ly sandwiched in the lateral direction are connected to the cylinder heads 2, 102 on the intake side and the exhaust side, respectively. Connected.
The piston 27 is driven by the pressure of the combustion gas generated by the combustion of the fuel in each combustion chamber to reciprocate, and the crankshaft 6 is rotationally driven in the rotational direction R (see FIG. 3) via the connecting rod 29. To do.
Here, when viewed from the axial direction A, the intake side and the exhaust side are connected to the cylinder head 2,102 and the exhaust device H is connected to the cylinder head 2,102 with respect to the cylinder axis Ly. Each side is meant. When one of the intake side and the exhaust side is set as one side, the other of the intake side and the exhaust side is the other side.

Each valve operating device disposed in a valve operating chamber as a head side space formed by the cooperation of each cylinder head 2, 102 and the cylinder head cover 5 is an intake air that is rotatably supported by the cylinder head 2, 102. Variable movement comprising a camshaft 10 and an exhaust camshaft 11, an intake rocker arm and an exhaust rocker arm, and an operation characteristic variable mechanism capable of changing a valve lift characteristic of the intake valve and the exhaust valve and a valve operation characteristic that is an opening / closing timing It is a valve device. The intake cam and the exhaust cam provided on the intake cam shaft 10 and the exhaust cam shaft 11 respectively open and close the intake valve and the exhaust valve via the intake rocker arm and the exhaust rocker arm, respectively.
Further, the operating characteristic variable mechanism is a connection capable of connecting and disconnecting the plurality of rocker arms in order to change valve lift amount characteristics in the intake rocker arm and the exhaust rocker arm composed of a plurality of rocker arms having different operation forms. A valve lift amount control mechanism (not shown) having a switching mechanism and the phases of the intake camshaft 10 and the exhaust camshaft 11 with respect to the phase of the crankshaft 6 are changed to change the opening / closing timing of the intake valve and the exhaust valve. In order to achieve this, it is composed of phase control mechanisms 12 and 13 for changing the relative rotational positions of the driven sprockets 21 and 22 and the camshafts 10 and 11 to be described later.

  The valve lift amount control mechanism and the phase control mechanisms 12 and 13 are hydraulic mechanisms that use oil discharged from the oil pump 7 (see FIG. 3) of the internal combustion engine E as a working oil, and are provided in the internal combustion engine E. Hydraulic control valves 14 to 16 comprising spool valves as parts (FIG. 1 shows hydraulic control valves 14.15 for controlling the phase control mechanisms 12 and 13, respectively. FIG. 3 shows the valve lift amount control mechanism. A hydraulic control valve 16 for controlling the pressure is schematically shown.) Is controlled by a hydraulic control mechanism. The hydraulic control valves 14 and 15 are disposed or inserted in window portions 60 and 160, which will be described later, and are inserted into mounting holes 17 and 18 (see FIGS. 4 and 11) which are mounting portions provided in the cylinder head 2 and 102. In this state, it is detachably attached to the cylinder head 2 102 with a bolt. A hydraulic control valve 16 is also attached to the cylinder head 2, 102.

  The camshafts 10 and 11 are rotationally driven by the torque of the crankshaft 6 that is transmitted via valve gear transmission mechanisms T1 and T2 as components provided in the internal combustion engine E. The transmission mechanisms T1 and T2 are driven sprockets 20 and 120, which are driving rotary bodies provided on the crankshaft 6, and driven rotary bodies provided on both camshafts 10 and 11 via phase control mechanisms 12 and 13, respectively. Driven sprockets 21, 22 and endless chains 23; 123, which are endless transmission belts that are transmitted to the driven sprockets 21, 22 by being passed over the sprockets 20, 120; The winding transmission mechanism includes a tensioner 24 that applies tension to the chains 23 and 123. The tensioner 24 includes a tensioner shoe 24a in which the chains 23 and 123 are in sliding contact with each other, and a tensioner lifter 24b that presses the tensioner shoe 24a against the chains 23 and 123.

The transmission mechanisms T1 and T2 include one end portions 1e, 2e, 102e, 3e, and 4e in the axial direction A of the cylinder block 1, the cylinder heads 2,102, the lower block 3, the oil pan 4, and the cylinder head cover 5, respectively. , 5e and a chain chamber 25 (see also FIGS. 6 to 9) formed by the cooperation of the end portions 1e, 2e, 102e, 3e and 5e.
The internal combustion engine is adjacent to the chain cover 40 in the axial direction A on the outer side of the chain cover 40 with respect to the inner side of the chain cover 40 where the transmission mechanisms T1 and T2 are arranged with the chain cover 40 as a boundary. An auxiliary machine drive transmission mechanism T3 for driving one or more auxiliary machines included in E by the torque of the crankshaft 6 is arranged.
The transmission mechanism T3 is for a generator that rotationally drives a drive pulley 30 provided at the shaft end 6e of the crankshaft 6, an AC generator and an air conditioning compressor that are attached to the cylinder block 1 and the lower block 3 via brackets. The driven pulley 31 and the driven pulley 32 for the compressor, the driven pulley 33 for the cooling water pump that rotationally drives the cooling water pump that pumps the cooling water that cools the internal combustion engine E, the idle pulley 34, and the pulleys 30 to 34 are hung. The passed endless belt 35 and a tensioner 36 that applies tension to the belt 35 are provided. The tensioner 36 is a support member that rotatably supports a tensioner pulley 36a around which the belt 35 is wound and a tensioner pulley 36a that is a pressing portion that presses the belt 35, and is supported by the cylinder block 1 so as to be swingable. Arm 36b. The support arm 36b swings about the swing center line Lp (see FIG. 1) according to the tension of the belt 35 so as to maintain the tension of the belt 35 substantially constant.

1 to 4, a chain cover 40 coupled to each end 1e, 2e, 102e, 3e, 4e, 5e is a single unit formed by casting from an aluminum alloy as a metal material as a forming material. And a pair of first and second bank portions 40a, 40b that form a V shape when viewed from the axial direction A, corresponding to both banks b1, b2.
The chain cover 40 has a surface composed of an inner surface 41 and an outer surface 42, and strip-shaped coupling seats 9a, 9b (FIG. 1) provided integrally with the end portions 1e, 2e, 102e, 3e, 4e, 5e. Shows a coupling seat 9a in the oil pan 4, and FIGS. 6 and 8 show a coupling seat 9b in the end 1e of the cylinder block 1.) A wall portion 50 serving as a covering portion that is located on the inner peripheral side of the outer edge portion 43 and covers the end portions 1e, 2e, 102e, 3e from the lower block 3 through the cylinder block 1 to the cylinder head 2,102 from the axial direction A. And have.
The wall portion 50 is disposed so as to face the end portions 1e, 2e, 102e, and 3e of the cylinder block 1, the cylinder heads 2, 102, and the lower block 3 in the axial direction A as a predetermined direction. 2e, 102e, 3e and the end 5e of the cylinder head cover 5 cooperate with each other to form a chain chamber 25 as a transmission chamber as an inner space.

The outer edge portion 43 extends in a strip shape corresponding to the coupling seats 9a and 9b and has mating portions 44a and 44b having mating surfaces 45a and 45b mated with the coupling seats 9a and 9b, and rises in the axial direction A from the mating portion 44b. It has a rising wall portion 44c (see also FIG. 7) and a pair of cover side contact portions 77, 177 located on the outer peripheral side of the mating portions 44a, 44b.
The mating portions 44a and 44b are composed of a mating portion 44a having a mating surface 45a that is mated in the vertical direction with the coupling seat 9a of the oil pan 4, and a mating portion 44b having a mating surface 45b mating with the coupling seat 9b in the axial direction A. Composed. The mating portions 44 a and 44 b have coupling boss portions 46 a and 46 b as a plurality of coupling portions arranged at intervals along the outer edge portion 43. The coupling boss 46a coupled to the coupling seat 9a is provided with a screw hole into which a bolt B1 serving as a coupling tool is screwed, and the bolt B2 serving as a coupling tool is inserted into the coupling boss 46b coupled to the coupling seat 9b. An insertion hole 46h is provided.
For this reason, the outer edge portion 43 is fastened by bolts B1 and B2 screwed into the coupling seats 9a and 9b at the coupling boss portions 46a and 46b. In addition, the mating surfaces 45a and 45b are also sealing surfaces that seal between the coupling seats 9a and 9b. Therefore, the mating portions 44a and 44b are seal portions that seal between the end portions 1e, 2e, 102e, 3e, 4e, and 5e. A liquid sealing material as a sealing member is applied to the mating surfaces 45a and 45b, and the space between the coupling seats 9a and 9b and the mating portions 44a and 44b is sealed.
The contact portions 77 and 177 constitute passage walls Wa1 and Wb1 of cover-side oil passages Pa and Pb, which will be described later, and contact portions 9m and 9n provided in the cylinder block 1 (see FIGS. 6 and 8). Contact surfaces 77a and 177a (see FIG. 4) that contact each other are provided.

The inner surface 41 constituting the surface of the chain cover 40 has an inner wall surface 41c facing the chain chamber 25 of the outer edge portion 43 and the wall portion 50, a mating surface 45a facing the end portion 4e in the vertical direction, and an end in the axial direction A. The mating surface 45b facing the portions 1e, 2e, 102e, 3e, 5e, mating surfaces 63, 163 of the peripheral walls 61, 161 described later, contact surfaces 77a, 177a, and cover side contact portions 87, 187 described later Contact surfaces 87a and 187a. Further, the outer surface 42 constituting the surface of the chain cover 40 is a surface facing the outer space which is the space opposite to the chain chamber 25 with the chain cover 40 as a boundary.
The mating surfaces 45b, 63, 163 and the contact surfaces 77a, 177a, 87a, 187a are located on the same plane orthogonal to the axial direction A in this embodiment, but as another example, the axial direction They may be located on a plurality of planes that intersect A and parallel to each other, or on the same plane that intersects the axial direction A in a manner other than orthogonal.
Here, it is assumed that the attaching direction of the chain cover 40 to the coupling seats 9a and 9b is a direction orthogonal to the mating surface 45b or an axial direction A.

  The wall portion 50 that covers the end portions 1e, 2e, 102e, 3e, 5e and the transmission mechanisms T1, T2 from the outside in the axial direction A has window portions 60, 160, which are spaces penetrating the wall portion 50 in the axial direction A. Annular peripheral walls 61, 161, 65, 68 forming 66, 69 and passage walls Wa1, Wa2, Wb1, Wb2 (FIG. 14) arranged in the respective bank portions 40a, 40b and forming cover side oil passages Pa, Pb. To FIG. 17), mounting seats 91 and 92 to which engine hangers 93 (see FIG. 1) to be attached to the chain cover 40 and mounted on the banks b1 and b2 are attached, and the wall 50 Step portions 51 and 52 for forming walls having step portions 55a and 55b in the axial direction A, and a plurality of ribs 58a and 58b for increasing the rigidity of the wall portion 50 and suppressing the film surface vibration of the wall portion 50. , 58c.

The wall portion 50 is formed as a step portion 51 in the axial direction A so that the first covering portion is a plurality of wall portions having different distances in the axial direction A from the coupling seat 9b or the mating surface 45b. It has the wall part 53a and the high wall parts 53b and 53c as a 2nd coating | coated part. The high wall portions 53b and 53c are separated from the end portions 1e, 2e, 102e, 3e, and 5e in the axial direction A with respect to the low wall portion 53a, and through a step portion 51 formed between the low wall portions 53a. Are formed in steps.
The high wall portions 53b and 53c whose distance from the mating surface 45b is larger than the low wall portion 53a are the first high wall portion 53b as the first wall portion formed by another stepped portion 52 and the second wall portion. A second high wall portion 53c. The distance from the mating surface 45b of the second high wall portion 53c is greater than that of the first high wall portion 53b. The low wall portion 53a and the first and second high wall portions 53b and 53c are substantially parallel to the mating surface 45b (or substantially perpendicular to the axial direction A) and substantially planar, It is a plane part.

  The step portion 51 forming a step on the inner wall surface 41c and the outer surface 42 is along the outer side of the slack side 23a of the chain 23 of the transmission mechanism T1 in the first bank portion 40a and on the intake side or near the bank space 8. The cylinder block 1 extends in the cylinder axial direction from the lower part 1c of the cylinder block 1 to the cylinder heads 2,102.

  In the first bank portion 40a, the low wall portion 53a is located mainly on the exhaust side, and a part of the low wall portion 53a is located near the cylinder axis Ly on the intake side, with the chain chamber 25 being sandwiched in the axial direction A. 1e and 2e are opposed to each other and extend in the cylinder axial direction so as to cover the end portions 1e and 2e from the lower part 1c of the cylinder block to the cylinder head 2. As shown in FIG. 1, the low wall portion 53a covers the portion of the chain 23 located between the driving sprocket 20 and the driven sprockets 21 and 22 from the outside in the axial direction A.

The first high wall portion 53b is located mainly on the intake side in the first bank portion 40a and faces the end portions 1e and 2e across the chain chamber 25 in the axial direction A, and the end portions 1e and 2e. Is extended in the cylinder axial direction so as to cover the cylinder head 2 from the lower part 1c. In the first bank portion 40a, the first high wall portion 53b covers the majority of the driven sprockets 21 and 22 and the cam shafts 10 and 11 from the axial direction A.
The first high wall portion 53b covers the end portions 1e and 102e from the lower portion 1c of the cylinder block to the cylinder heads 2 and 102 in almost the entire range on the intake side and the exhaust side in the second bank portion 40b. Thus, it extends in the cylinder axial direction.

The first high wall portion 53b of the first bank portion 40a is a wall that locally protrudes in the axial direction A in the first bank portion 40a, and the low wall portion in the axial direction A locally in the chain chamber 25. A protruding space 25a, which is a space portion protruding outward from 53a, is formed (see also FIG. 7), and the chain chamber 25 is provided between the ends 1e and 2e in the axial direction A including the protruding space 25a. As a part, a breather passage 54 is formed. Therefore, the breather passage 54 has a larger axial width by the protruding space 25a.
The breather passage 54 is a communication passage that communicates the crank chamber with the valve chamber in order to guide the blow-by gas in the crank chamber to the valve chamber formed by the cylinder head 2.
Then, the blow-by gas introduced into the valve operating chamber passes through the gas-liquid separator provided in the valve operating chamber, and then is guided to the intake device N to be mixed with the intake air and sucked into the combustion chamber 28. Is done.

In the wall portion 50 of the first bank portion 40a, the first high wall portion 53b and the breather passage 54 are, on the outer edge portion 43, the side edge portion 43i on the intake side sandwiching the cylinder axis Ly in the side direction and the exhaust side. In this embodiment, the side edge is adjacent to the side edge 43i located near the bank space 8 in the lateral direction and is located above the side edge 43e. It extends in the cylinder axis direction along the portion 43i.
Therefore, the protruding space 25a is formed by the first high wall portion 53b, the stepped portion 51, and the rising wall portion 44c of the side edge portion 43i (see FIG. 7). Further, since the breather passage 43 is located closer to the bank space 8, the blow-by gas flowing through the breather passage 54 is influenced by the high heat of the exhaust manifold Na because the breather passage 43 is further away from the side edge 43e near the exhaust manifold Ha. It is hard to receive.
Further, since the first high wall portion 53b is located above the lower wall portion 53a and the breather passage 54 constitutes a space portion at the upper end of the chain chamber 25, most of the oil in the chain chamber 25 is Since the fluid flows in the lower space formed between the end portions 1e, 2e and the low wall portion 53a in the axial direction A in the chain chamber 25, the oil in the chain chamber 25 is prevented from flowing into the breather passage 54. .

  In the first bank 1b, the first high wall portion 53b and the breather passage 54 extend from the outer side of the chain 23 along the slack side 23a when viewed from the axial direction A, and overlap with the tensioner shoe 24a. The cylinder bore 26a overlaps the cylinder bore 26a. The traveling direction of the chain 23 along the breather passage 54 is a direction along the direction in which blow-by gas is directed to the valve operating chamber.

Referring to FIGS. 3 to 5, the first high wall portion 53 b has a protrusion 59 formed on the inner wall surface 41 c facing the end portion 1 e in the axial direction A. The protrusion 59 protruding toward the end 1e in the axial direction A (that is, inward) extends linearly in a direction intersecting the cylinder axial direction when viewed from the axial direction A, and the step portion 51 and the side edge. The connecting boss portion 46b1 of the portion 43i is connected. The ridge 59 is inclined downward from the connecting boss portion 46b1 which is the upper connecting portion toward the step portion 51 which is the lower connecting portion, in a direction approaching the rotation center line Lc in the cylinder axial direction. Further, the step portion 51 is connected to the coupling boss portion 46b of the outer edge portion 43 at the end thereof.
The height of the ridge 59 is equal to the height of the end 51a in the axial direction A from the inner wall surface 41c, and the top of the ridge 59 is the top of the rib 58c provided on the inner wall 41c of the low wall portion 53a. The height is set to be the same or substantially equal to the step of the step portion 51. The protrusion 59 extends from the first high wall portion 53b side so as to substantially block the protruding space 25a at the inlet 54a as a passage portion in the upstream portion of the breather passage 54. The blow-by gas from the crank chamber flows in the breather passage 54 through the inlet 54a formed between the protrusion 59 and the end 1e in the axial direction A. Therefore, the protrusion 59 constitutes a weir that crosses the inlet 54 a of the breather passage 54.

  For this reason, when blow-by gas flowing out of the crank chamber flows into the breather passage 54, a part of the blow-by gas collides with the ridge 59, and oil mixed in the blow-by gas adheres to the ridge 59 and is separated. . Further, the oil transmitted along the inner wall surface 41c of the first high wall portion 53b outside the breather passage 54 is prevented or suppressed from flowing into the breather passage by the protrusion 59. The separated or attached oil flows down the ridge 59 upstream of the breather passage 54, returns to the oil pan 4 (see FIG. 1) along the inner wall surface 41c. In this way, the protrusion 59 separates the oil mixed in the blow-by gas, and reduces the amount of oil mixed in the blow-by gas flowing through the breather passage 54 or the blow-by gas guided to the valve operating chamber. An oil separation wall having a function of

Referring to FIGS. 1 and 3 to 5, by providing the low wall portion 53 a, the protruding amount of the wall portion 50 in the axial direction A from the coupling seat 9 b of the end portions 1 e and 2 e is partially suppressed. Therefore, by utilizing the space formed by the low wall portion 53a, a part disposed adjacent to the outside of the chain cover 40 in the axial direction A, in this embodiment, the support arm 36b of the tensioner 36 is disposed in the space. The The support arm 36b is disposed on the opposite side of the end portion 1e across the low wall portion 53a in the axial direction A, and is at a position (or the same position) that at least partially overlaps the stepped portion 51 in the axial direction A.
Further, the step portion 51 is formed outside the swinging range that is the moving range of the support arm 36b. A portion 51 a including a connecting portion with the protrusion 59 in the stepped portion 51 is a portion that defines a passage area in the vicinity of the inlet 54 a of the breather passage 54 in a direction in which the protrusion 59 extends. The portion 51a is a proximity portion where the support arm 36b that swings and moves is closest in the swing direction as the moving direction, and is formed in a shape that substantially follows the swing trajectory of the support arm 36b. By forming the portion 51a in a shape that follows the swinging trajectory of the support arm 36b, the breather in the vicinity of the inlet 54a and the inlet 54a despite the support arm 36b being disposed close to the stepped portion 51. Since the passage area of the passage can be increased, the flow of blow-by gas into the breather passage 54 can be promoted.

  1 to 4, in the second bank portion 40b, the wall portion 50 mainly has high wall portions 53b and 53c. The first high wall portion 53b is positioned between the drive sprocket 120 and the driven sprockets 21 and 22 corresponding to the drive sprocket 120 disposed closer to the wall portion 50 than the drive sprocket 20 in the axial direction A. A portion of the chain 123 is covered from the axial direction A. Further, the second high wall portion 53c is in a portion where an intersecting wall portion Wbc described later is provided, and further covers the majority of the driven sprockets 21 and 22 and the cam shafts 10 and 11 from the axial direction A.

10 and 11, the pair of peripheral walls 61 and 161 forming the pair of window portions 60 and 160, respectively, are arranged on the inner wall surface 41c in the axial direction A in the end portion 2e of the cylinder head 2,102. The ridge protrudes toward 102e, is integrally formed with the cylinder head 2, 102, and abuts on coupling seats 9c and 9d located on the inner peripheral side of the coupling seat 9b.
The peripheral wall 61 disposed in the first bank portion 40a is formed in the low wall portion 53a, and the peripheral wall 161 disposed in the second bank portion 40b is formed in the first high wall portion 53b. The height of the peripheral wall 161 is higher than the height of the peripheral wall 61 in the axial direction A.

Each of the peripheral walls 61 and 161 serving as an opening forming portion for forming the window portions 60 and 160 that are openings in the wall portion 50 is a plurality of four connecting portions provided at intervals along the peripheral walls 61 and 161. There are certain boss portions 62, 162 and mating surfaces 63, 163 which are seal surfaces mated with the coupling seats 9c, 9d.
Boss portions 62 and 162, which are portions of the peripheral walls 61 and 161 where the wall thickness is increased, are inserted into insertion holes 62a and 162a provided in the boss portions 62 and 162, and are coupled into the coupling seats 9c and 9d. It is fastened by a bolt B3 (see FIG. 1) as a tool. Therefore, the peripheral walls 61 and 161 are coupled to the coupling seats 9c and 9d at the boss portions 62 and 162. A liquid sealing material may be applied to the mating surfaces 63 and 163.
The peripheral walls 61 and 161 are portions for forming window portions 60 and 160 for enabling the hydraulic control valves 14 and 15 to be attached and detached with the chain cover 40 attached to the engine body Ea.
Therefore, the window portions 60 and 160 are spaces for inserting and removing the hydraulic control valves 14 and 15.

  Referring to FIGS. 12 and 13, a predetermined number of plural hydraulic control valves 14 and 15 in this embodiment are arranged in each of the windows 60 and 160, and the hydraulic control valves 14 and 15 are The two phase control mechanisms 12, 13 (see FIG. 1), which are the operation characteristic variable mechanisms equal to the predetermined number, are controlled separately.

  Each of the hydraulic control valves 14 and 15 has the axis L1 and L2 of the chain cover 40 and the end 2e and 102e of the cylinder head 2 and 102e in the axial direction A (see FIGS. 10 and 11) (see FIGS. 10 and 11). ) In the direction orthogonal to each other or in the axial direction A, and is inserted into the window portion 60 or the window portion 160 of the chain cover 40, and the mounting hole 17 or the mounting hole 18 (see FIGS. 4, 10, 10) of the cylinder head 2, 102. (See FIG. 11).

  The hydraulic control valves 14 and 15 having the same structure are attached to the cylinder heads 2 and 102 (see FIGS. 10 and 11), and are arranged in the window portions 60 and 160 as cylindrical portions. 14a and 15a and mounting portions 14b and 15b projecting in a mountain shape radially outward from the main body portions 14a and 15a. Each mounting portion 14b, 15b is connected to the main body portions 14a, 15a and includes a base portion 14b1, 15b1 close to the main body portions 14a, 15a in the radial direction and a tip portion including a portion farthest from the main body portions 14a, 15a in the radial direction. 14b2 and 15b2, and the width in the circumferential direction gradually decreases as the distance from the main body portions 14a and 15a increases in the radial direction. Further, the mounting portions 14b and 15b are arranged closer to the cylinder 26 (see FIG. 3) or closer to the crankshaft 6 (see FIG. 1) than the main body portions 14a and 15a in the cylinder axis direction.

  Here, the axis lines L1 and L2 of the hydraulic control valves 14 and 15 are the central axis lines of the cylindrical main body portions 14a and 15a, and the axis lines are in a state where the hydraulic control valves 14 and 15 are attached to the cylinder heads 2 and 102. L1 and L2 are parallel to the axial direction A. Further, in relation to the hydraulic control valves 14 and 15, it is assumed that the radial direction and the circumferential direction are a radial direction and a circumferential direction around the axes L1 and L2, respectively.

  In the case where the hydraulic control valves 14 and 15 are electric control valves, the hydraulic control valves 14 and 15 are provided on the hydraulic control valves 14 and 15 when viewed from the axial direction A as shown by a two-dot chain line in FIGS. Connector portions 14c and 15c projecting radially outward from the main body portions 14a and 15a are provided on the substantially opposite side of the mounting portions 14b and 15b in the radial direction across the main body portions 14a and 15a. For each of the window portions 60 and 160, the mounting portions 14b and 15b are located in the window portions 60 and 160 together with the main body portions 14a and 15a, while the connector portions 14c and 15c are arranged in the axial direction A (FIGS. 10 and 11). (See Fig. 4) or apart from the mounting portions 14b and 15b in the direction of the axes L1 and L2, and located outside the window portions 60 and 160.

  Each of the hydraulic control valves 14 and 15 has a bolt B7 as a coupling member inserted into an insertion hole (not shown) provided in the mounting portions 14b and 15b in the cylinder heads 2 and 102 (see FIGS. 10 and 11). It is screwed and fixed to the cylinder head 2,102. By connecting the mounting portions 14b and 15b and the cylinder heads 2 and 102 with the bolt B7, the hydraulic control valves 14 and 15 around the axes L1 and L2 are prevented from rotating with respect to the cylinder heads 2 and 102. The

  In each of the windows 60 and 160, the two hydraulic control valves 14 and 15 attached to the cylinder head 2 and 102 are juxtaposed so that the axes L1 and L2 are parallel to each other. In this state, in each of the hydraulic control valves 14 and 15, the mounting portions 14b and 15b are located below the main body portions 14a and 15a, while the connector portions 14c and 15c are located above the main body portions 14a and 15a. In particular, since the hydraulic control valves 14 and 15 arranged in the window 60 are located at the uppermost portions of the main body portions 14a and 15a, it is easy to connect the electric wires to the connector portions 14c and 15c.

12 to 17, four boss portions 62B, 62C, 62D, 62E; 162B, 162C, 162D, which are provided on the peripheral wall 61; 161 forming each window portion 60; 160 and are fastened by a bolt B3. Of the 162E, the two first boss portions 62B, 62C; 162B, 162C are located at positions facing each other with the window portion 60; 160 in between, and inside the window portion 60; 160 in a direction approaching each other. Projecting portions 62B1, 62C1; 162B1, 162C1 (see also FIGS. 10 and 11).
For this reason, the window portion 60; 160 has a pair of boss portions 62B, 62C; 162B, 162C projecting inward between the two hydraulic control valves 14, 15, so that each boss portion 62B, 62C; 162B, It has a pair of constricted portions 60c1, 60c2; 160c1, 160c2 (see also FIGS. 10 and 11) formed by 162C. The amount of protrusion of the boss portion 62C; 160C toward the inside of the window portion 60; 160 is larger than the amount of protrusion of the boss portion 62B; 162B toward the inside of the window portion 60; 160.

In each peripheral wall 61; 161, the two boss portions 62B, 62C; 162B, 162C are planes parallel to the axial direction A (see also FIGS. 10 and 11), and both the boss portions 62B, 62C; 162B, 162C or Plane P1; P2 (see FIGS. 12 and 13) intersecting with the insertion holes 62ab, 62ac; 162ab, 162ac (or both boss portions 62B, 62C; 162B, 162C or both insertion holes 62ab, 62ac; 162ab, 162ac) ), The window portions 60 and 160 are arranged so as to be divided into two accommodating spaces 60a and 60b; 160a and 160b. The planes P1 and P2 intersect with the constricted portions 60c1 and 60c2; 160c1 and 160c2 (or pass through the constricted portions 60c1 and 60c2; 160c1 and 160c2).
Therefore, each window portion 60, 160 is a straight line or plane passing through the pair of boss portions 62B, 62C; 162B, 162C or the pair of constricted portions 60c1, 60c2; 160c1, 160c2 when viewed from the axial direction A. It is divided into first and second accommodation spaces 60a, 60b; 160a, 160b with P1; P2 as a boundary.

  Then, the whole or almost the whole of the main body portions 14a, 15a and the mounting portions 14b, 15b of one hydraulic control valve 14, 15 is accommodated in one accommodating space 60a, 60b; 160a, 160b. The first and second hydraulic control valves 14 and 15 are disposed in the first and second accommodation spaces 60a and 60b; 160a and 160b, respectively, in the window portions 60 and 160. In addition, plane P1; P2 shown by FIG. 12, FIG. 13 is parallel to the axial direction A, and many planes which cross | intersect both boss | hub parts 62B, 62C; 162B, 162C or insertion hole 62ab, 62ac; 162ab, 162ac It is an example.

  Each peripheral wall 61; 161 is divided into two first and second peripheral wall portions 61a, 61b; 161a, 161b by planes P1; P2. In each peripheral wall 61; 161, the two boss portions 62D, 62E; 162D, 162E, which are the remaining second boss portions other than the two boss portions 62B, 62C; 162B, 162C, are respectively connected to the peripheral wall portions 61a. , 61b; one each at 161a, 161b. Further, the two boss portions 62D, 62E; 162D, 162E are located at portions where the maximum width or almost maximum width of the window portions 60; 160 in the direction orthogonal to the plane P1; P2 is formed.

  Therefore, the peripheral wall 61; 161 is fixed to the cylinder head 2; 102 by the bolt B3 in at least two boss portions 62B, 62C; 162B, 162C, and in this embodiment, another two boss portions 62D, 62E. In 162D and 162E, it is fixed to the cylinder head 2,102 by a bolt B3.

In each window portion 60; 160, the main body portions 14a and 15a and the attachment portions 14b and 15b of the two hydraulic control valves 14 and 15 are arranged across the plane P1; P2, and the attachment portions 14b and 15b are boss portions 62C; 162C and the constricted portion 60c2; Further, in both hydraulic control valves 14 and 15 disposed in the respective window portions 60; 160, the mounting portions 14b and 15b and the connector portions 14c and 15c pass vertically along the axis lines L1 and L2 when viewed from the axial direction A. When a straight line parallel to the direction or plane P1; P2 is set as a reference position, it is arranged at the same position in the circumferential direction from the reference position with respect to the axis lines L1, L2 or the main body portions 14a, 15a.
Further, with respect to the two hydraulic control valves 14 and 15 in each window portion 60; 160, the main body portions 14a and 15a are disposed closest to each other in the radial direction among the main body portions 14a and 15a and the mounting portions 14b and 15b. The main body portions 14a and 15a are arranged mainly along the upper peripheral wall portion 61c; 161c of the peripheral wall 61; 161, and the mounting portions 14b and 15b are mainly lower peripheral wall portions 61d of the peripheral walls 61 and 161. Arranged along 161d.
The main body portions 14a and 15a and the mounting portions 14b and 15b of the hydraulic control valves 14 and 15 in each window portion 60 and 160 are a pair of constrictions formed by a pair of boss portions 62B and 62C; 162B and 162C. The portions 60c1, 60c2; 160c1, 160c2 are used to be inserted into the window portions 60, 160 in a state substantially matching the shape of the window portions 60; 160.

  In general, in an internal combustion engine in which a hydraulic control valve having a mounting portion coupled to a cylinder head is arranged in a window provided in a chain cover, when a plurality of the hydraulic control valves are arranged in one window In some cases, the opening area of the window portion becomes large and the rigidity of the chain cover is lowered. Therefore, in this embodiment, in the chain cover 40 provided with the window portion 60; 160 in which the hydraulic control valves 14, 15 are arranged, a plurality of hydraulic control valves 14, 15 are arranged in one window portion 60; 160. In this case, by reducing the opening area of the window portion 60; 160, a reduction in rigidity of the chain cover 40 as a cover body due to the provision of the window portion 60; 160 is suppressed.

Specifically, in the peripheral wall 61; 161 formed in the chain cover 40 and forming the window portions 60; 160 in which the two hydraulic control valves 14, 15 are arranged, the boss portions 62C; 162C are both hydraulic control valves. 14 and 15 is located between the mounting portions 14b and 15b, and extends along the plane P1; P2 from the front end portions 14b2 and 15b2 of the mounting portions 14b and 15b in the direction close to the main body portions 14a and 15a. The opening area of the window portion 60; 160 between the mounting portions 14b and 15b can be reduced. Further, in the peripheral wall 161, the boss portion 162B enters between the main body portions 14a and 15a in the direction of approaching both the main body portions 14a and 15a along the plane P2, and therefore, between the main body portions 14a and 15a. The opening area of the window 160 can be reduced.
In each peripheral wall 61; 161, the bosses 62B, 62C; 162B, 162C projecting inward of the window 60; 160 are provided, so that the windows of the bosses 62B, 62C; 162B, 162C are provided. Since the opening area of the part 60; 160 can be reduced, the rigidity of the chain cover 40 is prevented from being lowered due to the provision of the window part 60; 160 in which the two hydraulic control valves 14, 15 are arranged.

  Further, since the boss portion 62C; 162C is positioned between the pair of attachment portions 14b, 15b, the one boss portion 62C; 162C can be provided close to both the attachment portions 14b, 15b, and the boss Since the mounting portions 14b and 15b are fastened in the vicinity of the cylinder head 2; 102 whose rigidity is enhanced by the bolt B7 that fastens the portion 62C; 162C, the peripheral wall is utilized by utilizing the rigidity of the bolt B7 that fastens the boss portion 62C; 162C. The two hydraulic control valves 14 and 15 can be firmly fixed to the cylinder heads 2 and 102 while reducing the number of boss portions provided at 61 and 161 and tightened by bolts.

  Further, the shape of each window portion 60; 160 is such that the hydraulic control valves 14, 15 substantially match the shape of the window portions 60,160 using a pair of constricted portions 60c1,60c2; 160c1,160c2. The two hydraulic control valves 14 and 15 can be compactly arranged in the respective window portions 60 and 160, and the opening area of the window portions 60 and 160 can be reduced. Contributes to

On the other hand, the pair of windows 66 is for allowing the tensioner lifter 24b to be attached and detached while the chain cover 40 is attached to the engine body Ea. Therefore, when the tensioner lifter 24 b is attached and detached, the tensioner lifter 24 b is inserted from the window portion 66 and disposed in the chain chamber 25, and is extracted from the chain chamber 25 through the window portion 66. A lid 67 (see FIG. 1) for sealing the window 66 is detachably attached to the peripheral wall 65 with a bolt B4.
Further, in the window portion 69 formed by the peripheral wall 68, the shaft end portion 6e of the crankshaft 6 is inserted, and the boss portion 30a of the drive pulley 30 is interposed via the annular seal member 8 as shown in FIG. Inserted.
Therefore, the crankshaft 6 and the drive pulley 30, which are parts provided in the internal combustion engine E, are disposed in the window 69, respectively.

  As described above, each of the window portions 60, 160, 66, and 69 is a space for part placement or part insertion into which parts provided in the internal combustion engine E are placed or inserted. A large load caused by vibration of the internal combustion engine E hardly acts on the peripheral walls 61, 161, 65, 68.

A pair of cover-side oil passages Pa and Pb provided in the chain cover 40 will be described with reference to FIGS. 2 to 4, 6 to 11, and 14 to 17.
2-4, in each bank part 40a, 40b, each cover side oil path Pa, Pb is the first main body side oil path Pi provided in the cylinder block 1 (see FIG. 1), and the cylinder head 2. , 102 is an oil passage that communicates with the second main body side oil passage Po, and communicates with the main body side oil passage Po and inlets 72a and 172a that are first openings that communicate with the main body side oil passage Pi. The oil passages Pa and Pb have substantially the same structure. The outlets 82a and 182a are the second openings.

Each of the oil passages Pa and Pb includes a first oil passage Pa1 and Pb1 having inlets 72a and 172a, and a second oil passage Pa2 and Pb2 having outlets 82a and 182a. The first oil passages Pa1, Pb1 and the second oil passages Pa2, Pb2 intersect and communicate with each other at the intersections Pac, Pbc. Therefore, the oil discharged from the oil pump 7 flows into the first oil passages Pa1, Pb1 from the main body side oil passage Pi as the working oil, and then flows through the second oil passages Pa2, Pb2 to the main body from the outlets 82a, 182a. The oil flows into the side oil passage Po, is controlled by the hydraulic control valve 16, and is supplied to the valve lift amount control mechanism.
The first oil passages Pa1 and Pb1 are inclined upward from the positions near the inlets 72a and 172a, and the second oil passages Pa2 and Pb2 are inclined upward from the positions near the outlets 82a and 182a toward the intersections Pac and Pac, respectively. ing. The intersecting portions Pac and Pbc are located in the vicinity of the uppermost portion in the oil passages Pa and Pb.
In FIGS. 6 to 11, the oil flow direction is indicated by white arrows.

  Referring to FIGS. 2 to 4, 6, and 8, each first oil passage Pa <b> 1, Pb <b> 1 has first opening end portions 71 a, 171 a that are one end portion that opens to the outer surface 42 of the wall portion 50, and an outer edge portion 43. Are formed by first holes 70 and 170 having inlets 72a and 172a as second opening end portions which are the other end portions opened to the contact surfaces 77a and 177a which are the inner surfaces 41 of the side portions. Specifically, each of the first holes 70 and 170 is a straight line having first open end portions 71a and 171a as first end portions and closed first closed end portions 71b and 171b as first other end portions. Linear second hole 72 having first holes 71 and 171 having a shape, inlets 72a and 172a as second ends, and closed second closed ends 72b and 172b as second other ends. , 172.

In each of the first holes 70, 170, the first hole portions 71, 171 and the second hole portions 72, 172 intersect at or near the first and second closed end portions 71b, 72b; 171b, 172b. Communicate. The first hole portions 71 and 171 gradually approach the mating surface 45b or the contact surfaces 77a and 177a in the axial direction A from the first opening end portions 71a and 171a toward the first closed end portions 71b and 171b. (I.e., from the outer surface 42 toward the inner surface 41) and a hole inclined downward.
The second holes 72 and 172 are holes that are parallel to the axial direction A and orthogonal to the contact surfaces 77a and 177a.

In addition, referring to FIGS. 14 to 17, in the first bank portion 40 a, the first hole portion 71 extending over the low wall portion 53 a, the first high wall portion 53 b, and the outer edge portion 43 has a low wall portion. 53a and the first high wall portion 53b to the outer raised portion 75 that protrudes outward on the outer surface 42, and the inner wall raised portion 76 that protrudes inward on the inner wall surface 41c in the first high wall portion 53b. The first cover side abutting portion 77, which is an outer protruding portion that protrudes outward on the outer surface 42 at the outer edge portion 43, is provided. On the other hand, the second hole 72 is provided in the contact portion 77.
In the second bank portion 40b, the first hole portion 171 extending across the second high wall portion 53c, the first high wall portion 53b, and the outer edge portion 43 has the second high wall portion 53c and the first high wall portion. An inner bulge projecting inwardly on the inner wall surface 41c across the second high wall portion 53c and the first high wall portion 53b on the outer bulge portion 175 projecting outward on the outer surface 42 over the portion 53b The first cover side abutting portion 177, which is an outer raised portion that protrudes outward on the outer surface 42 at the outer edge portion 43, is provided on the portion 176, respectively. On the other hand, the second hole portion 172 is provided in the first cover side contact portion 177.
In addition, it protrudes in the inside means that it protrudes in the direction approaching the mating surface 45b, the end 1e or the ends 2e, 102e (see FIGS. 7 and 9) in the axial direction A, The bulging outward means that in the axial direction A, the bulging is in a direction away from the mating surface 45b, the end 1e, or the ends 2e and 102e (see FIGS. 7 and 9).

Therefore, the outer raised portion 75, the inner raised portion 76, and the contact portion 77 constitute a passage wall Wa1 of the first oil passage Pa1, and the outer raised portion 175, the inner raised portion 176, and the first cover side contact portion 177. Constitutes the passage wall Wb1 of the first oil passage Pb1.
As shown in FIGS. 1, 3 and 4, the first oil passages Pa1 and Pb1 are transverse oil passages that cross the chains 23 and 123 at the transverse positions Ca1 and Cb1 when viewed in the axial direction A. In the passage walls Wa1 and Wb1 forming the first oil passages Pa1 and Pb1, the outer raised portions 75 and 175 are raised only on the outer surface 42 at the transverse positions Ca1 and Cb1, and the inner raised portions 76 and 176 are in the axial direction. As viewed from A, only or most of the inner wall surface 41c is raised on the inner wall surface 41c outside the chains 23 and 123.

3 to 6 and FIG. 8, the inlets 72a and 172a of the cover-side oil passages Pa and Pb are located on the outer peripheral side of the mating surface 45b in the outer edge portion 43, and protrude in the lateral direction from the mating portion 44b. The main body side oil passage Pi is provided in the first main body side contact portions 9m and 9n provided in the contact portions 77 and 177 protruding into the bank space 8 and provided in the cylinder block 1 and opening the main body side oil passage Pi. Communicate with.
The first cover side contact portions 77, 177 are contact surfaces 77a, 177a that contact the main body side contact portions 9m, 9n, and coupling boss portions 77b, which are coupled to the contact portions 9m, 9n. 177b, and the joint bosses 77b and 177b are fastened to the contact portions 9m and 9n by a bolt B5 (see FIG. 1) as a coupler. For this reason, the first oil passages Pa1, Pb1 and the main body side oil passage Pi communicate with each other in a state where the contact portions 77, 177 and the contact portions 9m, 9n are in contact in a direction parallel to the axial direction A.

  An O-ring G, which is an annular seal member, is provided between the contact surfaces 77a and 177a and the contact portions 9m and 9n so as to surround the inlets 72a and 172a and the oil passage Pi. The abutting surfaces 77a, 177a and the abutting portions 9m, 9n are in contact with the abutting surfaces 77a, 177a by the O-ring G that is crushed by the abutting surfaces 77a, 177a and the abutting portions 9m, 9n. Oil leakage from between the contact portions 9m and 9n is prevented. The O-ring G is mounted in annular mounting grooves 77c and 177c provided on the contact surfaces 77a and 177a.

  Referring to FIGS. 2 to 4, 7, 9 to 11, and 14 to 17, the second oil passages Pa <b> 2 and Pb <b> 2 are first opening ends that are one end portions that open to the outer surface 42 of the wall portion 50. The second holes 80 and 180 have the portions 81a and 181a and the outlets 82a and 182a as the second opening end portions which are the other end portions opened to the contact surfaces 87a and 187a which are the inner surfaces 41. Specifically, the second holes 80 and 180 are linear with first open end portions 81a and 181a as first end portions and closed first closed end portions 81b and 181b as first other end portions. Linear second hole portion 82 having outlets 82a and 182a as second end portions and closed second closed end portions 82b and 182b as second other end portions, 182.

In each of the second holes 80 and 180, the first hole portions 81 and 181 and the second hole portions 82 and 182 intersect at or near the first and second closed end portions 81b and 82b; 181b and 182b. Communicate. The first holes 81 and 181 gradually approach the mating surface 45b or the contact surfaces 87a and 187a in the axial direction A from the first opening end portions 81a and 181a toward the first closed end portions 81b and 181b. (I.e., from the outer surface 42 toward the inner surface 41) and a hole inclined downward.
The second holes 82 and 182 are holes parallel to the axial direction A and orthogonal to the contact surfaces 87a and 187a.

In the first bank portion 40a, the first hole 81 extending across the first high wall portion 53b and the low wall portion 53a is outside on the outer surface 42 across the first high wall portion 53b and the low wall portion 53a. The inner wall 86 c bulging inward on the inner wall 41 c in the lower wall 53 a, and the inner wall 86 c bulging inward on the inner wall 41 c in the lower wall 53 a The second cover side abutting portion 87 which is the inner raised portion is provided respectively. On the other hand, the second hole portion 82 is provided in the contact portion 87.
Further, in the second bank portion 40b, the first hole portion 181 extending over the second high wall portion 53c and the first high wall portion 53b extends over the second high wall portion 53c and the first high wall portion 53b. The outer raised portion 185 that protrudes outward on the outer surface 42, the inner raised portion 186 that protrudes inward on the inner wall surface 41 c in the first high wall portion 53 b, and the inner wall surface in the first high wall portion 53 b The second cover side abutting portion 187 is an inner raised portion that is raised in a columnar shape on the inside on 41c. On the other hand, the second hole portion 182 is provided in the contact portion 187.

Therefore, the outer raised portion 85, the inner raised portion 86, and the cylindrical abutting portion 87 constitute the passage wall Wa2 of the second oil passage Pa2, and the outer raised portion 185, the inner raised portion 186, and the cylindrical abutting portion. The part 187 constitutes the passage wall Wb2 of the second oil passage Pb2.
As shown in FIGS. 1, 3, and 4, the second oil passages Pa2 and Pb2 are transverse oil passages that cross the chains 23 and 123 at the transverse positions Ca2 and Cb2 when viewed in the axial direction A. In the passage walls Wa2 and Wb2 forming the second oil passages Pa2 and Pb2, the outer raised portions 85 and 185 are raised only on the outer surface 42 in the transverse position, and the inner raised portions 86 and 186 are seen from the axial direction A. Thus, the inner wall 41c is raised on the inner side of the chains 23 and 123.

3, 4, 7, and 9 to 11, the outlets 82 a and 182 a of the cover side oil passages Pa and Pb are provided at the contact portions 87 and 187, and are provided at the cylinder head 2 and 102. The main body side oil passage Po communicates with the oil passage Po at the second main body side contact portions 9s, 9t.
The second cover side contact portions 87 and 187 have contact surfaces 87a and 187a that contact the main body side contact portions 9s and 9t. For this reason, the cover side oil passages Pa and Pb and the main body side oil passage Po communicate with each other in a state in which the contact portions 77 and 177 and the contact portions 9s and 9t are in contact in a direction parallel to the axial direction A.

  An O-ring G is provided between the contact surfaces 87a and 187a and the main body side contact portions 9s and 9t so as to surround the outlets 82a and 182a and the main body side oil passage Po. The contact surface 87a is formed by the O-ring G that is crushed by the contact surfaces 87a and 187a and the main body side contact portions 9s and 9t in a state where the contact surfaces 87a and 187a and the main body side contact portions 9s and 9t are in contact. , 187a and the second main body side contact portions 9s, 9t are prevented from leaking oil. The O-ring G is mounted in annular mounting grooves 87c and 187c provided on the contact surfaces 87a and 187a.

3 to 7 and FIG. 9, the first hole portions 71 and 81 and the first and second oil passages Pa1 and Pa2 formed in the first bank portion 40a are first viewed from the axial direction A. It intersects with a step portion 55a formed by the high wall portion 53b, the step portion 51 and the low wall portion 53a. The outer raised portions 75 and 85 are integrally formed by integral molding across the first high wall portion 53b, the step portion 51, and the low wall portion 53a, and intersect the step portion 55a.
Similarly, the first hole portion 181 and the oil passage Pb2 formed in the second bank portion 40b are formed by the second high wall portion 53c, the step portion 52, and the first high wall portion 53b when viewed from the axial direction A. Intersects with the stepped portion 55b. The outer raised portion 185 is integrally formed across the second high wall portion 53c, the step portion 52, and the first high wall portion 53b, and intersects the step portion 55b.

Referring to FIGS. 6, 7, and 14, the first opening end 71 a formed by the first end wall 75 a that is a part of the outer protruding portion 75 in the low wall portion 53 a in the first hole 70, and the first In the two holes 80, the first opening end portion 81a formed by the second end wall 85a which is a part of the outer raised portion 85 in the first high wall portion 53b is an end portion from the first opening end portions 71a and 81a. The walls 75a and 85a are oil-tightly closed by plugs 78 and 88 serving as closing members inserted into the first holes 71 and 81, respectively. Therefore, the first hole 71 and the first hole 81 are closed by the plug 78 and the plug 88, respectively.
Referring to FIGS. 8, 9 and 16, a first opening end 171a formed by a first end wall 175a which is a part of the outer raised portion 175 in the second high wall portion 53c in the first hole 170, In the second hole 180, the first opening end 181a formed by the second end wall 185a which is a part of the outer raised portion 185 in the second high wall portion 53c is separated from the first opening end portions 81a and 181a. The end walls 85a and 185a are oil-tightly closed by plugs 178 and 188 respectively inserted into the first holes 171 and 181 of the end walls 85a and 185a. The first hole 171 and the first hole 181 are closed by a plug 178 and a plug 188, respectively.
In this embodiment, the plugs 78, 88, 178, 188 are threaded and screwed into the first holes 71, 81, 171, 181 at the end walls 75 a, 175 a, 85 a, 185 a. As another example, the closing member may be a plug that is press-fitted into the first holes 71, 81, 171 and 181 at the end walls 75a, 175a, 85a and 185a.

  The end walls 75a, 175a as the first raised portions and the end walls 85a, 185a as the second raised portions are thick portions having a large wall thickness in the passage walls Wa1, Wb1, Wa2, Wb2, and The first hole portions 71, 171 are formed so as to protrude only on the outer surface 42 of the inner surface 41 and the outer surface 42 of the chain cover 40 and include the first opening end portions 71a, 171a, 81a, 181a in the axial direction A. , 81, 181 and the outer surface 42 are continuous raised portions so that no gap is formed. The end walls 75a, 175a, 85a, and 185a are enhanced in rigidity by plugs 78, 178, 88, and 188 inserted into the first opening end portions 71a, 171a, 81a, and 181a.

  Further, the first hole portions 71, 171, 81, and 181 of the first and second oil passages Pa1, Pb1, Pa2, and Pb2 are respectively connected to the outer raised portions 75, 175, 85, and 185 with a drill as a processing tool. It is formed toward the contact portions 77, 177, 87, and 187 as a starting portion for forming an oil passage by machining. Further, the second hole portions 72, 172, 82, 182 of the first and second oil passages Pa1, Pb1, Pa2, Pb2 are respectively in contact surfaces 77a, 177a of the cover side contact portions 77, 177, 87, 187. , 87a, and 187a are formed as oil passage formation start sites with a drill.

3, 4, 10, and 11, in the first bank portion 40 a, the contact surface 87 a of the contact portion 87, the outlet 82 a, the outer raised portion 85, and the inner raised portion 86 are in the vicinity of the peripheral wall 61. Located in. Here, the vicinity of the peripheral wall 61 means that the vibration of the contact portion 87 provided integrally with the low wall portion 53a is suppressed by the rigidity of the peripheral wall 61 coupled to the cylinder head 2 by the bolt B3 (see FIG. 1). It is a range. The range is, for example, a range in which the distance between the contact surface 87a and the peripheral wall 61 or the mating surface 63 is smaller than the maximum outer diameter d1 of the contact surface 87a. In this range, the contact surface 87a, the outlet 82a, At least a portion of each of the outer ridge 85 and the inner ridge 86 is located.
Similarly, in the first bank portion 40a, the contact surface 187a of the contact portion 187, the outlet 182a, the outer raised portion 185, and the inner raised portion 186 are located in the vicinity of the peripheral wall 161. Here, the vicinity of the peripheral wall 61 means that the vibration of the contact portion 187 provided integrally with the first high wall portion 53b is suppressed by the rigidity of the peripheral wall 161 connected to the cylinder head 102 by the bolt B3 (see FIG. 1). It is a range. The range is, for example, a range in which the distance between the contact surface 187a and the peripheral wall 161 or the mating surface 163 is smaller than the maximum outer diameter d2 of the contact surface 187a. In this range, the contact surface 187a, the outlet 182a, At least a portion of each of the outer ridge 185 and the inner ridge 186 is located.

  Further, the outer raised portions 85 and 185 and the inner raised portions 86 and 186 of the passage walls Wa2 and Wb2 extend along the portions 61a and 161a extending linearly on the peripheral walls 61 and 161, and the outer raised portions 85 and The inner raised portion 86 is connected to the contact portion 87, and the inner raised portion 186 is connected to the contact portion 187. Further, the outer raised portions 85 and 185 and the inner raised portion 186 are in a range over the majority of the length of the portion 61a and the portion 161a, respectively.

In the peripheral wall 61, the portion closest to the outlet 82 a of the contact portion 87 is a boss portion 62 </ b> B that is a specific boss portion of the plurality of boss portions 62. The low wall portion 53a includes two ribs 56a and 56b that connect the contact portion 87 and the peripheral wall 61. The rib 56a is connected to the boss portion 62B, and the rib 56b is connected to the boss portion 62 adjacent to the boss portion 62B in the direction along the peripheral wall 61.
In the second bank portion 40b, the first high wall portion 53b has a 56c that connects the contact portion 187 and the peripheral wall 161. The rib 56c is connected to the peripheral wall 161 between two boss portions 62 adjacent in the direction along the peripheral wall 161.

Furthermore, as shown in FIG. 4, a large number of ribs 58 a, 58 b, 58 c are provided so as to protrude on the inner wall surface 41 c of the chain cover 40. A large number of coupling boss portions 46b of the outer edge portion 43 and the contact portions 87 and 187 are connected by a plurality of radial ribs 58a. Similarly, the coupling boss portion 46b and the inner raised portions 86, 186 are connected by a plurality of radial ribs 58b, and the coupling boss portions 46b, and the coupling boss portion 46b and the peripheral walls 61, 161 are a plurality of ribs 58c. It is connected by.
In the first bank portion 40a, the ribs 58a and 58b extend over the low wall portion 53a, the stepped portion 51 and the first high wall portion 53b. In the second bank portion 40b, the ribs 58a and 58b are the first It extends over the high wall portion 53b, the step portion 52, and the second high wall portion 53c, and intersects with the step portions 55a and 55b, respectively. The ribs 58a and 58b suppress bending vibration that vibrates so that the wall portion 50 is bent around the step portions 51 and 52.

Referring to FIG. 3 and FIG. 6 to FIG. 9, the intersections Pac and Pbc of the first and second oil passages Pa1 and Pa2; Pb1 and Pb2 are crossed by the outer bulges 75 and 85; The intersection wall portions Wac and Wbc (see also FIGS. 14 and 16) are formed. And it protrudes only in the outer surface 42 in both outer side protruding parts 75,85; 175,185 (or it is rather than the plane part of the low wall part 53a and the 1st, 2nd high wall parts 53b, 53c in the axial direction A. The intersecting portions P1c and P2c located at the portion protruding outward are located in the vicinity of the first opening end portions 71a, 81a; 171a, 181a of the first and second holes 70, 80;
More specifically, the intersections Pac and Pbc are closer to the first opening end portions 71a and 171a than the inlets 72a and 172a in the first holes 70 and 170, and from the outlets 82a and 182a in the second holes 80 and 180. Is also located closer to the first opening end portions 81a and 181a. Therefore, the intersecting portions Pac and Pbc are closer to the first opening end portions 71a and 171a than the first closed end portions 71b and 171b in the first hole portions 71 and 171 of the first holes 70 and 170, and the second holes The first hole portions 81 and 181 of 80 and 180 are closer to the first opening end portions 81a and 181a than the first closed end portions 81b and 181b, that is, the lengths of the first hole portions 71, 171, 81 and 181 are longer. It is located closer to the first opening ends 71a, 171a, 81a, 181a than the central position, which is a half position. Preferably, the intersecting portions Pac and Pbc are located closer to the first opening end portions 71a, 171a, 81a, and 181a within the range of 1/4 of the length of each of the first hole portions 71, 171, 81, and 181. Or at least part of the intersecting portions Pac and Pbc are separated from the first opening end portions 71a, 171a, 81a, and 181a along the first hole portions 71, 171, 81, and 181 by the first hole portion 71. , 171, 81, 181 are within the range of three times the hole diameter. In this embodiment, the diameter of the holes is the same in the first holes 71, 171, 81, 181.

1 to 3, 6 to 9, 14, and 16, the pair of mounting seats 91 and 92 are integrally formed on the pair of intersecting wall portions Wac and Wbc, respectively. . The mounting seats 91 and 92, to which the engine hanger 93, which is a support member that supports the internal combustion engine E, is fixed to the frame constituting the vehicle body, are protruding portions that protrude in the axial direction A from the intersecting wall portions Wac and Wbc. The engine hanger 93 is detachably attached to the attachment seats 91 and 92 by bolts B6 (see FIG. 1) screwed into the attachment seats 91 and 92.
Further, the mounting seats 91 and 92 have end walls 75a and 175a forming the first opening ends 71a and 171a of the first holes 70 and 170 and first opening ends 81a and 181a of the second holes 80 and 180, respectively. It is provided integrally over the end walls 85a and 185a to be formed.

Next, operations and effects of the embodiment configured as described above will be described.
The ends 1e, 2e, 102e, 3e, 5e of the engine body Ea are covered from the lower part 1c of the cylinder block 1 to the cylinder heads 2, 102 from the axial direction A of the crankshaft 6, and the ends 1e, 2e, 102e, 3e. , 5e and the wall portion 50 of the chain cover 40 that forms the chain chamber 25 in the first bank portion 40a and the low wall portion 53a facing the end portions 1e, 2e in the axial direction A and the axial direction A Are opposed to the end portions 1e and 2e and are spaced apart from the end portions 1e and 2e in the axial direction A with respect to the lower wall portion 53a, and are stepped from the lower wall portion 53a via the stepped portion 51 in the axial direction A. The first high wall portion 53b covers the end portions 1e and 2e from the lower portion 1c to the cylinder head 2, and blow-by gas in the crank chamber to the valve operating chamber. A leading breather passage 54 is formed. With this structure, the wall portion 50 that covers the ends 1e and 2e from the axial direction A and forms the chain chamber 25 is lower than the low wall portion 53a via the low wall portion 53a and the step portion 51 in the axial direction A. A first high wall portion 53b that is spaced apart from the end portions 1e and 2e in the axial direction A, and in the chain chamber 25 by a first high wall portion 53b that locally protrudes outward in the axial direction A at the wall portion 50. A protruding space 25a that protrudes outward in the axial direction is formed locally, and a breather passage 54 having an increased axial width is formed by the protruding space 25a. As a result, the blow-by gas smoothly flows in the breather passage 54 formed by expanding the chain chamber 25 in the axial direction A, so that the blow-by gas is smoothly guided to the valve operating chamber in the chain chamber 25. Can do.
Moreover, the low wall portion 53a, which is a portion of the wall portion 50 other than the first high wall portion 53b forming the breather passage 54, is positioned closer to the end portions 1e and 2e in the axial direction A than the first high wall portion 53b. Therefore, the chain cover 40 can be downsized in the axial direction A by the low wall portion 53a.
Further, the wall portion 50 is formed with a step portion 55a composed of the low wall portion 53a, the step portion 51, and the first high wall portion 53b in the first bank portion 40a, so that the wall portion is formed by the step portion 55a. The rigidity of 50 is increased, and the film surface vibration of the wall 50 caused by the vibration of the internal combustion engine E is suppressed.

  In the first bank portion 40a, the first high wall portion 53b is adjacent to the side edge portion 43i that is a portion of the outer edge portion 43 and is formed along the side edge portion 43i, so that the breather passage 54 is formed on the side edge portion. Since the blow-by gas flows in the breather passage 54 while being prevented from being disturbed by the side edge 43i, the blow-by gas is disposed in the chain chamber 25 such as the chain 23 of the transmission mechanism T1. Therefore, the blow-by gas in the breather passage 54 is not disturbed by the member moving in the chain chamber 25, so that the blow-by gas is prevented from diffusing from the breather passage 54 in the chain 25, and the blow-by gas is It can be smoothly led to the valve chamber.

  The internal combustion engine E includes a pair of banks b1 and b2, an intake manifold Na disposed inside the pair of banks b1 and b2, and an exhaust manifold Ha disposed outside the pair of banks b1 and b2. The first high wall portion 53b in the first bank portion 40a is located closer to the inner side of the pair of banks b1 and b2, that is, closer to the bank space 8, in the first bank portion 40a. In the first bank portion b1, the cylinder head 2 has an intake manifold Na on one side in the lateral direction and an exhaust manifold Ha on the other side in the lateral direction across the cylinder axis Ly as viewed from the axial direction A. The first high wall portion 53b is positioned closer to the intake manifold Na in the wall portion 50, so that the breather passage 54 is connected to the exhaust manifold in the first bank portion 40a of the chain cover 40. Since it is formed at a position closer to the distance from the door Ha, the flow of heat is prevented from being disturbed by the high heat of the exhaust manifold Ha, and the blowby gas can be smoothly guided to the valve operating chamber.

  In the first bank portion 40a, the low wall portion 53a forms a window portion 60 that opens to the low wall portion 53a and has a peripheral wall 61 that is coupled to the end portion 2e. Is tightened to the end 2e by a bolt B3 inserted into the boss portion 62, the rigidity of the low wall portion 53a is increased, and membrane vibration at the low wall portion 53a is suppressed. The Further, since the peripheral wall 61 is provided in the low wall portion 53a that is closer to the end portion 2e in the axial direction A than the first high wall portion 53b, the peripheral wall that forms a window portion in the first high wall portion 53b. Since the height in the axial direction A of the peripheral wall 61 can be reduced as compared with the case where is provided, the chain cover 40 having the peripheral wall 61 can be reduced in weight.

  In the first bank portion 40a, the first high wall portion 53b has a ridge 59 formed on the inner wall surface 41c facing the end portion 1e in the axial direction A, and the ridge 59 is viewed from the axial direction A. A weir extending in a direction intersecting the cylinder axis direction and crossing the breather passage 54 is formed, and the step portion 51 and the outer edge portion 43 are connected. With this structure, the ridge 59 constitutes a weir that crosses the breather passage 54 extending in the cylinder axial direction from the lower portion 1 c to the cylinder head 2, and therefore blow-by gas collides with the ridge 59 to cause blow-by. Since the oil mixed in the gas adheres to the protrusion 59 and is separated, the oil in the blow-by gas flowing through the breather passage 54 can be reduced. Further, since the protrusion 59 connects the outer edge portion 43 and the step portion 51, the rigidity of the first high wall portion 53b and the step portion 51 is enhanced by the protrusion 59, and the vibration of the wall portion 50 is suppressed. The

  A winding transmission mechanism T3 including a tensioner 36 that applies tension to the belt 35 is disposed in the outer space opposite to the chain chamber 25 across the wall 50 in the axial direction A, and the low wall 53a in the axial direction A is disposed. The support arm 36b of the tensioner 36 is disposed on the opposite side of the end 1e with the stepped portion interposed therebetween, and the step portion 51 is formed outside the swinging range of the support arm 36b. Since the support arm 36b is disposed using the space in the axial direction formed by the low wall portion 53a that is a portion close to the portion 1e, the tensioner 36 is disposed at a position close to the end portion 1e in the axial direction A. Therefore, the transmission mechanism T3 including the tensioner 36 can be arranged in the axial direction A in a compact manner.

  The passage walls Wa1 and Wa2 forming the first oil passages Pa1 and Pa22 are provided integrally with the step portion 51, and the passage walls Wa1 and Wa2 are provided integrally over the low wall portion 53a and the first high wall portion 53b. Accordingly, the passage wall Wb2 forming the second oil passage Pb2 is provided integrally with the step portion 52, and the passage wall Wb2 is provided integrally over the first high wall portion 53b and the second high wall portion 53c. As a result, the passage walls Wa1, Wa2, Wb2 forming the first oil passage Pa1, Pa2 or the second oil passage Pb2 intersect with the step portions 55a, 55b and are provided integrally with the step portions 55a, 55b. As a result, using the passage walls Wa1, Wa2, Wb2 forming the first oil passages Pa1, Pa2 or the second oil passage Pb2 provided in the chain cover 40, the direction crossing the step portions 51, 52 (or the intersecting direction). ), The rigidity of the wall portion 50, that is, the rigidity at the step portions 55a and 55b, is increased, so that the wall portion 50 is bent around the step portions 51 and 52 due to the step portions 51 and 52. Bending vibration can be suppressed.

  Located on the inner peripheral side of the outer edge portion 43 having a plurality of coupling boss portions 46a, 46b coupled to the end portions 1e, 2e, 102e, 3e, 4e, 5e of the engine body Ea and the end portions 1e, 2e, 102e, In the chain cover 40 provided with cover side oil passages Pa, Pb communicating with the main body side oil passage Po in the wall portion 50 forming the chain chamber 25 in cooperation with 3e, 4e, 5e, An annular peripheral wall 61, 161 that forms a window portion 60, 160 for placement or insertion of the control valves 14, 15 and is coupled to the cylinder head 2, 102, and a main body side contact that opens the main body side oil passage Po Cover side abutting portions 87 and 187 abutting against the portions 9s and 9t, and outlets 82a and 182a of the cover side oil passages Pa and Pb open to the abutting portions 87 and 187, and the main body side abutting portion 9s. , 9t communicates with the main body side oil passage Po and is located in the vicinity of the peripheral walls 61, 161. With this structure, the cover-side contact portions 87 and 187 where the outlets 82a and 182a, which are the openings of the cover-side oil passages Pa and Pb, are opened. Since the peripheral walls 61 and 161 that are connected to the cylinder head 2 and 102 are positioned in the vicinity of the peripheral walls 61 and 161 that form the window portions 60 and 160 provided on the cover, the rigidity of the cover-side contact portions 87 and 187 is enhanced. Moreover, since the window portions 60 and 160 forming the peripheral walls 61 and 161 are portions for forming a space in which the hydraulic control valves 14 and 15 are disposed or inserted, the peripheral walls 61 and 161 are provided with the internal combustion engine E. Since a large load due to vibration or the like hardly acts, there is no need to increase the rigidity of the peripheral walls 61 and 161 in order to suppress the vibration of the cover side contact portions 87 and 187 due to the load. As a result, the sealing performance between the cover side contact portions 87 and 187 and the body side contact portions 9s and 9t where the cover side oil passages Pa and Pb and the main body side oil passage Po communicate with each other is improved. The effect of preventing oil leakage from between the abutting portions 9s and 9t due to the vibration of the oil is improved. In addition, since it is not necessary to increase the rigidity of the peripheral walls 61 and 161 in order to suppress the vibration of the peripheral walls 61 and 161 themselves, the chain cover 40 having the peripheral walls 61 and 161 is reduced in size and weight.

  The peripheral wall 61 is coupled to the cylinder head 2 at a plurality of boss portions 62, and the specific boss portion 62B of the plurality of boss portions 62 is a portion closest to the outlet 82a in the peripheral wall 61. Since the wall thickness is increased and the cylinder head 2 is coupled, the specific boss portion 62B, which is one of the boss portions 62 that are high rigidity portions in the peripheral wall 61, is located closest to the outlet 82a. Therefore, the rigidity of the cover side contact portion 87 is further enhanced by the peripheral wall 61, and the sealing performance between the contact portion 87 and the main body side contact portions 9s, 9t is improved.

  The wall portion 50 has ribs 56a, 56b, and 56c. The ribs 56a and 56b connect the cover side contact portion 87 and the peripheral wall 61, and the rib 56c connects the cover side contact portion 187 and the peripheral wall 161. In other words, the ribs 56a and 56b connect the contact portion 87 and the boss portions 62B and 62, whereby the rigidity of the contact portion 87 is enhanced by the ribs 56a and 56b, and the rigidity of the contact portion 187 is increased by the rib 56c. As a result, the sealing performance between the contact portions 87 and 187 and the contact portions 9s and 9t is improved.

  The wall portion 50 includes a plurality of radial ribs 58a that respectively connect the plurality of coupling boss portions 46b of the outer edge portion 43 and the contact portions 87, 187, thereby providing the contact portions 87, 187 and the plurality of coupling boss portions 46b at the outer edge portion 43 are connected by the radial ribs 56a, so that the membrane vibration of the chain cover 40 is suppressed by the ribs 56a and the rigidity of the contact portions 87 and 187 is increased. As a result, the sealing performance between the contact portions 87 and 187 and the contact portions 9s and 9t is improved.

  The wall portion 50 has raised portions 85, 86, 186 extending along the peripheral walls 61, 161 and connected to the contact portions 87, 187, and the oil passage Pa2 or the oil passage Pb2 is the raised portions 85, 86, 186. The raised portions 85, 86 and 186, which are also the passage walls Wa2 and Wb2 forming the oil passages Pa2 and Pb2, are connected to the contact portions 87 and 187, and the raised portions 85, 86 and 186 are connected to the peripheral wall. Since it extends along 61, 161, the abutment portion 87 to which the raised portions 85, 86, 186 are connected is efficiently utilized by utilizing the rigidity of the peripheral walls 61, 161 connected to the cylinder head 2,102. , 187 can be suppressed, and the sealing performance between the contact portions 87, 187 and the contact portions 9s, 9t is improved.

  A first wall that intersects with each other at intersections Pac and Pbc at a wall 50 that is located on the inner peripheral side of the outer edge 43 having a plurality of coupling bosses 46a and 46b coupled to the engine body Ea and that forms the chain chamber 25. In the chain cover 40 provided with the cover side oil passages Pa and Pb constituted by the oil passages Pa1 and Pb1 and the second oil passages Pa2 and Pb2, the surface of the chain cover 40 faces the chain chamber 25 or the engine body Ea. The first oil passages Pa1 and Pb1 are formed from an inner surface 41 and an outer surface 42 facing the outer space opposite to the chain chamber 25 with the wall portion 50 as a boundary. 71a, 171a and first holes 70, 170 having inlets 72a, 172a which are second opening end portions opened to the contact surfaces 77a, 177a of the cover side contact portions 77, 177, and a second oil passage. Pa2 and Pb2 correspond to the contact between the first opening end portions 81a and 181a opened on the outer surface 42 and the cover side contact portions 87 and 187, respectively. It is constituted by second holes 80 and 180 having outlets 82a and 182a which are second opening ends opened to the contact surfaces 87a and 187a. The intersecting portions Pac and Pbc are inlets 72a and 172a at the first holes 70 and 170, respectively. The first opening end portions 71a and 171a and the second holes 80 and 180 are positioned closer to the first opening end portions 81a and 181a than the outlets 82a and 182a. With this structure, the intersecting portions Pac and Pbc are formed on the outer surface 42 of the chain cover 40 in the first and second holes 70, 80; 170 and 180 constituting the first and second oil passages Pa1 and Pa2; Pb2 and Pb2, respectively. Since the first opening end portions 71a, 81a; 171a, 181a are opened, the first and second holes 70, 80; 170, 180 are formed to form the first opening end portions 71a, 81a; 171a, 181a. Therefore, the formation accuracy of the intersections Pac and Pbc can be increased. Further, the first and second holes 70, 170; 80, 180 are holes in which the first opening end portions 71a, 171a; 81a, 181a and the inlets 72a, 172a or the outlets 82a, 182a are opened. , Second holes 70, 80; the first and second holes 70, 80 even when the inlets 72a and 82a, and the inlets 172a and 182a, which are the second opening ends of the 170, 180, are separated from each other. 170, 180 first opening end portions 71a, 81a; 171a, 181a are arranged close to each other, so that the formation accuracy of the intersecting portions P1c, P2c can be increased. As a result, the degree of freedom of the formation positions of the first and second oil passages Pa1, Pa2; Pb1; Pb2 and the formation positions of the intersections Pac, Pbc can be increased while increasing the formation accuracy of the intersections Pac, Pbc. .

  The first holes 70 and 170 include first hole portions 71 and 171 having first opening end portions 71a and 171a, and second hole portions 72 and 172a that intersect with the first hole portions 71 and 171 and have inlets 72a and 172a. 172, and the second holes 80 and 180 intersect with the first holes 81 and 181 having the first opening ends 81a and 181a, and the outlets 82a and 182a. The first holes 71 and 171 of the first holes 70 and 170 and the first holes 81 and 181 of the second holes 80 and 180 intersect at the intersecting parts Pac and Pbc. The intersecting portions Pac and Pbc communicate the first oil passages Pa1 and Pb1 and the second oil passages Pa2 and Pb2, and the other ends of the first holes 70 and 170 are inlets 72a and 172a, The other ends of the second holes 80 and 180 are outlets 82a and 182a. With this structure, the first oil passages Pa1, Pb1 communicating with the main body side oil passage Pi at the inlets 72a, 172a and the second oil communicating with the main body side oil passage Po at the outlets 82a, 182a are communicated at the intersections Pac, Pbc. In the cover side oil passages Pa and Pb constituted by the passages Pa2 and Pb2, the formation positions of the first and second oil passages Pa1 and Pa2; Pb1 and Pb2 and the intersection portion Pac are improved while increasing the formation accuracy of the intersections Pac and Pbc. , Pbc formation position can be increased.

  The first opening ends 71a, 171a of the first holes 70, 170 and the first opening ends 81a, 181a of the second holes 80, 180 are only on the outer surface 42 of the inner surface 41 and the outer surface 42 in the wall 50. The first end walls 75a and 175a that are the first bulging portions and the second end walls 85a and 185a that are the second bulging portions are respectively provided, and the intersecting portions Pac and Pbc are provided at both end walls 75a and 85a; The end walls 75a, 175a, 85a, and 185a provided with the first opening end portions 71a, 171a, 81a, and 181a are formed by the crossing wall portions Wac and Wbc at which the 175a and 185a intersect. Since the intersecting wall portions Wac and Wbc that protrude only on the outer surface 42 of the inner surface 41 and the outer surface 42 and that form the intersecting portions Pac and Pbc are formed by the both end walls 75a and 85a; 175a and 185a, the chain The rigidity of the cover 40 is increased, and the vibration of the chain cover 40 can be reduced. Further, in the wall portion 50 located on the inner peripheral side of the outer edge portion 43, first and second end portions provided with both first opening end portions 71a, 171a, 81a, 181a located at positions close to the intersecting portions Pac, Pbc. Since the walls 75a, 175a, 85a and 185a are raised only on the outer surface 42, the first and second holes 80 and 180 provided in the wall 50 can be easily formed.

  The mounting seats 91 and 92 are provided integrally with the intersecting wall portions Wac and Wbc, so that the mounting seats 91 and 92 are raised only on the outer surface 42 and the first and second end walls 75a, 175a and 85a. , 185a is provided in the crossing wall portions Wac and Wbc having high rigidity, the engine hanger 93 can be firmly attached to the mounting seats 91 and 92.

  The first holes 70 and 170 are closed by plugs 78 and 178 inserted from the first opening ends 71a and 171a into the first end walls 75a and 175a, and the second holes 80 and 180 are closed by the first opening ends 81a and It is closed by plugs 88 and 188 inserted into the second end walls 85a and 185a from 181a, and the mounting seats 91 and 92 are integrated over the first end walls 75a and 175a and the second end walls 85a and 185a. Are provided in the first and second end walls 75a, 175a, 85a, which form the first open end portions 71a, 171a, 81a, 181a of the first and second holes 70, 170, 80, 180, respectively. Since the rigidity of 185a is enhanced by the plugs 78, 178, 88, 188 inserted from the first opening end portions 71a, 171a, 81a, 181a, the first and second end wall portions 75a, 175a, 85a, Since the rigidity of the mounting seats 91 and 92 provided integrally with the 185a is also increased, the engine hanger 93 can be firmly attached to the mounting seats 91 and 92.

In the chain chamber 25, winding transmission mechanisms T1, T2 and T3 having chains 23 and 123 for transmitting the torque of the crankshaft 6 are arranged, and the first oil passages Pa1, Pb1 and the second oil passages Pa2, Pb2 are A transverse oil passage that crosses the chain 23 or the chain 123 at the transverse positions Ca1, Cb1, Ca2, and Cb2 when viewed from the axial direction A, and the passage walls Wa1, Wb1, Wa2, and Wb2 that form the transverse oil passages are transverse positions. As a result of bulging only on the outer surface 42 at Ca1, Cb1, Ca2, and Cb2 and bulging on the inner wall surface 41c that is the inner surface 41 inside or outside of the chains 23 and 123 when viewed from the axial direction A, the first, Even when the second oil passages Pa1, Pb1, Pa2, and Pb2 are transverse oil passages provided so as to cross the chains 23 and 123 arranged in the chain chamber 25 when viewed from the axial direction A, the transverse position Ca1 is also obtained. , Cb1, Ca2, and Cb2, the passage walls Wa1, Wb1, Wa2, and Wb2 are on the outer surface 42. Therefore, the chain cover 40 can be arranged close to the chains 23 and 123 in the axial direction A, and the passage walls Wa1 and Wb1 are located outside and inside the chains 23 and 123 when viewed from the axial direction A. , Wa2 and Wb2 are raised on the inner surface 41, so that the chain cover 40 provided with the first and second oil passages Pa1, Pb1, Pa2 and Pb2 can be downsized in the axial direction A.
Hereinafter, a mode in which a part of the above-described embodiment is changed will be described focusing on the changed portion.

As shown in FIG. 18, the first high wall portion 53b in the first bank portion 40a of the chain cover 40 sandwiches the low wall portion 53a between the side edge portion 43i and the side edge portion 43e in the lateral direction. Thus, it may be formed at an intermediate portion between the side edge portions 43i and 43e. In this case, the wall portion 50 has a pair of step portions 51 that face each other in the lateral direction, and the first high wall portion 53b extends from the lower portion 1c (see FIG. 1) of the cylinder block 1 to the cylinder head 2. It extends across the cylinder axis. Therefore, in the breather passage 54 formed by the first high wall portion 53b, the protruding space 25a is formed by the first high wall portion 53b and the pair of step portions 51.
The first high wall portion 53b and the breather passage 54 extend along the slack side 23a of the chain 23 when viewed from the axial direction A, and overlap with the slack side 23a and overlap with the cylinder bore 26a. Provided. Since the travel direction of the chain 23 along the breather passage 54 is a direction along the direction in which the blow-by gas faces the valve chamber, the chain 23 that travels causes the blow-by gas that travels toward the valve chamber in the breather passage 54. Flow is promoted.

In each of the above embodiments, the transmission mechanism is for driving the valve gear, but it may be for driving an auxiliary machine or the like. Further, the transmission mechanism may be a winding transmission mechanism including a belt as an endless transmission band, or may be a gear mechanism.
Parts other than the engine hanger 93, for example, parts constituting a transmission mechanism, an engine mount bracket, an auxiliary machine for an internal combustion engine, and the like may be attached to the mounting seats 91 and 92.
The cover side oil passages Pa and Pb may be provided only on the wall portion 50 among the outer edge portion 43 and the wall portion 50 of the chain cover 40.
At least one of the first hole portions 71, 171, 81, 181 and the second hole portions 72, 172, 82, 182 may be a hole having both ends opened. The first holes 70 and 170 and the second holes 80 and 180 may be configured by only one linear hole.
The cover side oil passage is constituted by the first holes 70 and 170 and the second holes 80 and 180 which are two holes forming one intersecting portion Pac and Pbc in the above embodiment, but at least two intersecting portions are formed. It may be configured by three or more holes to be formed (for example, first and second holes forming one intersecting portion and second and third holes forming another one intersecting portion).
The engine body side member may include an intermediate member that is coupled to the engine body Ea and integrated with the engine body Ea, and a cover body such as a chain cover 40 may be coupled to the intermediate member. In this case, the cover body is coupled to the engine body Ea via the intermediate member.
Of the two hydraulic control valves arranged in one window, one may be a valve that controls the hydraulic oil of the phase control mechanism, and the other may be a valve that controls the hydraulic oil of the lift amount control mechanism. .
Two hydraulic control valves arranged in one window may be used to control the hydraulic fluid of one or more hydraulic mechanisms.
In the predetermined number of hydraulic control valves, at least one hydraulic control valve may control the valve operating device, and the remaining hydraulic control valves may control devices other than the valve operating device. Further, all the hydraulic control valves arranged in one window portion may control devices other than the valve operating device.
The window portion formed by the peripheral wall coupled to the engine body side member may be a window portion in which a component other than the hydraulic control valve, for example, a tensioner lifter or a crankshaft is disposed or inserted.
The internal combustion engine may be a multi-cylinder internal combustion engine other than the V type, or may be a single cylinder internal combustion engine. Further, the valve gear may be of the SOHC type having a common cam shaft on which an intake cam and an exhaust cam are provided.
A plurality of oil passages similar to the cover-side oil passage Pa or the cover-side oil passage Pb may be provided in each of the bank portions 40a and 40b of the chain cover 40. In this case, a plurality of peripheral walls that respectively form a plurality of window portions corresponding to the respective oil passages may be provided.
The cover-side oil passage may be an oil passage through which lubricating oil flows.
The internal combustion engine may be used in a machine other than a vehicle, such as a ship propulsion device such as an outboard motor having a crankshaft oriented in the vertical direction, or a generator.

It is a figure of the principal part when an internal combustion engine provided with the chain cover to which the present invention is applied is viewed from the axial direction of the crankshaft. It is a perspective view of the chain cover of FIG. It is the figure which looked at the chain cover of FIG. 1 from the outer side in the axial direction. It is the figure which looked at the chain cover of FIG. 1 from the inner side in the axial direction. FIG. 5 is a perspective view of the vicinity of the ridge in FIG. 4. It is the VI-VI sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. It is the VIII-VIII sectional view taken on the line of FIG. It is the IX-IX sectional view taken on the line of FIG. FIG. 5 is a sectional view taken along line XX in FIG. 4. It is the XI-XI sectional view taken on the line of FIG. In the chain cover of FIG. 1, it is the principal part enlarged view centering on the window part by the side of the 1st bank. In the chain cover of FIG. 1, it is the principal part enlarged view centering on the window part by the side of the 2nd bank. It is a principal part perspective view centering on the window part by the side of the 1st bank when the chain cover of FIG. 1 is seen from the outer side. It is a principal part perspective view centering on the window part by the side of the 1st bank when the chain cover of FIG. 1 is seen from an inner side. It is a principal part perspective view centering on the window part by the side of the 2nd bank when the chain cover of FIG. 1 is seen from the outer side. It is a principal part perspective view centering on the window part by the side of the 2nd bank when the chain cover of FIG. 1 is seen from the inner side. FIG. 4 shows another embodiment of the present invention and is a main part of a diagram corresponding to FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylinder block, 2,102 ... Cylinder head, 5 ... Cylinder head cover, 6 ... Crankshaft, 23, 123 ... Chain, 40 ... Chain cover, 41 ... Inner surface, 42 ... Outer surface, 43 ... Outer edge part, 50 ... Wall part , 51, 51 _1, stepped portion, 53 a, low wall portion, 53 b, high wall portion, 54, breather passage, 59, protrusion Ea, engine body, Pa, Pb, oil passage.

Claims (7)

A cover body coupled to an end portion of an engine main body side member of an internal combustion engine, the outer edge portion coupled to the end portion, and the end portion covering from the crankcase to the cylinder head from the axial direction of the crankshaft And a wall having a wall portion that cooperates with the end portion to form an inner space, wherein the wall portion includes a low wall portion facing the end portion in the axial direction, and the end portion in the axial direction. And a high wall portion that is spaced apart from the end portion in the axial direction than the low wall portion and formed stepwise with the low wall portion through a step portion in the axial direction,
The high wall portion covers the end portion from the crankcase to the cylinder head, and guides a blow-by gas in a crank chamber formed by the crankcase to a head side space formed by the cylinder head. A cover body that forms a passage.   The cover body according to claim 1, wherein the high wall portion is formed along the outer edge portion and adjacent to the outer edge portion. The internal combustion engine is a V-type internal combustion engine including a pair of banks, an intake device disposed inside the pair of banks, and an exhaust device disposed outside the pair of banks.
The cover body according to claim 1, wherein the high wall portion is positioned closer to the inside of the pair of banks in the wall portion.   The cover body according to any one of claims 1 to 3, wherein the low wall portion includes a peripheral wall that forms a window portion opening in the low wall portion and is coupled to the end portion. The high wall portion has a protrusion formed on an inner surface facing the end portion in the axial direction,
The ridge extends in a direction intersecting the cylinder axial direction of the internal combustion engine as viewed from the axial direction, constitutes a weir crossing the breather passage, and connects the stepped portion and the outer edge portion. The cover body according to any one of claims 1 to 4, wherein: A winding transmission mechanism including a tensioner that applies tension to the endless transmission band is disposed in the outer space opposite to the inner space across the wall portion in the axial direction,
The tensioner is disposed on the opposite side of the end portion across the low wall portion in the axial direction,
6. The cover body according to claim 1, wherein the stepped portion is formed outside a swinging range of the tensioner. A passage wall forming an oil passage is provided integrally with the step portion,
The cover body according to any one of claims 1 to 6, wherein the passage wall is integrally provided across the low wall portion and the high wall portion.

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