JP6092813B2 - Lubricating oil supply structure for internal combustion engine bearings - Google Patents

Description

  The present invention relates to a lubricating oil supply structure for a bearing, and more particularly to a lubricating oil supply structure for a bearing of an internal combustion engine that supports a chain-driven shaft.

  Some internal combustion engines are provided with a pair of camshafts that drive intake and exhaust valves above the cylinder head. The camshaft is driven by the rotation of the crankshaft via a chain spanned between a crank sprocket provided at one end of the crankshaft and each cam sprocket provided at one end corresponding to each camshaft. The The camshaft is rotatably supported by the camshaft bearing portion at a plurality of locations in the axial direction. A cam is partially provided on the camshaft, and it is difficult to incorporate an integral bearing such as a ball bearing. Therefore, a split slide bearing or the like is generally used for the camshaft bearing portion.

  On the other hand, since it is easy to incorporate an integral bearing at the axial end of the camshaft, a rolling bearing such as a ball bearing or a needle bearing is used for the bearing in order to promote low fuel consumption by reducing friction. Some have been adopted. Grease and oil lubrication are available for rolling bearings, but oil lubrication is suitable for high temperature and high-speed rotation environments. Therefore, in the bearing on the side where the cam sprocket that is one side of the axial end of the camshaft is provided, a baffle plate that covers the upper half of the cam sprocket is provided, and the front side of the cam sprocket in the rotational direction of the cam sprocket is provided. An oil guide piece that has an oil contact portion having a lower surface that extends laterally at the portion, and supplies lubricating oil scattered from the chain to the lower surface of the oil contact portion to the oil seal side of the rolling bearing (the side opposite to the cam sprocket) (For example, refer to Patent Document 1).

JP 2001-59409 A

  As described above, one side of the camshaft on which the cam sprocket is provided protrudes in the axial direction from the rolling bearing, and the cam sprocket is fixed to the end in the axial direction. Therefore, the cam sprocket and the rolling bearing are the camshaft. Are spaced apart from each other in the axial direction. Therefore, in patent document 1, an oil application part and an oil guide piece are provided in a baffle plate, and lubricating oil is led to the rolling bearing. Therefore, there is a problem that separate parts such as a baffle plate are separately required and the number of mounting steps is increased.

  In view of the above background, it is an object of the present invention to supply lubricating oil to a bearing that supports a camshaft without using another component.

  In order to solve the above problems, the present invention includes an intake side camshaft (30) and an exhaust side camshaft (37), and a plurality of bearings (22, 36) that rotatably support the camshaft. A lubricating oil supply structure for a bearing of an internal combustion engine, which is hung between a cam sprocket (41, 43) provided at one axial end of the camshaft and a sprocket of a crankshaft and the cam sprocket, respectively. A chain disposed above the chain between the passed chain (44) and a cam sprocket (41) located on the upstream side and a cam sprocket (43) located on the downstream side in the running direction of the chain A guide (45), wherein the chain guide collects lubricating oil scattered by driving the chain, In order to guide to the first bearing (36) adjacent to the cam sprocket located on the flow side, it has a protruding portion (47e) protruding from the chain guide toward the first bearing, and the housing ( 25, 35) has an oil passage (52, 53) for collecting the lubricating oil transmitted from the projecting portion and guiding it to the shaft support portion (40) supporting the camshaft.

  According to this structure, the chain spanned between the sprocket of the crankshaft and the cam sprocket of the intake side and the exhaust side camshaft is connected to each of the cam sprocket located on the upstream side and the cam sprocket located on the downstream side. When the sliding contact is made with the chain guide disposed above, the lubricating oil adhering to the chain adheres to the lower surface of the chain guide (sliding contact surface with the chain). Further, the lubricating oil scattered by the driving of the chain and the lubricating oil floating in the valve chamber adhere to the upper surface (the surface opposite to the sliding surface with the chain) and the side surface of the chain guide. The lubricating oil adhering to the chain guides travels along the outer surface including the upper and lower surfaces of the projecting portion projecting from the chain guide toward the first bearing, and drops from the projecting portion. By collecting the lubricating oil dropped from the projecting part and guiding it to the shaft support part by the oil passage provided in the first bearing, the lubricating oil adhering to the chain can be supplied to the first bearing, The lubricating oil can be supplied with a simple configuration using existing parts without providing the lubricating oil supply structure according to.

  In the above invention, the oil passage may include an oil receiving portion (52) recessed upward and a communication passage (53) communicating the oil receiving portion and the shaft support portion. . According to this configuration, it is possible to reliably receive the lubricating oil from the protruding portion, and it is also possible to collect the lubricating oil that travels down the surface of the housing of the first bearing, and to supply more lubricating oil to the shaft support portion. be able to. Further, since the lubricating oil collected by the oil receiving portion is quantified and supplied through the communication path, the supply of the lubricating oil can be stabilized without being influenced by the storage amount in the oil receiving portion.

  In particular, the oil receiver (52) may be inclined toward the communication path (53). According to this configuration, since the oil receiving portion is inclined toward the communication path, the lubricating oil collected by the oil receiving portion can flow toward the communication path and be supplied to the shaft support portion. Thereby, the supply efficiency of the lubricating oil to the first bearing can be increased without staying in the oil receiving portion.

  Moreover, the said communicating path (53) is good to be provided in the lowest part of the said oil receiving part (52). According to this configuration, it is possible to further improve the flow of the lubricating oil collected by the oil receiving portion supplied to the shaft support portion.

  The housing includes a bearing body (32) that supports a lower portion of the camshaft, and a bearing cap (35) that supports an upper portion of the camshaft. A communication path may be provided. According to this configuration, the oil passage can be configured only by processing the bearing cap, and the cost of the lubricating oil supply structure can be reduced.

  Moreover, the said protrusion part (47e) is good to have the bent piece part (54) which covered the upper part of the said oil receiving part, and was bent by the said oil receiving part side. According to this configuration, the lubricating oil scattered from the chain to the first bearing side can be collected by the bent piece portion, and a larger amount of lubricating oil adhering to the chain can be collected and supplied for lubricating the bearing. Therefore, the supply efficiency of the lubricating oil can be improved.

  The chain guide includes a guide shoe that is in sliding contact with the chain, and a bracket that integrally holds the guide shoe and is fixed to the first bearing, and the protruding portion is formed by a part of the bracket. It is good to be formed. According to this structure, the lubricating oil adhering to a chain can be supplied to a 1st bearing by the simple change of processing a part of bracket which is a component part of a chain guide.

  As described above, according to the present invention, the lubricating oil adhering to the chain can be supplied to the first bearing by processing the chain guide and the housing of the bearing, so that there is no need to provide a lubricating oil supply structure with dedicated parts. The lubricating oil can be supplied with a simple configuration using existing parts.

The perspective view which shows the cylinder head of the engine to which this invention was applied The principal part expansion perspective view seen from the arrow II line direction of FIG. FIG. 2 is a perspective view of the main part viewed from the direction of arrow III in FIG. Fig. 2 is an enlarged plan view of the main part viewed from the direction of the arrow IV line. FIG. 4 is a cross-sectional side view of an essential part taken along line VV in FIG. The principal part expansion perspective view seen from the arrow VI line direction of FIG. The figure corresponding to FIG. 4 which shows 2nd Embodiment. The figure seen from the arrow VIII line direction of FIG. 4 which shows 2nd Embodiment The principal part expansion perspective view seen from the arrow IX line direction of FIG. 7 which shows 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a cylinder head 1 of an in-line four-cylinder four-valve DOHC type gasoline direct injection engine that is an example of an engine to which the present invention is applied.

  As shown in FIG. 1, the cylinder head 1 has a substantially rectangular parallelepiped lower portion elongated in the left-right direction, and a box-shaped upper portion provided at the upper end of the lower portion and having an upper surface opened. In the lower part of the cylinder head 1, there are four combustion chambers (not shown) recessed in the lower surface of the cylinder head 1, an exhaust port (not shown) extending forward from each combustion chamber, and a rear side from each combustion chamber. An intake port (not shown) that extends to the rear side surface of the cylinder head 1 is formed. On the front side surface of the cylinder head 1, a front end (downstream end) of the exhaust collecting chamber 2 formed so that the exhaust ports are gathered inside the lower portion of the cylinder head 1 is opened.

  The upper part of the cylinder head 1 includes a rear edge wall 11, a front edge wall 12, a left edge wall 13, a right edge wall 14, which are erected along the lower four sides of the cylinder head 1, and an upper surface of the lower part. A substantially rectangular parallelepiped box-shaped valve chamber 16 opening upward is formed by the bottom wall 15 formed. A head cover 61 (see FIG. 2) and a fuel injection pump (not shown) are fastened to the upper ends of the rear edge wall 11, the front edge wall 12, the left edge wall 13 and the right edge wall 14, thereby receiving the drive system. The upper part of the valve operating chamber 16 is covered. The bottom wall 15 of the cylinder head 1 is formed with a cylindrical plug insertion cylinder portion 17 into which a spark plug (not shown) is inserted, and an intake valve 18 and an exhaust valve 19 constituting a drive system are provided. An injector hole (not shown) is provided in which a non-injector is inserted.

  In the illustrated example, an intake side camshaft 30 is provided on the rear edge wall 11 side, and an exhaust side camshaft 37 is provided on the front edge wall 12 side so as to extend in the cylinder row direction and to be parallel to each other. The intake side camshaft 30 is rotatably supported by a plurality of intake side camshaft bearings 21 arranged at predetermined intervals in the cylinder row direction, and the exhaust side camshaft 37 is also arranged similarly. A plurality of exhaust-side camshaft bearings 22 are rotatably supported.

  Here, in the plurality of exhaust side camshaft bearings 22, the one disposed on the right edge wall 14 in the drawing is referred to as a first bearing 36. A portion of the bottom wall 15 corresponding to the right edge wall 14 is provided with a wall-shaped bearing body 25 that constitutes the housing of the first bearing 36. The bearing body 25 also serves as the bearing body of the intake camshaft bearing 21 disposed on the right edge wall 14. An intake side rocker shaft 26 is fixedly supported on the bearing body 25.

  An intake side rocker arm 27 for driving the intake valve 18 in the valve opening direction is rotatably supported on the intake side rocker shaft 26. A semi-cylindrical recess is formed in a portion corresponding to the intake side camshaft 30 at the protruding end (upper end) of the bearing body 25, and an intake side bearing cap 28 is fastened so as to cover the recess. The protruding end of the bearing body 25 and the intake side bearing cap 28 form the intake side camshaft bearing 21 disposed on the right edge wall 14. The other intake-side camshaft bearing 21 is formed by a bearing body (reference numeral omitted) and a bearing cap (reference numeral omitted) projecting from the bottom wall 15. The intake side camshaft bearing 21 may be a known sliding bearing.

  An exhaust side rocker shaft (not shown) is fixedly supported on the right edge wall 14, and an exhaust side rocker arm 34 connected to an exhaust valve 19 is rotatably supported on the exhaust side rocker shaft.

  A semicircular recess is formed in a portion corresponding to the exhaust camshaft 37 at the protruding end (upper end) of the bearing body 25, and an exhaust bearing cap 35 is fastened so as to cover the recess. The housing is formed. In the first bearing 36, a ball bearing 40 as a shaft support portion is supported by the bearing body 25 and the exhaust side bearing cap 35. The ball bearing 40 may have a known structure, for example, an outer ring press-fitted into a circular inner peripheral surface formed by the bearing body 25 and the exhaust-side bearing cap 35, and an inner ring into which the exhaust-side camshaft 37 is press-fitted, for example. And a plurality of balls interposed between the outer ring and the inner ring. The exhaust-side camshaft 37 is rotatably supported by the first bearing 36 configured as described above and a plurality of other exhaust-side camshaft bearings 22 made of sliding bearings. The shaft support of the first bearing 36 is not limited to the ball bearing 40, and a general rolling bearing such as a needle bearing or a roller bearing can be applied. The other exhaust side camshaft bearing 22 may be a sliding bearing.

  The intake-side camshaft 30, the exhaust-side camshaft 37, the intake-side rocker shaft 26, and the exhaust-side rocker shaft each extend in the longitudinal direction (left-right direction) of the cylinder head 1. An intake side cam 38 that drives the intake side rocker arm 27 is formed on the intake side camshaft 30, and an exhaust side cam 39 that drives the exhaust side rocker arm 34 is formed on the exhaust side camshaft 37.

  As shown in FIGS. 2 and 3, an intake side cam sprocket 41 is fixed to one end in the axial direction protruding outward from the right edge wall 14 of the intake side camshaft 30, and the intake side cam sprocket 41. A variable valve timing device 42 is provided on the outside. The variable valve timing device 42 variably controls the intake side cam sprocket 41, the intake side camshaft 30, and the relative advance angle.

  An exhaust side cam sprocket 43 is fixed to one end in the axial direction protruding outward from the right edge wall 14 of the exhaust side camshaft 37. The intake side cam sprocket 41 and the exhaust side cam sprocket 43 are fixed to the outward projecting ends of the crankshaft in order to transmit the rotational force of the crankshaft (not shown) to the intake side camshaft 30 and the exhaust side camshaft 37. A chain 44 is looped between the sprocket (not shown) and the cam sprockets 41 and 43. In the present embodiment, the chain 44 travels in the direction indicated by the arrow A in FIG. 2 so as to rotate clockwise when the right edge wall 14 is viewed in front. Therefore, the chain 44 travels from the intake side cam sprocket 41 located on the upstream side toward the exhaust side cam sprocket 43 located on the downstream side in the portion spanned between the cam sprockets 41 and 43. Thus, a chain guide 45 is provided above the portion of the chain 44 that spans between the cam sprockets 41 and 43 in order to suppress the swinging of the chain 44 between the cam sprockets 41 and 43.

  The chain guide 45 includes a guide shoe 46 that is in sliding contact with the chain 44 and a bracket 47 that integrally holds the guide shoe 46. In the illustrated example, the guide shoe 46 is provided so as to extend linearly over substantially the entire length of the portion where the chain 44 travels linearly between the cam sprockets 41 and 43. At both ends in the extending direction of the guide shoe 46, a pair of engagement holding portions 46a that form grooves that open in opposite directions and in two directions on the left edge wall 13 side are provided, and the pair of engagement holding portions 46a Both ends of the support plate portion 47a of the bracket 47 formed in a long plate shape protrude into the groove.

  The bracket 47 includes a leg piece portion 47b bent and extended from the intake side cam sprocket 41 side of the support plate portion 47a toward the intake side bearing cap 28, and an exhaust side bearing from an intermediate portion in the extending direction of the support plate portion 47a. A leg piece 47 c bent and extended toward the cap 35. One leg piece portion 47b is fixed to the intake side bearing cap 28 by fastening bolts 51, and the other leg piece portion 47c is similarly fastened to the exhaust side bearing cap 35 by fastening bolts 51. A bracket 47 is supported by the intake side camshaft bearing 21 and the first bearing 36 adjacent to the right edge wall 14. Thereby, the chain guide 45 is attached to the cylinder head 1 without requiring a separate fixed support structure.

  The guide shoe 46 is provided with a protruding engagement piece portion 46b formed so as to protrude between both leg piece portions 47b and 47c of the support plate portion 47a of the bracket 47. Between the leg piece portions 47b and 47c of the support plate portion 47a is recessed so as to be narrower than both end portions, and the engaging piece portion 46b is fitted into and engaged with the recessed portion 47d formed in the recess. ing. The guide shoe 46 and the bracket 47 are integrated by the engagement between the engagement piece 46b and the recess 47d and the engagement between the pair of engagement holding portions 46a and both ends of the support plate portion 47a. Note that the lower surface of the support plate portion 47 a is in contact with the upper surface of the guide shoe 46 in the mounted state.

  Further, one end portion on the exhaust side cam sprocket 43 side in the extending direction of the guide shoe 46 extends beyond a position where the chain 44 starts to be wound around the exhaust side cam sprocket 43. The chain guide 45 configured in this manner is provided so as to guide the exhaust side cam sprocket 43 at least from the front side in the traveling direction of the chain 44 to the exhaust side cam sprocket 43.

  The leg piece 47c fixed to the exhaust side bearing cap 35 is fastened together with a bolt 51 on the center side of the cylinder head 1 in the exhaust side bearing cap 35. The support plate portion 47a of the bracket 47 extends outward (front edge wall 12 side) from the leg piece portion 47c, and includes a leg piece portion 47c in the support plate portion 47a and extends outward. Is extended over substantially the entire length of the exhaust side bearing cap 35 in the width direction (substantially extending direction of the chain guide 45).

  As shown in FIGS. 4 to 6, in the bracket 47, an L-shaped protruding portion 47 e is provided in a portion from the leg piece portion 47 c of the support plate portion 47 a to the extending end. The protrusion 47e is wider than the guide shoe 46, and extends from the support plate 47a in the axial direction of the exhaust camshaft 37 to a position above the exhaust bearing cap 35, and from the extended end to the exhaust side. It is formed in a bent shape so as to hang down toward the upper surface of the bearing cap 35.

  The exhaust-side bearing cap 35 is formed with a protrusion that surrounds the upper half of the exhaust-side camshaft 37 and protrudes toward the exhaust-side cam sprocket 43. The exhaust-side camshaft is formed on the upper surface of the protrusion. An oil receiving portion 52 extending so as to cross the upper side of 37 perpendicular to the axial direction is recessed. Above the oil receiving portion 52, the protruding portion 47e is positioned so as to overlap the oil receiving portion 52 in a plan view as shown in FIG.

  In the present embodiment, the exhaust side cam sprocket 43 is disposed at a position lower than the intake side cam sprocket 41, and accordingly, the chain guide 45 is also inclined so that the exhaust side cam sprocket 43 side is lowered. Further, the bottom surface 52a of the oil receiving portion 52 is also formed by a slope that becomes lower toward one side (the front side of the cylinder head 1) so as to match the inclination of the chain guide 45.

  As described above, the oil receiving portion 52 is provided on the upper surface of the protruding portion that protrudes toward the exhaust side cam sprocket 43 of the exhaust side bearing cap 35. A groove shape formed by recessing a part of the exhaust side bearing cap 35 on the exhaust side cam sprocket 43 side in the axial direction of the exhaust side camshaft 37 at a position relative to the lowest part of the bottom surface 52 a of the oil receiving part 52. The communication path 53 is provided. The upper end of the communication path 53 is opened to the bottom surface 52a of the oil receiving portion 52, and the lower end is opened so that a part of the outer ring of the ball bearing 40 is exposed.

  Thus, the lubricating oil supply structure of the 1st bearing 36 is comprised, and the supply procedure of the lubricating oil is demonstrated below.

  During operation of the engine, the lubricating oil adhering to the chain 44 is carried by the chain 44 to a portion that travels from the intake side cam sprocket 41 toward the exhaust side cam sprocket 43. A chain guide 45 is provided between the intake side cam sprocket 41 and the exhaust side cam sprocket 43, and when the chain 44 is in sliding contact with the chain guide 45, the lubricating oil adhering to the chain 44 is removed from the chain guide 45. Can be transmitted to the lower surface.

  Further, as indicated by arrows O1 to O3 in FIG. 3, the lubricating oil adhering to the chain 44 is scattered mainly in the traveling direction of the chain 44 by driving the chain 44. Since the chain 44 travels from the intake-side cam sprocket 41 toward the exhaust-side cam sprocket 43, the lubricating oil scattered in the traveling direction tends to adhere to the bracket 47. In particular, since the protruding portion 47e is disposed on the downstream side in the traveling direction, the lubricating oil suitably adheres to the protruding portion 47e, and the lubricating oil is collected by the protruding portion 47e.

  Further, the lubricating oil scattered toward the lower surface of the head cover 61 gathers with the already-attached lubricating oil into a large lump, and can fall from the head cover 61 as shown by an arrow O4 in FIG. Lubricating oil that has dropped onto the chain guide 45 from the lower surface of the head cover 61 can adhere to the chain guide 45. In addition, lubricating oil is floating in the valve operating chamber 16, and a part of the lubricating oil that has gathered and grown and dropped can also adhere to the chain guide 45.

  The lubricating oil adhering to the chain guide 45 in this way flows toward the lower side of the bracket 47 because the chain guide 45 is inclined so as to become lower toward the exhaust side cam sprocket 43. A protrusion 47e is provided on the lower side of the bracket 47 constituting the chain guide 45, and the lubricating oil flowing on the upper surface and the lower surface of the bracket 47 is transmitted to the outer surface including the upper surface and the lower surface of the protrusion 47e (arrow O5). O6), dropped from the projecting portion 47e and reliably collected by the oil receiving portion 52 (arrow O7), and flows to the lowermost portion of the oil receiving portion 52 due to the inclination of the bottom surface 52a of the oil receiving portion 52. The lubricating oil that has flowed to the lowermost portion of the oil receiving portion 52 is supplied to the ball bearing 40 through the communication path 53 (arrow O8). As described above, the exhaust-side bearing cap 35 is provided with the lubricating oil recovery mechanism by the oil receiver 52 and the lubricating oil supply mechanism by the communication path 53, and the mechanism for dropping the lubricating oil to the oil receiver 52 on the chain guide 45. By providing, a mechanism for supplying lubricating oil can be configured. Thereby, it is not necessary to provide a dedicated part for supplying lubricating oil separately, and a lubricating oil supply structure for the bearing can be provided with the same number of work steps as in the prior art.

  In addition, in the rolling bearing such as the ball bearing 40, the amount of lubricating oil supplied may be smaller than that in the sliding bearing. For example, in the case of a sliding bearing, the cylinder head 1 is provided with a lubricating oil supply port that opens on the journal bearing surface and an oil passage leading to the lubricating oil supply port, or an oil passage for supplying lubricating oil is provided inside the camshaft. It becomes a complicated oil supply structure. On the other hand, since the lubricating oil can be supplied with the simple configuration described above and it is not necessary to provide a separate lubricating oil supply circuit, the structure on the cylinder head 1 side is not changed.

  FIG. 7 is a diagram corresponding to FIG. 4 showing the second embodiment, and FIG. 8 is a diagram corresponding to FIG. 5 showing the second embodiment. In addition, about the part similar to the above, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted. In the second embodiment, the upper portion of the oil receiving portion 52 is extended from the support plate portion 47a of the bracket 47 so as to cover with a predetermined width, and is bent downward toward the exhaust side bearing cap 35 at the extended end. A substantially L-shaped bent piece 54 is provided.

  As shown in FIG. 9, in the exhaust side bearing cap 35, a rib 35 b is formed between the pair of boss portions 35 a through which the bolts 51 are inserted to connect the boss portions 35 a to each other. The center side of the cylinder head 1 in both the boss portions 35a is formed higher than the other side, and the height of the rib 35b is also inclined according to the height difference of the both boss portions 35a. A lower end portion extending downward from the bent piece portion 54 is provided so as to be close to the upper portion of the rib 35b and extend along the rib 35b.

  By providing the bent piece portion 54 in this way, the lubricating oil (O9 in FIG. 8) scattered from the chain 44 to the exhaust side bearing cap 35 side is collected by the bent piece portion 54. The lubricating oil collected by the bent piece portion 54 is transferred down to the lower end portion of the bent piece portion 54 (O10 in FIG. 8), dripped onto the rib 35b, and the wall surface of the rib 35b on the exhaust side cam sprocket 43 side. It is transmitted down to the oil receiver 52 (O11 in FIG. 8). Thereby, more lubricating oil can be guide | induced to the oil receiving part 52, and the supply efficiency of the lubricating oil to the ball bearing 40 can be improved.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to such embodiments and can be easily understood by those skilled in the art. As long as it does not deviate from the above, it can be appropriately changed. In the illustrated example, the oil receiving portion 52 is provided on the exhaust side bearing cap 35. However, any bearing housing may be used. For example, the exhaust side shaft support portion 32 may be provided with a portion that avoids the exhaust side camshaft 37 in plan view. A concave portion similar to the oil receiving portion 52 may be provided. In that case, the communication path 53 is provided so as to flow into the lower portion of the ball bearing 40. Further, the lubricating oil supply structure for the ball bearing 40 provided in the first bearing 36 has been described. However, the structure is not limited to that for the first bearing 36, and can be applied to the intake-side camshaft bearing 21. It may apply to both. In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the spirit of the present invention.

22 Exhaust side camshaft bearing (bearing)
25 Bearing body (housing)
35 Exhaust side bearing cap (housing, bearing cap)
36a First bearing 37 Exhaust side camshaft (camshaft)
40 Ball bearing (rolling bearing)
43 Exhaust side cam sprocket (cam sprocket)
44 Chain 45 Chain guide 46 Bracket (Chain guide)
47 Guide shoe (chain guide)
47e Protruding part 52 Oil receiving part (oil passage)
52a Bottom surface 53 Concavity (oil passage, communication passage)
54 Curved pieces

Claims (8)

An intake camshaft and an exhaust camshaft;
A plurality of bearings for rotatably supporting the camshaft ;
Cam sprockets respectively provided at one axial end of the camshaft;
A chain spanned between the crankshaft sprocket and each of the cam sprockets;
A chain guide disposed above the chain between a cam sprocket located on the upstream side and a cam sprocket located on the downstream side in the running direction of the chain;
A bearing for an internal combustion engine in which a first bearing provided at a position adjacent to the cam sprocket located on the downstream side of the plurality of bearings is configured as a rolling bearing including a shaft support portion and a housing that supports the shaft support portion. The lubricating oil supply structure of
The chain guide is arranged to be inclined so as to become lower from the upstream side to the downstream side in the running direction of the chain,
The chain guide has a protrusion formed in a shape bent so as to hang down toward the upper surface of the housing,
The housing includes a protrusion that is formed to protrude toward the cam sprocket located on the downstream side, and an oil passage that is recessed in the upper surface of the protrusion and communicates with the shaft support.
The lubricating oil supply structure for a bearing of an internal combustion engine, wherein the protruding portion and the oil passage are provided at positions overlapping each other in plan view . 2. The lubricating oil supply structure for a bearing of an internal combustion engine according to claim 1, wherein the oil passage extends along a direction in which the chain guide extends. 3. The oil passage according to claim 1 or 2 , wherein the oil passage has an oil receiving portion that is recessed upward, and a communication passage that communicates the oil receiving portion and the shaft support portion. Lubricating oil supply structure for internal combustion engine bearings. The lubricating oil supply structure for a bearing of an internal combustion engine according to claim 3 , wherein the oil receiving portion is inclined toward the communication path. 5. The lubricating oil supply structure for a bearing of an internal combustion engine according to claim 4 , wherein the communication passage is provided at a lowermost portion of the oil receiving portion. The housing includes a bearing body that supports a lower portion of the camshaft, and a bearing cap that supports an upper portion of the camshaft;
6. The lubricating oil supply structure for a bearing of an internal combustion engine according to claim 5 , wherein the bearing cap is provided with the oil receiving portion and the communication passage. Said projection covers the upper side of the oil receiving portion, and the internal combustion engine according to any one of claims 3 to 6, characterized in that it has the oil receiving portion side bent piece which is bent to Lubricating oil supply structure for bearings. The chain guide includes a guide shoe that is in sliding contact with the chain; and a bracket that integrally holds the guide shoe and is fixed to the first bearing;
Lubricating oil supply structure of a bearing for an internal combustion engine according to any of claims 1 to 7, characterized in that the projecting portion is formed by a portion of the bracket.

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