JP2015068215A - Lubricant supply structure of dynamic valve device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant supply structure of a dynamic valve device of an internal combustion engine which further increases an amount of oil feed by achieving engine high rotation.SOLUTION: A lubrication structure of a dynamic valve device comprises locker arms 43, 44 which are pivoted at pivot base parts 43a, 44a by oscillation/support locker arm shafts 45, 46 at each pair of intake/exhaust machine valves 18, 19, interposed between valve stem end parts 18c, 19c and cam faces 34a, 35a of cam shafts 32, 33 and make them contact with each other, make oscillation arms 43b, 44b receive pressing forces generated by the cam faces 34a, 35a, also make them transmit the pressing forces to valve stems 18a, 19a, and open and close the machine valves 18, 19. The lubrication structure of the dynamic valve device also comprises: an oil passage 62 which is arranged at a cylinder head 4 in axial directions of the cam shafts 32, 33, and formed of a single passage between the intake/exhaust valves 18, 19 and at a lower position rather than the locker arm shafts 45, 46; and oil injection oil passages 75, 76 which are formed in pair so as to be independently oriented at each of the locker arms 43, 44 from the oil passage 62.

Description

  The present invention relates to a lubricating oil supply structure for a valve operating apparatus of an internal combustion engine.

  As a lubricating oil supply structure to a valve operating device of an internal combustion engine, a rocker arm provided with a lubricating oil passage for discharging oil directed to a contact portion between an adjusting bolt and a valve stem among sliding portions of the rocker arm. is there. Conventionally, as a structure for supplying lubricating oil to such a valve operating apparatus, there is one disclosed in Patent Document 1, for example. In this lubricating oil supply structure to the valve operating device, an oil supply passage is provided in the rocker arm shaft, oil is supplied to the sliding surface between the rocker arm shaft and the rocker arm from the supply passage, and the oil supplied to the sliding surface is The oil is injected from the lubricating oil passage provided in the rocker arm shaft toward the contact portion between the adjusting bolt and the valve stem.

  In such a technique, the amount of oil that is diverted by diverting the oil supply to the rocker arm jet outlets to each rocker arm shaft is reduced, and the oil supply path to the injection hole of the rocker arm is lengthened and further adjusted. Since a part of the oil supplied to the sliding surfaces of the bolt and the valve stem is injected, there is a limit in securing the oil supply amount. For this reason, when a further amount of oil supply is required due to an increase in engine speed, etc., it has been necessary to improve the oil supply method.

Japanese Patent No. 4220415

  The present invention solves such problems of the prior art, and an object of the present invention is to provide a lubricating oil supply structure for a valve operating device of an internal combustion engine that increases the amount of oil supplied by increasing the engine speed. To do.

In order to achieve the object, the invention according to claim 1 is used for an internal combustion engine having a cylinder head that rotatably supports a camshaft,
Each pair of intake and exhaust engine valves is pivotally supported at the pivot base by a rocker arm shaft that swings and supports the engine valves, and is interposed between the valve stem end of each engine valve and the cam surface of the camshaft. In a lubrication structure of a valve operating apparatus having a rocker arm that opens and closes an engine valve by a peristaltic arm receiving a pressing force by the cam surface and transmitting it to the valve stem, the cylinder head along the axial direction of the camshaft A pair of oil passages formed between the intake / exhaust valves and below the rocker arm shaft and formed by a single passage and directed independently from the oil passage for each rocker arm. A lubricating oil supply structure for a valve operating device for an internal combustion engine, comprising an oil injection oil passage formed.

  The invention according to claim 2 is a portion of the rocker arm that contacts the valve stem side, and includes a valve stem pressing portion formed so as to be continuous with a lower surface of the rocking arm of the rocker arm, and the oil injection oil 2. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 1, wherein a direction in which a path is directed to the rocker arm is directed to a lower surface of the swing arm.

  According to a third aspect of the present invention, the lower surface of the rocker arm is formed in a curved concave portion that is the lowermost portion toward the valve stem pressing portion, and the operation of the internal combustion engine according to the first or second aspect It is the lubricating oil supply structure of a valve apparatus.

  According to a fourth aspect of the present invention, a clearance adjusting member for adjusting a gap between the valve stem shaft end and the rocker arm is provided as a separate unit so as to be exchangeable between the valve stem and the valve stem pressing portion of the rocker arm. 4. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 3, wherein the lubricating oil supply structure is provided.

  According to a fifth aspect of the present invention, the oil passage is provided in the cylinder head and bulges from a lower surface of a connecting bottom wall that connects lower portions of a pair of supporting wall portions that support both shaft ends of the rocker arm shaft. The lubricating oil supply structure for a valve operating device for an internal combustion engine according to any one of claims 1 to 4, wherein the lubricating oil supply structure is provided in the bulged portion.

  According to a sixth aspect of the present invention, the camshaft is configured independently for intake and exhaust, each camshaft is disposed above the rocker arm, and the rocker arm and the cam are arranged on the upper surface of the rocker arm. 6. The lubricating oil supply structure for a valve operating device for an internal combustion engine according to claim 1, wherein a sliding portion with the surface is provided.

  According to a seventh aspect of the present invention, the rocker arm shaft is disposed between the intake / exhaust camshafts so that the sliding portions of the rocker arms face each other. The rocker arm shaft is disposed at different height positions with reference to an extension line of a cylinder central axis, and the oil passage is disposed near the rocker arm shaft on the side disposed at the high position. 7. A lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 6.

  According to an eighth aspect of the present invention, when the internal combustion engine is mounted on a vehicle, the rocker arm on the side disposed at the high position of the two rocker arm shafts has the tip directed obliquely upward and the rocker arm on the side disposed at the low position. Is mounted so that the cylinder of the internal combustion engine is inclined with respect to the vertical direction so that the tip is directed obliquely downward, and the oil injection into the valve stem pressing portion on the side where the oil passage in the rocker arm is arranged in a biased manner The oil injection oil passage is formed so that the injection direction of the oil passage is directed toward the tip of the rocker arm, and the injection direction of the oil injection oil passage to the valve stem pressing portion of the other rocker arm is pivotally supported by the rocker arm. 8. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 7, wherein the oil injection oil passage is formed so as to be directed to a base portion.

  In the lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 1, a single oil passage is provided between the intake and exhaust valves and at a position below the rocker arm shaft along a camshaft. A pair of oil injection oil passages formed by passages and directed independently from each oil passage to each rocker arm are provided, so that oil is supplied directly to each rocker arm from a single oil passage while shortening the passage of the injection oil. In addition, the amount of oil can be easily secured by supplying the oil supplied to each oil injection oil passage from a common oil passage. Furthermore, since the oil injection oil passage is provided from the single oil passage, the space for the lubricating oil supply structure can be saved and the manufacturing cost can be reduced.

  In the lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 2, the bottom surface of the swing arm of the rocker arm is formed so as to be continuous with the valve stem pressing portion, and the direction directed to the rocker arm of the oil injection oil passage is By forming toward the lower surface of the swing arm, even if there is oil that does not reach the valve stem pressing portion directly in the injected oil, it is transmitted to the lower surface of the swing arm and supplied to the valve stem pressing portion. Thus, the oil supply amount to the valve stem pressing portion can be increased.

  In the lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 3, since the lower surface of the rocker arm is formed in a curved recess that is the lowermost portion toward the valve stem pressing portion, the oil adhering to the lower surface is positively The oil can be collected by being transmitted to the sliding portion side between the valve stem pressing portion and the valve stem end portion.

  In the lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 4, the clearance adjusting member is disposed separately between the valve stem pressing portion of the rocker arm and the valve stem shaft end. The screw adjusting mechanism arranged at the tip of the rocker arm is not necessary, and the sliding surface of the valve stem pressing part can be configured with a curved surface. It becomes possible to supply reliably.

  6. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 5, wherein the oil passage is provided in a connecting bottom wall of a pair of supporting wall portions that support both shaft ends of the rocker arm shaft, and is bulged from the lower surface. Since the oil passage is provided in the cylinder head, it is possible to suppress an increase in size of the cylinder head in the height direction.

  7. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 6, wherein the sliding portion is arranged on the upper surface of the rocker arm so that the injected oil is not obstructed by the cam crest of the camshaft. Oil can be supplied to the end on the stem side.

  In the lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 7, when the intake and exhaust rocker arm shafts are arranged close to each other, they are arranged differently in the cylinder axial direction, and the oil passage is provided. By disposing to the rocker arm shaft side that is disposed at a high position, the oil passage can be disposed in a compact manner by effectively utilizing the empty space.

  9. The lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to claim 8, wherein the internal combustion engine is mounted on the vehicle such that the two rocker arms are directed obliquely upward and obliquely downward, and disposed at a high position. By directing the direction of the oil injection oil path to the rocker arm toward the tip of the rocker arm and directing the direction of the oil injection oil path to the rocker arm arranged at a low position toward the pivot base of the rocker arm shaft of the rocker arm Even if it is difficult to direct the oil injection oil passage directly to the tip of the rocker arm, it is possible to supply oil from the pivot base of the rocker arm to the tip of the rocker arm, thereby shortening the oil injection oil passage. It is possible to reliably supply oil while achieving the above.

1 is a left side view of an internal combustion engine having a lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the internal combustion engine cut | disconnected by the plane which passes along the centerline of an intake / exhaust valve. It is a secondary section of an internal combustion engine cut by a plane passing through the center line of a combustion plug cylinder. It is a perspective view of the internal combustion engine which removed the head cover. It is the VV arrow line view of FIG. It is a principal part expanded sectional view of FIG. It is a VII-VII arrow line view of FIG. It is a principal part expanded sectional view of FIG. It is the perspective view which showed the lubricating oil supply structure of the valve operating apparatus. It is sectional drawing of the internal combustion engine cut | disconnected by the center axis line of an intake rocker arm shaft and an exhaust rocker arm shaft.

  A lubricating oil supply structure for a valve operating apparatus for an internal combustion engine according to an embodiment of the present invention shown in FIGS. 1 to 9 will be described below. In the present embodiment, front and rear, up and down, and left and right directions mean front and rear, up and down, and left and right of a vehicle body (not shown) on which the internal combustion engine 1 is mounted.

  FIG. 1 is a side view of a state in which an internal combustion engine 1 equipped with a lubricating oil supply structure 70 for a valve operating apparatus according to an embodiment of the present invention is mounted on a vehicle not shown, as viewed from the left. In the internal combustion engine 1, a cylinder block 3, a cylinder head 4, and a head cover 5 are sequentially stacked on a crankcase 2, and are fastened together with a bolt (not shown), and an oil pan 6 is fastened with a bolt (not shown) on the lower surface of the crankcase 2. It is a thing. The internal combustion engine 1 is a four-cylinder in-line internal combustion engine in which four cylinders 11 are formed in the left-right direction in a cylinder block 3, and an intake valve 18 and an exhaust valve 19 are provided as shown in FIGS. A valve operating device 30 of a DOHC type four-valve system that is driven to open and close is accommodated in a valve operating chamber 31 that includes a cylinder head 4 and a head cover 5.

  As shown in FIG. 1, a crankshaft 10 is supported between the crankcase 2 and the cylinder block 3 so as to be rotatable in the left-right direction. As shown in FIG. 2, a piston 12 that slides up and down is fitted in a cylinder 11 formed in the cylinder block 3, and the piston 12 is connected to a crankshaft 10 via a connecting rod (not shown). It is connected to. The cylinder head 4 is formed with a combustion chamber 13 formed of a concave portion at a position facing the cylinder hole 11a of the cylinder 11 in the cylinder axial direction, and the piston 12 becomes a cylinder by the explosion of fuel burned in the combustion chamber 13. The crankshaft 10 is driven to rotate by the vertical movement of the piston 12, which is slid in the vertical direction inside the piston 16.

In each combustion chamber 13, two intake ports 14 and two exhaust ports 15 are formed, and an intake port 16 for introducing intake air into the combustion chamber 13 and an exhaust port 17 for discharging exhaust gas generated in the combustion chamber 13. Is communicated. An intake valve 18 and an exhaust valve 19 for opening and closing the intake port 14 and the exhaust port 15 are slidably supported by a valve guide 20 and are fixed to valve stem end portions 18c and 19c at the upper ends of the valve stems 18a and 19a. A spring 23 fitted between the retainer 21 and the lower retainer 22 fixed to the cylinder head 4 is always urged in the valve closing direction.

  As shown in FIGS. 3 and 5 to 7, a spark plug cylinder 25 is inserted and positioned substantially at the center of the intake port 14 and the exhaust port 15 in one cylinder of the cylinder head 4. A spark plug hole 24 to which a spark plug inserted into the cylinder 25 is attached is formed.

  As shown in FIG. 6, the spark plug hole 24 is formed by connecting a plurality of circular holes having different concentric inner diameters, and is directed downward from the joint surface 59 between the upper surface of the cylinder head 4 and the camshaft holder 50. The main plug hole 24a is formed, and is connected to the lower portion of the main plug hole 24a to form a plug cylinder insertion part 24b into which the tip part 25a of the spark plug cylinder 25 is inserted, and the plug cylinder insertion part 24b. A spark plug contact portion 24c having a smaller inner diameter is formed in communication with the lower portion, and a screw portion 24d is formed in communication with the lower portion of the spark plug contact portion 24c and screwed into the screw portion 26a of the spark plug 26. The tip of the screw portion 36a is in communication with the combustion chamber 13.

  A spark plug cylinder 25 is inserted into the spark plug hole 24. The spark plug cylinder 25 has a cylindrical shape, and the outer diameter of the cylindrical intermediate portion 25c occupying most of the spark plug cylinder 25 is smaller than the inner diameter of the main plug hole 24a of the spark plug hole 24. The upper end portion 25a of the spark plug cylinder 25 is provided with a flange portion 25d having a diameter larger than the inner diameter of the main plug hole 24a of the spark plug hole 24. A lower end portion 25b of the spark plug cylinder 25 is fitted into a plug cylinder insertion portion 24b of the ignition plug hole 24, and a groove portion 25f into which the annular seal member 27 is fitted is formed in the lower end portion 25b. ing.

  The spark plug cylinder 25 is fixed and secured from above by a camshaft holder 50 described later. The camshaft holder 50 is formed with a contact portion 50a that contacts the flange portion of the spark plug cylinder 25, and a groove portion 50b into which the annular seal member 28 is fitted is formed in the corresponding contact portion 50a. ing. Further, the camshaft holder 50 is formed with a plug hole 50c that communicates with the inside of the spark plug cylinder 25 and into which the spark plug is inserted.

  The spark plug cylinder 25 is inserted into the spark plug hole 24 with the annular seal member 27 fitted in the groove 25d of the lower end portion 25b, and is moved upward by the camshaft holder 50 in which the annular seal member 28 is fitted in the groove 50b. When it is secured from slipping off, the space formed by the inner peripheral surface of the spark plug hole 24 and the outer peripheral surface of the spark plug cylinder 25 (plug cylinder outer oil path 63 described later) is formed by the annular seal members 27 and 28. The upper end portion 25 a and the lower end portion 25 b of the spark plug cylinder 25 are liquid-tight, and the inside of the cylinder head 4 and the spark plug hole 24 are partitioned by the spark plug cylinder 25.

  After the inside of the spark plug cylinder 25 is secured to the cylinder head 4 by the camshaft holder 50, the spark plug 26 is inserted into the spark plug cylinder 25 from the plug hole 50c of the camshaft holder 50, and the tip of the spark plug 26 is inserted. The screw portion 26 a formed in the above is screwed into the screw hole 24 a of the spark plug hole 24, and the electrode portion 26 b of the spark plug 26 is attached so as to face the combustion chamber 13.

  As shown in FIGS. 2 to 4, an intake cam shaft 32 provided with an intake cam 34 and an exhaust cam shaft 33 provided with an exhaust cam 35 are disposed in the valve operating chamber 31 in the left-right direction of the internal combustion engine 1. The bearing is formed in the lower bearing portion 38b as a bearing half formed in the cylinder head 4 and the camshaft holder 50, and is arranged in parallel in the front-rear direction so as to sandwich the spark plug hole 24. A cam bearing 38 composed of an upper bearing portion 38a as a half body is rotatably supported.

  As shown in FIGS. 3 and 4, the cylinder head 4 is provided with two bolt screw holes 53, 54 on the front and rear sides of each spark plug hole 24. The bolt screw holes 54 are formed at positions sandwiching the lower bearing portion 38b. The camshaft holder 50 is provided with two bolt insertion holes 51 and 52 for the front and rear of the spark plug hole 24 corresponding to the bolt screw holes 53 and 54 formed in the cylinder head, The bolt insertion hole 51 and the bolt insertion hole 52 are respectively formed at positions sandwiching the upper bearing portion 38a.

  After the spark plug cylinder 25 is inserted into the spark plug hole 24 formed in the cylinder head 4 and the intake cam shaft and the exhaust cam shaft are placed at predetermined positions on the lower bearing portion 38b formed in the cylinder head, the intake cam The camshaft holder 50 is placed so as to sandwich the shaft and the exhaust camshaft, and the flange bolts 55 and 56 are inserted into the bolt insertion holes 51 and 52 of the annular seal member 57 and the camshaft holder 50, and the bolt screw of the cylinder head 4 is inserted. The camshaft holder 50 is integrally fastened to the cylinder head 4 by screwing into the holes 53 and 54, and the intake camshaft 32 and the exhaust camshaft 33 are rotatably supported by the cam bearing 38. Since the annular seal member 57 is interposed between the flange bolts 55 and 56 and the camshaft holder 50, the bolt holes 51 and 52 and the bolt screw holes 53 and 54 are liquid-tight.

  As shown in FIG. 4, a driven sprocket 41 is integrally attached to the right end portion of the intake camshaft 32, and the driven sprocket 41 and the drive sprocket 40 provided on the crankshaft 10 include An endless timing chain 42 is stretched over, and the intake camshaft 32 is rotated by the rotational driving force of the crankshaft 10.

  An intake cam gear 36 is attached to substantially the center in the right direction of the intake cam shaft 32 so as to rotate integrally with the intake cam shaft 32, and an exhaust cam gear 37 is attached to the exhaust cam shaft 33 so as to mesh with the intake cam gear 36. It is attached integrally. The intake cam gear 36 and the exhaust cam gear 37 are formed with the same number of teeth, and the rotational drive force of the intake cam shaft 32 that is rotationally driven by the crankshaft 10 is supplied to the exhaust cam shaft via the intake cam 34 and the exhaust cam 37. The exhaust camshaft 33 is driven to rotate in the reverse direction at the same rotational speed as the intake camshaft 34.

  As shown in FIG. 2, an intake rocker arm 43 and an exhaust rocker arm 44 are supported on the cylinder head 4 by an intake rocker arm shaft 45 and an exhaust rocker arm shaft 46 so as to be freely slidable.

  As shown in FIGS. 8 and 9, the intake / exhaust rocker arms 43, 44 include pivot support bases 43a, 44a through which the intake / exhaust rocker arm shafts 45, 46 are pivoted, and the pivot support bases 43a, Peristaltic arms 43b and 44b extending from 44a are provided. The intake / exhaust rocker arms 43, 44 are formed with valve stem pressing portions 43f, 44f that press the valve stems 18a, 19a of the intake / exhaust valves 18, 19 so as to be continuous with the lower surfaces 43d, 44d of the swing arms 43b, 44b. Has been. Further, curved recesses 43g and 44g are formed on the lower surfaces 43d and 44d of the rocker arms 43 and 44 toward the valve stem pressing portions 43f and 44f. When the internal combustion engine 1 is mounted on a vehicle not shown, The curved recess 44g of the exhaust rocker arm 44 is at the lowest position.

  The upper surfaces 43c and 44c of the intake / exhaust rocker arms 43 and 44 are provided with sliding portions 43e and 44e that contact the intake / exhaust rocker arms 43 and 44 and the cam surfaces 34a and 35a of the intake and exhaust cams 34 and 35, respectively. . The upper retainer 21 of the intake / exhaust valves 18, 19 is fitted with a separately adjustable clearance adjustment member 29 that adjusts the gap between the valve stem shaft ends 18c, 19c and the intake / exhaust rocker arms 43, 44. Yes. The intake / exhaust rocker arms 43 and 44 are disposed between the valve stem end portions 18c and 19c of the intake and exhaust valves 18 and 19 and the cam surfaces 34a and 35a of the intake and exhaust cams 34 and 35, respectively. Yes. The sliding portions 43e and 44e of the intake / exhaust rocker arms 43 and 44 are in contact with the cam surfaces 34a and 35a, and the valve stem pressing portions 43f and 44f are configured to press the valve stem shaft ends 18c and 19c via the clearance adjusting member 29. It has become.

  As shown in FIGS. 9 and 10, the cylinder head 4 has support walls 71 and 72 for supporting both end portions 45 a and 45 b of the rocker arm shaft 45 that slidably supports the intake and exhaust rocker arms 43 and 44. Is formed. The support wall 71 is provided so as to be positioned at the center in the left-right direction of the cylinder, and a spark plug hole 24 is formed at the center in the left-right direction of the support wall 71. A pair of support walls 72 are formed on the left and right sides of the support wall 71, and the lower portions of the support wall 71 and the support wall 72 are connected by a connection bottom wall 73. On the lower surface 73a of the connecting bottom wall 73, a bulging portion 74 bulging downward is formed.

  As shown in FIG. 10, the support walls 71 and 72 are provided with rocker arm shaft fitting holes 71a and 72a for inserting the intake / exhaust rocker arm shafts 45 and 46 in the left-right direction. The rocker arm shaft fitting hole 71 a of 71 is in communication with the spark plug hole 24.

  After the intake / exhaust rocker arms 43, 44 are inserted between the support wall 71 and the support wall 72, the intake / exhaust rocker arm shafts 43, 44 are inserted from the rocker arm shaft fitting holes 72a of the support wall 72, and the rocker arm 3, The pivot support holes 43h and 44h formed in the pivot support bases 43a and 44a of 44 are inserted into the rocker arm shaft fitting holes 71a of the support wall 71, and the intake / exhaust rocker arms 43 and 44 are supported by the support walls 71 and 72. It comes to be supported by.

  As shown in FIG. 8, the intake / exhaust rocker arms 43, 44 are arranged so that the sliding portions 43e, 44e face each other outward, and in the front-rear direction, the intake / exhaust camshafts 32, 33 are arranged. It arrange | positions so that it may be located between.

  The intake rocker arm shaft 45 and the exhaust rocker arm shaft 46 are arranged at different height positions with respect to the extension line L of the cylinder central axis, and the intake rocker arm shaft 45 and the exhaust rocker arm shaft are mounted in a vehicle not shown. The cylinder of the internal combustion engine 1 is arranged such that the tip of the intake rocker arm 43 on the side disposed at the high position of 46 is directed obliquely upward and the tip of the exhaust rocker arm 44 on the side disposed on the low position is directed obliquely downward. It is mounted with the 11 tilted with respect to the vertical direction.

  The support wall 72 is formed with an engagement hole 72b into which an engagement member 68 is screwed to prevent the intake / exhaust rocker arm shafts 45, 46 from falling off. An engagement member 68 having a male screw (not shown) at the tip is screwed into a female screw (not shown) formed in the engagement hole 72b. The engagement member 68 engages with the engagement recess 45a of the intake rocker arm shaft 45 and the engagement recess 46a of the exhaust rocker arm shaft 46. The intake / exhaust air rocker arm shafts 45, 46 are connected to the cylinder head 4 by the engagement member 68. Dropping from is prevented. Note that a hole having a regular hexagonal cross-sectional shape is formed in the head of the engagement member 68, and the engagement member 68 can be screwed by inserting a regular hexagonal tip of a tool (not shown) into the hole. It is like that.

  When the internal combustion engine 1 starts, when the intake / exhaust cam shafts 32, 33 are rotated by the rotational driving force transmitted from the crankshaft 10, the intake / exhaust cams 34, 35 are rotated, and the intake / exhaust cams 34, With the shape of the 35 cam surfaces 34a, 35a, the cam contact portions 43b, 44b of the intake / exhaust rocker arms 43, 44 are pressed and the intake / exhaust rocker arms 34, 35 are oscillated, so that the valve stem contact portions 43c, 44c The valve stems 18a, 19a of the intake / exhaust valves 18, 19 are pressed via the clearance adjusting member 29, and the intake valve 18 and the exhaust valve 19 are opened and closed at a predetermined timing and lift amount.

  Next, the cam bearing oil supply mechanism 60 for supplying the lubricant to the cam bearing 38 of the internal combustion engine 1 and the lubricant oil supply structure 70 for the valve gear 30 will be described. As shown in FIG. 1, an oil pump 7 driven by the power of the crankshaft 10 is provided in the crankcase 2, and the oil pump 7 includes a strainer 8 disposed in the oil pan 6. When the oil pump 7 is driven by the crankshaft 10, the lubricating oil stored in the oil pan 6 is sucked from the strainer 8 and is supplied from the oil pump 7 through the supply oil passage 9 to the internal combustion engine. 1 is sent to various places.

  Lubricating oil pumped from the oil pump 7 passes through a supply oil passage 9 a extending upward to the joint surface of the crankcase 2 and the cylinder block 3 toward the crankshaft 10, and joins the crankcase 2 and the cylinder block 3. A supply oil passage 9c formed in the cylinder head 4 from the cylinder block 3 passes obliquely upward from a front end portion of the supply oil passage 9b through a supply oil passage 9b formed forward of the cylinder block 3 along the surface. As shown in FIG. 5, the cylinder head 4 is sent to a main lubricating passage 62 formed in the left-right direction.

  As shown in FIG. 2, the main lubricating oil passage 62 is formed as a single passage between the intake valve 18 and the exhaust valve 19 and below the intake rocker arm shaft 45 and the exhaust rocker arm shaft 46. ing. The main lubricating oil passage 62 is formed in a bulging portion 74 that bulges downward from a connecting bottom wall 73 to which the lower portion of the supporting wall 71 and the supporting wall 72 is connected.

  As shown in FIG. 5, the right end 62 a of the main lubricant passage 62 is connected to the supply oil passage 9 c, and the left end 62 b of the main lubricant passage 62 is closed by a plug 67. As shown in FIGS. 3 and 5, the main lubricating oil passage 62 is formed so as to penetrate through the four spark plug holes 24 formed in the cylinder head 4.

  As shown in FIGS. 6 and 7, a spark plug cylinder 25 is inserted into the spark plug hole 24, and a space formed by the inner peripheral surface of the spark plug hole 24 and the outer peripheral surface of the spark plug cylinder 25. The plug cylinder outer peripheral oil passage 63 is made fluid-tight at the upper end 25a and the lower end 25b of the spark plug cylinder 25 by the annular seal members 27, 28, and the inside of the cylinder head 4 and the spark plug hole 24 are connected to the spark plug. Partitioned by a cylinder 25. As shown in FIG. 7, since the spark plug hole 24 communicates with the main lubricating oil passage 62, the lubricating oil flowing through the upstream main lubricating oil passage 62 flows from the inlet 63a of the plug cylinder outer peripheral oil passage 63. It flows into the plug cylinder outer peripheral oil path 63, bypasses along the outer peripheral surface of the spark plug cylinder 25, and flows out into the main lubricating oil path 62 downstream from the outlet 63b of the plug cylinder outer peripheral oil path 63. Yes.

  As shown in FIGS. 3 and 6, the plug cylinder outer peripheral oil passage 63 passes through the lower bearing portion 38 b formed in the cylinder head 4, and is connected to the joint surface 59 between the camshaft holder 50 and the cylinder head 4. A guide passage 64 is formed to connect to the sliding surfaces of the intake camshaft 32 and the bearing 38, and the exhaust camshaft 33 and the bearing 38 so as to incline toward the spark plug hole 24. The inlet 64a of the guide passage 64 communicates with the plug cylinder outer peripheral oil passage 63, and the outlet 64b to the cam bearing portion 38 is on the ignition plug hole 24 side with respect to the rotation center of the intake and exhaust camshafts 32 and 33. Is provided on the semicircular circumferential surface 38c.

  As shown in FIG. 6, the spark plug cylinder 25 is positioned above the inlet 64 a of the guide passage 64 communicating with the plug cylinder outer peripheral oil path 63 and below the upper end portion 25 a of the spark plug cylinder 25. Thus, a raised portion 25g that is raised in an annular shape from the outer peripheral surface of the intermediate portion 25c is formed. The raised portion 25g promotes the flow of the lubricating oil that has flowed into the plug cylinder outer peripheral oil passage 25 from below into the inlet 64a of the guide passage 64.

  As shown in FIGS. 3 and 5, the guide passage 64 is formed so as to pass through a screw hole 53 provided between the spark plug hole 24 and the intake cam shaft 32 or the exhaust cam shaft 32. The flange bolts 55 and 56 and the annular seal member 57 that are screwed into the screw hole 53 are sealed so that the lubricating oil does not leak from the guide passage 64.

  As shown in FIGS. 8 and 9, the main lubricating oil passage 62 is formed of a connecting bottom wall 73 that connects lower portions of a pair of support walls 71 and 72 that support both shaft ends of the intake and exhaust rocker arm shafts 45 and 46. It is formed in the bulging portion 74. The main lubricating oil passage 62 is arranged so as to be biased toward the intake rocker arm shaft 45 on the side arranged at a high position with reference to the extension line L of the cylinder central axis. Further, an intake side oil injection oil passage 45 and an exhaust side oil injection oil passage 76 are formed in pairs so as to be directed independently from the main lubricating oil passage 62 for each of the intake rocker arm 43 and the exhaust rocker arm 44. The intake side oil injection oil passage 45 and the exhaust side oil injection oil passage 76 are opened in the valve operating chamber 31 by an intake side oil injection port 77 and an exhaust side oil injection port 78.

  In the intake side oil injection oil passage 75, the direction in which the lubricating oil is injected from the intake side oil injection port 77 and directed to the intake rocker arm 43 is the lower surface 43d of the swing arm 43b of the intake rocker arm 43, and the tip of the intake rocker arm 44 The lubricating oil is supplied to the valve stem pressing portion 43f of the intake rocker arm 43 by the lubricating oil injected from the intake side oil injection port 77 of the intake side oil injection oil passage 75. ing.

  Further, in the exhaust side oil injection oil passage 76, the direction in which the lubricating oil is injected from the intake side oil injection port 78 and directed to the exhaust rocker arm 44 is the lower surface 44 d of the swing arm 44 b of the exhaust rocker arm 44. Lubricating oil is injected into the pivot base 44a of the exhaust rocker arm 44 by the lubricant injected from the exhaust side oil injection port 78 of the exhaust side oil injection oil passage 76. Lubricating oil is supplied to the valve stem pressing portion 44f along the lower surface 44d of the swing arm 44b.

  As shown in FIG. 10, the intake / exhaust rocker arm shafts 45 and 46 are provided with rocker shaft oil passages 45b and 46b from the surface on the support wall 71 side in the longitudinal direction, Bearing oil supply passages 45c and 46c are formed so as to communicate with the pivotal support holes 43h and 44h of the intake / exhaust rocker arms 43 and 44, respectively. The rocker shaft oil passages 45 b and 46 b communicate with the plug outer peripheral oil passage 63 formed between the spark plug hole 24 and the spark plug cylinder 25.

  In the cam bearing oil supply structure 60 of the present embodiment, when the internal combustion engine 1 is started and the oil pump 7 starts to feed the lubricant, the lubricant passes through the supply oil passage 9 as shown in FIG. As shown in the figure, the main oil passage provided in each cylinder is supplied from the supply oil passage 9 to the right end 62a of the main lubricating oil passage 62 and sequentially from the right end 62a through the plug cylinder outer peripheral oil passage 63 provided in each cylinder. Sent to 62.

  The lubricating oil sent to the main lubricating oil passage 62 passes through the intake-side oil injection oil passage 75, and from the intake-side oil injection port 77 to the lower surface 43d of the swing arm 43b of the intake rocker arm 43, at the tip of the intake rocker arm 44. The lubricating oil is supplied to the valve stem pressing portion 43f of the intake rocker arm 43. Furthermore, it passes through the exhaust side oil injection oil passage 76 and is injected from the exhaust side oil injection port 78 toward the pivotal base 44a of the rocker arm 44 on the lower surface 44d of the rocker arm 44b of the exhaust rocker arm 44. Lubricating oil is supplied to the valve stem pressing portion 44f through the lower surface 44d and downward from the curved concave portion 44g.

  Furthermore, the lubricating oil sent to the main lubricating oil passage 62 flows into the rocker shaft oil passages 45b and 46b formed in the intake / exhaust rocker arm shafts 45 and 46, and is absorbed and absorbed from the bearing oil supply passages 45c and 46c. Lubricating oil is supplied to the sliding surfaces of the exhaust rocker arm shafts 45 and 46 and the pivot support holes 43h and 44h of the pivot support bases 43a and 44a of the intake and exhaust rocker arms.

  Since the lubricating oil supply structure 70 for the valve operating device of the internal combustion engine 1 according to the embodiment of the present invention is configured as described above, the main lubricating oil passage 62 is interposed between the intake / exhaust valves 18 and 19 and sucked. A single passage along the intake / exhaust camshafts 32, 33 is formed at a position below the exhaust rocker arm shafts 45, 46, and the intake / exhaust rocker arms 43, 44 are separated from the main lubricating oil passage 62. Since a pair of independently directed oil injection oil passages are provided, each intake / exhaust is directly from a single intake-side oil injection oil passage 75 and exhaust-side oil injection oil passage 76 while shortening the injection oil passage. Oil is supplied to the rocker arms 43 and 44 and oil supplied to the intake and intake side oil injection oil passages 75 and the exhaust side oil injection oil passages 76 is supplied from a common oil passage to facilitate securing the oil amount. be able to. Furthermore, the intake and intake side oil injection oil passages 75 and the exhaust side oil injection oil passages 76 are provided from the single main lubricating oil passage 62, so that the lubricating oil supply structure 70 of the valve operating device is saved and manufactured. Cost can be reduced.

  Further, the lower surfaces 43d, 44d of the swing arms 43b, 44b of the intake / exhaust rocker arms 43, 44 are formed so as to continue to the valve stem pressing portions 43f, 44f, and the intake / exhaust of the intake / exhaust side oil injection oil passages 75, 76 are formed. Even if there is oil that does not reach the valve stem pressing portions 43f and 44f directly in the injected oil by forming the direction directed to the rocker arms 43 and 44 toward the lower surfaces 43d and 44d of the swing arms 43b and 44b, The oil supply amount to the valve stem pressing portions 43f and 44f can be increased by transmitting this to the lower surfaces 43d and 44d of the swing arms 43b and 44b and supplying them to the valve stem pressing portions 43f and 44f.

  Further, since the lower surface 44d of the exhaust rocker arm 44 is formed in the curved concave portion 44g which is the lowest part toward the valve stem pressing portion 44f, the oil adhering to the lower surface 44d is positively attached to the valve stem pressing portion 44f and the exhaust valve stem end portion. Oil can be collected by being transmitted to the sliding part 44e side with 19c.

  Furthermore, since the clearance adjustment member 29 is arranged separately between the valve stem pressing portions 43f, 44f of the intake / exhaust rocker arms 43, 44 and the intake / exhaust valve stem shaft ends 18c, 19c, Such a screw adjusting mechanism disposed at the tip of the rocker arm is not necessary, and the sliding surface of the valve stem pressing portions 43f, 44f can be configured by a curved surface, so that the lower surfaces 43d, 44d of the intake / exhaust rocker arms 43, 44 are transmitted. Oil can be reliably supplied to the sliding surfaces of the valve stem pressing portions 43f and 44f.

  Also, the main lubricating oil passage 62 is provided on the connecting bottom wall 73 of the pair of supporting walls 71 and 72 supporting the shaft ends of the intake / exhaust rocker arm shafts 45 and 46, and bulges from the lower surface of the connecting wall 73. Since the main lubricating oil passage 62 is provided in the cylinder head 4, the size of the cylinder head 4 in the height direction can be suppressed.

  Further, by arranging the sliding portions 43e, 44e on the upper surfaces 43c, 44c of the suction / exhaust rocker arms 43, 44, the injected oil is cams of the suction / exhaust cams 34, 35 of the suction / exhaust cam shafts 32, 33. Oil can be supplied to the intake / exhaust valve stem end portions 18c and 19c without being hindered by mountains.

  When the intake / exhaust rocker arm shafts 45 and 46 are arranged closer to each other, they are arranged differently in the cylinder axial direction, and the main lubricating oil passage 62 is biased toward the intake rocker arm shaft 45 side on the side where it is arranged at a high position. Thus, the main lubricating oil passage 62 can be arranged in a compact manner by effectively utilizing the empty space.

  The internal combustion engine 1 is mounted on the vehicle so that the intake rocker arm 43 and the exhaust rocker arm 44 are directed obliquely upward and obliquely downward, and the intake side oil injection oil passage 75 to the intake rocker arm 43 disposed at a high position is provided. By directing the directivity direction toward the tip of the intake rocker arm 43 and directing the directivity direction of the exhaust side oil injection oil passage 76 to the exhaust rocker arm 44 arranged at a low position toward the pivot base 44a of the exhaust rocker arm 44, Even when it is difficult to direct to the tip of the rocker arm 44 as in the case of the exhaust side oil injection oil passage 76, it is possible to supply oil from the pivot base 44a of the rocker arm 44 to the tip of the rocker arm 44. Thus, it is possible to reliably supply oil while shortening the oil injection oil passage 76.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 4 ... Cylinder head, 4a ... Support wall, 4b ... Connection bottom wall, 4c ... Expansion part, 11 ... Cylinder, 18 ... Intake valve, 18a ... Valve stem, 18c ... Valve stem end part, 19 ... Exhaust valve, 19a ... Valve stem, 29 ... Clearance adjusting member, 32 ... Intake cam shaft, 33 ... Exhaust cam shaft, 34 ... Intake cam, 34a ... Intake cam surface, 35 ... Exhaust cam, 35a ... Exhaust cam surface, 38a ... Upper bearing portion, 38b ... lower bearing portion, 44 ... intake rocker arm, 43a ... pivot support base, 43b ... swing arm, 43c ... upper surface, 43d ... lower surface, 43e ... sliding portion, 43f ... valve stem pressing portion, 44 ... exhaust Rocker arm, 44a ... Pivot support base, 44b ... Peristaltic arm, 44c ... Upper surface, 44d ... Lower surface, 44e ... Sliding portion, 44f ... Valve stem pressing portion, 45 ... Intake rocker arm shaft, 46 ... Exhaust rocker arm shaft, 62 ... Main lubrication Oil passage, 71 ... support wall, 72 ... support wall, 73 ... connected bottom wall, 74 ... bulge , 75 ... intake side oil jetting oil passage, 76 ... exhaust-side oil jet oil passage L ... extension line of the cylinder center axis.

Claims (8)

It is used for an internal combustion engine (1) having a cylinder head (4) that rotatably supports a camshaft (32, 33),
Each of the pair of intake and exhaust engine valves (18, 19) is pivotally supported at the pivot base (43a, 44a) by a rocker arm shaft (45, 46) that supports the engine valve (18, 19). Between the valve stem end portions (18c, 19c) and the cam surfaces (34a, 35a) of the camshafts (32, 33) to contact each other, and the pressing force by the cam surfaces (34a, 35a) In the lubrication structure of the valve operating apparatus provided with the rocker arm (43, 44) that receives the swing arm (43b, 44b) and transmits it to the valve stem (18a, 19a) to open and close the engine valve (18, 19),
It is provided on the cylinder head (4) along the axial direction of the camshaft (32, 33), and is located between the intake and exhaust valves (18, 19) and below the rocker arm shaft (45, 46). An oil passage (62) formed by a single passage,
A valve operating apparatus for an internal combustion engine comprising an oil injection oil passage (75, 76) formed in a pair so as to be directed independently from the oil passage (62) for each rocker arm (43, 44) Lubrication structure. A portion of the rocker arm (43, 44) in contact with the valve stem (18a, 19a) side, which is continuous with the lower surface (43d, 44d) of the swing arm (43b, 44b) of the rocker arm (43, 44). A valve stem pressing part (43f, 44f) formed as follows,
The direction in which the oil injection oil passage (75, 76) is directed to the rocker arm (43, 44) is directed to the lower surface (43d, 44d) of the swing arm (43b, 44b). 2. The lubricating structure of the valve operating device according to 1.   3. The lubrication of a valve operating device according to claim 2, wherein the lower surface (44d) of the rocker arm (44) is formed in a curved concave portion (44g) which is the lowermost portion toward the valve stem pressing portion (44f). Construction.   A clearance adjusting member (29) for adjusting a gap between the valve stem shaft end (18c, 19c) and the rocker arm (43, 44) is provided on the valve stem (18a, 19a) and the rocker arm (43, 44). 4. The lubrication structure for a valve operating apparatus according to claim 3, wherein the valve stem pressing portion (43f, 44f) is provided as a separate member so as to be exchangeable.   The oil passage (62) is provided in the cylinder head (4), and is a connecting bottom wall for connecting the lower portions of a pair of support wall portions (71, 72) that support both shaft ends of the rocker arm shaft (45). The lubricating structure for a valve operating apparatus according to any one of claims 1 to 4, wherein the lubricating structure is provided in a bulging portion (74) bulged from a lower surface of (73). The camshafts (32, 33) are configured independently for intake (32) and exhaust (33), and each camshaft (32, 33) is disposed above each rocker arm (43, 44). ,
The upper surface (43c, 44c) of the rocker arm (43, 44) is provided with sliding portions (43e, 44e) between the rocker arm (43, 44) and the cam surface (34a, 35a). The lubricating structure for a valve operating apparatus according to any one of claims 1 to 5. The sliding portions (43e, 44e) of the respective rocker arms (43, 44) are arranged so as to face each other,
The rocker arm shaft (45, 46) is disposed between the intake and exhaust camshafts (32, 33),
The rocker arm shafts (45, 46) are arranged at different height positions with reference to an extension line (L) of the cylinder central axis,
The lubrication structure for a valve operating apparatus according to claim 6, wherein the oil passage (62) is arranged to be biased toward a rocker arm shaft (45) on a side where the oil passage is arranged at a high position. When the internal combustion engine (1) is mounted on a vehicle, the rocker arm (43) on the side located at the high position of the two rocker arm shafts (45, 46) has its tip pointed obliquely upward and the side located at the low position. The rocker arm (44) is mounted with the cylinder (11) of the internal combustion engine (1) inclined with respect to the vertical direction so that the tip is directed obliquely downward,
The injection direction of the oil injection oil passage (75) to the valve stem pressing portion (43f) on the side where the oil passage (62) of the rocker arm (43, 44) is biased is arranged so that the rocker arm (43) The oil injection oil passage (75) is formed so as to be directed to the tip,
The oil injection oil so that the injection direction of the oil injection oil passage (76) to the valve stem pressing portion (44f) of the other rocker arm (44) is directed to the pivot base (44a) of the rocker arm (44). The lubrication structure for a valve operating apparatus according to claim 7, wherein a passage (76) is formed.

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