JP2019044682A - Internal combustion engine - Google Patents

Abstract

To provide an internal combustion engine capable of properly lubricating a cam shaft with a simple structure.SOLUTION: An internal combustion engine is a slant type in which a cylinder bore axis is largely inclined to a vertical line, and a cam shaft 13 for an intake valve is positioned higher than a cam shaft 14 for an exhaust valve. An intake-side vertically-long passage 40 is formed in a region near an intake side of a cylinder head 4, and an oil is supplied from the intake-side vertically-long passage to a hydraulic lash adjuster for adjusting a valve clearance. Further a horizontally-long branch passage 52 branched from the intake-side vertically-long passage 40 is formed on a butting face of the cam cap 15 and the cylinder head 4, and both of the cam shaft 13 for the intake valve and the cam shaft 14 for the exhaust valve are lubricated by the horizontally-long branch passage 52. As the oil is directed toward the cam shaft 14 for the exhaust valve by gravity force, the cam shaft 14 for the exhaust valve can be also surely lubricated.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an internal combustion engine and is characterized by the structure of an oil passage in a head portion.

  In an internal combustion engine that opens and closes an intake / exhaust valve with a rocker arm, automatic adjustment of the valve clearance with a hydraulic lash adjuster is widely performed (for example, Patent Document 1). The hydraulic lash adjuster is disposed below each rocker arm, and oil is supplied to each hydraulic lash adjuster through a vertically long passage extending in parallel with the camshaft.

  Further, the sliding portion between the cam shaft and the cam cap is lubricated with oil. As a lubricating means for this cam shaft, Patent Document 2 discloses a separate system for an intake valve cam shaft and an exhaust valve cam shaft. Is disclosed.

JP2013-241908A JP 2006-194154 A

  The lubrication of the camshaft and the oil supply to the hydraulic lash adjuster are necessary, but if the oil supply system is provided separately, the structure becomes complicated accordingly. Regarding this point, it is conceivable to make the vertical passage of the hydraulic lash adjuster and the oil passage for the camshaft common on the intake side and the exhaust side, but simply the vertical passage of the hydraulic lash adjuster and the oil passage for the camshaft. In order to secure the necessary amount of oil and pressure, there is a risk that the burden on the oil pump will increase.

  The present invention has been made in view of such a current situation, and utilizes a characteristic of an internal combustion engine in which a cylinder bore axis is inclined with respect to a vertical line such as a slant type internal combustion engine or a V type internal combustion engine. It is intended to make it possible to operate the lash adjuster and lubricate the camshaft with a simple structure.

The present invention is
"The cylinder bore axis is inclined with respect to the vertical line so that the intake valve camshaft is higher than the exhaust valve camshaft.
Inside the cylinder head, a hydraulic lash adjuster for adjusting a valve clearance is arranged for each intake valve, and the cam shaft is freely rotatable by a cam cap fixed to the cylinder head. Held in "
This is the basic configuration.

And in invention of Claim 1, in the said basic composition,
An intake side vertically long passage extending in the direction of the intake valve cam shaft is provided in a portion of the cylinder head that is closer to the intake side surface than the intake valve cam shaft and the hydraulic lash adjuster. Side longitudinal passages and the hydraulic lash adjusters communicate with each other, and for each cam cap, branch from the intake side longitudinal passage to the exhaust valve camshaft via the intake valve camshaft. A leading branch passage is formed.

  The present invention also includes the structures of claims 2 and 3. Of these, the invention of claim 2 is the invention according to claim 1, wherein the branch passage has a horizontally long branch passage formed of a groove formed on a surface of the cam cap facing the cylinder head and the cam shaft. The cam shafts rotate in the flow direction of the oil flowing through the horizontally long branch passage.

  According to a third aspect of the present invention, in the second aspect, an oil passage for showering oil to the cam is branched from a portion between the intake valve cam shaft and the exhaust valve cam shaft in one horizontally long branch passage. ing.

  In the present invention, the oil flowing into the branch passage from the intake side vertically long passage is not only pressed by the pressure of the oil pump but also flows toward the exhaust valve camshaft by gravity (by its own weight). Therefore, without forming a longitudinal passage for lubricating the exhaust cam, or without branching the passage from the intake-side longitudinal passage for adjusting the valve clearance of the exhaust valve to the exhaust-side camshaft, Furthermore, the intake valve camshaft and the exhaust valve camshaft can be accurately lubricated without increasing the discharge pressure of the oil pump.

  Therefore, according to the present invention, the camshaft can be lubricated and the valve clearance can be optimized while simplifying the structure. Moreover, since it is not necessary to increase the discharge pressure of the oil pump, it can contribute to the improvement of fuel consumption.

  The branch passage may be formed by a groove formed on the upper surface of the cylinder head. However, when the structure of claim 2 is adopted, oil flowing on the arc surface of the cam cap is accelerated by the cam shaft. Can be firmly lubricated. In addition, since the camshaft plays the role of an oil pump, the burden on the oil pump can be reduced to further contribute to the improvement of fuel consumption.

  When the oil shower device for lubricating the cam is provided in the head portion, it is possible to pass through a passage independent from the main gallery, but in this case, the structure becomes complicated and the design of the cylinder head becomes troublesome. On the other hand, when the configuration of claim 3 of the present application is adopted, no special processing is required for the cylinder head, and the structure can be simplified. Further, since the oil flowing through the horizontally long branch passage is pressurized and pumped by the intake valve cam shaft as described above, the oil as the oil shower for the cam can be secured firmly.

1 is an overall front view of an internal combustion engine. It is a separation perspective view of a head part concerning an embodiment. It is the figure which looked at the cylinder head from the horizontal direction. (A) is a longitudinal front view seen from the IV-IV view direction of FIG. 3 in a display state in which the camshafts are arranged horizontally, (B) is a partial cross-sectional view taken along line BB of (A), It is the fragmentary perspective view which looked at the cam cap from the downward direction. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3. (A) is the elements on larger scale of the hydraulic lash adjuster shown in FIG. 5, (B) is BB sectional drawing of (A). It is a schematic diagram which shows arrangement | positioning of an oil path. It is a partial top view of a gasket. It is a separation perspective view of a head cover and a baffle plate. It is a separation perspective view of a head cover and a gasket. It is the perspective view which looked at the head cover with which the baffle plate was mounted | worn from the downward direction. (A) is a partially longitudinal front view at the location of the exhaust valve cam, (B) is a bottom view of the portion indicated by X in FIG. 9 of the baffle plate, and (C) is a CC line of (B). (D) is a DD cross-sectional view of (C).

(1). Outline of Internal Combustion Engine Next, an embodiment of the present invention will be described based on the drawings. The present embodiment is applied to an internal combustion engine for automobiles, and as shown in FIG. 1, the internal combustion engine is a slant type in which a cylinder bore axis O is brought close to the horizontal (the cylinder bore axis O is in the horizontal direction). Inclines to form an angle of slightly less than 30).

  FIG. 1 is a view as seen from the axial direction of the crankshaft 1. In this embodiment, this state is defined as a front view. Further, in the following, front / rear / up / down / left / right terms are used to specify the direction, but the front / rear direction is the direction of the crank axis 2, and the upper / lower direction is the direction of the cylinder bore axis O unless otherwise specified. A direction perpendicular to the cylinder bore axis O is defined. When the vertical direction is used in the vertical direction, this is clearly indicated. As a precaution, the direction is clearly shown in FIG.

  As shown in FIG. 1, the basic configuration of the internal combustion engine is the same as that of the prior art, a cylinder block 3 in which the crankshaft 1 is rotatably held, a cylinder head 4 fixed to the upper surface thereof, and a bolt on the upper surface of the cylinder head 4. The head cover 5 is fixed. Although the internal combustion engine includes an oil pan 6, the cylinder bore axis O is greatly laid down, so that the oil pan 6 is fixed to the lower surface of the cylinder block 3 via an auxiliary block 7.

  The cylinder block 3 and the cylinder head 4 are covered with a front cover (not shown) from the front side, and a timing chain is arranged at a location hidden by the front cover. Reference numeral 8 shown in FIG. 1A denotes a crank pulley.

  In this embodiment, the intake side surface 9 of the cylinder head 4 is upward in the vertical direction, the exhaust side surface 10 is downward in the vertical direction, and an intake manifold 11 in which a surge tank is integrated with the exhaust side surface 10 of the cylinder head 4. Is fixed. In FIG. 1, the cylinder head 4 and the head cover 5 show a rough layout, and do not exactly match the form described below.

(2). Cylinder Head and Valve Mechanism Next, the structure of the cylinder head 4 and the valve mechanism will be described mainly with reference to FIGS. As clearly shown in FIGS. 2 and 4, the cylinder head 4 of the present embodiment has a laminated structure of an upper portion 4 a and a lower portion 4 b, and an intake valve camshaft is mounted on a bearing portion provided on the upper portion 4 a. 13 and the exhaust valve cam shaft 14 are rotatably held via a cam cap 15. Of course, the cam shafts 13 and 14 are formed with a pair of cams 16 and 17 corresponding to the respective cylinders for opening and closing the valves. In the upper portion 4a of the cylinder head 4, both the front and rear sides of the bearing portion are opened up and down.

  As shown in FIG. 4, the cam cap 15 is fixed to the upper portion 4 a of the cylinder head 4 by bolts 18 on both sides of the cam shafts 13 and 14. Further, VVT devices 19 and 20 are provided at the front end portions of the cam shafts 13 and 14, and a portion where the VVT devices 19 and 20 are provided is rotatably held by a front cap 21.

  3 and 5, a pair of left and right rocker arms 22 and 23 corresponding to the pair of cams 16 and 17 are arranged on the upper portion 4a of the cylinder head 4 (in FIG. One rocker arm 22 on the side is omitted.). As shown in FIG. 5, the rocker arms 22 and 23 of the present embodiment are free types having no rotational axis, and one end portion located inside the cylinder head 4 abuts the valve shafts 24 and 25 from above. The valve shafts 24 and 25 are urged upward by a spring 27 through a spring receiver 26 and a shim 25a.

  The other end of the intake valve rocker arm 22 is supported by a hydraulic lash adjuster 28, while the other end of the exhaust valve rocker arm 23 is supported by a fixed support 29. The positional relationship between the rocker arms 22 and 23 and the spring 27 is clearly shown in FIG. In FIG. 3, reference numeral 31 denotes an intake side receiving portion into which the hydraulic lash adjuster 28 is fitted, reference numeral 32 denotes an exhaust side receiving portion into which the fixed support 29 is fitted, and reference numeral 33 denotes a hole for mounting the ignition device.

  The hydraulic lash adjuster 28 has a conventionally known structure and includes a plunger 34 that supports the rocker arm 22 and an upwardly opening body 35 in which the plunger 34 is fitted. A pressure adjusting hole 36 is formed at the lower end of the plunger 34, and a check ball 38 urged by a spring 37 is in contact with the pressure adjusting hole 36 from below. A lubrication hole is formed at the upper end of the plunger 34.

  The body 35 is provided with an outer oil hole 39 that opens toward the intake side. The outer oil hole 39 is formed on the intake side surface side of the body 35 and is formed in the upper portion 4 a of the cylinder head 4. 40. In addition, the plunger 34 has an inner oil hole 41 that is displaced upward from the outer oil hole 39, and the inner and outer oil holes 39, 41 communicate with each other via an annular space 42. When the pressing force of the rocker arm 22 against the plunger 34 becomes weak, the oil passes through the pressure adjusting hole 36 and the plunger 34 moves forward, and the pressing force (valve clearance) of the rocker arm 22 against the plunger 34 is kept constant.

  The fixed support 29 for the exhaust valve is obtained by removing the pressure adjusting spring 37 and the check ball 38 from the hydraulic lash adjuster 28 and replacing it with a spacer 43. Adjustment of the valve clearance of the exhaust valve is performed by a shim 25 a provided on the valve shaft 25. Since the fixed support 29 also needs lubrication, an exhaust side longitudinal passage 44 located on the exhaust side surface with the body 35 interposed therebetween is provided in the upper portion 4a of the cylinder head 4 so that the exhaust side longitudinal passage 44 and the body are connected. The inside of 30 is connected.

(3) Oil supply structure As schematically shown in FIG. 7, an upper and lower main passage 47 branched from the main gallery is formed in the front portion of the lower portion 4 b of the cylinder head 4. From the upper end, an intake side side branch passage 48 and an exhaust side side branch passage 49 are divided into left and right branches. As clearly shown in FIG. 3, the side branch passages 48 and 49 are formed by grooves formed on the upper surface of the front end edge portion of the lower portion 4b, and the grooves are closed by the upper portion 4a. Yes. In addition, a groove | channel may be formed in the lower surface of the upper part 4a, and may be formed in both.

  The end of the intake side side branch passage 48 communicates with an intake side downward side passage 50 formed in the lower portion 4 b of the cylinder head 4, and the intake side vertically elongated passage 40 described above is formed at the lower end of the intake side downward side passage 50. Communicate. As shown in FIG. 4, an upward branch passage 51 is formed from the intake side longitudinal passage 40 toward the end of each cam cap 15, and the cam cap 15 and the cylinder head are formed at the upper end of the upward branch passage 51. 4 (the upper portion 4a) and a horizontally long branch passage 52 formed on the mating surface communicate with each other. The upward branch passage 51 is formed in the upper part 4 a and the lower part 4 b of the cylinder head 4. In the present embodiment, the branch passage described in the claims includes an upward branch passage 51 and a horizontally long branch passage 52.

  As shown in FIG. 4, the horizontally long branch passage 52 is formed by a groove formed in the lower surface of the cam cap 15, and extends so as to surround the intake valve cam shaft 13 and the exhaust valve cam shaft 14 from above. Yes. Therefore, a vertically long passage for the exhaust valve cam shaft 14 is not required. In the cam cap 15 located between the first and second cylinders from the front, a portion of the cam cap 15 between the intake valve cam shaft 13 and the exhaust valve cam shaft 14 extends from the horizontally long branch passage 52. A branched auxiliary upward passage 53 is formed. The auxiliary upward passage 53 is for a cam oil shower and will be described in detail later.

  The end of the exhaust-side side branch passage 49 communicates with an exhaust-side downward side passage 55 formed in the lower portion 4b of the cylinder head 4, and the above-described exhaust-side longitudinal passage 44 is formed at the lower end of the intake-side downward side passage 55. Communicate. Each passage is formed by drilling, and when the open end is exposed to the outside, the open end is closed with a plug (not shown).

  As indicated by a one-dot chain line in FIG. 7, control passages 56 and 57 connected to a control valve (OCV: not shown) for controlling the VVT device are provided from both side branch passages 48 and 49 on the intake side and the exhaust side. Branching upward.

  The exhaust-side longitudinal passage 44 only supplies oil that lubricates the contact surface between the rocker arm 23 for the exhaust valve and the fixed support 29, and the amount of oil and the pressure are sufficient. Therefore, as shown in FIG. 3, a throttle part 58 having a reduced passage cross-sectional area is provided in a portion of the exhaust side side branch passage 49 on the downstream side of the control passage 57, and the oil flowing toward the exhaust side longitudinal passage 44 is provided. The amount is adjusted.

(4). Overview of the upper part of the engine As described above, this embodiment includes an oil shower device that showers oil on the cam. As described above, the oil shower device includes one horizontal elongated branch passage 52. Oil is supplied from This point will be described mainly with reference to FIGS. 8 to 12 (see FIGS. 2 and 4). First, an overview of the upper part of the engine will be described.

  As shown in FIGS. 4, 9, and 11, a baffle plate 60 is disposed inside the head cover 5, and is fixed to the top plate 63 of the head cover 5 with screws 61 (see FIG. 11). A synthetic resin gasket 62 as shown in FIGS. 8 and 10 is interposed between the mating surfaces of the cylinder head 4 and the head cover 5. The gasket 62 has a loop portion 62b in which the left and right long portions 62a are connected by the front and rear short portions, and the left and right long portions 62a are connected by a single connecting portion 61c. The head cover 5 and the baffle plate 60 of the present embodiment are made of metal (for example, aluminum die-cast product or cast product), but synthetic resin can also be used.

  The head cover 5 has a substantially rectangular shape that is long in the crank axis direction. As shown in FIG. 11, a plug hole 64 for mounting an ignition device (not shown) is provided at a position along the longitudinal center line of the top plate 63. Four are formed at intervals. Therefore, the internal combustion engine of this embodiment has four cylinders.

  As shown in FIGS. 4, 9, and 10, a part of the top plate 63 of the head cover 5 protrudes upward to form a recess, and the recess is closed with a baffle plate 60, thereby providing a blow-by gas passage (gas-liquid). A separation chamber) 65 and a fresh air passage 66 are formed. The blow-by gas passage 65 and the fresh air passage 66 are located on both sides of the row of plug holes 64. Precisely, the blow-by gas passage 65 is located on the intake side, and the fresh air passage 66 is located on the exhaust side.

(5). Oil Shower Structure As shown in FIG. 9, for example, the baffle plate 60 includes an intake side portion 67 and an exhaust side portion 68, and a joint portion 69 that connects the two. The intake side portion 67 corresponds to the blow-by gas passage 65, and the exhaust side portion 68 corresponds to the fresh air passage 66. The intake side portion 67 and the exhaust side portion 68 are entirely surrounded by the oil passage rib 70 and the auxiliary rib 71.

  The oil passage ribs 70 of the intake side portion 67 and the exhaust side portion 68 extend long in the camshaft direction, and both are connected by a connecting oil passage rib 72 provided in the joint portion 69. In FIG. 9, the oil passage rib 70 is shown with parallel oblique lines. This is for facilitating the grasp of the form, not the display of the cross section.

  The intake-side and exhaust-side oil passage ribs 70 are for showering oil into the intake valve cam 16 and the exhaust valve cam 17, and as clearly shown in FIGS. A trapezoidal groove 73 is formed on the top surface of the oil passage rib 70 (72). The oil passage is formed by closing the groove 73 with the top plate 63 of the head cover 5. The oil flowing through the groove 73 is ejected from the oil ejection hole 74 provided in the baffle plate 60 toward the cams 16 and 17. In addition, a bowl-shaped oil guide 75 having a shape that surrounds the oil ejection hole 74 from the exhaust side protrudes downward from each oil ejection hole 74.

  Note that the rear portion 70 a indicated by the arrow X in FIG. 9 in the oil passage rib 70 of the exhaust side portion 68 does not overlap the top plate 63 of the head cover 5, and the groove 73 cannot be formed. Therefore, as shown in FIG. 12 (B), by passing a drill 76 from the rear end, a tunnel hole 77 communicating with the groove 73 is formed and the opening end is closed with a plug (not shown). As shown in FIG. 12C, the oil ejection hole 74 is opened in a state where it communicates with the tunnel hole 77.

  The intake-side and exhaust-side oil passage ribs 70 are connected by a connecting oil passage rib 72, but the exhaust-side oil passage rib 70 and the connecting oil passage rib 72 are in a three-way connection state. In addition, an oil introduction cylinder portion 78 shown in FIG. The oil introduction cylinder part 78 is connected to a relay cylinder part 79 having an upper and lower opening formed in the coupling part 62 c of the gasket 62, and the auxiliary upward passage 53 of the cam cap 15 is connected to the relay cylinder part 79.

  As shown in FIG. 2, the relay cylinder portion 79 is formed on the cam cap 15 so as to protrude rearward, and a rearward projecting portion 80 corresponding to the relay cylinder portion 79 is also formed on the upper portion 4 a of the cylinder head 4. Has been. As shown in FIG. 4C, a branch passage is provided in the horizontally long branch passage 52 and the auxiliary upward passage 53 is connected to the tip of the branch passage at the relay cylinder portion 79 and the rearward projecting portion 80.

  As shown in FIG. 4, the loop portion 62 b of the gasket 62 is fitted in a seal groove 81 formed on the lower surface of the head cover 5. The connecting portion 62c is basically in the form of a band plate and is provided with a relief hole 82 in which the head of the bolt 18 that fixes the cam cap 15 is loosely fitted. Further, since the upper surface of the cam cap 15 has an uneven shape, a downward projecting portion 83 that is placed on a lower portion of the cam cap 15 is provided to ensure stability.

  Further, a communication boss portion 84 through which blow-by gas passes is formed at an end portion of the connection portion 62c that is closer to the intake side. The communication boss portion 84 has a cylindrical shape and communicates with a blow-by gas inlet 85 formed in the baffle plate 60.

(6) Summary In the above configuration, the intake valve camshaft 13 and the exhaust valve camshaft 14 are lubricated by the single horizontally long branch passage 52, but the internal combustion engine is of a slant type and is used for the intake valve. Since the cam shaft 16 is high and inclined so that the exhaust valve cam shaft 14 becomes lower, the oil flows from the intake valve cam shaft 13 toward the exhaust valve cam shaft 14 by its own weight. Accordingly, both the intake valve cam shaft 13 and the exhaust valve cam shaft 14 can be appropriately lubricated without excessively increasing the oil pressure. That is, the cam shafts 13 and 14 can be firmly lubricated with a simplified structure without specially forming a passage for the exhaust valve cam shaft 14.

  Normally, the crankshaft 1 and the camshafts 13 and 14 rotate clockwise in a front view of the engine. However, as in the embodiment, the camshafts 13 and 14 are surrounded by the horizontally long branch passage 52 from above. When employed, the oil tends to be pumped by rotation of the intake valve camshaft 13, so that the lubrication of the exhaust valve camshaft 14 can be further ensured and the oil supply to the cam oil shower device can also be ensured. .

  In the present embodiment, a hydraulic lash adjuster 28 is used as the valve clearance adjusting means for the intake rocker arm 22, and a fixed support 29 is used as the valve clearance adjusting means for the exhaust valve rocker arm 23. Therefore, in both cases, the required oil pressure can be reduced as compared with the case where the hydraulic lash adjuster 28 is used, and as a result, the burden on the oil pump can be reduced and the fuel efficiency can be improved.

  Further, from the viewpoint of the importance of engine control, control of intake valve opening / closing timing is more important than control of exhaust valve opening / closing timing. However, since the exhaust valve is not necessarily as severe as the intake valve, the shim 25a attached to the valve shaft 25 is not necessarily required. It is possible to cope with even the adjustment by.

  Further, when the amount of oil supplied to the exhaust-side vertically long passage 44 is adjusted by the throttle portion 58 as in this embodiment, there is an advantage that the adjustment of the amount of oil supplied can be realized with a simple structure.

  The present invention can actually be embodied in an internal combustion engine. Therefore, it can be used industrially.

O Cylinder bore axis 4 Cylinder head 4a Upper part 4b Lower part 5 Head cover 9 Intake side face 10 Exhaust side face 13 Intake valve camshaft 14 Exhaust valve camshaft 15 Cam cap 16, 17 Cam 18 Bolt 22, 23 Rocker arm 25a Provided shims 28 Hydraulic lash adjuster 29 Fixed support 40 Intake side longitudinal passage 44 Exhaust side longitudinal passage 47 Main passage 48, 49 Side branch passage 51 Upward branch passage constituting the branch passage according to claim 52 Horizontally long branch passage constituting the branched branch passage 58 Restricted portion 60 Baffle plate 62 Gasket 62c Gasket connecting portion 74 Oil ejection hole 78 Oil introducing cylinder portion 79 Relay cylinder portion

Claims (3)

The cylinder bore axis is inclined with respect to the vertical line so that the intake valve camshaft is higher than the exhaust valve camshaft.
Inside the cylinder head, a hydraulic lash adjuster for adjusting the valve clearance is arranged for each intake valve, and the cam shaft is freely rotatable by a cam cap fixed to the cylinder head. A retained configuration,
In the cylinder head, an intake side vertically long oil passage extending in the direction of the intake valve camshaft is provided at a portion closer to the intake side surface than the intake valve camshaft and the hydraulic lash adjuster, The intake-side vertical oil passage communicates with each of the hydraulic lash adjusters, and for each cam cap, branches from the intake-side vertical oil passage and passes through the intake valve camshaft for the exhaust valve. A branch passage leading to the camshaft is formed,
Internal combustion engine. The branch passage has a horizontally long branch passage formed by a groove formed on a surface of the cam cap facing the cylinder head and the cam shaft, and both the cam shafts are oils flowing through the horizontally long branch passage. It is designed to rotate in the flow direction of
The internal combustion engine according to claim 1. An oil passage for showering oil to the cam is branched from a portion between the intake valve cam shaft and the exhaust valve cam shaft in one horizontally long branch passage.
The internal combustion engine according to claim 2.

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