JP6713710B2 - Slant type internal combustion engine - Google Patents

Description

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

BACKGROUND ART In an internal combustion engine in which a rocker arm opens and closes an intake/exhaust valve, automatic adjustment of valve clearance by a hydraulic lash adjuster is widely performed (for example, Patent Document 1). The hydraulic lash adjuster is arranged at the lower part of each rocker arm, and the oil is supplied to each hydraulic lash adjuster through a vertically long passage extending in parallel with the cam shaft.

Further, the sliding portion between the cam shaft and the cam cap is lubricated with oil, and as a lubrication means for this cam shaft, in Patent Document 2, an intake valve cam shaft and an exhaust valve cam shaft are separated from each other. It is disclosed to be done in.

JP, 2013-241908, A JP 2006-194154 A

It is necessary to lubricate the camshaft and supply oil to the hydraulic lash adjuster, but if the oil feeding system is provided separately, the structure becomes complicated accordingly. Regarding this point, it may be considered to make the vertical passage of the hydraulic lash adjuster and the oil passage for the cam shaft common on the intake side and the exhaust side, but simply use the vertical passage of the hydraulic lash adjuster and the oil passage for the cam shaft. Just by sharing the above and the above, there is a risk that the load on the oil pump will increase in order to secure the necessary oil amount and pressure.

The present invention has been made in view of the above circumstances, and utilizes the characteristics of an internal combustion engine, such as a slant type internal combustion engine or a V type internal combustion engine, in which the cylinder bore axis is inclined with respect to the vertical line, and a hydraulic type It is intended to enable the operation of the lash adjuster and the lubrication of the cam shaft with a simple structure.

The present invention is
"A cylinder head in which an intake valve cam shaft and an exhaust valve cam shaft are rotatably held via a plurality of cam caps extending across the both cam shafts, and fixed to the top surface of the cylinder head. With a head cover,
The cam shaft for intake valves is a cylinder bore axis is inclined with respect to the vertical line so that a position higher than the camshaft for the exhaust valve "
The target is a slant type internal combustion engine called
"Inside of the cylinder head, said each portion of the intake valves with are arranged a hydraulic lash adjuster for adjusting valve clearance, prior Symbol intake side than the cam shaft and the hydraulic lash adjusters for the intake valves while the site closer to the side, provided with a long extending intake side longitudinal passage in the direction of the intake valve camshaft, and communicates with said a air intake side Vertical passage the hydraulic lash adjuster,
A horizontally long branch passage is formed on the mating surface between the cam caps and the cylinder head and branches from the vertically long passage on the intake side and extends to the side of the exhaust valve camshaft via the intake valve camshaft ."
It has a basic configuration.

And in invention of Claim 1, in the said basic structure,
“ One cam cap of the plurality of cam caps is provided with an auxiliary passage branching from the laterally long branch passage toward the head cover at a portion between the intake valve cam shaft and the exhaust valve cam shaft. The head cover has a cam shower passage for dropping the oil flowing from the auxiliary passage to the cams of the both cam shafts."
Is added.

The present invention also includes the configuration of claim 2 . Of these, the invention is based on claim 1.
"A loop-shaped gasket is provided on the mating surface between the outer peripheral portion of the head cover and the outer peripheral portion of the cylinder head,
The gasket has a connecting portion interposed between the one cam cap and the head cover, and the connecting portion has an oil relay cylinder portion sandwiched between the cam cap and the head cover and communicating with the auxiliary passage. Has been done,
In addition, downward protrusions that come into contact with the cam cap are provided on both sides of the connecting portion of the gasket that sandwich the oil relay cylinder portion.
It is configured as.

In the present invention, the oil that has flowed into the horizontal branch passage from the intake side Vertical passage is not only pushed by the pressure oil pump (under its own weight) by gravity rather flowing toward the cams axis.

Thus, according to the present invention, while simplifying the structure, Ru can be performed and appropriate of lubricating the valve clearance of the camshaft.

The laterally long branch passage may be formed by a groove formed on the arc surface of the cylinder head at the position of the intake valve cam shaft, but as in the embodiment, it has a groove formed on the arc surface of the cam cap. When adopting, the oil flowing on the arc surface of the cam cap is accelerated by the cam shaft, so that the cam shaft can be lubricated firmly. Further, since the cam shaft plays the role of the oil pump, the load on the oil pump can be reduced and the fuel consumption can be further improved.

When an 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 complicated. On the other hand, in the present invention, the cylinder head does not require any special processing, and the structure can be simplified. Further, since the oil flowing in the laterally long branch passage is pressurized and pumped by the intake valve cam shaft as described above, it is possible to securely secure the oil as the oil shower for the cam.
According to the second aspect of the present invention, the stability of the gasket can be ensured by the downward projection even if the upper surface of the cam cap is uneven.

1 is an overall front view of an internal combustion engine. FIG. 3 is an exploded perspective view of the head unit according to the embodiment. It is the figure which looked at the cylinder head from the horizontal direction. (A) is a vertical sectional front view seen from the IV-IV viewing direction of FIG. 3 in a state where the cam shafts are horizontally arranged, (B) is a partial sectional view of (A) taken along BB, and (C) is It is a partial perspective view which looked at a cam cap from the lower part. FIG. 5 is a sectional view taken along line V-V of FIG. 3. 6A is a partially enlarged view of the hydraulic lash adjuster shown in FIG. 5, and FIG. 6B is a sectional view taken along line BB of FIG. It is a schematic diagram which shows arrangement|positioning of an oil passage. It is a partial top view of a gasket. It is a separation perspective view of a head cover and a baffle plate. FIG. 6 is a perspective view showing a head cover and a gasket separated from each other. It is the perspective view which looked at the head cover with which the baffle plate was attached from the lower part. (A) is a partial vertical sectional front view at the location of the exhaust valve cam, (B) is a bottom view of a portion of the baffle plate indicated by X in FIG. 9, and (C) is CC of (B). Sectional view, (D) is a sectional view taken along line D-D of (C).

(1). Outline of Internal Combustion Engine Next, an embodiment of the present invention will be described with reference to 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 the cylinder bore axis O is greatly approached horizontally (the cylinder bore axis O is horizontal. It is inclined to form an angle of less than 30).

Although FIG. 1 is a view seen from the axial direction of the crankshaft 1, this state is defined as a front view in the present embodiment. Further, in the following, the terms front-rear, up-down, left-right are used to identify the direction. It is defined as the direction orthogonal to the cylinder bore axis O. When the vertical direction is used in the vertical direction, the fact is clearly stated. As a precaution, the direction is clearly shown in FIG.

As shown in FIG. 1, the basic structure of the internal combustion engine is the same as that of the conventional one, and a cylinder block 3 in which a 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 are provided. It has a head cover 5 fixed by. Further, the internal combustion engine is provided with the oil pan 6, but the cylinder bore axis O is greatly laid down, so the oil pan 6 is fixed to the lower surface of the cylinder block 3 via the 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 position hidden by the front cover. Reference numeral 8 shown in FIG. 1(A) is a crank pulley.

In this embodiment, the intake side surface 9 of the cylinder head 4 is vertically upward, and the exhaust side surface 10 is vertically downward. The intake side surface 11 of the cylinder head 4 is an intake manifold 11 in which a surge tank is integrated. 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 Operating Mechanism Next, the structure of the cylinder head 4 and the valve operating mechanism will be described mainly with reference to FIGS. As clearly shown in FIGS. 2 and 4, the cylinder head 4 of this embodiment has a laminated structure of an upper portion 4a and a lower portion 4b, and a bearing portion provided in the upper portion 4a has a camshaft for intake valves. 13 and an exhaust valve cam shaft 14 are rotatably held via a cam cap 15. As a matter of course, a pair of cams 16 and 17 for opening and closing valves are formed on the cam shafts 13 and 14 corresponding to each cylinder. In the upper portion 4a of the cylinder head 4, the front and rear sides of the bearing portion are open vertically.

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

As shown in FIGS. 3 and 5, a pair of left and right rocker arms 22 and 23 are arranged on the upper portion 4a of the cylinder head 4 in correspondence with the pair of cams 16 and 17 (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 rotation axis, and one end located inside the cylinder head 4 contacts the valve shafts 24 and 25 from above. The valve shafts 24 and 25 are biased upward by the spring 27 via the spring bearing 26 and the shim 25a.

The other end of the rocker arm 22 for the intake valve is supported by the hydraulic lash adjuster 28, while the other end of the rocker arm 23 for the exhaust valve is supported by the 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 is an intake side receiving portion into which the hydraulic lash adjuster 28 is fitted, reference numeral 32 is an exhaust side receiving portion into which the fixed support 29 is fitted, and reference numeral 33 is a hole for mounting an 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 in the lower end of the plunger 34, and a check ball 38 urged by a spring 37 contacts the pressure adjusting hole 36 from below. The upper end of the plunger 34 has a lubricating hole.

An outer oil hole 39 that opens toward the intake side is formed in the body 35, and the outer oil hole 39 is formed in the upper portion 4a of the cylinder head 4 on the intake side surface side of the body 35. It communicates with 40. Further, the plunger 34 has an inner oil hole 41 which is displaced upward from the outer oil hole 39, and the inner and outer oil holes 39, 41 communicate with each other through 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, so that 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 them with the spacer 43. The valve clearance of the exhaust valve is adjusted by a shim 25a provided on the valve shaft 25. Since the fixed support 29 also needs to be lubricated, the upper side 4a of the cylinder head 4 is provided with an exhaust side vertical passage 44 located on the side of the exhaust side with the body 35 sandwiched between the exhaust side vertical passage 44 and the body. It communicates with the inside of 30.

(3). Oil supply structure As shown schematically in FIG. 7, in the front part of the lower portion 4b of the cylinder head 4, a vertically elongated main passage 47 branched from the main gallery is formed. From the upper end, an intake side side branch passage 48 and an exhaust side side branch passage 49 are branched left and right. 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 to form passages. There is. The groove may be formed on the lower surface of the upper portion 4a or may be formed on both surfaces.

The end of the intake side branch passage 48 communicates with an intake side downward side passage 50 formed in the lower portion 4b of the cylinder head 4, and the intake side vertical elongated passage 40 described above is provided at the lower end of the intake side downward side passage 50. It is in communication. 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 15 are formed at the upper end of the upward branch passage 51. 4 (upper part 4a) and the laterally long branch passage 52 formed in the mating surface are connecting. The upward branch passage 51 is formed in the upper portion 4a and the lower portion 4b of the cylinder head 4. In the present embodiment, the branch passage described in the claims is composed of the upward branch passage 51 and the horizontally long branch passage 52.

As shown in FIG. 4, the laterally long branch passage 52 is formed by a groove formed on 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. There is. Therefore, a vertically long passage for the exhaust valve camshaft 14 is unnecessary. In the cam cap 15 located between the first and second cylinders from the front, from the laterally long branch passage 52 to the portion of the cam cap 15 between the intake valve cam shaft 13 and the exhaust valve cam shaft 14. A branched upward auxiliary passage 53 is formed. The auxiliary passage 53 is for an oil shower for cams and will be described in detail later.

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

As shown by the alternate long and short dash 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 the intake side and exhaust side side branch passages 48 and 49. It branches 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 oil amount and pressure are sufficient. Therefore, as shown in FIG. 3, a throttle portion 58 having a smaller 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, so that the oil flowing toward the exhaust side vertical passage 44 is prevented. Adjusting the amount.

(4). Overview of the upper part of the engine As described above, the present embodiment is provided with the oil shower device for showering the oil on the cam. As described above, the oil shower device includes one horizontally long 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 outline of the upper part of the engine will be described.

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

The head cover 5 has a substantially rectangular shape that is long in the direction of the crank axis, and 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 is projected upward to form a recess, and the recess is closed by the baffle plate 60, whereby the 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. To be precise, 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 For example, as shown in FIG. 9, the baffle plate 60 is composed of an intake side portion 67 and an exhaust side portion 68, and a joint portion 69 connecting the both. 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 an oil passage rib 70 and an auxiliary rib 71.

The oil passage ribs 70 of the intake side portion 67 and the exhaust side portion 68 extend long in the cam axis direction, and they 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 by hatching. This is for facilitating understanding of the form, not for displaying the cross section.

The intake-side and exhaust-side oil passage ribs 70 are for showering oil to the intake valve cam 16 and the exhaust valve cam 17, and as shown in FIGS. 12(A) and 12(D), A trapezoidal groove 73 is formed on the top surface of the oil passage rib 70 (72), and an 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 toward the cams 16 and 17 from the oil ejection hole 74 provided in the baffle plate 60. A trough-shaped oil guide 75, which surrounds the oil ejection hole 74 from the exhaust side, is provided at the location of each oil ejection hole 74 so as to project downward.

The rear portion 70a of the oil passage rib 70 of the exhaust side portion 68 indicated by the arrow X in FIG. 9 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), a drill 76 is passed from the rear end to form a tunnel hole 77 communicating with the groove 73, 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 of communicating 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 connecting state. An oil introducing cylinder portion 78 shown in FIG. 4 is provided so as to project downward at the three-way portion. The oil introducing cylinder portion 78 is connected to a relay cylinder portion 79 formed in the connecting portion 62 c of the gasket 62 and having an upper opening and a lower opening. The auxiliary cylinder portion 79 is connected to the auxiliary passage 53 of the cam cap 15.

As shown in FIG. 2, the relay cylinder portion 79 is formed on the cam cap 15 in a state of protruding rearward, and a rearwardly extending portion 80 corresponding to the relay cylinder portion 79 is also formed on the upper portion 4a of the cylinder head 4. Has been done. As shown in FIG. 4(C), a branch passage is provided in the horizontally long branch passage 52 at the location of the relay cylinder 79 and the rearwardly extending portion 80, and the auxiliary passage 53 is connected to the tip of the branch passage.

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

Further, a communication boss portion 84 through which blow-by gas passes is formed at an end portion of the connecting portion 62c that is closer to the intake side. The communication boss portion 84 has a cylindrical shape and communicates with the 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 laterally long branch passage 52, but the internal combustion engine is a slant type and is used for the intake valve. Since the camshaft 16 is inclined so that it is high and the exhaust valve camshaft 14 is low, the oil flows from the intake valve camshaft 13 toward the exhaust valve camshaft 14 due to its own weight. Therefore, both the intake valve camshaft 13 and the exhaust valve camshaft 14 can be appropriately lubricated without excessively increasing the oil pressure. That is, both the cam shafts 13 and 14 can be firmly lubricated with a simplified structure without forming a passage for the intake valve cam shaft 13 and the exhaust valve cam shaft 14.

Normally, the crankshaft 1 and the camshafts 13 and 14 rotate clockwise when viewed from the front of the engine. However, as in the embodiment, the laterally long branch passage 52 surrounds the camshafts 13 and 14 from above. If adopted, the oil tends to be pumped by the rotation of the intake valve cam shaft 13, so that the lubrication of the exhaust valve cam shaft 14 can be further ensured and the supply of oil to the cam oil shower device can be ensured. ..

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

Furthermore, in terms of the importance of control of the engine, the control of the opening/closing timing of the intake valve is more important than the control of the opening/closing timing of the exhaust valve, and therefore the valve clearance of the intake valve is also severe. Since the hydraulic lash adjuster 28 can be used for accurate control, the exhaust valve is not necessarily required to be as severe as the intake valve. It can be fully adjusted by adjusting.

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

The present invention can be actually 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 For valve shaft Provided shim 28 Hydraulic lash adjuster 29 Fixed type support 40 Longitudinal passage on intake side 44 Longitudinal passage on exhaust side 47 Main passage 48, 49 Side branch passage 51 Upward branch passage constituting the branch passage described in claim 52. Laterally long branch passages
53 Cam Shower Auxiliary Passage 58 Throttling Part 60 Baffle Plate 62 Gasket 62c Gasket Connecting Part 74 Oil Jet Hole 78 Oil Introducing Cylinder 79 Relay Cylinder

Claims (2)

A cylinder head in which an intake valve cam shaft and an exhaust valve cam shaft are rotatably held via a plurality of cam caps extending over both cam shafts, and a head cover fixed to the top surface of the cylinder head. With and
A slant internal combustion engine camshaft for the intake valve is a cylinder bore axis is inclined with respect to the vertical line so that the higher position than the camshaft for the exhaust valves,
Wherein the interior of the cylinder head, the side of the hydraulic lash adjuster with are disposed, an intake side than the cam shaft and the hydraulic lash adjusters for the front Symbol intake valve for the valve clearance adjusted for each portion of the intake valves to the closer site, it provided extending long intake side longitudinal passage in the direction of the intake valve camshaft, while being communicated with said the air intake side Vertical passage the hydraulic lash adjuster,
In a configuration in which a laterally long branch passage that branches from the intake-side longitudinally long passage and extends toward the exhaust valve camshaft via the intake valve camshaft is formed on the mating surface of each cam cap and the cylinder head . ,
In one of the plurality of cam caps, an auxiliary passage is formed at a portion between the intake valve cam shaft and the exhaust valve cam shaft to branch from the laterally long branch passage toward the head cover. A cam shower passage is formed in the head cover for dropping the oil flowing from the auxiliary passage to the cams of the cam shafts.
Slant type internal combustion engine. A loop-shaped gasket is provided on the mating surface between the outer peripheral portion of the head cover and the outer peripheral portion of the cylinder head,
The gasket has a connecting portion interposed between the one cam cap and the head cover, and the connecting portion has an oil relay cylinder portion sandwiched between the cam cap and the head cover and communicating with the auxiliary passage. Has been done,
In addition, a downward projection that abuts on the cam cap is provided on both sides of the connecting portion of the gasket that sandwich the oil relay cylinder.
The slant type internal combustion engine according to claim 1.

Images