JP2018184893A - Structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide suppress the pulsation of a working fluid or a lubricant flowing toward a cylinder head cover from a cam cap.SOLUTION: A structure of an internal combustion engine has: a cylinder head cover in which an oil passage in which a working fluid or a lubricant flowing toward an oil control valve circulates is opened at a joining face; a cam cap which communicates with the oil passage of the cylinder head cover, and in which the oil passage in which the working fluid or the lubricant circulates is opened at a joining face which abuts on or extremely approximates the joining face of the cylinder head cover; a peripheral part interposed between the cylinder head cover and the cam cap, and surrounding openings of the opposing oil passages of the cylinder head and the cam cap; and a boss part which is formed at the peripheral part integrally therewith, inserted into the oil passage of the cylinder head or that of the cam cap, and internally encapsulating a passage for making the working fluid or the lubricant pass. The structure also comprises a gasket which is elastically deformable so that the boss part is relatively displaced to the peripheral part.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an oil passage connection and a seal structure between a cylinder head cover and a cam cap in an internal combustion engine.

  As a cam cap for holding the intake camshaft and the exhaust camshaft in a journal bearing formed on the cylinder head or cam housing, an intake camshaft cam cap portion and an exhaust camshaft cam cap portion are integrated. Exists. A cylinder head cover is disposed above the cam cap, and an oil control valve for controlling hydraulic pressure is provided on the cylinder head cover.

  Each of the cam cap and the cylinder head cover is formed with an oil passage through which hydraulic oil (also lubricating oil) flows. The oil passage opens at a joint surface between the cam cap and the cylinder head cover, and the oil passage in the cam cap communicates with the oil passage in the cylinder head cover by connecting both of them.

  The hydraulic oil discharged from the oil pump is pumped toward the cylinder head and the cam housing, supplied to the chain tensioner that maintains the tension of the timing chain, and reaches the cylinder head cover via the cam cap. Then, the pressure is adjusted by the oil control valve and then supplied to the variable valve timing mechanism. The variable valve timing mechanism is used to drive the vane to achieve a desired valve timing (see the following patent document). reference).

JP 2008-057518 A

  The chain tensioner that presses the timing chain receives vibration from the timing chain as a reaction. This vibration is transmitted to the hydraulic oil, causing pulsation of the pressure or flow rate of the hydraulic oil from the cam cap toward the cylinder head cover, and may generate abnormal noise near the oil control valve.

  The present invention has been made by paying attention to the above-mentioned problem for the first time, and an object thereof is to suppress pulsation of hydraulic oil or lubricating oil from the cam cap toward the cylinder head cover.

  In the present invention, a cylinder head cover in which an oil passage through which hydraulic oil or lubricating oil flows toward the oil control valve is open at the joint surface, and an oil passage through which hydraulic oil or lubricating oil flows are communicated with the oil passage of the cylinder head cover Is located between the cylinder head cover and the cam cap, and the cylinder head cover and the cam cap are opposed to each other. And a boss part that is formed integrally with the peripheral part and is inserted into the oil passage of the cylinder head cover or the cam cap and contains a passage through which hydraulic oil or lubricating oil passes, and the boss part is a peripheral part. Internal combustion engine comprising a gasket that can be elastically deformed so as to be displaced relative to a part It has a structure.

  A clearance is provided between the outer surface of the boss portion facing the predetermined direction and the inner surface of the oil passage into which the boss portion is inserted, and the outer surface of the boss portion facing the predetermined direction is inserted into the boss portion. If it is in contact or pressure contact with the inner surface of the oil passage, the boss portion of the gasket is allowed to be displaced in a predetermined direction, but is difficult to be displaced in a direction intersecting the predetermined direction. Then, it is possible to suppress the peripheral edge of the gasket from being dragged (or pulled in) by the boss portion while exhibiting a damping effect that reduces the pulsation of the lubricating oil by the movement of the boss portion. That is, it can be avoided that the position of the peripheral edge engaged with the cylinder head cover and the cam cap is unduly biased to deteriorate the sealing performance.

  According to the present invention, it is possible to suppress pulsation of working oil or lubricating oil from the cam cap toward the cylinder head cover.

1 is a front view showing a cylinder head cover, a cam housing, and a cylinder head cover of an internal combustion engine according to an embodiment of the present invention. The rear view which shows the cam cap and cam housing in the state which removed the cylinder head cover of the internal combustion engine of the embodiment. The top view which shows the cam cap and cam housing in the state which removed the cylinder head cover of the internal combustion engine of the embodiment. The top view of the cam cap of the internal combustion engine of the embodiment. The top view of the gasket of the internal combustion engine of the embodiment. FIG. 3 is a cross-sectional view taken along line AA showing a cylinder head cover, a cam cap, and a gasket of the internal combustion engine of the embodiment. The BB sectional view which shows the cylinder head cover, cam cap, and gasket of the internal combustion engine of the embodiment.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, in the upper part of the internal combustion engine of the present embodiment, a cylinder head cover 1 is mounted on a cam housing 3 located above the cylinder head. 2 and 3 show a state in which the cylinder head cover 1 is removed and the cam cap 2 is exposed. As shown in FIG. 2, the cam cap 2 in the internal combustion engine of the present embodiment includes an exhaust camshaft cam cap portion 22 that engages with an exhaust camshaft shaft portion (camshaft journal), and an intake camshaft shaft portion. This is a member in which an intake camshaft cam cap portion 23 that engages with is integrated. The cam cap 2 is produced, for example, by grinding a metal casting made of an aluminum alloy or the like.

  Each of the cam cap portions 22 and 23 is formed with a bearing surface 24 having a semi-cylindrical shape in front view that opens downward. The cam cap 2 is fastened to a cam housing 3 located above the cylinder head of the internal combustion engine or to the cylinder head. The bearing surface 24 of the cam cap 2 sandwiches the shaft portions of the exhaust camshaft and the intake camshaft between the bearing surface 31 formed on the cam housing 3 and rotatably supports these camshafts.

  As shown in FIGS. 2 to 4, 6, and 7, a connection portion 21 that protrudes upward is provided on the upper portion of each cam cap portion 22, 23. The connection part 21 is a part joined to the cylinder head cover 1 that covers the cam housing 3 and the cam cap 2 from above. Inside the cam cap 2, there is formed an oil passage 20 through which hydraulic oil that also serves as lubricating oil for lubricating various parts of the internal combustion engine flows, and the end of the oil passage 20 is the top surface of the connecting portion 21, in other words, For example, an opening is formed on the joint surface with the cylinder head cover 1.

  On the other hand, as shown in FIGS. 6 and 7, a connecting portion 11 that hangs downward is provided on the lower surface side of the cylinder head cover 1. The connection part 11 is a part joined to the connection part 21 of the cam cap 2. An oil passage 10 through which hydraulic oil flows is also formed inside the cylinder head cover 1, and the starting end of the oil passage 10 opens to the lower surface of the connecting portion 11, in other words, the joint surface with the cam cap 2. In a state where the cylinder head cover 1 is fastened to the cam housing 3 or the cylinder head, the opening 101 of the oil passage 10 on the joining surface on the cylinder head cover 1 side and the opening 201 of the oil passage 20 on the joining surface on the cam cap 2 side are: At least a part of the plan view overlaps. Then, the oil passage 20 on the cam cap 2 side communicates with the oil passage 10 on the cylinder head cover 1 side.

  An oil pump (not shown) associated with the internal combustion engine sucks and discharges hydraulic oil stored in an oil pan provided below the cylinder block of the internal combustion engine. The hydraulic oil is pumped toward the cylinder block and the cylinder head, and lubricates the crankshaft, piston, cylinder bore, and the like. Further, the hydraulic oil is supplied to a chain tensioner for maintaining the tension of the timing chain that is an element of a winding transmission device that interlocks the crankshaft and the camshaft, and flows into the cam cap 2 from the cam housing 3. The cylinder head cover 1 is reached through the oil passages 20 and 10 in the connecting portions 21 and 11. The cylinder head cover 1 is provided with an oil control valve (not shown), which is a hydraulic control valve, and the hydraulic fluid that has flowed into the cylinder head cover 1 opens and closes the intake and exhaust valves via the oil control valve. Is supplied to a variable valve timing mechanism that adjusts

  A gasket 4 is provided between the connecting portion 11 of the cylinder head cover 1 and the connecting portion 21 of the cam cap 2, and the gasket 4 connects the oil passage 10 on the cylinder head cover 1 side and the oil passage 20 on the cam cap 2 side. Seal the place. In FIG. 4, the gasket 4 is attached to the left connection portion 21 and the gasket 4 is not attached to the right connection portion 21. As shown in FIGS. 4 and 5, the gasket 4 has an annular peripheral portion 41 surrounding the openings 101 and 201 of the oil passages 10 and 20 facing each other in the cylinder head cover 1 and the cam cap 2, and an inner side of the peripheral portion 41. The boss portion 42 that protrudes downward and is inserted into the opening of the oil passage 20 of the cam cap 2 and the support piece portion 43 that connects the boss portion 42 to the peripheral edge portion 41 are integrally formed. The gasket 4 is manufactured using an elastically deformable material such as rubber.

  The peripheral edge 41 of the gasket 4 has a shape that borders the outer periphery of the openings 101 and 201 of the oil passages 10 and 20 of the cylinder head cover 1 and the cam cap 2 in plan view. As shown in FIG. 4, in this embodiment, three openings 10, 20 are formed in one connection portion 11, 21, one of which is larger than the other two. Correspondingly, the gasket 4 fitted to each connecting portion 21 also includes three annular peripheral portions 41, one of which is larger than the other two.

  A concave groove 211 that is recessed downward is formed on the top surface of the connecting portion 21 of the cam cap 2 so as to trace the outer side of the opening 201 of the oil passage 20 that opens to the top surface of the connecting portion 21 in plan view. In other words, the edge of the opening 201 of the oil passage 20 urges upwards higher than the bottom surface of the concave groove 211 just like a bank for the concave groove 211. As shown in FIGS. 6 and 7, the peripheral edge 41 of the gasket 4 is fitted into the concave groove 211 from above.

  The upper and lower thickness of the peripheral edge portion 41 of the gasket 4 is larger than the depth of the concave groove 211 carved in the connecting portion 21 of the cam cap 2, and the peripheral edge portion 41 of the gasket 4 fitted in the concave groove 211 is a cylinder. The head cover 1 and the cam cap 2 are clamped from above and below by both connecting portions 11 and 21.

  A protrusion 411 protruding toward the inner side is formed on the inner surface of the peripheral edge portion 41 of the gasket 4. The distance from the outer surface of the peripheral edge portion 41 of the gasket 4 to the inner end of the protrusion 411 is slightly larger than the opening width of the concave groove 211 formed in the connection portion 21 of the cam cap 2. Due to the presence of the protrusion 411, the peripheral edge portion 41 of the gasket 4 is press-fitted into the concave groove 211 so as to be crimped to the inner wall of the concave groove 211, and the position thereof is fixed.

  The boss portion 42 of the gasket 4 is a cylindrical portion having a passage 421 penetrating in the vertical direction at the center thereof. In the present embodiment, the outer periphery of the boss portion 42 has a planar view shape. The boss portion 42 is inserted from above into the oil passage 20 formed in the connection portion 21 of the cam cap 2 and opening larger than the other two oil passages 20.

  The opening 201 of the oil passage 20 into which the boss portion 42 is inserted has an opening width along the front-rear direction of the internal combustion engine (the direction in which a plurality of cylinders included in the internal combustion engine are arranged, the direction in which the intake camshaft and the exhaust camshaft extend). It is larger than the opening width along the left-right direction of the internal combustion engine (direction perpendicular to the front-rear direction). In contrast, the boss portion 42 of the gasket 4 has an outer dimension along the left-right direction of the internal combustion engine substantially equal to the opening width of the oil passage 20, but an outer dimension along the front-rear direction of the internal combustion engine is the oil passage 20. Is smaller than the opening width. In addition, the outer surface 423 facing the left-right direction in the boss portion 42 is provided with a protrusion 422 protruding slightly outward. The protrusion 422 has a rib shape extending along the vertical direction. Therefore, when the boss portion 42 is inserted into the opening 201 of the oil passage 20, the outer surface 423 facing the left-right direction of the boss portion 42 is the inner surface facing the left-right direction of the opening 201 as shown in the cross-sectional view along line AA in FIG. 7 (with or through the projection 422), while facing the front and rear direction of the boss portion 42 and the opening 201 as shown in the cross-sectional view along the line BB in FIG. A clearance 5 is provided between the inner surface. The outer surface 423 of the boss portion 42 that is in close contact with the inner surface of the opening 201 is close to the concave groove 211 and the peripheral edge portion 41 that are seal lines. In comparison, the outer surface 424 of the boss portion 42 that is separated from the inner surface of the opening 201 via the clearance 5 is further away from the recessed groove 211 and the peripheral edge portion 41.

  The support piece portion 43 of the gasket 4 extends in the outward direction from the upper end portion of the boss portion 42 and has a thin plate shape connected to the inner surface of the peripheral edge portion 41. As shown in FIG. 5, the support piece 43 is not continuously connected over the entire circumference of the peripheral edge portion 41, and a defect portion 44 is formed in which the both sides are not connected but become a gap. Yes. The defect portion 44 penetrates the support piece portion 43 in the vertical direction.

  In this embodiment, the gasket 4 is obtained by integrally molding the peripheral edge portion 41, the boss portion 42, and the support piece portion 43. As already described, the gasket 4 is manufactured using a material that is easily elastically deformed, such as rubber. The connecting portion 21 of the cylinder head cover 1 and the connecting portion 21 of the cam cap 2 are joined together with a gasket 4 interposed therebetween. The hydraulic fluid flowing (rising) from the oil passage 20 in the connection portion 21 of the cam cap 2 toward the oil passage 10 in the connection portion 11 of the cylinder head cover 1 passes through the passage 421 in the boss portion 42 of the gasket 4. . At that time, due to the elastic deformation of the gasket 4, the boss portion 42 is displaced relative to the peripheral edge portion 41 and the oil passage 20 along the front-rear direction and / or the left-right direction of the internal combustion engine. Thereby, a damping action is performed, and the pulsation of the hydraulic oil flowing from the cam cap 2 into the cylinder head cover 1 is attenuated.

  In the present embodiment, the cylinder head cover 1 in which an oil passage 10 through which hydraulic oil or lubricating oil flows toward the oil control valve circulates opens at the joint surface, and the hydraulic oil or lubricating oil communicates with the oil passage 10 of the cylinder head cover 1. Is interposed between the cylinder cap cover 1 and the cam cap 2, and the cylinder head cover 1 is interposed between the cam cap 2 that opens to the joint surface that is in contact with or in close proximity to the joint surface of the cylinder head cover 1. 1 and the peripheral edge 41 surrounding the openings of the oil passages 10 and 20 of the cam cap 2, and the peripheral edge 41 formed integrally with the peripheral edge 41 and inserted into the oil passage 20 of the cam cap 2 and operating oil or lubricating oil. It has a boss part 42 containing a passage 421 to be passed, and the boss part 42 is displaced relative to the peripheral part 41. To constitute a structure of an internal combustion engine; and a gasket 4 which can be elastically deformed.

  According to the present embodiment, the pulsation of hydraulic oil or lubricating oil from the cam cap 2 toward the cylinder head cover 1 can be suppressed or alleviated. As a result, it is possible to prevent the generation of abnormal noise in the vicinity of the oil control valve.

  In addition, in the present embodiment, the clearance 5 is provided between the outer surface 424 facing the predetermined direction (front-rear direction of the internal combustion engine) in the boss portion 42 and the inner surface of the oil passage 20 into which the boss portion 42 is inserted. The outer surface 423 of the boss portion 42 that faces the predetermined direction (the left-right direction of the internal combustion engine) is in contact with or pressed against the inner surface of the oil passage 20 into which the boss portion 42 is inserted. While the displacement of the boss portion 42 in the predetermined direction is allowed, the displacement in the direction intersecting the predetermined direction is suppressed. Therefore, the peripheral edge 41 of the gasket 4 is prevented from being dragged by the boss 42 and drawn inward while exhibiting a damping effect that reduces the pulsation of the lubricating oil by the movement of the boss 42. That is, it can be avoided that the position of the peripheral edge portion 41 engaged with the concave groove 211 of the cam cap 2 is unduly biased to deteriorate the sealing performance.

  The present invention is not limited to the embodiment described in detail above. For example, in the above embodiment, the boss portion 42 of the gasket 4 protrudes downward, and the boss portion 42 is inserted from above into the opening 201 of the oil passage 20 formed in the connection portion 21 of the cam cap 2. The four bosses protrude upward and the bosses are not prevented from being inserted from below into the opening 101 of the oil passage 10 formed in the connecting part 11 of the cylinder head cover 1. Also in this case, the clearance is provided between the outer surface facing the predetermined direction in the boss portion and the inner surface of the oil passage 10 into which the boss portion is inserted, while the outer surface facing the direction intersecting the predetermined direction in the boss portion. However, it is preferable to contact or press contact with the inner surface of the oil passage 10 into which the boss portion is inserted.

  In addition, the specific configuration of each part can be variously modified without departing from the gist of the present invention.

  The present invention can be applied to an internal combustion engine mounted on a vehicle or the like.

DESCRIPTION OF SYMBOLS 1 ... Cylinder head cover 10 ... Oil path 2 ... Cam cap 20 ... Oil path 4 ... Gasket 41 ... Peripheral part 42 ... Boss part 421 ... Passage 5 ... Gasket

Claims (2)

A cylinder head cover in which an oil passage through which hydraulic oil or lubricating oil flows toward the oil control valve is open at the joint surface;
A cam cap that communicates with an oil passage of the cylinder head cover and in which an oil passage through which hydraulic oil or lubricating oil circulates opens on a joint surface that is in contact with or in close proximity to the joint surface of the cylinder head cover;
The cylinder head cover and the cam cap are interposed between the periphery of the cylinder head cover and the cam cap that surround the opening of the oil path facing each other, and the periphery of the cylinder head cover or the cam cap is formed integrally with the periphery. A structure of an internal combustion engine comprising a boss portion that includes a passage that allows insertion of hydraulic oil or lubricating oil and that can be elastically deformed so that the boss portion is displaced relative to the peripheral portion. A clearance is provided between the outer surface of the boss portion facing the predetermined direction and the inner surface of the oil passage into which the boss portion is inserted, while the boss portion is inserted into the outer surface of the boss portion facing the predetermined direction. 2. The structure of an internal combustion engine according to claim 1, wherein the structure is in contact with or in pressure contact with the inner surface of the oil passage.

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