JP2013096268A - Cylinder head cover device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a joint strength of a cover body without blocking a smooth flow of blow-by-gas in a cylinder head cover device in which a blow-by-gas passage is constituted by disposing a baffle plate within the cover body.SOLUTION: A blow-by-gas passage 23 includes vertical cut parts 23b, 23c which are positioned at both sides with a length centerline of a cover body 1 therebetween and a horizontal cut part 23d connecting both. The cover body 1 is fixed to a cylinder head by a bolt also at a position of the horizontal cut part, such that the horizontal cut part 23d becomes a narrow bottleneck because of the existence of a joint tubular part. Therefore, a passage area is secured by providing an expansion part 28 which protrudes downward, at a position of the horizontal cut part 23d on a baffle plate 2. On the bottom of the expansion part 28, an oil drop hole 29 and an oil drain wall 30 are provided.

Description

  The present invention relates to a cylinder head cover device that covers a valve mechanism of an internal combustion engine.

  A cylinder head cover device that covers the valve mechanism is attached to the cylinder head that constitutes the internal combustion engine. The cylinder head cover has a cover body. As a fastening means for the cover body, a large number of flange-like fastening portions are formed on the outer peripheral portion thereof, and the flange-like fastening portions are fixed to the cylinder head with bolts. In addition, a flat baffle plate is arranged inside the cover body, and the space enclosed by the cover body and the baffle plate is formed as a blow-by gas passage to collect oil mist contained in the blow-by gas. (For example, Patent Documents 1 and 2).

  In addition, the cylinder head cover is formed with an ignition plug detachable cylinder portion into which a tool such as a socket wrench can be inserted in order to attach / remove the ignition plug. In the case of a multi-cylinder (multi-cylinder) internal combustion engine, There are as many plug removable cylinders as the number of cylinders, and they are arranged in the axial direction of the crankshaft. As a matter of course, the spark plug attaching / detaching cylinder portion penetrates the baffle plate.

CD-ROM of Japanese Utility Model Publication No. 5-92453 Japanese Utility Model No. 63-164540 microfilm

  Now, in Patent Documents 1 and 2, the cylinder head cover is fastened only with a bolt at its peripheral edge, but in order to ensure high fastening strength, it is preferable that the cylinder head cover is fastened to the cylinder head also at the inner part. The cover body is generally a resin molded product, but the inner portion is also fastened to the cylinder head in this way, so that it is possible to contribute to weight reduction and cost reduction by thinning. Since the cover body has a box-like shape that opens toward the cylinder head, a fastening cylinder portion (foot) that extends toward the cylinder head is provided in order to fasten at the inner portion. Then, the bolt inserted into the fastening cylinder is screwed into the cylinder head.

  On the other hand, the blow-by gas passage needs a certain cross-sectional area (cross-sectional area), but if the fastening cylinder is provided in the inner part of the cylinder head cover, the fastening cylinder passes through the blow-by gas passage. As a result, the cross-sectional area of the blow-by gas passage is reduced at the portion of the cylinder portion, and as a result, the flow of blow-by gas is deteriorated and the oil mist collecting function and the ventilation performance may be deteriorated.

  Furthermore, in order to stably fix the cylinder head cover, it is preferable to provide the fastening cylinder portion as close to the center line as possible in the cylinder head cover. Therefore, in the case of a multi-cylinder (multi-cylinder) internal combustion engine, The fastening cylinder part is preferably provided at a part of the adjacent spark plug attaching / detaching cylinder part or in the vicinity thereof, but the blow-by gas passage has a transverse part passing through the part of the adjacent spark plug attaching / detaching cylinder part. In this case, it can be said that the flow of blow-by gas particularly deteriorates at the crossing portion. That is, there is a contradiction between fastening the cylinder head cover with high strength and ensuring an appropriate flow of blow-by gas.

  With regard to this point, it can be said that the interval between the spark plug attachment / detachment cylinder portions may be increased. However, since the interval between the cylinder bores increases in this way, new problems such as an increase in the size of the engine and a reduction in fuel consumption associated therewith arise.

  The present invention has been made to improve the current situation in this way.

  The present invention relates to a cylinder head cover device for an internal combustion engine. The cylinder head cover device includes a cover body whose outer peripheral portion is fixed to the cylinder head by fasteners (fasteners), and a baffle plate disposed inside the cover body. A space surrounded by the cover main body and the baffle plate is formed as a blow-by gas passage, and the cover main body includes a plurality of ignition plug attaching / detaching cylindrical portions arranged in the axial direction of the crankshaft. It has a basic structure of being formed.

  And in order to fasten the said cover main body to the said cylinder head with a fastener (fastener) also in the location between between the adjacent spark plug attaching / detaching cylinder parts among the said cover main bodies, or its vicinity part. The fastening cylinder portion is formed in a state of penetrating the baffle plate, while the blow-by gas passage is a pair positioned on both sides of a longitudinal center line connecting the axial centers of the ignition plug attaching / detaching cylinder portions. And a transverse portion that communicates with both longitudinal portions and extends across a portion between the adjacent spark plug attaching / detaching cylindrical portions, and the location of the transverse portion of the baffle plate In addition, a bulging portion protruding toward the cylinder head is provided.

  The present invention includes various configurations. For example, as a first specific embodiment, an oil trap hole can be provided at the lower end of the inverted ridge-shaped bulging portion, with the baffle plate converging downward toward the cylinder head. Furthermore, as a second specific mode, in addition to or instead of providing the oil drop hole, an oil cut wall where blow-by gas collides with the bulging portion can be provided. As a third specific embodiment suitable for providing an oil pit and an oil pit wall, the oil pit can be arranged so as to cross the oil pit in a plan view.

  Further, as a fourth specific aspect, in the case of the double overhead camshaft system, the bulging portion is located between the two camshafts and is downwardly convex with both the left and right sides inclined when viewed from the axial direction of the camshaft. It can be in the form of Yamagata. Furthermore, as a fifth specific aspect, in the case of having three or more spark plug attaching / detaching cylinder portions and providing a fastening cylinder portion in the vicinity of each of adjacent spark plug attaching / detaching cylinder portions, these It is possible to alternately arrange a plurality of fastening tube portions on both sides of the longitudinal center line.

  Since the cover main body of the present invention is fixed to the cylinder head even at the inner part thereof, high fastening strength can be ensured without increasing the thickness. In particular, the fastening cylinder is formed between or in the vicinity of the adjacent ignition plug attaching / detaching cylinders (because it is formed in a portion of the cover body that is as close to the inside as possible). Stability can be further improved.

  And in this invention, since the bulging part is provided in the location of the said crossing part among baffle plates, it prevents that the cross-sectional area of a crossing part becomes excessively small resulting from having provided the cylinder part for fastening. As a result, a smooth flow of blow-by gas can be ensured without causing an increase in the size of the cover body and the size of the internal combustion engine. As a result, the fastening strength of the cover body can be improved without deteriorating ventilation performance or oil mist collection performance, or causing an increase in engine size or fuel consumption. Moreover, since the baffle plate can be rigid because the bulging portion exhibits the rib function, it is possible to improve the adhesion to the cover body and improve the sealing performance of the blow-by gas passage.

  If the 1st specific aspect is employ | adopted, since the state which oil mist remains adhering to blow-by gas can be prevented or suppressed significantly, it can contribute to suppression of deterioration of oil. Moreover, when the 2nd specific aspect is employ | adopted, there exists an advantage which can improve the collection function of an oil mist. In this case, when the third specific mode is adopted, the oil mist adhering to the oil cutting wall is immediately dropped into the oil dropping hole, so that the oil collecting effect can be further promoted.

  If the 4th specific aspect is employ | adopted, the bulging part can guide the smooth flow of blow-by gas, avoiding interference with the cam shaft and cam which comprise a valve operating mechanism. Moreover, since oil mist collects in the bottom of a bulging part, it is excellent in the collection property of oil mist. Further, when the fifth specific mode is adopted, the inner side portion of the cover main body is fixed to the cylinder head at both sides sandwiching the center line, which can further contribute to an increase in fastening strength.

(A) is the perspective view which looked at the cover main body which concerns on this invention from the top, (B) is the perspective view which looked at the baffle plate which concerns on this invention from the top. (A) is a perspective view in a state where the baffle plate is turned over, and (B) is a separated perspective view in a state where the cover body and the baffle plate are turned over. (A) is the perspective view which looked at the cover main body from the top, (B) is the perspective view in the state where the cover main body was turned over. It is a bottom view of the cover main body equipped with the baffle plate. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4. FIG. 6 is a sectional view taken along line VI-VI in FIG. 4. It is a bottom view of the cover main body which attached the baffle plate, Comprising: The rib which was originally hidden is shown by the parallel oblique line. It is sectional drawing which looked at the baffle plate from the VIII-VIII view direction of FIG. It is sectional drawing which looked at the baffle plate from the IX-IX view direction of FIG.

  Next, a description will be given based on an embodiment of the present invention. 5 and 6 are opposite to each other in FIG. 4, and FIGS. 8 and 9 are opposite to those in FIG.

  For example, as shown in FIGS. 1 and 2, the cylinder head cover device includes a resin cover body 1 that opens downward, and a resin baffle plate 2 that is disposed inside the cover body 1. This embodiment is applied to a three-cylinder internal combustion engine. For this reason, the cover body 1 and the baffle plate 2 have a plan view shape close to a rectangle that is long in the axial direction of the crankshaft. The cover main body 1 has a top plate 3 and a peripheral wall 4 and has a box-like (or deep tray-like) appearance that opens downward.

(1) Cover body As shown in FIGS. 1 to 3, for example, one corner portion of the main body 1 is an overhanging portion 1a protruding in a diagonal direction, and an oil supply port 5 is provided at the position of the overhanging portion 1a. Is provided. Further, the main body 1 is provided with first to third spark plug attaching / detaching cylinder portions 6, 7, and 8 projecting downward in order to attach / remove the spark plug attached to the cylinder head (for convenience). The first to third numbers are assigned in order from the one close to the oil supply port 5).

  The spark plug attaching / detaching cylinder portions 6, 7, and 8 are opened vertically. The lower ends of the spark plug attaching / detaching cylinder portions 6, 7, and 8 are set so as to contact the upper surface of the cylinder head. The valve operating mechanism of the internal combustion engine to which the present embodiment is applied is a double overhead cam system, and the two camshafts are arranged on both sides across the row of ignition plug attaching / detaching cylindrical portions 6, 7, 8.

  As is clear from FIG. 1 (A) and FIG. 2 (A), on the upper surface (top surface) of the cover main body 1, the longitudinal center line 9 passing through the axis of each of the spark plug attaching / detaching cylinder portions 6, 7, 8. The part along the line is a recess 10 except for the end where the oil supply port 5 is provided. In other words, the spark plug attaching / detaching cylinder portions 6, 7, 8 are formed in the recess 10 (note that the longitudinal center line 9 does not necessarily coincide with the center line of the cover body 1). Further, an outward flange 11 is formed at the lower end of the peripheral wall 2 constituting the cover body 1 (that is, the opening of the cover body 1), and a bolt (not shown) is attached to the cylinder head at the flange 11 position. A large number of mounting holes (bolt fastening portions) 12 for fastening with a zipper.

  Further, as shown in FIGS. 2 and 3, the cover body 1 is bolted to the cylinder head in the vicinity between the adjacent spark plug attaching / detaching cylindrical portions 6, 7, 8 of the cover body 1. Fastening cylinders 14 and 15 for fastening at 13 (see FIG. 6) are formed. More precisely, a first fastening cylinder part 14 is provided in the vicinity between the first spark plug attaching / detaching cylinder part 6 and the second spark plug attaching / detaching cylinder part 7, and the second spark plug attaching / detaching cylinder part 7. A second fastening cylinder 15 is provided in the vicinity of the first spark plug attaching / detaching cylinder 8.

  The bolt for fixing the cover body 1 to the mounting hole 12 and the cylinder head is an example of a fastener, and the cover body 1 is provided with tapped holes at the mounting holes 12 and the fastening cylinder portions 14 and 15. It is also possible to adopt a combination of a stud bolt and a nut as a fastener and screw the nut into a stud bolt planted on the cylinder head for rolling.

  The first fastening cylinder 14 is formed in an area opposite to the oil supply port 5 with the longitudinal center line 9 interposed therebetween, and the second fastening cylinder 15 is supplied with oil with the longitudinal center line 9 interposed therebetween. It is formed in an area close to the mouth 5. Thus, by providing the two fastening cylinders 14 and 15 separately on both sides of the longitudinal center line 9, the fastening position of the cover body 1 can be equalized and the cover body 1 can be made thicker (or It can be tightened firmly and stably with a small number of bolts (thinner than conventional).

(2) Baffle plate / passage The baffle plate 2 has a shape almost similar to the shape of the cover body 1 in plan view, but has a size with a slight space between the inner peripheral surface of the cover body 1. . Further, a portion of the baffle plate 2 that is close to the oil supply port 5 of the cover body 1 has a cutout portion 17, and a projection portion that protrudes in the direction of the longitudinal center line while being connected to the cutout portion 17. 18 is formed.

  Further, the baffle plate 2 has a first escape hole 19 having a generally U-shape in plan view in which the first and second spark plug detachable cylinder portions 6 and 7 and the first fastening cylinder portion 14 are fitted, The 3rd spark plug attaching / detaching cylinder part 8 and the 2nd escape hole 20 in which the 2nd fastening cylinder part 15 fits are formed. For example, as shown in FIG. 2, the baffle plate 2 is provided with a number of oil dropping holes 22.

  For example, as shown in FIG. 1B, a large number of ribs 25 for defining the blow-by gas passage 23 and the fresh air passage 24 are formed on the upper surface of the baffle plate 2. On the other hand, as shown in FIGS. 2 (B), 3 (B), 5, 6, and 8, the cover body 1 has a large number of wall plates 26 corresponding to the ribs 25 of the baffle plate 2, The rib 25 and the wall plate 26 form a blow-by gas passage 23 and a fresh air passage 24. Further, the top surface of the rib 25, the top surface of the cover body 1 and the wall plate 26, and the baffle plate 2 are welded to each other by high frequency, ultrasonic waves, etc., thereby fixing the baffle plate 2 to the cover body 1. A blow-by gas passage 23 and a fresh air passage 24 are formed between the cover body 1 and the baffle plate 2. A step portion 27 is formed on the inner periphery of the cover body 1, and the outer peripheral rib 25 of the baffle plate 2 overlaps the step portion 27.

  As shown in FIG. 1B and FIG. 7, blow-by gas flows from the location of the protrusion 18 of the baffle plate 2. That is, the location of the protrusion 18 is an inflow portion 23a. As shown by arrows in FIG. 7, the blow-by gas passage 23 includes first and second longitudinal sections 23 b and 23 c located on both sides of the first escape hole 19 of the baffle plate 2, and a second spark plug. It has a crossing part 23d that passes between the detachable cylinder part 7 and the third spark plug detachable cylinder part 8 and is continuous with the two longitudinal sections 23b and 23c.

  The first longitudinal section 23b is located on the side opposite to the oil supply port 5 with the longitudinal center line 9 interposed therebetween, and the second longitudinal section 23c is located on the side of the oil supply port 5 with the longitudinal center line 9 interposed therebetween. . The end of the second longitudinal section 23 c extends to the vicinity of the oil supply port 5, and this end is the outlet 23 e of the blow-by gas passage 23. Therefore, the blow-by gas passage 23 is configured to surround the group of the first spark plug attaching / detaching cylinder portion 6 and the second spark plug attaching / detaching cylinder portion 7.

(3). Swelling portion / new air passage Well, there is a second fastening cylinder portion 15 in the vicinity between the second spark plug attaching / detaching tube portion 7 and the third spark plug attaching / detaching tube portion 8. Therefore, a narrow bottleneck exists in the cross section 23d of the blow-by gas passage 23 in a bottom view (or a plan view), and the flow of the blow-by gas is obstructed unless any countermeasure is taken. Therefore, as shown in FIGS. 2 and 8, the baffle plate 2 is formed with a bulging portion 28 projecting downward at the position of the crossing portion 23d, whereby the blow-by gas is smoothly supplied to the crossing portion 23d. The cross-sectional area that can be washed away is secured.

  The bulging portion 28 has a downwardly convex mountain shape with inclined surfaces 28a on both the left and right sides when viewed from the direction of the longitudinal center line 9, and is considered so as not to hit the cam for driving the valve. An oil dropping hole 29 is provided at the bottom (lower end) of the bulging portion 28. For this reason, it can prevent that oil mist stays and deteriorates. Further, the bulging portion 28 is provided with an oil cutting wall 30 that protrudes upward in a state of crossing the oil dropping hole 29 in the front-rear direction. Due to the presence of the oil cutting wall 30, oil mist can be collected efficiently.

  On the other hand, as shown by a dotted arrow in FIG. 7, the fresh air passage 24 includes a first passage 24 a located outside the third spark plug attaching / detaching cylinder portion 8 and an outer side of the second longitudinal section 23 c in the blow-by gas passage 23. And a second passage 24b located at the same position. As shown in FIG. 1 (A) and FIG. 3 (A), an air cleaner is provided on the end of the cover body 1 opposite to the oil supply port 5 and on the side of the oil supply port 5 across the longitudinal center line 9. The fresh air inlet 31 connected to is provided.

  The air sent from the fresh air inlet 31 to the inside of the cover main body 1 branches into the first passage 24a and the second passage 24b and is discharged to the cam chamber. In this case, in the second passage 24b, a portion outside the third spark plug attaching / detaching cylinder portion 8 along the longitudinal center line 9 is a narrow narrow passage, and the baffle plate 2 constituting this portion is there. An auxiliary bulging portion 32 protruding downward is provided (see FIGS. 2 and 9). For this reason, although it is compact, high ventilation performance can be secured. An oil dropping hole 33 is also provided at the bottom of the auxiliary bulging portion 32.

(4). Others The present invention can be embodied in various ways other than the above embodiment. For example, the present invention can be applied to a two-cylinder internal combustion engine or an internal combustion engine having four or more cylinders. Further, the form of the cover main body and the baffle plate, or the specific form of the blow-by gas passage can be arbitrarily designed as necessary. When the number of cylinders is large, it is possible to provide a plurality of crossing portions and to provide a bulging portion at each crossing portion.

  The present invention is actually applicable to an internal combustion engine. Therefore, it can be used in industry.

DESCRIPTION OF SYMBOLS 1 Cover body 2 Baffle plate 5 Oil supply port 6-8 Spark plug attaching / detaching cylinder part 12 Mounting hole provided in the outer peripheral part of the cover body 14, 15 Fastening cylinder part 19, 20 Relief hole 23 Blow-by gas passage 23b, 23c Section 23d Transverse section 24 Fresh air passage 28 Swelling section 28a Inclined surface 29 Oil pit 30 Oil cut wall

Claims (1)

A cover main body whose outer peripheral portion is fixed to the cylinder head with a fastener and a baffle plate disposed inside the cover main body are provided, and a space surrounded by the cover main body and the baffle plate is formed as a blow-by gas passage. In addition, the cover body has a configuration in which a plurality of ignition plug detachable cylinders are formed side by side in the axial direction of the crankshaft,
A fastening cylinder portion for fastening the cover body to the cylinder head with a fastener also at the inner portion of the cover body between adjacent spark plug attaching / detaching cylinder portions or the vicinity thereof. , While being formed through the baffle plate,
The blow-by gas passage is connected to the longitudinal section that is located on both sides of a longitudinal center line that connects the axial centers of the spark plug detachable cylinder sections, and communicates with both longitudinal sections and the adjacent spark plug detachment And a bulging portion protruding toward the cylinder head at the location of the crossing portion of the baffle plate.
A cylinder head cover device for an internal combustion engine.

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