WO2012115123A1

WO2012115123A1 - Internal combustion engine head-cover structure

Info

Publication number: WO2012115123A1
Application number: PCT/JP2012/054185
Authority: WO
Inventors: 智也藤本; 正雄坂下; 平野　浩司; 圭上田; 剛久立川
Original assignee: 本田技研工業株式会社
Priority date: 2011-02-22
Filing date: 2012-02-22
Publication date: 2012-08-30
Also published as: CN103403332A; EP2679792A4; JP5581438B2; CN103403332B; EP2679792B1; JPWO2012115123A1; EP2679792A1

Abstract

The goal of the present invention is to provide an internal combustion engine head-cover structure capable of suppressing an increase in the wall thickness and size of a head cover and enhancing the rigidity of the head cover. An internal combustion engine (E) head-cover structure is provided with the following: a covering part (11) which is disposed on a cylinder head (2) and which covers, from above, a valve gear (3) that includes cam shafts (31, 32); an outer peripheral edge part (12) which is provided along the outer peripheral edge of the covering part (11) and is fastened to the cylinder head (2); and a plurality of upper bearing parts (13) which are provided integrally with the covering part (11) and the outer peripheral edge part (12) and rotatably hold the cam shafts (31, 32) in cooperation with a plurality of lower bearing parts (23) provided on the cylinder head (2). The internal combustion engine (E) head-cover structure is characterized by the following: the upper bearing parts (13) are fastened and fixed to the lower bearing parts (23); and the covering part (11) has an expansion part (111) expanding in a substantially hemispherical shape between adjacent upper bearing parts (13).

Description

Internal combustion engine head cover structure

The present invention relates to a head cover structure for an internal combustion engine.

Conventionally, a valve operating mechanism for driving an intake valve and an exhaust valve for opening and closing an intake port and an exhaust port respectively communicating with a combustion chamber is provided on an upper portion of a cylinder head of an internal combustion engine. A head cover that covers the valve mechanism is attached to the upper part of the cylinder head.

For example, in the head cover structure described in Patent Document 1, an upper member arranged on the upper side of the cam shaft among a plurality of bearing members that are pivotally supported with the cam shaft interposed therebetween is formed integrally with the head cover. The upper members are arranged at equal intervals in the axial direction of the cam shaft, and the covering portion that covers between the adjacent upper members is formed in a substantially flat plate shape.

China Utility Model Notice CN201206478Y

By the way, in recent years, considering the layout of the internal combustion engine, auxiliary devices such as a cam angle sensor (TDC sensor) for detecting the rotation angle of the cam shaft and a common rail for supplying high-pressure fuel to the fuel injection device are attached to the head cover. Is considered.
However, in the conventional head cover structure, there is a possibility that the detection accuracy of the cam angle sensor may be lowered due to vibration of the head cover. Further, when an auxiliary device such as a common rail that has been conventionally attached to the cylinder head is attached to a head cover that is relatively less rigid than the cylinder head, vibration and noise may increase. Therefore, further enhancement of the rigidity of the head cover has been desired.
On the other hand, since there is a demand for a lighter and more compact internal combustion engine, there is a limit to improving rigidity by increasing the thickness and size of the head cover.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a head cover structure for an internal combustion engine that can improve the rigidity of the head cover while suppressing the increase in thickness and size of the head cover. And

A head cover structure for an internal combustion engine according to the present invention is provided along the outer periphery of the covering portion that covers a valve operating mechanism including a cam shaft disposed on the cylinder head from above, and is fastened to the cylinder head. A plurality of outer peripheral edge portions integrally provided with the covering portion and the outer peripheral edge portion, and rotatably supporting the camshaft in cooperation with a plurality of lower bearing portions provided on the cylinder head. An upper bearing portion, wherein the upper bearing portion is fastened and fixed to the lower bearing portion, and the covering portion is substantially hemispherical between the adjacent upper bearing portions. It has the bulging part which bulges in a shape.

According to such a configuration, since the bulging portion that bulges in a substantially hemispherical shape is provided between the adjacent upper bearing portions, the rigidity of the covering portion is enhanced by the substantially hemispherical bulging portion. And the rigidity of a head cover is improved by this bulging part, and it becomes possible to suppress a vibration and a noise. In addition, since the rigidity of the head cover is enhanced by the shape of the bulging portion, it is possible to suppress an increase in thickness and size of the head cover.

The upper bearing portion has a bearing-side fastening and fixing portion that is fastened and fixed to the lower bearing portion, and the outer peripheral edge portion is provided in the middle of the adjacent upper bearing portion in the cylinder head. An outer peripheral side fastening and fixing portion to be fastened and fixed, a first reinforcing rib is provided between the bearing side fastening and fixing portion and the outer peripheral side fastening and fixing portion, and the adjacent upper bearing portion and the first reinforcing rib It is preferable that the bulging portion is provided in a portion surrounded by.

According to such a configuration, the first reinforcing rib is provided between the bearing side fastening and fixing portion and the outer periphery side fastening and fixing portion, and the bulging portion is located at a portion surrounded by the adjacent upper bearing portion and the first reinforcing rib. Since it is provided, the rigidity of the head cover can be further increased, and vibration and noise can be further suppressed.

Moreover, it is preferable that the lower surface of the bulging part has a configuration in which second reinforcing ribs are extended from the apex of the bulging part toward the bearing side fastening and fixing part and the outer peripheral side fastening and fixing part. .

According to such a configuration, since the rigidity of the bulging portion can be further increased, the rigidity of the head cover can be further increased, and vibration and noise can be further suppressed.

The cam shaft includes an intake side cam shaft and an exhaust side cam shaft, and a plurality of the upper bearing portions are arranged along each of the intake side cam shaft and the exhaust side cam shaft, and the intake side cam shaft It is preferable that the bulging portion is provided between at least one of the upper bearing portions of the shaft and between the upper bearing portions of the exhaust cam shaft.

According to such a configuration, in a so-called DOHC (Double Overhead Camshaft) type internal combustion engine, the rigidity of the head cover can be increased, and vibration and noise can be suppressed.

According to the present invention, it is possible to provide a head cover structure for an internal combustion engine that can improve the rigidity of the head cover.

It is a perspective view of the head cover structure of the internal combustion engine which concerns on this embodiment. It is a perspective view which shows the state which looked up at the head cover from the bottom, (a) is a general view, (b) is an enlarged view of the A section shown in (a). It is the II sectional view taken on the line shown in FIG. It is the II-II sectional view taken on the line shown in FIG.

Embodiments of the present invention will be described in detail with reference to FIGS. In the present embodiment, a case where the present invention is applied to a head cover of an automobile engine will be described as an example. In the description, the same elements are assigned the same numbers, and duplicate descriptions are omitted. Further, the direction will be described based on front (F) rear (B) left (L) right (R) shown in FIG.

As shown in FIG. 1, the internal combustion engine E is an in-line four-cylinder DOHC (Double Overhead Camshaft) type engine. A basic structure such as a cylinder block for storing oil and an oil pan for storing oil is provided. The internal combustion engine E is placed horizontally so that the cylinder row direction is the left-right direction with respect to the vehicle, and is configured to intake from the rear and exhaust from the front.

The cylinder head 2 is a member constituting a combustion chamber, an intake port, and an exhaust port (not shown). The cylinder head 2 has an intake valve and an exhaust valve (not shown) that open and close the intake port and the exhaust port, respectively, and a valve operating mechanism that drives the intake valve and the exhaust valve above the cylinder head 2. 3 is installed. Further, a transmission mechanism 4 for transmitting the rotation of the crank to the valve operating mechanism 3 is provided at the side of the cylinder head 2 (more specifically, the internal combustion engine E).

As shown in FIG. 4, the cylinder head 2 has an outer peripheral wall 21 that rises in a frame shape along the outer peripheral edge of the upper surface 2a, and a central wall 22 that rises from the center in the front-rear direction of the upper surface 2a. As shown in FIG. 3, the cylinder head 2 includes a plurality of lower bearing portions 23 for supporting

cam shafts

31 and 32 of the valve operating mechanism 3 between the outer peripheral wall 21 and the central wall 22. Have. The lower bearing portion 23 is a wall-like portion extending in the front-rear direction, and has a semicircular recess 23 a at the center of the upper surface thereof. The lower bearing portion 23 is provided at a position corresponding to the upper bearing portion 13 provided in the head cover 1 described later.

The valve operating mechanism 3 includes a pair of

cam shafts

31 and 32 arranged in parallel to each other along the cylinder row direction, and a plurality of cams 33 (see FIG. 4) fixed to the cam shaft 31 and the cam shaft 32, respectively. ,have. The cam shaft 31 is an intake side cam shaft for opening and closing the intake valve, and the cam shaft 32 is an exhaust side cam shaft for opening and closing the exhaust valve.

As shown in FIGS. 1 to 4, the head cover 1 is an aluminum alloy member that is attached to the upper part of the cylinder head 2 and covers the valve mechanism 3.
The head cover 1 includes a covering portion 11 that covers the valve operating mechanism 3, an outer peripheral edge portion 12 that forms the outer peripheral edge of the head cover 1, an upper bearing portion 13 that supports the

cam shafts

31 and 32 of the valve operating mechanism 3, It has mainly. Further, a concave groove portion 14 for installing a fuel injection device (not shown) extends in the left-right direction at the center portion of the head cover 1 in the front-rear direction.

The outer peripheral edge portion 12 is a frame-shaped portion provided on the outer peripheral edge of the covering portion 11. The outer peripheral edge 12 is installed on an outer peripheral wall 21 provided on the upper surface of the cylinder head 2. The outer peripheral edge portion 12 has a plurality of bolt insertion holes 12a for inserting bolts B as fastening members, and some of them are provided between the adjacent upper bearing portions 13. The bolt insertion hole 12a corresponds to an “outer periphery side fastening portion” in the claims. A bolt fastening hole 21a for fastening the bolt B is formed in the outer peripheral wall 21 of the cylinder head 2 at a position corresponding to the bolt insertion hole 12a (see FIG. 4).

The upper bearing portion 13 is a portion that rotatably holds the

cam shafts

31 and 32 of the valve operating mechanism 3 in cooperation with a plurality of lower bearing portions 23 provided in the cylinder head 2. The upper bearing portion 13 is a wall-like portion extending in the front-rear direction, and is provided apart from each other in the left-right direction between the outer peripheral edge portion 12 and the recessed groove portion 14. The upper bearing portion 13 is disposed on both the left and right sides of each cylinder. In the present embodiment, the upper bearing portion 13c disposed on the left side of the leftmost cylinder also serves as the left end portion 12b (see FIG. 2A) of the outer peripheral edge portion 12.

As shown in FIGS. 2 and 3, a semicircular recess 13 a is provided at the center of the lower surface of the upper bearing portion 13 in the front-rear direction. The concave portion 13a provided in the upper bearing portion 13 and the concave portion 23a provided in the lower bearing portion 23 constitute a bearing portion that rotatably supports the

cam shafts

31 and 32, respectively. Bolt insertion holes 13b for inserting bolts B as fastening members are provided on both front and rear sides of the recess 13a. The bolt insertion hole 13b corresponds to a “bearing side fastening and fixing portion” in the claims. A bolt fastening hole 23b for fastening the bolt B is formed in the lower bearing portion 23 of the cylinder head 2 at a position corresponding to the bolt insertion hole 13b.

The coating | coated part 11 is a thin-plate-shaped site | part which coat | covers the valve mechanism 3, and is spaced apart and arrange | positioned upwards with respect to the valve mechanism 3 (refer FIG. 4). The covering portion 11 has a bulging portion 111 that bulges substantially hemispherically toward the upper side between the adjacent upper bearing portions 13. Further, as shown in FIG. 1, the covering portion 11 has a first reinforcing rib 15 for reinforcing the bulging portion 111. The first reinforcing rib 15 extends so as to rise between the bolt insertion hole 12a of the outer peripheral edge portion 12 provided between the adjacent upper bearing portions 13 and the bolt insertion hole 13b of the upper bearing portion 13. Yes. Thereby, the bulging part 111 will be in the state where the circumference | surroundings were reinforced by being surrounded by the adjacent upper side bearing part 13 and the 1st reinforcement rib.
In addition, regarding the bulging part 111, “substantially hemispherical” includes a hemispherical shape and a shape that can be regarded as equivalent to a hemispherical shape (so-called dome shape or the like).

As shown in FIG. 2B, the lower surface of the bulging portion 111 is provided between the bolt insertion hole 13 b of the upper bearing portion 13 and the adjacent upper bearing portions 13 from the apex 111 a of the bulging portion 111. The second reinforcing ribs 16 extend radially toward the bolt insertion holes 12a of the outer peripheral edge portion 12 and the concave groove portion 14. The second reinforcing ribs 16 are arranged substantially symmetrically with the vertex 111a as the center. Thereby, since the bulging part 111 is reinforced uniformly, a vibration and a noise can be reduced. Further, the second reinforcing rib 16 is curved so as to be convex upward along the lower surface of the bulging portion 111 in order to avoid interference with the cam 33 (see FIG. 4).

As shown in FIG. 1, a common rail 5 for supplying high-pressure fuel to a fuel injection device (not shown) is attached to the rear end portion of the head cover 1. A cam angle sensor 6 that detects the rotation angle of the cam shaft 32 is attached to the upper surface of the head cover 1. A negative pressure pump 7 that supplies hydraulic pressure to a variable valve timing mechanism (not shown) of the valve operating mechanism 3 is attached to the left end of the head cover 1. An engine hanger 8 for holding the internal combustion engine E on a body frame (not shown) is attached to the left side of the front end portion of the head cover 1. Further, an opening 9 for discharging blow-by gas to a gas-liquid separation chamber (not shown) provided separately from the head cover 1 is provided on the upper surface of the right end portion of the head cover 1.

The head cover structure of the internal combustion engine according to the present embodiment is basically configured as described above. Next, the function and effect will be described.

According to the head cover structure of the internal combustion engine according to the present embodiment, the upper bearing portion 13 that pivotally supports the

cam shafts

31 and 32 is provided integrally with the head cover 1, and is substantially between adjacent upper bearing portions 13. Since the bulging portion 111 bulging in a hemispherical shape is formed, the rigidity of the covering portion 11 is enhanced by the substantially hemispherical bulging portion 111. Therefore, the rigidity of the head cover 1 can be improved as a whole while suppressing the increase in thickness and size of the head cover 1, and vibration and noise can be suppressed.

Further, according to this configuration, the first reinforcing rib 15 is provided between the bolt insertion hole 12 a of the outer peripheral edge portion 12 provided between the adjacent upper bearing portions 13 and the bolt insertion hole 13 b of the upper bearing portion 13. In addition, since the bulging portion 111 is provided at a portion surrounded by the adjacent upper bearing portion 13 and the first reinforcing rib 15, the rigidity of the head cover 1 can be further enhanced, and vibration and noise can be suppressed. become.

Further, on the lower surface of the bulging portion 111, the bolt of the outer peripheral edge portion 12 provided between the bolt insertion hole 13 b of the upper bearing portion 13 and the adjacent upper bearing portions 13 from the apex 111 a of the bulging portion 111. Since the second reinforcing ribs 16 extend radially toward the insertion hole 12a and the recessed groove portion 14, the rigidity of the bulging portion 111 can be further increased, and vibration and noise can be further suppressed. Can do.

Further, since the second reinforcing ribs 16 are arranged substantially symmetrically with the vertex 111a as the center, the bulging portion 111 can be uniformly reinforced, and vibration and noise can be reduced.

Further, since the rigidity of the head cover 1 is enhanced as a whole by the bulging portion 111, auxiliary devices such as the common rail 5, the cam angle sensor 6, the negative pressure pump 7, and the engine hanger 8 can be attached to the head cover 1. it can. Therefore, the degree of freedom in the layout of the internal combustion engine E can be improved.

As mentioned above, although embodiment of this invention was described in detail with reference to drawings, this invention is not limited to this, In the range which does not deviate from the main point of invention, it can change suitably.

For example, in the present embodiment, the present invention is applied to a so-called DOHC type internal combustion engine E. However, the present invention is not limited to this, and may be applied to an SOHC (Single Overhead Camshaft) type internal combustion engine, for example.

In this embodiment, the gas-liquid separation chamber is provided separately from the head cover 1, but the gas-liquid separation chamber may be provided inside the head cover 1. In the present embodiment, the head cover 1 can be reduced in weight and size by providing, for example, a resin-made gas-liquid separation chamber that communicates with the opening 9 separately from the head cover 1.

Moreover, in this embodiment, although the bulging part 111 was formed between all the adjacent upper bearing parts 13, this invention is not limited to this, A plurality of adjacent upper bearing parts 13 The bulging part 111 should just be formed in the location where reinforcement is required among them.

DESCRIPTION OF SYMBOLS 1 Head cover 11 Covering part 111 Swelling part 12 Outer peripheral edge part 13 Upper bearing part 13b Bolt insertion hole 15 1st reinforcement rib 16 2nd reinforcement rib 2 Cylinder head 23 Lower bearing part 3 Valve mechanism

Claims

A covering portion that covers from above the valve operating mechanism including a camshaft disposed in the cylinder head;
An outer peripheral edge provided along the outer peripheral edge of the covering portion and fastened to the cylinder head;
A plurality of upper bearing portions that are provided integrally with the covering portion and the outer peripheral edge portion, and that rotatably support the camshaft in cooperation with a plurality of lower bearing portions provided in the cylinder head;
An internal combustion engine head cover structure comprising:
The upper bearing portion is fastened and fixed to the lower bearing portion,
The head cover structure for an internal combustion engine, wherein the covering portion has a bulging portion that bulges in a substantially hemispherical shape between the adjacent upper bearing portions.
The upper bearing portion has a bearing side fastening and fixing portion fastened and fixed to the lower bearing portion,
The outer peripheral edge portion has an outer peripheral side fastening fixing portion that is fastened and fixed to the cylinder head at a portion that is intermediate between the adjacent upper bearing portions,
A first reinforcing rib is provided between the bearing side fastening and fixing portion and the outer periphery side fastening and fixing portion,
The head cover structure for an internal combustion engine according to claim 1, wherein the bulging portion is provided at a portion surrounded by the adjacent upper bearing portion and the first reinforcing rib.
The second reinforcing rib extends from the apex of the bulging portion toward the bearing side fastening and fixing portion and the outer peripheral side fastening and fixing portion on the lower surface of the bulging portion. 3. A head cover structure for an internal combustion engine according to item 2.
The cam shaft is composed of an intake side cam shaft and an exhaust side cam shaft,
A plurality of the upper bearing portions are arranged along each of the intake side camshaft and the exhaust side camshaft,
The bulge portion is provided between at least one of the upper bearing portions of the intake-side cam shaft and between the upper bearing portions of the exhaust-side cam shaft. A head cover structure for an internal combustion engine according to any one of claims 3 to 5.