JP3414192B2 - Engine cylinder head structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head structure of an engine in which a cam cap as a mounting member is mounted on an upper portion of a cylinder head.

[0002]

2. Description of the Related Art Internal combustion engines for automobiles
In general, an intake port and an exhaust port communicating with the combustion chamber are provided on both sides of the cylinder head, and an intake valve and an exhaust valve are provided at the intake port and the exhaust port, respectively. Therefore, when the engine is driven, the intake valve and the exhaust valve are moved up and down, so that the intake port and the exhaust port are opened and closed with respect to the combustion chamber. Then, the intake valve and the exhaust valve are driven to suck the air-fuel mixture from the intake port into the combustion chamber and discharge the combustion gas from the combustion chamber to the exhaust port.

The intake valve and the exhaust valve are driven by an intake valve camshaft and an exhaust valve camshaft. FIG. 7 shows a cross section showing a schematic structure of a general DOHC engine.

As shown in FIG. 7, an intake port 3 and an exhaust port 4 communicating with the combustion chamber 2 are provided on both sides of the cylinder head 1, and a communicating portion between the intake port 3 and the exhaust port 4 and the combustion chamber 2 is provided. The front ends of the intake valve 5 and the exhaust valve 6 face the. Therefore, by driving the intake valve 5 and the exhaust valve 6 up and down, the combustion chamber 2 and the intake port 3 and the exhaust port 4 are opened and closed.

A cam chamber 20 is provided above the cylinder head 1, and an intake valve camshaft 7 and an exhaust valve camshaft 8 which are parallel to each other are disposed in the cam chamber 20. An intake cam 9 and an exhaust cam 10 each having a predetermined lift amount are integrally formed. The intake valve camshaft 7 and the exhaust valve camshaft 8 are rotatably supported in the respective cam chambers 20 by a plurality of cam caps 11.

Further, rocker arms 12 and 13 are mounted on the cylinder head 1, and the rocker arms 12 and 13 are mounted on the lash adjuster 1 by an intake cam 9 and an exhaust cam 10.
Swing with 4, 15 as a fulcrum. The tip ends of the rocker arms 12 and 13 contact the upper ends of the intake valve 5 and the exhaust valve 6, and the rocker arms 12 and 13 swing to drive the intake valve 5 and the exhaust valve 6 up and down. Reference numeral 16 in the drawing is a plug hole for attaching the ignition plug. The cylinder head 1 is provided with a rocker cover 24 so as to cover the upper side of the cam chamber 20.

A camshaft sprocket (not shown) is fixed to one end of each of the intake valve camshaft 7 and the exhaust valve camshaft 8, and a timing belt is laid between each camshaft sprocket and the crankshaft sprocket. ing. Therefore, each camshaft sprocket rotates in synchronization with the rotation of the crankshaft sprocket, and the intake valve camshaft 7 and the exhaust valve camshaft 8 can be rotationally driven.

The rocker cover 24 has two convex portions 25 and 26 so as to cover the intake side and exhaust side cam chambers 20, and the central portion 27 is recessed. Therefore, when rainwater or the like is splashed above the engine when the engine is mounted on the vehicle, the water is collected in the central recess 27 of the rocker cover 24, and the water enters the plug hole 16 communicating with the central portion 27. There is a risk that the spark plug may get wet. Therefore, conventionally, the rocker cover 24 is formed with a through hole 28 that communicates from the central concave portion 27 to the outside of the convex portion 25 and is inclined. Therefore, the water that has entered the central recess 27 of the rocker cover 24 will be discharged to the outside of the rocker cover 24 through the through hole 28, and will not accumulate in this central recess 27 and adversely affect the spark plug. .

[0009]

By the way, in recent years, the cam chamber 20 in which the intake valve camshaft 7 and the exhaust valve camshaft 8 are arranged is made independent, and each cam chamber is covered by a separate rocker cover. The engine is being considered. By covering the cam chamber independently and covering it with a separate rocker cover, a spark plug, a manifold, etc. can be directly coupled to the main body of the engine between the separate rocker covers. As a result, the rocker cover can be floatingly supported on the engine body side while being separated from the ignition plug, manifold, etc., and the influence of vibration from the body side can be minimized to shut off vibration noise in the cam chamber. be able to.

In this way, when the intake-side cam chamber and the exhaust-side cam chamber are made independent and each cam chamber is covered with a dedicated rocker cover, the intake-side cam chamber and the exhaust-side cam chamber in the cylinder head. At the center of the partition, there will be a recess defined by the intake-side rocker cover and the exhaust-side rocker cover. Rainwater from above the engine will collect in this recess, so this water will be discharged. It is necessary to provide a through hole.

However, in such a cylinder head structure, even if the rocker cover is provided with a through hole for discharging water as in the conventional case, the water accumulated in the central portion of the rocker cover cannot be reliably discharged to the outside. Can not. That is, the intake-side rocker cover and the exhaust-side rocker cover are fixed to the cylinder head via the seal member, and the inner parts of the intake-side rocker cover and the exhaust-side rocker cover and the cylinder head to which the inner part is fixed. Water collects in the recess between the center of the and. Therefore, even if the rocker cover is provided with a through hole for discharging water, the recess side opening of this through hole is located higher than the bottom of the recess, and the water accumulated in the recess cannot be completely discharged.

The present invention solves such a problem, and an object of the present invention is to provide a cylinder head structure of an engine capable of reliably discharging the water, which has entered the concave portion above the engine, to the outside. .

[0013]

In order to achieve the above object, in the cylinder head structure of the engine according to the invention of claim 1, a mounting member having a flange portion is placed above the cylinder head, and the mounting member is mounted on the mounting member. A cover member that covers the space portions on both sides of the flange portion without covering the flange portion is mounted, and a communication passage that communicates from the upper surface of the flange portion to the outer peripheral side of the mounting member and the cylinder head is provided. Therefore, even if rainwater from above impinges on the engine and penetrates into the flange, the water in this flange is discharged from the upper surface of the flange to the outer peripheral side of the mounting member and cylinder head by the communication passage. , It does not collect on the flange.

Further, in the cylinder head structure of the engine according to the second aspect of the invention, the flange is provided with a mounting hole for the spark plug. Therefore, the water that has entered the flange is
It will not be collected in the flange portion and will be discharged to the outside from the communication passage, and the water of the flange portion will not enter the mounting hole and wet the ignition plug, and deterioration of the ignition plug can be prevented.

In the cylinder head structure for an engine according to the third aspect of the present invention, the tip of the communication passage is open to the intake port side, the exhaust port side or the engine rear side. Therefore, the water discharged from the communication passage to the outside does not flow to the front of the engine, and does not wet the timing belt to cause malfunction.

Further, in the engine cylinder head structure according to the invention of claim 4, the base end opening of the communication passage communicating with the upper surface of the flange portion when mounted on a vehicle has a tip communicating with the outer peripheral side of the mounting member and the cylinder head. It is located above the opening. Therefore, the water that has entered the flange portion flows from the base end opening communicating with the upper surface through the communication passage to the tip end opening located at a position lower than the base end opening, so that the water in the flange portion can be quickly discharged. Can be discharged to the outside.

Further, in the engine cylinder head structure of the present invention as claimed in claim 5, the mounting member is mounted on the vehicle at an inclination of a predetermined angle, and the base end opening of the communication passage communicating with the upper surface of the flange portion is of this flange portion. It is provided at the lowest position. Therefore, the water that has entered the flange portion flows from the base end opening communicating with the lowest position thereof through the communication passage to the tip end opening located at a position lower than the base end opening, so that the water of the flange portion is removed. Can be completely discharged.

Further, in the cylinder head structure of the engine according to the invention of claim 6, the cover member includes a first cover and a second cover for covering a plurality of independent spaces, and each of the first cover and the second cover. It is composed of a first connecting portion and a second connecting portion that connect the end portions to each other, and the flange portion is surrounded by this cover member. Therefore, water is likely to collect in the central portion surrounded by the first cover, the second cover, the first connecting portion, and the second connecting portion, but since the communication passage is open here, the water is completely removed from the outside. Can be discharged to.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an exploded perspective view of a V6 cylinder in-cylinder injection type engine showing a cylinder head structure of an engine according to an embodiment of the present invention, FIG. 2 is a vertical cross section of the cylinder head portion of the engine, and FIG. A plan view of the cam cap plate showing the inside of the engine is shown in FIG. 4, a IV-IV cross section of FIG. 3, a perspective view of the rocker cover is shown in FIG. 5, and a plan view of the rocker cover is shown in FIG.

As shown in FIG. 1, the engine of this embodiment is a V-type 6-cylinder DOHC gasoline engine consisting of three cylinders on one bank side, which directly injects high-pressure fuel into the combustion chamber and also from an upright intake port. This is an in-cylinder injection engine in which intake air is sucked into a combustion chamber and a mixture of fuel and air is ignited in the combustion chamber. The structures shown in FIGS. 2 to 6 are for the cylinder head portion of the left bank.

As shown in FIGS. 1 and 2, the engine 31
A pair of cylinder heads 33 on the right bank side and the left bank side are fixed to the cylinder block 32, and a cam cap plate 34 as a mounting member is fixed to each cylinder head 33. An intake valve camshaft 35 and an exhaust valve camshaft 36, which are parallel to each other, are arranged in each cylinder head 33, and are rotatably held by the cam cap plate 34.

The cam sprocket 3 is attached to one end of the intake valve camshaft 35 and the exhaust valve camshaft 36 in the axial direction.
A crank sprocket 40 is fixed to one end of the crank shaft 39. And
A timing belt 41 is wound around the cam sprockets 37, 38 and the crank sprocket 40. Therefore, when the engine 31 operates and the crankshaft 39 rotates, the intake valve camshaft 35 and the exhaust valve camshaft 36 rotate in synchronization via the crank sprocket 40, the timing belt 41, and the cam sprockets 37 and 38. be able to. The cam sprockets 37, 38, the crank sprocket 40, and the timing belt 41 are covered with a timing belt cover 70 divided into three parts, respectively.
Is closely held on the end surface of the rocker cover 42 fixed to the cam cap plate 34.

The rocker cover 42 is floatingly supported on the upper surface of the cam cap plate 34 via a seal member 63, and the rocker cover 42 is provided with an outlet 43 for blow-by gas. That is, the upper space of the cylinder head 33 formed between the cylinder head 33, the cam cap plate 34, and the rocker cover 42 is the outlet 43.
It is connected to the intake system via and can communicate. Therefore, the blow-by gas leaking into the cylinder block 32 is sent from the outlet 43 to the intake system through the upper space of the cylinder head 33, mixed with fresh air, and then flowed into the combustion chamber again to enable combustion. ing.

An intake port 45 and an exhaust port 46 are connected to the combustion chamber 44 formed in the cylinder head 33, and the combustion chamber 44 of the intake port 45 and the exhaust port 46 is connected.
The tips of the intake valve 47 and the exhaust valve 48 face the communicating portion with. Therefore, by driving the intake valve 47 and the exhaust valve 48 up and down, the combustion chamber 44 and the intake port 45 and the exhaust port 46 are opened and closed. The intake port 45 stands upright and opens to the intake hole 53 in the central portion 56 of the cam cap plate 34, and the exhaust port 46 opens to the side of the cylinder head 33. The flange 55 of the intake manifold 54 is rigidly coupled to the upper surface of the central portion 56 of the cam cap plate 34 via a gasket 91, and the intake manifold 54 communicates with the intake hole 53.

An intake cam chamber 49 and an exhaust cam chamber 50 are independently formed on both sides of the cam cap plate 34 with the central portion 56 interposed therebetween. The intake cam chamber 49 and the exhaust cam chamber 50 are respectively described above. The intake valve camshaft 35 and the exhaust valve camshaft 36 are disposed. The intake valve camshaft 35 and the exhaust valve camshaft 36 are integrally formed with an intake cam 51 and an exhaust cam 52 having a predetermined lift amount for each cylinder.

The rocker arm 5 is attached to the cylinder head 33.
7 and 58 are mounted, and the rocker arms 57 and 58 swing by the intake cam 51 and the exhaust cam 52 with the lash adjusters 59 and 60 as fulcrums.
The tips of the rocker arms 57 and 58 are attached to the intake valve 4
The intake valve 47 and the exhaust valve 48 can be driven up and down by abutting on the upper ends of the valve 7 and the exhaust valve 48 and swinging the rocker arms 57 and 58 respectively.

Here, the cam cap plate 34 will be described in detail. As shown in FIGS. 2 and 3, the cam cap plate 34 has a frame shape and has a cylinder head 22.
A plurality of cap portions 61 fixed on the cam chambers 49 and 50 are integrally provided in the cam chambers 49 and 50, respectively.
The camshafts 35 and 36 can be rotatably supported by being fixed to the support portion of the cylinder head 33 with the 36 interposed therebetween. Further, a plug mounting hole 62 for mounting a spark plug and a pair of intake holes 53 are provided in the central portion 56 of the cam cap plate 34 for each cylinder. As described above, the intake manifold 54 is provided in the central portion 56.
Is fixed, the intake manifold 54 becomes
3 is communicated with the intake port 45.

The rocker cover 42 is floatingly supported on the upper surface of the cam cap plate 34 via a seal member 63. That is, the rocker cover 42 is floatingly supported by the cam cap plate 34, which is the main body side of the engine 31, and the intake manifold 54 is rigidly coupled to penetrate through the central portion of the rocker cover 42.

Further, as shown in FIGS. 3 and 4, the cam cap plate 34 is provided with a pair of front and rear vertical wall portions 81 that intersect the axial direction of the exhaust valve cam shaft 36 so as to partition the inside of the exhaust cam chamber 50. A communication passage 82 is formed in each of the vertical wall portions 81 for discharging water that has entered the central portion of the rocker cover 42 to the outside. One end of the communication passage 82 opens as a base end opening 84 on the upper surface of a flange portion 83 integrally formed with the central portion 56 of the cam cap plate 34, and the other end of the communication passage 82 has a side surface on the exhaust side of the cam cap plate 34. Is opened as a tip opening 85. The communication passage 82 is formed by the cylinder head 33 and the cam cap plate 3.
Cylinder head 3 though it is horizontal to 4 mag
By fixing 3 to the cylinder block 32 of the V-type engine, the inclined state as shown in FIG. 4 is obtained.

Therefore, when rainwater splashes from the upper portion of the engine when the vehicle is running in the rain, the rainwater reaches from above the rocker cover 42, which will be described later, to above the flange portion 83 in the central portion 56 of the cam cap plate 34. Then, it enters the communication passage 82 from the base end opening 84 opened on the upper surface of the flange portion 83, and is discharged to the side of the cam cap plate 34 from the tip end opening 85 through the inclined communication passage 82. Even if water enters the flange portion 83 as described above, the water in the flange portion 83 is discharged to the side of the cam cap plate 34 through the communication passage 82. Therefore,
Water does not collect in the flange portion 83, water in the flange portion 83 does not enter the plug mounting hole 62 and wets the ignition plug, and deterioration of the ignition plug can be prevented.

Next, the rocker cover 42 and the seal member 6
3 will be described in detail. As shown in FIGS. 5 and 6, the rocker cover 42 includes a first cover member 71 that covers the intake cam chamber 49 of the cam cap plate 34, and a second cover member 72 that covers the exhaust cam chamber 50 of the cam cap plate 34. Are provided separately. The ends of the first cover member 71 and the second cover member 72 on the cam sprocket 37, 38 side are connected by a first connecting portion 73. A seal surface 74 is formed on the surface of the first connecting portion 73 on the cam sprocket 37, 38 side along the outer peripheral portion thereof.
Is fitted to the stepped portion of the first connecting portion 73, and the end face thereof is closely attached to the sealing surface 74 to be mounted. That is, the sealing of the end portions of the first cover member 71 and the second cover member 72 with respect to the timing belt cover 70 is performed by the sealing surface 74 of the first connecting portion 73.
This makes it possible to form them flush. Further, the intake cam chamber 49 and the exhaust cam chamber 50 of the engine 31 and the cam sprocket 37, 38 side are separated by the first connecting portion 73 being in close contact with the cam cap plate 34 via the seal member 63. It is in a state.

The opposite ends of the first cover member 71 and the second cover member 72 are connected to each other by the second connecting portion 75, so that a predetermined rigidity is ensured. As described above, since the respective ends of the first cover member 71 and the second cover member 72 are connected by the first connecting portion 73 and the second connecting portion 75, one rocker cover 42 is formed.
Is configured. Then, the first cover member 71, the second
An air intake manifold 54 is provided so as to pass through a space 76 surrounded by the cover member 72, the first connecting portion 73, and the second connecting portion 75, and is rigidly coupled to the cam cap plate 34.

The rocker cover 42 is floatingly supported by the cam cap plate 34 via a single seal member 63. That is, as shown in FIG. 1, the seal member 63 has a shape along the outer circumference of the intake cam chamber 49 and is interposed between the first cover member 71 and the cam cap plate 34, and the exhaust cam. It has an exhaust seal portion 78 which is formed along the outer periphery of the chamber 50 and is interposed between the second cover member 72 and the cam cap plate 34. Then, one ends of the intake seal portion 77 and the exhaust seal portion 78 are connected to each other by a first connection seal portion 79 interposed between the first connection portion 73 and the cam cap plate 34, and the intake seal portion 77 and the intake seal portion 77 are connected to each other. The other ends of the exhaust seal portions 78 are connected to each other by a second connection seal portion 80 interposed between the second connection portion 75 and the cam cap plate 34.

As described above, the seal member 63 is a single member in which both ends of the intake seal portion 77 and the exhaust seal portion 78 are connected by the first connecting seal portion 79 and the second connecting seal portion 80. Therefore, the first cover member 71,
Second cover member 72, first connecting portion 73, second connecting portion 75
The rocker cover 42 consisting of can keep the sealing height of all the mounting surfaces of the cam cap plate 34 to which the rocker cover 42 is mounted uniform, and can make the sealing surface uniform over the entire circumference. Therefore, even the engine 31 having the upright intake port 45 can support the first cover member 71 and the second cover member 72 in a state where the sealing performance is ensured. Therefore, the first connecting portion 73 on the timing belt 41 side and the cover member 7
Since 1 and 72 are integrated, there is no risk of water leaking between the first connecting portion 73 and the cover members 71 and 72, and it is possible to prevent the timing belt 41 from getting wet with water and causing malfunction.

As described above, in the engine cylinder head structure of this embodiment, the cam cap plate 34 is provided with the communication passage 82 that communicates from the upper surface of the flange portion 83 to the outer surface portion on the exhaust side. The water that has entered the portion 83 is opened from the base end opening portion 84 that is opened on the upper surface to the communication passage 8
2 can be discharged to the side of the cam cap plate 34 on the exhaust side through the communicating passage 82. Therefore, water does not collect in the flange portion 83, and the water in the flange portion 83 does not fit in the plug mounting hole 6.
It is possible to prevent the ignition plug from deteriorating because it does not get into the inside of 2 to wet the ignition plug. Further, since the communication passage 82 is provided in the cam cap plate 34, the communication passage 82 exists above the engine valve operating device, so that the valve operating device can be assembled more easily than the one in which the communication passage is provided in the cylinder head or the like. Workability is not deteriorated.

In the engine cylinder head structure of this embodiment, since the engine 31 is V-shaped, the communication passage 82 is inclined, and the water in the flange portion 83 flows through the communication passage 82 to the outside. Can be discharged promptly. Also,
The upstream end of the communication passage 82 communicates with a base end opening 84 formed on the upper surface of the flange portion 83. The base end opening 84 is formed at the lowest position of the flange portion 83. As a result, the water in the flange portion 83 can reliably flow into the base end opening portion 84 and can be completely discharged to the outside through the communication passage 82.

Further, in the cylinder head structure of the engine of the present embodiment, the tip opening 85 of the communication passage 82 is formed on the outer side surface of the cam cap plate 34 on the exhaust side, so that the tip opening portion passes through the communication passage 82. The water discharged from 85 to the outside does not flow to the front of the engine 31, and it is possible to prevent malfunction due to wetting of the timing belt 41. The formation position of the front end opening portion 85 of the communication passage 82 is not limited to the exhaust-side outer surface portion of the cam cap plate 34 as in the above-described embodiment, but may be the intake-side outer surface portion or the rear surface of the engine 31. It may be formed on the surface portion or the cylinder head 33.

In the engine to which the cylinder head structure of the engine of the present invention described above is applied, high-pressure fuel is directly injected into the combustion chamber as in the above-described embodiment, and the intake air sucked from the intake port and the combustion chamber The present invention is not limited to a V6 DOHC in-cylinder injection type engine that mixes and ignites an air-fuel mixture, but the intake port and the exhaust port are opened to the side of the cylinder head to inject fuel into the intake passage. It can also be applied to an engine. Also, the state of the cylinder is not limited to the V-type 6 cylinder, and the in-line 6 cylinder and the in-line 4 cylinder
It is also possible to apply to engines other than the above-mentioned embodiment, such as a cylinder engine.

[0040]

As described above in detail in the embodiments, according to the engine cylinder head structure of the invention of claim 1, the mounting member having the flange portion is mounted above the cylinder head, and the mounting member is mounted. Install a cover member that covers the space on both sides of the flange without covering the flange,
Since a communication passage that connects the upper surface of the flange to the outer peripheral side of the mounting member and cylinder head is provided, even if rainwater splashes from above the engine and water enters the flange, the water in this flange is The water can flow out from the upper surface of the portion to the outer peripheral side of the mounting member and the cylinder head, and the water that has entered the flange portion can be reliably discharged.

According to the engine cylinder head structure of the second aspect of the present invention, since the flange is provided with the mounting hole for the spark plug, the water that has entered the flange can be reliably discharged through the communication passage. The water of the flange portion does not enter the mounting hole and wet the spark plug, and the spark plug can be prevented from deterioration.

According to the cylinder head structure of the engine of the third aspect of the invention, the tip end of the communication passage is on the intake port side,
Since it is opened to the side of the exhaust port or to the rear of the engine, water discharged to the outside from the communication passage does not flow to the front of the engine, and malfunctions due to wetting of the timing belt can be prevented.

According to the engine cylinder head structure of the fourth aspect of the invention, the base end opening of the communication passage communicating with the upper surface of the flange portion is communicated with the mounting member and the outer peripheral side of the cylinder head when mounted on a vehicle. Since it is located above the tip opening, water that has entered the flange can flow from the base opening communicating with the upper surface to the tip opening through the communication passage, and the water in the flange can be quickly externalized. Can be discharged to.

According to the cylinder head structure of the engine of the fifth aspect of the present invention, the mounting member is mounted on the vehicle with a predetermined angle of inclination, and the base end opening of the communication passage communicating with the upper surface of the flange is formed in the flange. Since it is installed at the lowest position, the water that has entered the flange can flow from the base end opening communicating with the lowest position to the tip opening through the communication passage, and the water in the flange can be completely discharged to the outside. be able to.

According to the engine cylinder head structure of the sixth aspect of the present invention, the cover member includes a first cover and a second cover for covering a plurality of independent spaces, and the first cover.
Since the cover and the second cover are configured by the first connecting portion and the second connecting portion that connect the respective end portions of the second cover, and the flange portion is surrounded by this cover member, the first cover, the second cover, and the first connecting portion. Although water is likely to collect in the central portion surrounded by the second connecting portion, the water can be completely discharged to the outside because the communication passage is open here.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a V6 cylinder direct injection engine showing a cylinder head structure of an engine according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a cylinder head portion of an engine.

FIG. 3 is a plan view of a cam cap plate showing the inside of the engine.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view of a rocker cover.

FIG. 6 is a plan view of a rocker cover.

FIG. 7 is a sectional view showing a schematic structure of a general DOHC engine.

[Explanation of symbols]

31 engine 33 cylinder head 34 Cam cap plate 35 Camshaft for intake valve 36 Camshaft for exhaust valve 42 rocker cover 49 Intake cam chamber 50 Exhaust cam chamber 53 Intake hole 54 Intake manifold 56 Central 61 Cam cap part 62 plug mounting hole 63 seal member 70 Timing belt cover 71 First Cover Member 72 Second cover member 73 First connection part 74 Sealing surface 75 Second connection part 76 vacant place 77 Air intake seal 78 Exhaust seal part 81 Vertical wall 82 passages 83 Flange 84 Base end opening 85 Tip opening 91 Gasket

Continuation of the front page (56) Reference JP-A-9-13975 (JP, A) JP-A-7-259641 (JP, A) JP-A-5-133207 (JP, A) JP-A-2-215907 (JP , A) JP-A-8-232614 (JP, A) Actually open 3-65837 (JP, U) Actually open 62-64849 (JP, U) Actually open 61-178049 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02F 1/24 F02F 7/00

Claims (6)

(57) [Claims] 1. A mounting member to be mounted above a cylinder head of an engine, a flange portion provided at a substantially central portion of the mounting member along the axial direction of a cam shaft, and on both sides of the flange portion. A plurality of space portions provided, and a cover member that covers the space portion without covering the flange portion,
A cylinder head structure for an engine, comprising: a communication passage that communicates from an upper surface of the flange portion to an outer peripheral side of the mounting member and the cylinder head. 2. The cylinder head structure for an engine according to claim 1, wherein a mounting hole for an ignition plug is provided in the flange portion. 3. The cylinder head structure for an engine according to claim 1, wherein a tip end portion of the communication passage is open to the intake port side, the exhaust port side, or the rear side of the engine. Construction. 4. The cylinder head structure for an engine according to claim 1, wherein a base end opening of the communication passage communicating with an upper surface of the flange portion when mounted on a vehicle has an outer periphery of the mounting member and the cylinder head. A cylinder head structure for an engine, wherein the cylinder head structure is located above a tip opening communicating with the side. 5. The engine cylinder head structure according to any one of claims 1 to 4, wherein the mounting member is mounted on a vehicle while being inclined at a predetermined angle, and a base end opening of the communication passage communicating with an upper surface of the flange portion is provided. A cylinder head structure for an engine, wherein the cylinder head structure is provided at the lowest position of the flange portion. 6. The engine cylinder head structure according to claim 1, wherein the cover member includes a first cover and a second cover that cover the plurality of independent spaces.
An engine having a first connecting portion and a second connecting portion that connect the respective longitudinal end portions of the first cover and the second cover to each other, and the flange portion is surrounded by the cover member. Cylinder head structure.