JPH0144898B2 - - Google Patents

Abstract

PURPOSE:To make the promotion of lightweightiness attainable, by forming a valve gear chamber of a cylinder head into a grilled structure with a pair of oiling passage constituent parts and plural cam shaft support wall parts. CONSTITUTION:The inside of a valve gear chamber is formed into a grilled structure with a pair of oiling passage constituent parts 37 and 38 provided with a main oiling passage for feeding lubricating oil to a valve gear mechanism and plural cam shaft support walls 41 and 42. With this constitution, the promotion of sharp lightweightiness comes possible as keeping up rigidity in a cylinder head. In addition, the valve gear chamber of the cylinder head is formed into the grilled bridge frame structure with a pair of these oiling passage constituent parts and plural cam shaft support wall parts whereby still more lightweightiness in the cylinder head is thus attainable.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Industrial Application Field The present invention relates to a lightweight and robust cylinder head structure for an in-line multi-cylinder internal combustion engine equipped with a DOHC type valve train.

(2) Prior Art Generally, the above-mentioned engine is equipped with a DOHC type valve train having two valve train cams in the valve train chamber formed in the cylinder head. It is necessary to have the necessary rigidity to maintain the rigidity, and in conventional cylinder heads of this type, the walls of the valve chamber and the supporting walls of the valve mechanism are formed thickly to maintain the above-mentioned rigidity. As a result, the cylinder head had to be heavier and larger, and there was also the problem that it was difficult to locate the spark plug in the center of the combustion chamber because it was obstructed by the DOHC valve mechanism.

(3) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned circumstances, and provides a cylinder head structure for a multi-cylinder internal combustion engine that achieves significant weight reduction without impairing the rigidity of the cylinder head. The purpose is to provide

Furthermore, the present invention provides a cylinder head structure for a multi-cylinder internal combustion engine that is designed to reduce the weight of the cylinder head without sacrificing its rigidity, and to improve combustion efficiency by arranging the spark plug in the center of the combustion chamber. The purpose is to provide the following.

B. Structure of the Invention (1) Means for Solving Problems According to the first invention, a valve train has a plurality of combustion chambers arranged in series in the vertical direction, and has two valve train camshafts in the upper part. In the cylinder head forming a valve chamber for accommodating the valve mechanism, the valve chamber includes a pair of oil supply passage components provided with a main oil supply passage for supplying lubricating oil to the valve mechanism; A camshaft supporting wall portion rotatably supports the valve camshaft, and the pair of oil supply passage components extend vertically parallel to each other in the central portion of the valve chamber, and both ends thereof are connected to the valve camshaft. The plurality of camshaft supporting walls are integrally connected to both end walls of the valve chamber, and extend vertically at intervals and perpendicular to the pair of oil supply passage forming sections, and both ends thereof are connected to both sides of the valve chamber. The valve train chamber is integrally connected to the wall, and the pair of oil supply passage forming parts and the plurality of camshaft supporting wall parts form a lattice-like structure inside the valve operating chamber.

According to the second invention, a gap is formed between the pair of oil supply path components and the plurality of camshaft supporting walls and the bottom wall of the valve operating cam chamber, and the gap is formed between the pair of oil supply path components and the plurality of camshaft support walls. Together with the support wall, the inside of the valve train chamber is constructed into a lattice-like bridge structure.

According to the third aspect of the present invention, a plug mounting tube for mounting a spark plug is formed at each intersection between the pair of oil supply path forming portions and the plurality of camshaft support wall portions.

(2) Effects According to the configuration of the first invention, the valve operating chamber of the cylinder head is formed into a lattice-like structure with a pair of oil supply passage components and a plurality of camshaft supporting walls, and the cylinder head is configured to have a lattice-like structure. It is possible to significantly reduce the weight while maintaining the required rigidity, and ensures accurate operation of the valve mechanism over a long period of time.

Further, according to the configuration of the second aspect of the present invention, the valve train chamber is configured in a lattice-like bridge structure with a pair of oil supply passage components and a plurality of camshaft supporting walls, making it possible to further reduce the weight of the cylinder head. It is.

Furthermore, according to the configuration of the third aspect of the present invention, a mounting tube for a spark plug is provided at each intersection between the pair of oil supply passage components and the plurality of camshaft supporting walls, and the valve chamber is formed into a highly rigid lattice-like structure. Even with this configuration, the spark plug can be disposed in the center of the combustion chamber, and the combustion efficiency of the engine can be improved.

(3) Embodiments Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

At the bottom of the rectangular cylinder head H, four combustion chambers 1 corresponding to each cylinder are formed along its longitudinal axis L ₁ -L ₁ , that is, along the crank axis, and the openings of these combustion chambers 1 are formed. The lower surface faces the top surface of the piston P in the cylinder of the cylinder block B.

As shown in FIG. 2, two intake valve ports 3, 3 are opened in parallel in the crankshaft direction on one side of the ceiling wall 2 of each combustion chamber 1, which has a mountain-shaped longitudinal section. On the other side, two exhaust valve ports 4, 4 are opened in parallel in the crankshaft direction, and the two intake valve ports 3, 3 and the exhaust valve ports 4, 4 are aligned with the center axis of the cylinder.
L ₂ - They are arranged symmetrically with respect to L ₂ . 2
Intake ports 5, 5 are communicated with the two intake valve ports 3, 3, respectively.
extends along the lateral direction of the cylinder head H and is opened on one side of the head H (right side in Figure 2), and exhaust ports 6, 6 are opened in the two exhaust valve ports 4, 4, respectively. , their exhaust ports 6,6
extends along the lateral direction of the cylinder head H, and is opened on the other side of the head H (left side in FIG. 2). A valve support part 9 for supporting the intake valve 7 that opens and closes the intake valve port 3 is formed on the upper wall of each intake port 5, and a valve insertion hole 10 is bored in the valve support part 9. A guide sleeve 11 is press-fitted into the valve insertion hole 10. As shown by the chain line in FIG. 2, the stem portion 7a of the intake valve 7 is attached to the guide sleeve 11,
It is slidably inserted from the side, and the poppet valve portion 7b of the intake valve 7 is seated in the intake valve port 3. Further, a spring seat surface 12 is formed on the valve support portion 9, and the lower surface of a valve spring 14 surrounding the stem portion 7a is seated on this spring seat surface 12 via a lower spring 13. The upper surface of the valve spring 14 is seated on an upper spring seat 15 that is engaged with the upper end of the stem portion 7a, and the valve spring 14 urges the intake valve 7 in the closing direction.

Similarly, another valve support part 16 is provided on the upper wall of each exhaust port 6 to support the exhaust valve 8 that opens and closes the exhaust valve port 4.
A valve insertion hole 17 is formed, and a guide sleeve 18 is press-fitted into the valve insertion hole 17. As shown by chain lines in FIG. 2, the stem portion 8a of the exhaust valve 8 is slidably inserted into each guide sleeve 18 from the combustion chamber 1 side, and the poppet valve portion 8b of the exhaust valve 8 is inserted into the exhaust valve port 4. Be seated. Further, a spring seat surface 19 is formed on the valve support portion 16, and the lower surface of the valve spring 21 surrounding the stem portion 8a is seated on this spring seat surface 19 via a lower spring seat 20. The upper surface is seated on an upper spring seat 22 that is locked to the upper end of the stem portion 8a, and the valve spring 21 is attached to the exhaust valve 8.
is biased in the valve closing direction.

At the top of the cylinder head H, there is a bottom wall 40 ₁ ,
A pair of opposing walls 40 ₂ , 40 ₂ and a pair of side walls 40 ₃ ,
A valve train chamber C surrounded by 40 ₃ is formed. In the valve train chamber C, a plurality of central blocks 23 are arranged above the plurality of combustion chambers 1, respectively, above the bottom wall 40 _{1 .}
A hollow cylindrical plug mounting tube 24 is integrally formed above the center of each combustion chamber 1 of these central blocks 23, which are integrally erected upward. A plug insertion hole 25 with an open upper surface and a concave cross section is bored in the plug mounting cylinder 24, and the bottom surface of the plug insertion hole 25 is inserted through a screw hole 26 formed in the upper wall of the combustion chamber 1. It communicates with the combustion chamber 1. As shown by the chain line in FIG. 3, the spark plug Pu inserted into the plug insertion hole 25 is attached to the cylinder head H by screwing its threaded portion into the screw hole 26.

As shown in FIGS. 1 and 2, each plug mounting cylinder 24
On both sides, an intake valve side rocker arm support 27 corresponding to the intake valve 7 and an exhaust valve side rocker arm support 28 corresponding to the exhaust valve 8 are integrally bulged outward. The rocker arm support parts 27 and 28 have screw holes 29 and 30, respectively.
are drilled, and rocker arm support members 31 and 32 are screwed into these screw holes 29 and 30. The lower end of an adjustment screw 34 screwed onto the base end of the end pivot type rocker arm 33 is rotatably engaged with the upper surface of the intake valve side rocker arm support member 31 .
The tip of each intake-side rocker arm 33 is brought into contact with the upper end of the intake valve 7 . Similarly, the lower end of an adjustment screw 36 screwed onto the base end of the end pivot type rocker arm 35 is rotatably engaged with the upper surface of the exhaust side rocker arm support member 32. The tip of the exhaust side rocker arm 35 is brought into contact with the upper end of the exhaust valve 8.

In the center of the valve chamber C, a pair of oil supply passage forming parts 37 and 38 are arranged parallel to each other in the crankshaft direction, that is, in the longitudinal direction of the cylinder head, so as to pass through both sides of the plurality of central blocks 23. It is formed integrally with the central block 23, and both ends thereof are integrally connected to the left and right end walls ₄₀₂ , ₀₂ of the valve operating chamber C. A plurality of reinforcing rib pieces 39 are provided protruding from the upper surfaces of the oil supply path forming portions 37 and 38.

Thus, the oil supply passage forming parts 37 and 38 and the valve operating chamber C
A gap 60 is formed between the bottom walls of the valve chamber C. Therefore, the oil supply passage forming portions 37 and 38 bridge the left and right end walls 40 ₂ and 40 ₂ of the valve chamber C, thereby reinforcing the valve chamber C. Also serves as.

A pair of main oil supply passages 45, 46 are formed longitudinally in the pair of oil supply passage components 37, 38, and these main oil supply passages 45, 46 are connected to a connecting oil passage that crosses the center portion thereof, as shown in FIG. They are communicated with each other by a channel 47. The communication oil passage 47 extends upward from the cylinder head H and communicates with an oil feed passage 48 that is connected to an oil pump (not shown). the pair of main oil supply passages 45;
The open ends of 46 and communication oil passage 47 toward the outer end surface of the cylinder head are sealed with blind plugs 49, 50, and 51.

As shown in FIG. 3, a plurality of branch oil passages 52 and 53 are branched from the main oil supply passages 45 and 46, respectively, and one of the branch oil passages 52 is opened at the bearing surface of the intake side bearing portion 41a. The other branch oil passage 53 is opened to the exhaust side bearing portion 42a.

In addition, as shown in FIG. 2, a pair of main oil supply passages 45,
46 is a plurality of intake side and exhaust side screw holes 29,
The oil reservoirs 54, 55 are directly connected to the intake side and the oil reservoirs 54, 55 formed at the lower part of the rocker arm support members 31, 32, through oil passages 56, 57, formed in the rocker arm support members 31, 32, respectively. It communicates with the bearing portions of the exhaust side rocker arms 33..., 35....

As shown in FIGS. 1 and 3, from the plurality of central blocks 23..., a plurality of camshaft support wall parts 4 are arranged in the lateral direction of the valve chamber C at intervals in the crankshaft direction.
1..., 42 are integrally extended, and their camshaft support wall portions 41..., 42... are integrally connected to the inner surfaces of the front and rear side walls 40 ₃ , 40 ₃ of the valve operating cam chamber C, respectively. . Semicircular bearing portions 41a..., 42a... on the upper surfaces of the plurality of support walls 41..., 42..., respectively.
is formed. The intake side camshaft 61 is rotatably supported by one of the bearing portions 41a and a bearing cap 43 fixed to the upper surface thereof, and the other bearing portion 42a and a bearing cap 44 fixed to the upper surface thereof. The exhaust side camshaft 62 is rotatably supported by....

A gap 60 is formed between the camshaft support walls 42..., 42... and the bottom wall ₄₀₁ of the valve train cam chamber C, and the support portions 41..., 42... bridge the side walls ₄₀₃ , ₄₀₃ . It also serves as a reinforcing member for the valve chamber C.
The pair of oil supply passage forming portions 37, 38 and the plurality of camshaft support wall portions 41..., 42... intersect at a substantially right angle, and each intersecting portion is connected to the central block 23...
are joined together by.

As is clear from the schematic diagrams of the cylinder head in FIGS. 7 to 9, the pair of oil supply passage forming portions 37,
38 has the above-mentioned gap 60 between it and the bottom wall 40 ₁ of the valve operating chamber C, and passes vertically through the inside of the valve operating chamber C.
The plurality of camshaft supporting walls ₄₁ ..., 42... have a gap 60 between them and the bottom wall ₄₀₁ of the valve chamber C, and are connected to the right end walls 402 _{, 402} . Room C
40 ₃ , 40 ₃
Since the pair of oil supply passage forming portions 3 are coupled to
8 and 39 serve as reinforcing longitudinal beams in the valve chamber C;
On the other hand, the plurality of camshaft supporting walls 41..., 42... serve as cross beams for reinforcing the valve chamber C, and these vertical and horizontal beams form a lattice-like bridge structure inside the valve chamber C, and the cylinder head without increasing the weight of H.
The rigidity of the cylinder head H, especially its valve chamber C, can be increased.

C Effect of the invention As is clear from the above examples, the present inventions 1 to 3
The invention has the following effects.

According to the first aspect of the invention, the pair of oil supply passage components extend vertically parallel to each other in the central portion of the valve chamber, and both ends thereof are integrally connected to both end walls of the valve chamber, and the plurality of cams The shaft support wall extends perpendicularly to the pair of oil supply passage components at intervals in the vertical direction, and its both ends are integrally connected to both side walls of the valve chamber. The inside of the valve train chamber can be formed into a lattice-like structure by using the oil supply passage component and the plurality of camshaft supporting walls that are essential for the valve train system, and the cylinder head, especially its valve train chamber, can have the required rigidity. It is possible to significantly reduce the weight of the cylinder head while ensuring the same, contributing to improving the performance of the engine.

Further, according to the second aspect of the present invention, a gap is formed between the pair of oil supply passage forming parts and the plurality of camshaft supporting wall parts and the bottom wall of the valve operating cam chamber, and the space between the pair of oil supply passage forming parts and the plurality of camshaft supporting walls is Since the inside of the valve train chamber is formed into a lattice-like bridge structure with the camshaft support wall, waste material is effectively removed from the cylinder head, making it possible to further reduce the weight of the cylinder head.

Further, according to the third aspect of the present invention, a plug mounting tube for mounting a spark plug is provided at each intersection between the pair of oil supply passage components and the plurality of camshaft supporting walls, so that a lattice structure is formed inside the valve train chamber. This allows the spark plug to be placed in the center of the combustion chamber while increasing its rigidity and reducing its weight, contributing to improving the combustion efficiency of DOEC engines.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of a cylinder head, and FIG. 2 is a plan view of a cylinder head.
Line sectional view, Figure 3 is Figure 1 - Line sectional view, Figure 4
The figure is Fig. 1 - Line cross-sectional view, Fig. 5 is Fig. 1 -
6 is a line sectional view taken from FIG. 3, FIG. 7 is a plan view schematically showing the framework of the cylinder head, FIG. 8 is a line sectional view taken from FIG. It is a cross-sectional view along the line shown in FIG. C... Valve train chamber, H... Cylinder head, 1...
Combustion chamber, 37, 38... Oil supply passage component, 41, 4
2...Camshaft support wall portion, 45...Main oil supply path.

Claims (1)

[Scope of Claims] 1. A cylinder head in which a plurality of combustion chambers are arranged in series in the vertical direction and a valve train chamber is formed in the upper part for accommodating a valve train having two valve train camshafts. The chamber includes a pair of oil supply passage components provided with a main oil supply passage for supplying lubricating oil to the valve mechanism, and a camshaft support wall that rotatably supports the two valve drive camshafts. are integrally formed, the pair of oil supply passage components extend longitudinally in parallel to each other in the central part of the valve chamber, and both ends thereof are integrally connected to both end walls of the valve chamber, and the plurality of cams are integrally formed. The shaft support wall portion extends perpendicularly to the pair of oil supply passage components at intervals in the vertical direction, and has both ends integrally connected to both side walls of the valve operating chamber, and is connected to the pair of oil supply passage construction parts. A cylinder head structure for a multi-cylinder internal combustion engine, characterized in that the inside of a valve train chamber is configured in a grid-like structure with a camshaft support wall. 2. In a cylinder head in which a plurality of combustion chambers are arranged in series in the vertical direction and a valve train chamber is formed in the upper part for accommodating a valve train having two valve train camshafts, the valve train chamber has a valve train that accommodates a valve train having two valve train camshafts. A pair of oil supply passage components provided with a main oil supply passage for supplying lubricating oil to the valve mechanism, and a camshaft support wall portion that rotatably supports the two valve operating camshafts are integrally formed. , the pair of oil supply passage components extend vertically parallel to each other in the central portion of the valve chamber, and both ends thereof are integrally bridge-connected to both end walls of the valve chamber, and the plurality of camshaft supporting wall portions are Extending perpendicularly to the pair of oil supply passage components at intervals in the longitudinal direction, both ends of which are integrally bridged to both side walls of the valve operating chamber, and comprising the pair of oil supply passage construction parts and a plurality of camshaft supports. A gap is formed between the wall portion and the bottom wall of the valve train cam chamber, and the valve train chamber is configured into a lattice-like bridge structure by the pair of oil supply passage forming parts and the plurality of camshaft supporting walls. Cylinder head structure of a multi-cylinder internal combustion engine. 3. In a cylinder head in which a plurality of combustion chambers are arranged in series in the vertical direction, and a valve train chamber is formed in the upper part for accommodating a valve train having two valve train camshafts, the valve train chamber has a valve train that accommodates a valve train having two valve train camshafts. A pair of oil supply passage components provided with a main oil supply passage for supplying lubricating oil to the valve mechanism, and a camshaft support wall portion that rotatably supports the two valve operating camshafts are integrally formed. , the pair of oil supply passage components extend vertically parallel to each other in the central portion of the valve chamber, and both ends thereof are integrally connected to both end walls of the valve chamber, and the plurality of camshaft supporting wall portions are vertically connected to each other. a plurality of camshaft support walls, each of which extends perpendicularly to the pair of oil supply passage components at intervals in the direction, and whose both ends are integrally connected to both side walls of the valve operating chamber; A plug mounting part cylinder for mounting a spark plug is formed at each intersection with the part, and the inside of the valve train chamber is configured in a lattice-like structure by the pair of oil supply passage forming parts and the plurality of camshaft supporting wall parts. The cylinder head structure of a multi-cylinder internal combustion engine is characterized by: