JPH0121324B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve train for a torch-ignited multi-cylinder internal combustion engine.

In conventional torch-ignited multi-cylinder internal combustion engines,
A cylinder head joined to a cylinder block having a plurality of cylinders arranged in parallel with each other, a plurality of main combustion chambers corresponding to the cylinders, and a plurality of auxiliary combustion chambers disposed close to each of the main combustion chambers and each having a spark plug. and a torch nozzle for communicating between each of the main combustion chambers and the sub-combustion chambers, and two main intake valves whose axes are inclined at a predetermined angle with respect to the cylinder axis are provided on one side of the roof surface of each of the main combustion chambers. arranged in parallel, and on the other side of the roof surface, the axis is inclined at an angle smaller than the predetermined angle with respect to the cylinder axis,
In addition, one exhaust valve is provided whose umbrella part is larger than the umbrella part of the main intake valve, and each of the sub-combustion chambers is provided with a sub-intake valve, and exhaust gas is ejected from each of the sub-combustion chambers through a torch nozzle into each main combustion chamber. The structure in which the air-fuel mixture in the main combustion chamber is combusted by a torch flame has the advantage that it not only reduces the generation of harmful components and improves fuel efficiency, but also improves the engine's intake and exhaust efficiency and provides high output. However, since the number of valves as a whole is very large and there are many cylinders, there are many restrictions on the structure and arrangement of each part of the valve train in the cylinder head. It was also not easy to form them into the same shape for compatibility.

The present invention was proposed in view of the above, and although it is a torch ignition multi-cylinder internal combustion engine, one of the two main intake valve locker arms of each cylinder,
It is an object of the present invention to provide a valve train in which a rocker arm for an exhaust valve can be formed into the same shape without any problem, thereby achieving compatibility.

In order to achieve this object, the present invention provides a cylinder head joined to a cylinder block having a plurality of cylinders arranged in parallel with each other, a plurality of main combustion chambers corresponding to the cylinders, and a plurality of main combustion chambers adjacent to each of the main combustion chambers. A plurality of auxiliary combustion chambers each having a spark plug are provided, and a torch nozzle is provided for communicating between each main combustion chamber and the auxiliary combustion chamber, and one side of the roof surface of each of the main combustion chambers is provided with a Two main intake valves whose axes are inclined at a predetermined angle are arranged side by side, and on the other side of the roof surface, the axis is inclined at an angle smaller than the predetermined angle with respect to the cylinder axis,
In addition, one exhaust valve is provided whose umbrella part is larger than the umbrella part of the main intake valve, and each of the sub-combustion chambers is provided with a sub-intake valve, and exhaust gas is ejected from each of the sub-combustion chambers through a torch nozzle into each main combustion chamber. In a torch-ignited multi-cylinder internal combustion engine, in which the air-fuel mixture in the main combustion chamber is combusted by a torch flame, a single valve train extends through the cylinder head between the main intake valve and the exhaust valve. A camshaft is disposed, and first and second rocker arm shafts are provided between the main intake valve and the valve drive camshaft, and between the exhaust valve and the valve drive camshaft, passing through the cylinder head vertically and parallel to the valve drive camshaft. are arranged on the first rocker arm shaft above each main combustion chamber, and two intake rocker arms connecting the upper ends of the two main intake valves and the valve drive cam on the valve drive camshaft are also arranged. Exhaust and auxiliary intake rocker arms, which connect the upper ends of the exhaust valve and auxiliary intake valve and the valve drive cam on the valve drive camshaft, are each swingably supported on the second rocker arm shaft. The bisecting position between the axes of the rocker arm shaft and the axis of the valve drive cam shaft are respectively offset from the cylinder axis toward the main intake valve side, and the intake rocker arm comes into contact with the valve drive cam from the center of the first rocker arm shaft. and the distance from the center of the second rocker arm axis to the point of contact with the valve drive cam of the exhaust rocker arm, and also from the center of the first rocker arm axis to the point of contact with the main intake valve of the intake rocker arm. and the distance from the center of the second rocker arm axis to the point of contact between the exhaust rocker arm and the exhaust valve are respectively set equal, so that one of the two intake rocker arms and the exhaust rocker arm are the same. It is characterized by being formed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a four-cylinder internal combustion engine will be described below with reference to FIGS. 1 to 6.

The engine body E of a cross-flow type torch ignition type four-cylinder internal combustion engine includes a cylinder block 1 and a cylinder head 2 which is polymerized and bonded to the cylinder block 1 through a gasket 3, and is bored in parallel with the cylinder block 1. A piston 5 is slidably fitted into each of the four cylinders 4. Further, the cylinder head 2 is formed with a main combustion chamber 6 facing the upper surface of each piston 5, and each roof surface 7 of these main combustion chambers 6 is an inclined surface having a different area facing each other, as shown in FIG. It is formed into a roof shape. On one side of each roof surface 7, two main intake valve ports 8a, 8b having approximately the same diameter are opened in parallel. Intake ports 9a and 9b are communicated with each other, and these main intake ports 9a and 9b are collected into one in the cylinder head 2 and communicated with a fuel supply device, for example, a main carburetor 10 via an intake manifold In. The main carburetor 10 is adjusted to produce a relatively lean air-fuel mixture.

The main intake valve ports 8a and 8b are both main intake valves 11a and 11a, which are slidably provided in the cylinder head 2, respectively.
11b, and when these valves open, a relatively lean air-fuel mixture generated by the main carburetor 10 is sucked into the main combustion chamber 6.

Further, on the other side of each of the roof surfaces 7, an exhaust valve port 12 is opened to one side, that is, opposite to one main intake valve port 8b, and this exhaust valve port 12 is formed in the cylinder head 2. Exhaust port 1
It is connected to 3. Each exhaust valve port 12 is opened and closed by an exhaust valve 14 provided in the cylinder head 2.

As shown in FIG. 6, the main intake valve ports 8a, 8
b has a slightly smaller diameter than the exhaust valve port 12, and has a diameter slightly smaller than that of the main intake valve 11.
The inclination angle θ ₁ that the axis l ₁ - _{l 1} of a, 11b makes with respect to the cylinder axis LL is the axis l ₂ - _{l 2} of the exhaust valve 14.
is slightly larger than the inclination angle θ ₂ made with respect to the cylinder axis LL.

Sub-combustion chambers 17 are formed above the main combustion chamber 6 in the cylinder head 2, and sub-intake valve ports 18 are opened in the upper surfaces of these sub-combustion chambers 17. Each sub-intake port 19 is opened on the intake side side of the cylinder head 2 and is connected to a sub-fuel supply device, such as a sub-carburetor 20, through the intake manifold In. is communicated with. The auxiliary carburetor 20 is adjusted to a relatively rich air-fuel mixture.

Sub-intake valves 22 that open and close each sub-intake valve port 18 are supported in the cylinder head 2 in a vertically slidable manner. The relatively rich air-fuel mixture is quickly introduced into the sub-combustion chamber 17 through the sub-intake port 19.

Plug mounting holes 15 for mounting spark plugs P are formed below the auxiliary combustion chamber 17, biased toward one side of each. The plug mounting holes 15 are opened on the side surface of the cylinder head 2 on the exhaust side, and each spark plug P is screwed into the side surface, and the electrodes of the spark plugs P are respectively connected to the sub-combustion chamber 1.
7 is on the way.

Two torch nozzles 26 and 27 are bored in the partition wall 24 that separates the main combustion chamber 6 of the cylinder head 2 from the corresponding sub-combustion chamber 17, and the upper ends of these torch nozzles 26 and 27 are connected to the sub-combustion chamber, respectively. 17, and its lower end communicates with the main combustion chamber 6. Therefore, two torch nozzles 26, 27
The opening end on the side of the main combustion chamber 6 is located parallel to the exhaust valve port 12 on the other inclined surface of the roof surface 7, and is located opposite to the one main intake valve 11a. It forms the ignition source for the combustion chamber 6.

From the middle of the two torch nozzles 26, 27, two sub-nozzles 28, 29 with a smaller diameter are branched, respectively.
The lower end of 9 opens into a squish area S formed by the piston 5 and the lower surface of the cylinder head 2.

The two main intake valves 11a, 11b and the exhaust valve 1
4 and the sub-intake valve 22, one valve drive camshaft 30 is arranged along the longitudinal direction of the cylinder head 2, and is rotatably mounted on the cylinder head 2 via a plurality of bearings 31. is supported by. This camshaft 30 is rotationally driven in conjunction with a crankshaft as usual.

As clearly shown in FIG. 5, the camshaft 30 has two main intake valve drive cams 32, 3 per cylinder.
3 are integrally provided at intervals in the axial direction, and furthermore, one valve operating cam 34 for exhaust and one valve operating cam 35 for sub-intake are integrally provided between them.
and the two valve operating cams 32, 33 for the main intake.
The bearing 31 is disposed close to the outside of the cylinder, and the camshaft 30 is rotatably supported by the pair of bearings 31 per cylinder.

In addition, two main intake valves 11a, 11b and a camshaft 3
A first rocker arm shaft 36 is supported on the cylinder head 2 between the cylinder head 2 and the camshaft 30 in parallel with the camshaft 30 via a plurality of bearings 38. A second rocker arm shaft 37 is supported on the head 2 in parallel with the camshaft 30 via a plurality of bearings 39. Two main intake rocker arms 40a and 40b per cylinder are pivotally supported on the first rocker arm shaft 36 with a compression spring 41 in between, and the outer ends of these rocker arms 40a and 40b are connected to an adjuster 42, respectively. Main intake valves 11a, 11
The slipper surface 43 at the inner end is in contact with the upper end of the main intake valve operating cam 3 on the camshaft 30.
2 and 33, respectively. In addition, one rocker arm 44 for exhaust per cylinder and one rocker arm 45 for sub-intake per cylinder are swingably supported on the second rocker arm shaft 37 with compression springs 46 in between, and the outer end of the rocker arm 44 for exhaust is pivotally supported. The outer ends of the sub-intake rocker arm 45 are brought into contact with the upper ends of the exhaust valve 14 and the sub-intake valve 22 via adjusters 47 and 48, respectively, and the slipper surfaces 49 and 50 at their inner ends are The rocker arms 40a, 40b are in contact with the exhaust valve operating cam 34 and the sub-intake valve operating cam 35 on the camshaft 30 on the inside of the rocker arms 40a, 40b. When the camshaft 30 is rotated, the main intake rocker arms 40a, 4
0b swings around the first rocker arm shaft 36, the exhaust rocker arm 44 and the sub-intake rocker arm 45 swing around the second rocker arm shaft 37, and the main intake valves 11a, 11b, exhaust valve 14 and sub-intake valve 22 The valves cooperate with valve springs 51, 52, and 53 to open and close at predetermined valve timing.

By the way, in the present invention, as described above, the axes l ₁ -l ₁ of the main intake valves 11a and 11b and the exhaust valve 14
Despite the fact that the inclination angles θ _{1 and θ 2 that} the axes l ₂ - l 2 of The rocker arm 44 is formed identically so that compatibility between these 40b and 44 can be obtained. Therefore, the main intake valve 11
a, 11b, exhaust valve 14, sub-intake valve 22, camshaft 30, and first and second rocker arm shafts 36, 37
are arranged in the following relationship. That is, since it is necessary to arrange the camshaft 30 in the center of the main intake valves 11a, 11b, the exhaust valve 14, and the auxiliary intake valve 22, the axis of the camshaft 30 is offset from the main intake valve 11a by an eccentric amount ε with respect to the cylinder axis LL. , 11b side. In this case, as the difference in inclination angles θ ₁ -θ ₂ increases, the amount of eccentricity ε naturally increases. Along with the offset of the camshaft 30, the bisecting position c between the axes of the first and second rocker arm shafts 36 and 37 is similarly offset toward the main intake valves 11a and 11b with respect to the cylinder axis LL. . Furthermore, the first
From the center of the Rotsuka arm shaft 36 to the Rotsuka arm 40
The distance d ₁ from the point of contact between a and 40b with the valve operating cams 32 and 33 is equal to the distance d ₂ from the center of the second rocker arm shaft 37 to the contact point between the rocker arm 44 and the valve operating cam 34, that is, d ₁ = d ₂ , and furthermore, the distance d ₁ ' from the center of the first rocker arm shaft 36 to the contact point of the rocker arms 40a, 40b with the main intake valves 11a, 11b, and the second rocker arm shaft 37
The first and second rocker arm shafts 3 are arranged so that the distance d ₂ ' from the center of the rocker arm 44 to the contact point of the exhaust valve 14 is equal, that is, d ₁ '=b ₂ '.
The positions of 6 and 37 are determined.

Furthermore, in addition to the above relationship, as shown in FIG.
It is determined to have the above-mentioned compatibility while ensuring the necessary slipper area and cam gap within the range of 1.31. In particular, there is little freedom in arranging the four valve drive cams 32 to 35 between the bearings 31 and 31, but by arranging them as in the embodiment described above, it is possible to secure the slipper surface and the cam gap. .

As described above, the camshaft 30, the main intake valves 11a, 1
1b, the exhaust valve 14 and the first and second rocker arm shafts 36, 37 are defined, and the valve drive cams 32, 3 are defined.
By determining the arrangement of the main intake valves 3, 34, and 35, one of the main intake rocker arms 40b and the exhaust rocker arm 44 can be formed identically, achieving compatibility between them, and furthermore, the two main intake valves 11
a and 11b can also be formed identically, and their compatibility can also be obtained.

When the engine is operated, during its suction stroke,
A relatively lean air-fuel mixture generated by the main carburetor 10 is sucked into the main combustion chamber 6, and a relatively rich mixture generated by the sub-vaporizer 20 is sucked into the sub-combustion chamber 17. A mixture of air and air is inhaled.
Then, near the end of the engine's compression stroke, the spark plug P
When ignited, the rich air-fuel mixture in the auxiliary combustion chamber 17 burns, and the torch flame ejects into the main combustion chamber 6 from the torch nozzles 26 and 27.
Stratified combustion occurs when the lean mixture in the combustion chamber burns.

A second embodiment of the invention is shown in FIGS. 7 and 8. In this second embodiment, the main combustion chamber 6 and the sub-combustion chamber 1
7 through one torch nozzle 26',
Further, the torch nozzle 26' and the main combustion chamber 6 are connected to one another.
Furthermore, the exhaust valves 14 of the two main combustion chambers 6 on the central side of the cylinder head 2 are arranged opposite to the outer main intake valves 11a, and the main combustion chambers 6 of the torch nozzle 26' are connected to each other. The opening end on the chamber 6 side faces the inward main intake valve 11b,
In addition, the spark plugs P are arranged close to each other near the center, and the shapes of the main intake ports 9a and 9b are slightly different, but other configurations are the same as those of the first embodiment, and the operation and effect are also different. However, there is no such thing.

As described above, according to the present invention, a cylinder head joined to a cylinder block having a plurality of cylinders arranged in parallel with each other has a plurality of main combustion chambers corresponding to the cylinders, and a plurality of main combustion chambers disposed close to each of the main combustion chambers. A plurality of auxiliary combustion chambers each having a spark plug, and a torch nozzle that communicates between each main combustion chamber and the auxiliary combustion chamber are provided, and one side of the roof surface of each of the main combustion chambers has an axis line with respect to the cylinder axis. Two main intake valves inclined at a predetermined angle are arranged side by side, and on the other side of the roof surface, the axis is inclined at an angle smaller than the predetermined angle with respect to the cylinder axis, and the umbrella part is an umbrella part of the main intake valve. one exhaust valve larger than the above is provided, and each of the sub-combustion chambers is provided with a sub-intake valve, and a torch flame is ejected from each of the sub-combustion chambers to each main combustion chamber via a torch nozzle to cause mixing in the main combustion chamber. In a torch-ignited multi-cylinder internal combustion engine that burns air, between the main intake valve and the exhaust valve,
A single valve drive camshaft is provided that runs vertically through the cylinder head, and the valve drive cam is connected vertically through the cylinder head between the main intake valve and the valve drive camshaft, and between the exhaust valve and the valve drive camshaft. First and second rocker arm shafts are respectively arranged parallel to the shafts, and above each main combustion chamber, the first rocker arm shaft has upper ends of the two main intake valves and a valve train cam on the valve train cam shaft. The two intake rocker arms that connect the two intake rocker arms, and the exhaust and auxiliary intake rocker arms that connect the upper ends of the exhaust valve and auxiliary intake valve and the valve drive cam on the valve drive camshaft are pivoted on the second rocker arm shaft. The cylinder is pivotably supported, and the bisecting position between the axes of the first and second rocker arm shafts and the axis of the valve train camshaft are respectively offset from the cylinder axis toward the main intake valve side,
The distance from the center of the first rocker arm shaft to the point of contact with the valve drive cam of the intake rocker arm is equal to the distance from the center of the second rocker arm shaft to the point of contact with the valve drive cam of the exhaust rocker arm, and 1
The distance from the center of the rocker arm axis to the contact point of the intake rocker arm with the main intake valve and the distance from the center of the second rocker arm axis to the contact point of the exhaust rocker arm with the exhaust valve are set equal, respectively, and Since either one of the two intake rocker arms and the exhaust rocker arm are formed the same,
Although the main intake valve and exhaust valve have different cap sizes and different angles of inclination with respect to the cylinder axis, the main intake valve and exhaust valve are different in size and have different inclination angles with respect to the cylinder axis. Although there are many restrictions on the structure and arrangement of the valve mechanism in the cylinder head, the rocker arm for one main intake valve and the rocker arm for the exhaust valve can be formed into the same shape without any problems. Therefore, one valve drive camshaft and two rocker arm shafts are respectively disposed longitudinally through the cylinder head, and are commonly used for multiple valve systems corresponding to each cylinder. Together with its use, it can greatly contribute to reducing the cost of the valve train as a whole.

[Brief explanation of drawings]

1 to 6 show a first embodiment of the device of the present invention, FIG. 1 is a longitudinal sectional view taken along the line of FIG. 3 of an internal combustion engine equipped with the device of the present invention, and FIG. Figure 3 is a bottom view of the cylinder head taken along line 3, Figure 4 is a plan view of the valve mechanism section taken along line 1, and figure 5 is a bottom view of the cylinder head taken along line 1. , FIG. 4 is a vertical cross-sectional view taken along the line, FIG. 6 is a schematic diagram of the valve train, and FIGS. 7 and 8 show a second embodiment of the present invention, and FIG. 7 shows the same cylinder as in FIG. 3. The bottom view of the head, FIG. 8, is a plan view of the same valve mechanism as FIG. 4. c... Bisection position, d ₁ , d ₂ , d ₁ ', d ₂ '... distance,
l ₁ - l ₁ , l ₂ - l ₂ ... Axis line, L - L ... Cylinder axis line, P ... Spark plug, θ ₁ , θ ₂ ... Angle, 1 ...
Cylinder block, 2... Cylinder head, 4...
...Cylinder, 5...Piston, 6...Main combustion chamber,
11a, 11b...main intake valve, 14...exhaust valve,
17...Sub-combustion chamber, 22...Sub-intake valve, 26,2
6'...Torch nozzle, 27...Torch nozzle,
30... Valve train camshaft, 31... Bearing, 32, 33
...Main intake valve train cam, 34...Exhaust valve train cam, 35...Sub-intake valve train cam, 36, 37...
First and second rocker arm shafts, 40a, 40b...
Intake rocker arm, 44...Exhaust rocker arm, 45...Sub-intake rocker arm.

Claims (1)

[Claims] 1 A cylinder head 2 joined onto a cylinder block 1 having a plurality of cylinders 4 arranged in parallel with each other.
A plurality of main combustion chambers 6 are provided corresponding to the cylinders 4.
, a plurality of auxiliary combustion chambers 17 disposed close to each of the main combustion chambers 6 and each having a spark plug P, and torch nozzles 26, 17, 26' for communicating between each of the main combustion chambers 6 and the auxiliary combustion chambers 17. , on one side of the roof surface of each of the main combustion chambers 6 is a cylinder axis L.
- Axis l ₁ - l ₁ inclined at a predetermined angle θ ₁ with respect to L 2
Two main intake valves 11a and 11b are installed in parallel, and on the other side of the same roof surface, an axis line with respect to the cylinder axis LL is provided.
One exhaust valve 14 is provided, in which l ₂ - l ₂ is inclined at an angle θ ₂ smaller than the predetermined angle θ ₁ and whose umbrella portion is larger than the umbrella portions of the main intake valves 11a and 11b, and each of the sub-combustion chambers 17 is provided with a sub-intake valve 22, and the air-fuel mixture in the main combustion chamber 6 is combusted by a torch flame ejected from each sub-combustion chamber 17 into each main combustion chamber 6 through torch nozzles 26, 27, 26'. In a torch-ignited multi-cylinder internal combustion engine,
A single valve drive camshaft 30 is provided between the main intake valves 11a, 11b and the exhaust valve 14, and a valve drive camshaft 30 passing through the cylinder head 2 vertically is provided. , and between the exhaust valve 14 and the valve drive camshaft 30, first and second rocker arm shafts 36 and 37 are disposed, respectively, passing through the cylinder head 2 vertically and parallel to the valve drive camshaft 30. 6, the first rocker arm shaft 36 has a
Two intake rocker arms 40a, 40b connecting the upper ends of the two main intake valves 11a, 11b and the valve drive cams 32, 33 on the valve drive camshaft 30 are connected, and an exhaust valve is connected to the second rocker arm shaft 37. 14 and the upper end of the auxiliary intake valve 22 and the valve operating cams 34 and 35 on the valve operating camshaft 30 are pivotably supported for rocker arms 44 and 45 for exhaust and auxiliary intake, respectively. The bisecting position c between the axes of the rocker arm shafts 36 and 37 and the axis of the valve drive camshaft 30 are respectively located on the main intake valve 11 from the cylinder axis LL.
a, 11b side, and the distance d ₁ from the center of the first rocker arm shaft 36 to the point of contact with the valve drive cams 32, 33 of the intake rocker arms 40a, 40b, and the distance from the center of the second rocker arm shaft 37 to the exhaust gas. The distance d ₂ from the point of contact between the intake rocker arm 44 and the valve drive cam 34 is made equal, and the distance from the center of the first rocker arm shaft 36 to the intake rocker arm 40 is made equal.
a, 40b to the contact point with the main intake valves 11a, 11b, and a distance _d2 ' from the center of the second rocker arm shaft 37 to the contact point of the exhaust rocker arm 44 with the exhaust valve ₁₄ . The two intake rocker arms 40a, 40 are set equally.
Either one 40b of b and the exhaust rocker arm 44
A valve train for a torch-ignited multi-cylinder internal combustion engine, characterized in that the two are identically formed.