JPS6260909A - V-type engine - Google Patents

Abstract

PURPOSE:To improve the combustion performance or output performance and to enhance the disconnect accessibility for ignition plugs by driving the intake and exhaust valves on the center side by one cam shaft and those on both sides by each one cam shaft, in a V-type engine in which respective cylinder heads are staggeredly arranged. CONSTITUTION:In a V-type engine in which the bank angle theta on both sides is narrow and the respective cylinder head faces are staggeredly arranged, the intake and exhaust valves on the center side of both banks are driven by one cam shaft 13 arranged on the center. And the intake and exhaust valves located on each outside of both banks are driven by respective cam shafts 14, 15 arranged on both sides of heads. Thus, the intake and exhaust valves on respective cylinders are inclined nearly symetrically, enabling each of the combustion chambers to form a penthouse roof shape, and the cylinder head parts are simplified to facilitate the maintenance of ignition plugs 20 and fuel injection valves 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a ■-type engine, and particularly to a closed-angle type ■type engine in which the angle between the axes of the left and right cylinders is set to be small.

(Prior technology) ■-type engines, in which multiple cylinders are arranged in a V-shape on either side around the crankshaft, have a shorter overall length than an in-line engine, but are significantly wider; therefore, they are difficult to install in automobiles, for example. In this case, the layout may be difficult due to the space in the engine room and the suspension system installed around the engine room. Therefore, as shown in, for example, Japanese Utility Model Application Publication Nos. 59-90003, a closed-angle type V-type engine has been proposed. In this engine, the angle formed by the axes of the left and right cylinders arranged in a V-shape is set to be relatively small, and each cylinder is arranged with a crankshaft 1? The cylinders are arranged in a staggered manner in the vertical direction, and although the overall length is longer than that of a normal V-type engine, the overall length is shorter than that of an in-line engine.
In addition, an engine with a narrower width than a normal ■ type engine can be obtained.

However, in this narrow-angle type V-type engine, since the opening at the top of the left and right cylinders is small, it is customary to configure the combustion chamber of the gold cylinder with a single cylinder head, as in the case of an in-line engine.

In that case, the intake of the left and right cylinders in one cylinder head,
Must be equipped with an exhaust valve and its driving hoe mechanism,
Also, each cylinder must be equipped with a spark plug, but the placement and orientation of the intake and exhaust valves are related to the shape of the combustion chamber, and the position of the spark plug also depends on the propagation of the flame and the service provided to the spark plug. The arrangement and configuration of these intake and exhaust valves and spark plugs is an important issue because it greatly affects performance.

In other words, for example, in the engine shown in the above-mentioned publication, two camshafts B and C are arranged in left and right parallel to each other above the cylinder head A, as shown in FIG. The left valve D1 of the cylinder E located on the right side and the left valve E1 of the cylinder E located on the right side are driven by the left cam shirt I-B, and the right valve D2 of the cylinder head D located on the left side of the cylinder head A is driven. A configuration is shown in which the right-side valve E2 of the cylinder E located on the right-hand side is driven by the right-side camshaft C. According to such a configuration, one camshaft drives the right-side valve E2 of the cylinder E located directly below. Since it is necessary to drive the valves of the cylinder located on the opposite side of the valve, the valves D+ and E2 of the cylinder located directly below the camshaft are set vertically, and the valves E+ and D2 of the cylinder located on the opposite side are driven. This means that they have no choice but to be arranged in an inclined manner. Therefore, the upper surfaces D' and E' of the combustion chamber, in which the boat openings opened and closed by these valves are formed, have an asymmetrical shape consisting of a horizontal plane on the negative side and an inclined plane on the other side, and The shape of the combustion chamber also becomes irregular and unnatural, and as a result, for example, the formation of air-fuel mixture and the propagation of flame are not performed well, resulting in deterioration of the combustion state or f [F] of output. Also, as mentioned above, one valve in each cylinder is installed vertically, so the angle between the two valves is small, so if you try to install the spark plug in the center of the combustion chamber, the intake and exhaust valves will be opposite each other. Compared to the case where the spark plug is inclined to the side, the installation space for the spark plug is narrower, making it difficult to install and remove the spark plug, and serviceability is significantly deteriorated.

(Object of the Invention) The present invention deals with the above-mentioned problems in a narrow angle type V-type engine, and aims to improve the intake and exhaust valves and valve train mechanism of the left and right cylinders installed in a single cylinder head. By improving the configuration of the combustion chamber, it is possible to make the combustion chamber into a shape that allows for good combustion, and while ensuring good attachment and removal of the spark plug, it is possible to place the spark plug in the center of the combustion chamber. to ensure good flame propagation. As a result, it is an object of the present invention to realize a V-type engine of this type that has excellent combustion performance and output performance, and also has excellent spark plug attachment/detachability.

(Structure of the Invention) That is, in the present invention, a plurality of cylinders are arranged in a staggered manner along the crankshaft direction, and the intersection angle of the axes of the left and right cylinders is set small, and each cylinder head is arranged in a staggered manner along the crankshaft direction. In a narrow angle type V-type engine in which combustion chambers of cylinders are formed, one of the intake and exhaust valves of each cylinder installed in the cylinder head is placed in the center of the cylinder head, and the other is placed in the side of the cylinder head. Three camshafts extending in the direction of the crankshaft are arranged at the center and both sides of the upper part of the cylinder head. The camshaft located in the center of the upper part of the cylinder head controls the valves located in the center of the cylinder head (the right valve of the cylinder located on the left side and the left valve of the cylinder located on the right side). The camshafts on both sides in the upper part connect the valves (the left valve of the cylinder located on the left side and the right valve of the cylinder located on the right side) located in the corresponding side band of the cylinder head, respectively, directly or with a swing arm. Configured to drive via.

According to this configuration, the valves located near the center and both sides of the cylinder head are driven by camshafts located corresponding to these positions, respectively.
The intake and exhaust valves in each cylinder can be arranged in a V-shape that slopes in opposite directions. This makes it possible to form the upper surface of the combustion chamber, where the openings of the intake and exhaust ports that are opened and closed by these valves, into an inverted ■-shaped so-called vent roof type, and the space between the intake and exhaust valves. Since the space becomes wider, it becomes possible to arrange the spark plug in the center of the upper surface of the combustion chamber while ensuring good attachability and detachability.

(Effects of the Invention) As described above, according to the present invention, in a narrow angle type V-type engine, the spark plug can be arranged in the center of the combustion chamber while ensuring serviceability such as the ease of attaching and removing the spark plug. This makes it possible to obtain good flame propagation, and also allows the adoption of a pent roof type combustion chamber with excellent combustibility, resulting in output performance comparable to that of an in-line engine or a normal V-type engine. . Furthermore, since each valve is driven directly or via a swing arm by a camshaft located substantially directly above each valve, it is possible to increase the engine rotation speed more than when the valves are driven via a rocker arm.

(Example) Examples of the present invention will be described below.

As shown in FIGS. 1 and 2, an engine 1 according to this embodiment
consists of a cylinder block 2 and a single cylinder head 3 attached to the upper surface of the block 2, and has four cylinders 51 to 54 in which pistons 4 are fitted, respectively. The axis of the third cylinder 51.53 and the second cylinder. The axes of the fourth cylinders 52 and 54 form a small intersecting angle θ with the axis O of the crankshaft (not shown), and each cylinder 51 to 54 is arranged in the shape of They are arranged in a staggered manner left and right along x. In the cylinder head 3, each cylinder 51 to
54 are provided with two intake ports 7.7 and two exhaust ports 8.8 which communicate with the combustion chamber 6, and each exhaust port 8 of these boats is connected to the side of the cylinder head 3. The first one is located closer to the left side. The third cylinders 5+ and 53 are located on the left side, and the second and fourth cylinders 52 and 54 are located on the right side, and are opened to the left and right side surfaces 3a and 3b of the cylinder head 3, respectively. Further, each intake boat 7 has a first degree cylinder located near the center of the cylinder head 3, that is, on the left side, a third cylinder 51,53 located on the right side, and a second cylinder located on the right side. 4th cylinder 52.54
The intake boats 7 of the left cylinders 51 and 53 are located on the right side of the top surface of the cylinder head 3, and the intake boats 7 of the right cylinders 52 and 54 are located on the left side of the top surface of the cylinder head 3. They are opened at the respective positions. In addition, in correspondence with this arrangement of the intake and exhaust ports 7.8, two intake valves 9 and two exhaust valves 10 are provided for each cylinder, and each intake valve 9 is located closer to the center of the cylinder head 3. Each exhaust valve 10 is disposed at a position closer to both left and right sides of the cylinder head 3. Therefore, in each of the cylinders 51 to 54, the intake and exhaust valves 9.10 are arranged in a V-shape with inclinations in opposite directions.
The upper surface of the combustion chamber 6, in which the openings of the intake and exhaust ports 7.8 which are opened and closed by the combustion chamber 6 are provided, is shaped like a so-called bengle roof. Here, each of the valves 9 and 10 is biased in the closing direction by a valve spring 11, and in this embodiment, two intake boats 7 and 7 are connected to each cylinder 51 to 54 at the downstream side. A fuel injector 12 is provided at the junction.

On the other hand, the intake camshaft 1 is located at the center of the upper part of the cylinder head 3, that is, between the cylinders 51 and 53 located on the left side of the cylinder tappet 3 and the cylinders 52 and 54 located on the right side.
3 is provided on both sides of the upper part of the cylinder head 3, that is, on the upper left side of the cylinders 51 and 53 located on the left side, and on the upper right side of the cylinders 52 and 54 located on the right side.
．． The 2nd tJl Kiki Mushi 11ft 14.15 was deployed,
These three camshaft A feet 13, 14, and 15 are arranged parallel to the direction of the crankshaft 11 feet. The intake force shafts 1 to 13 are rotatably supported by bearing members 16...16 fixed to the cylinder head 3, and each cylinder 51 to 54
Two intake cams 13a, 13a are arranged correspondingly to the cylinders 51 to 5 located in the center of the cylinder head 3.
4 intake valves 9...9 respectively with tappets 17...1
It is designed to be opened via 7. In addition, the above 1. The second exhaust force shafts 1-14, 15 are rotatably supported by bearing members 18...18 fixed to the cylinder head 3, respectively. 1 exhaust camshaft 14
are provided with two exhaust cams 14a, 14a at positions corresponding to the left cylinders 51 and 53, respectively, and a second exhaust camshaft 15 disposed on the right side of the upper part of the cylinder head 3 has a Two exhaust cams 15a, 15a are provided at positions corresponding to the exhaust cams 1i52.!5+ of the first exhaust camshaft 14, respectively.
14a and the first exhaust camshafts 15a...15a, the exhaust valves 10 of the cylinders 5+ and 53 located on the left side are
...10 and the exhaust valves 10...10 of the cylinders 52, 54 located on the right side are rotated via tappets 19...19, respectively.

In addition to the above configuration, a plug insertion boss 3CS is provided above the center of each cylinder 51 to 54 in the cylinder head 3, and the spark plug 20 is attached to the boss 3c in a posture substantially along the axis of the cylinder. .

The tips of these spark plugs 20 are connected to each cylinder 51 to
54, the center of the upper surface of the combustion chamber 6, that is, the intake and exhaust boats 7.
It faces the position surrounded by the opening to the combustion chamber 6 of 7.8.8. Note that a cord 21 is connected to each spark plug 20.

According to the above configuration, the intake valves 9 of each cylinder 51 to 54
, 9 are driven by an intake force valve 11 located at the center of the upper part of the cylinder head 3, and an exhaust valve 10 is driven by a foot 13.
．． 10 is driven by a first exhaust camshaft 14 located on the upper left side of the cylinder head 3 and a second exhaust camshaft 15 located on the right side. That is, each of the intake valves 9...9 and the exhaust valves 10...10 is driven by three camshafts 13, 14, and 15 provided corresponding to the respective installation positions. Therefore, each cylinder 51 to 54 has suction, 1)
It becomes possible to arrange the 1-air valves 9 and 10 in a V-shape inclined in opposite directions while ensuring a required angle. Along with this, it becomes possible to form the upper surface of the combustion chamber 6 into a vent roof type with excellent combustibility, and the
Since there is a large space between the exhaust valves 9 and 10,
The spark plug 20 is inserted into the combustion chamber 6 while ensuring good removability.
It is possible to place it in the center of As a result, it has excellent combustion performance or output performance, and the spark plug 20
This results in an engine with good serviceability.

Furthermore, each camshaft 13 to 15 has intake and exhaust valves 9 and 15.
... 9, 10... 10, so the intake and exhaust valves 9... 9, 10... 10 can be directly driven without using a rocker arm, and therefore the engine High rotation speed is possible.

Incidentally, in the above embodiment, the intake and exhaust valves 9 and 10 are directly driven by the camshafts 13 to 15, but they may also be driven via a swing arm. The effect of this can be obtained.

[Brief explanation of the drawing]

1 and 2 do not show embodiments of the present invention.
The figure is a schematic plan view of the cylinder head, and Figure 2 is Figure 1 I-
FIG. 2 is a vertical cross-sectional view taken along line II. Moreover, FIG. 3 is a longitudinal sectional view showing a conventional example. 3...Cylinder head, 51-54...Cylinder, 6.
... Combustion chamber, 9, 10... Valve, 13-15...
camshaft.

Claims (1)

[Claims] (1) A V-type cylinder in which multiple cylinders with V-shaped axes are arranged in a staggered manner left and right along the crankshaft direction, and the upper part of the combustion chamber of each cylinder is formed by a single cylinder head.
type engine, one of the intake and exhaust valves of each cylinder is arranged in the center of the cylinder head, the other is arranged near the side of the cylinder head in a V-shape, inclined in opposite directions, and the intake and exhaust valves are arranged in a V-shape in the direction of the crankshaft. Three camshafts extending from the top of the cylinder head are disposed at the center and both sides of the cylinder head, and the camshaft at the center of the top of the cylinder head causes the valves disposed at the center of the cylinder head to be connected to the cylinder head. A V-type engine characterized in that valves disposed near the corresponding sides of the cylinder head are driven by camshafts on both sides of the upper part, either directly or via swing arms. .