JPS63143332A - Multicylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To aim at the promotion of shortening various dimensions, by tilting each of adjacent cylinders alternately so as to become a specific nip angle, while setting a mating face between each cylinder and a cylinder head down to a common plane orthogonal with a bisector of this nip angle. CONSTITUTION:In this internal combustion engine, plural cylinders 2 are formed in a single cylinder block 3. In this case, these adjacent cylinders 2 are formed as being alternately titled so as to cause each center line L to become the specified nip angle theta looking from the longitudinal direction of a crankshaft 4. And, a mating face between these cylinders 2 a cylinder head 5 to be attached to the cylinder block 3 is formed into a common plane almost orthogonal with a bisector M of the nip angle theta. With this constitution, these cylinders 2 are superposed in a direction being orthogonalized with the crankshaft 4 whereby size going along the longitudinal direction of the crankshaft 4 is shortened, while each space among these cylinders is narrowed, thus size going along the direction orthogonal with the crankshaft 4 is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a multi-cylinder internal combustion engine, and particularly to a multi-cylinder internal combustion engine suitable for application to a four-stroke engine.

``Prior Art'' Conventionally, multi-cylinder internal combustion engines installed in vehicles etc. have two types: a parallel type in which each cylinder is arranged in parallel, and a parallel type in which each cylinder is arranged in parallel, and a multi-cylinder internal combustion engine in which cylinders are arranged in parallel, V-shaped cylinders are arranged so that their center lines are alternately inclined at a predetermined angle when viewed from the length direction of the crankshaft (including horizontally opposed cases where the angle is 180°) It is roughly divided into two parts.

"Problems to be Solved by the Invention" The present invention aims to solve the following problems in the conventional technology described above.

In other words, in the above-mentioned parallel-type internal combustion engine, since multiple cylinders are arranged in parallel, the engine body becomes larger in the length direction of the crankshaft, and this tendency increases as the output of internal combustion engines increases. This problem becomes more pronounced as the number of cylinders increases.

This problem arises when the internal combustion engine is applied to motorcycles, where the crankshaft is often arranged along the width direction of the vehicle body. Therefore, it becomes a factor that limits the bank angle of the vehicle body, or causes an increase in aerodynamic drag.

On the other hand, in the latter V-type internal combustion engine, the length of the internal combustion engine in the crankshaft direction is reduced compared to the parallel type, since adjacent cylinders can be arranged to overlap each other in the direction perpendicular to the crankshaft. Since it can be shortened, it is possible to minimize the problems mentioned above with the parallel type, but since multiple cylinders must be tilted at a predetermined angle alternately around the crankshaft, The problem is that the dimension in the direction of

In addition, as mentioned above, since multiple cylinders must be distributed to the armrests of the crankshaft, at least two independent cylinder blocks, cylinder heads, and
A 4-stroke engine requires an independent valve mechanism, which increases the number of components and the weight of the internal combustion engine.Furthermore, since the cylinder block and cylinder head are installed independently, the intake system and exhaust A separate system must be provided for each engine, and as a result, there are problems such as the exhaust pipe layout being complicated, which affects the performance and production cost of the internal combustion engine. ing.

Therefore, in general vehicles, parallel-type internal combustion engines and ■-type internal combustion engines are currently used depending on the specifications required for the vehicle.

"Means for Solving the Problems" The present invention aims to provide a multi-cylinder internal combustion engine that can effectively solve the problems in the conventional technology described above, and in order to achieve this purpose, the present invention has been made. In the invention, in a multi-cylinder internal combustion engine in which a plurality of cylinders are formed in a single cylinder block, the center lines of each adjacent cylinder are arranged at a predetermined angle when viewed from the longitudinal direction of the crankshaft. The cylinders are formed to be alternately inclined so that the cylinder head attached to the cylinder block is formed, and the mating surfaces of each cylinder and the cylinder head attached to the cylinder block are a common plane substantially perpendicular to the bisector of the angle of inclination. do.

"Operation" The multi-cylinder internal combustion engine according to the present invention is formed by alternately inclining each of the seven adjacent rings so that their center lines form a predetermined angle when viewed from the longitudinal direction of the crankshaft. By doing so, each cylinder is overlapped in the direction perpendicular to the crankshaft, thereby shortening the dimension along the length direction of the crankshaft, and the mating surface between each cylinder and the cylinder head attached to the cylinder block is angle 2
By forming a common plane substantially perpendicular to the equal dividing line, it is possible to narrow the distance between the cylinders distributed around the crankshaft, thereby shortening the dimension along the direction perpendicular to the crankshaft, This makes it possible to create a cylinder head with multiple cylinders, thereby suppressing an increase in the number of parts.

Embodiment A first embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, reference numerals indicate a multi-cylinder internal combustion engine (hereinafter simply referred to as an internal combustion engine) according to this embodiment, and as shown in FIGS. Two cylinders 2 (2 cylinders, 2B, 2C, 2D) are formed in a single cylinder block 3, and each adjacent cylinder 2 (two cylinders and 2B, cylinders 2D and 2C) is aligned with the respective center line L ( The center lines La and 1.b1 (center lines Ld and Lc) are alternately inclined at a predetermined angle θ when viewed from the length direction of the crankshaft 4, and each cylinder 2 (2Δ 2B, 2C, 2D) and the mating surface 3a of the cylinder head 5 attached to the cylinder block 3
The schematic configuration is such that M is a common plane that is substantially orthogonal to the bisector M of the angle θ.

Next, to explain these details, each cylinder 2 (2A, 2B, 2C, 2D) has a through hole 6 (6a, 6b, 6c, 6d) formed in the cylinder block 3.
) is formed by fitting a cylindrical sleeve 8 into which the piston 7 is slidably fitted, and each of the through holes (6a, 6b, 6c, 6d) is formed at its upper end. That is, on the mating surface 3a side (hereinafter, explanation will be made assuming that the top dead center side of the piston is the top and the bottom dead center side is the bottom), as shown in FIG. As shown in FIG. The dimensions are such that there is no such thing.

Further, the upper end surface of the sleeve 8 is attached to the cylinder block 3 so as to be the same as the mating surface 3a formed on the upper surface of the cylinder block 3, and the mating surface 3a is As shown in each cylinder 2 (
2A, 2B, 2C, 2D) center line L (La-Lb-L
Since the sleeve 8 is formed on a single plane orthogonal to the bisector M of the angle θ formed by
Similarly, the upper end surface is formed to be inclined with respect to the length direction of the sleeve 8. On the other hand, the lower end surface of the sleeve 8 is formed perpendicular to the length direction and projects outward from the lower end of the cylinder block 3.

Therefore, the four cylinders 2 (2A, 2B, 2C
・2D) is every other two cylinders 28・2C(2
B and 2D) are set as one set, and each set is parallel to each other.

Hereinafter, a parallel set of two cylinders 2C will be taken as the back row, and another set of cylinders 2B and 2D will be taken as the front row.

In this way, cylinder 2 (2 people, 2B, 2C, 2D)
The cylinder block 3 is formed with the crankshaft 4.
As shown in FIG. 1, the crankcase 9 is integrally connected to the upper part of the crankcase 9 with a plurality of bolts 10, and the abutting surface 3b with the crankcase 9 is formed parallel to the upper abutting surface 3a. has been done.

In the crankcase 9, each of the sleeves 8 is inserted into a connecting portion with the cylinder block 3, and
Communication holes 9a that communicate the insides of these sleeves 8 and the insides of the crankcase 9 are formed as shown in FIG. A connecting rod 11 connecting the piston 7 is inserted.

The cylinder head 5 has a mating surface 5a formed on its lower surface, which is brought into contact with the upper mating surface 3a of the cylinder block 3 over the entire surface, and when the cylinder head 5 is attached to the cylinder block 3, the cylinder head As shown in FIGS. 1, 4, and 5, a recess 13 forming a continuous combustion chamber 12 in the upper part of each cylinder 2 (2 people, 2B, 2C, and 2D) is connected to each cylinder 2 (2A, 2B, and・2C・
2D).

Further, the cylinder head 5 is formed with an intake passage 14 and an exhaust passage 15 that communicate with each of the recesses 13.

Each of the intake passages 14 and the exhaust passages 15 is branched into two near the recess 13, as shown in FIG.
Each of the branched ends forms an intake boat 14a and an exhaust port 15a that open into the recess 13.

Each of the intake passages 14 extends from the recess 13 in one direction perpendicular to the crankshaft 4, and the intake passages 14 connected to the cylinders 2B and 2D in the front row are connected to the cylinders 2B and 2D in the rear row. The cylinder 2 in the rear row passes between the four parts 13 formed corresponding to the cylinders 2A and 2C.
It is formed parallel to the intake passage 14 connected to A and 2C. Each of the exhaust passages 15 extends from each recess 13 in a direction opposite to the intake passage 14, and the exhaust passages 15 connected to the rear row cylinders 2A and 2C are connected to the front row cylinders. It is formed so as to pass between the recesses 13 formed corresponding to the cylinders 2B and 2D, and to be parallel to an exhaust passage 15 communicating with the cylinders 2B and 2D in the front row.

Therefore, each intake passage 14 and exhaust passage 15 are led out to respective sides of the cylinder block 3 on a passage-by-passage basis.

Further, the cylinder head 5 has a structure shown in FIGS.
As shown in the figure, an intake valve 16 and an exhaust valve 1 for opening and closing each intake boat 14a and exhaust port 15a.
A valve operating mechanism 18 for opening and closing these road valves 16 and 17 is attached to the valve mechanism 18 which is slidably attached to the valve 7 and the valve mechanism 18 which opens and closes the road valves 16 and 17, respectively.

The intake valve 16 and the exhaust valve 17 are connected to the cylinder head 5.
A retainer 19 is integrally attached to this protruding portion, and is normally urged in the closing direction by a valve spring 20 interposed between the retainer 19 and the cylinder head 5. has been done.

As shown in FIGS. 1 and 4, the valve mechanism 18 includes a camshaft 21 rotatably attached to the cylinder head 5, and a camshaft 21 integrally formed with the camshaft 21.
a cam C that controls the opening/closing timing of the intake valve I6 and the exhaust valve 17 according to the rotation of the valve I6;
7, and a rocker arm 22 that is swung by a cam C to slide the six valves 16 and 17.

Furthermore, in this embodiment, the camshaft 21 is connected to each cylinder 2B and 2D in the front row, as shown in FIGS. 1 and 6.
a first camshaft 21a that controls the opening and closing timing of the exhaust valve 17;
and cylinders 2B and 2D in the front row and cylinders 2A and 2D in the rear row.
2C, a second camshaft 21b that controls the opening and closing timing of the conventional intake valve 16 and the latter exhaust valve 17;
The third camshaft 21c controls the opening and closing timing of the intake valve 16 of the two rear row cylinders 2C, and each camshaft 2
1a to 21c are parallel to the crankshaft 4.

A cam gear 23 is provided at one end of the first camshaft 21a and the second camshaft 21b among these camshafts 21a to 2Lc.
are integrally attached to each other, and between these cam gears 23 and the crankshaft 4, as shown in FIGS. 2 camshaft 21. A cam chain 24 that transmits data to b is wound around the cam chain 24. Further, the second camshaft 21
b and the other end of the third camshaft 21c,
As shown in FIG. 6, cam gears 25 similar to the cam gear 23 are integrally attached, and these cam gears 25 transfer the rotation of the second cam shaft 21b to the third cam shaft 2.
A cam chain 26 for transmitting data to 1c is wound thereon.

Here, each of the cam gears 23 and 25 is connected to a sprocket 27 attached to the crankshaft 4 so that the rotation of the first and second camshafts 21a and 21b is [/2] of the rotation of the crankshaft 4. The shape of the three camshafts 21a to 21c is set.
However, they can be rotated synchronously at half the rotation speed of the crankshaft 4.

On the other hand, in this embodiment, on the upper part of the cylinder head 5,
As shown in FIG. 6, a peripheral wall 28 is formed that surrounds each of the filter cam shafts 21a to 2+, c, and is continuous at a position surrounding the cam gears 23 and 25.
"Secondly, by attaching the head cover 29 as shown in FIGS. 1 and 4, each of the camshafts 21a to 2
1c and cam gears 23 and 25 are held in a sealed manner. Moreover, between each of the camshafts 21a to 21c,
A space 30 surrounded by the peripheral wall 28 and the outer surface of the head cover 29 and extending approximately to the center of the six valves 16 and 17 is provided for each cylinder 2 (2 persons, 2B, 2B, 2B, etc.).
2C and 2D), and a screw hole 31 continuous to the center of the combustion chamber 12 is formed at the bottom of each of these spaces 30, and an ignition plug 32 is attached to the screw hole 31. It is being

However, in the internal combustion engine l of this embodiment, which is constructed in pairs in this way, a plurality of cylinders 2 (2A, 2B, 2C, 2D) are arranged in a single cylinder block 3 and tilted alternately around the axis of the crankshaft 4. 2A, 2B, 2C, 2C.
The bisector M of the angle θ formed by the center line of D)
Since the common plane is substantially orthogonal to It is narrowed to the extent that no interference occurs, and the V of the super crisscross angle is
A type of internal combustion engine can be obtained, and the cylinder head 5 can be made common.

As the angle θ is narrowed, the dimensions of the cylinder block 3 in the direction orthogonal to the crankshaft 4 are narrowed, and each cylinder 2 (2A, 2B, 2C, 2D)
Due to the fact that the cylinders 2 (2A, 2B, 2C, 2D) are arranged at an angle with respect to each other, the adjacent cylinders 2 (2A, 2B, 2C, 2D) are overlapped in a direction perpendicular to the crankshaft 4, and the cylinder block 3 is aligned with the crankshaft by this overlap. 4 narrowed in the length direction.

In addition, by narrowing the included angle θ, the intake valve 16 provided corresponding to the front row cylinders 2B and 2D and the exhaust valve I provided corresponding to the rear row cylinders 2A and 2C.
7 are brought closer to each other, it becomes possible to have them contact the same camshaft (second camshaft 21c), which eliminates the need for four camshafts, which were required for conventional V-type internal combustion engines. One of them is omitted, thereby simplifying the valve mechanism 18.

Furthermore, by making it possible to share the cylinder head 5 attached to each cylinder 2 (2 persons, 2B, 2C, 2D), a plurality of intake passages 14 and exhaust passages 15 are provided on one side of the cylinder head 5. This simplifies, in particular, the exhaust pipe routing in a manner similar to that of a parallel internal combustion engine.

Note that the shapes and dimensions of each component shown in the above embodiments are merely examples, and can be variously changed based on design requirements and the like.

For example, an example has been shown in which the piston 7 and the connecting rod 11 are located near the center line of the cylinder 2, but if the upper surface of the piston 7 is made to have an inclined shape as shown in the embodiment described above, When gas pressure acts on the piston pin surface during the combustion stroke of the engine, side pressure acts on the piston 7, so in order to reduce this side pressure, the piston 7 and the connecting rod 11 are connected as shown in FIG. The position of the piston pin 33, which is connected to the piston pin 33, may be biased toward the side receiving the side pressure.

Next, a second embodiment of the present invention will be explained based on FIGS. 9 to 13.

This embodiment has two intake valves 16 and two exhaust valves 17, for a total of four valves, as shown in the first embodiment, and a camshaft corresponding to each of the intake valves 16 and exhaust valves 17. Instead of a so-called 4-valve DOHC type internal combustion engine equipped with 21, as shown in FIG. The so-called two-valve SOI- in which the valve 17 is driven by one camshaft 21
The present invention is applied to an IC-type internal combustion engine, and the cylinder head 34 is modified in accordance with the difference in the number of intake valves 16, exhaust valves 11, and camshafts 21. In the following, the internal combustion engine of this embodiment will be described using the reference numerals shown in the first embodiment for constituent members other than the cylinder head 34.

As shown in FIGS. 9 and 10, the cylinder head 34 has a joint 34a with the cylinder block 3.
Recesses 35 that form a combustion chamber [2 together with the sleeve 8 fitted in the cylinder block 3] are formed at a plurality of locations corresponding to each cylinder 2 (2 persons, 2B, 2C, 2D), and An intake passage 36 and an exhaust passage 37 are formed which communicate with each of these recesses 35, and an intake boat 36a and an exhaust boat 37a, which are the openings of these intake passages 36 and exhaust passages 37 to the recess 35, are opened and closed. An intake valve 16 and an exhaust valve 17 penetrate toward the top of the cylinder head 34 and are slidably mounted thereon.

On the other hand, as shown in FIGS. 9 and 11, on the upper part of the cylinder head 34, there is a line connecting the centers of two recesses 35 formed corresponding to the front row cylinders 2B and 2D, and a line connecting the centers of the two recesses 35 corresponding to the rear row cylinders. The cam shafts 2 are aligned along lines connecting the centers of the two recesses 35 formed corresponding to 2A and 2C.
1 is rotatably attached to each camshaft 21, and a cam C that controls the timing of opening and closing of each intake valve 16 and exhaust valve 17 is integrally formed on each camshaft 21.

Between these cams C and the six valves 16 and 17, there is a rocker arm 38 that slides into contact with each of them and opens and closes the six valves 16 and 17 by being swung by the cam C. Front 32 cylinder head 34
It is provided in a state where it is swingably supported.

Further, a cam gear 39 is integrally attached to one end of each of the camshafts 21, as shown in FIG. 11, and each of these cam gears 39 is connected to the crankshaft 4, as shown in FIG. It is connected to a provided sprocket 27 via a cam chain 24.

Furthermore, the six valves 16 and 17, the camshaft 21. The rocker arm 38 and a peripheral wall 40 surrounding the cam gear 38 are integrally formed.

By the way, in this embodiment, since the camshaft 21 is positioned above the center of the recess 35 as described above, the ignition plug 32 is moved along the center line of the recess 35 as in the first embodiment. Therefore, as shown in FIG. 10, the four parts 35 are installed at a position offset from the center of the recess 35 of the cylinder head 34, as shown in FIG.
By forming a screw hole 41 inclined with respect to the center line of the cylinder head 3 and screwing the ignition plug 32 into the screw hole 41, the camshaft 21 and the six valves 16 and 17 can be avoided and the cylinder head 3
The ignition plug 32 can be attached and detached from the outside of the ignition plug 4.

Furthermore, what is indicated by the reference numeral 42 in FIG. 9 is a helad cover.

Also in this embodiment configured as above, the first
The same effects as in the first embodiment can be obtained except that one camshaft 21 in the embodiment can be omitted.

"Effects of the Invention" As explained above, in the multi-cylinder internal combustion engine according to the present invention, in which a plurality of cylinders are formed in a single cylinder block, each adjacent cylinder is The cylinders are formed so that their center lines are alternately inclined at a predetermined angle when viewed from the length direction of the crankshaft, and the mating surfaces of each cylinder and the cylinder head attached to the cylinder block are formed at the angle between the cylinders. angle 2
It is characterized by having a common plane that is substantially orthogonal to the equal dividing line, and has the following excellent effects.

By narrowing the angle formed by the center line of each cylinder, it is possible to obtain a super-angle V-shaped internal combustion engine, and by narrowing the angle, the cylinder block is perpendicular to the crankshaft. The dimension in the direction can be narrowed, and
By arranging each cylinder at an angle to each other, adjacent staggered cylinders are superimposed in a direction perpendicular to the crankshaft.
The cylinder block can be narrowed in the length direction of the crankshaft by this overlap.

Furthermore, by making the mating surfaces of each cylinder and the cylinder head a common plane, it is possible to share the cylinder head, and the plurality of intake passages and exhaust passages connected to each cylinder can be connected to a single cylinder head. The exhaust pipe can be led out to the side, thereby making it particularly easy to manage the exhaust pipe.

Therefore, the scope of application to vehicles will be greatly expanded.

[Brief explanation of the drawing]

In the drawings, FIGS. 1 to 7 show a first embodiment of the present invention, in which FIG. 1 is a vertical cross-sectional side view of the main part, and FIG.
A sectional view along the line ■-■ in the figure, Figure 3 is II of Figure 1.
A sectional view along the line I-III, Figure 4 is I in Figure 1.
A combination of cross-sectional views along the V-IV a line and the IV-1'v' b line, FIG. 5 is the v-■ of FIG. 1.
6 is a plan view of the cylinder head, FIG. 7 is a schematic diagram showing the winding state of the cam chain, and FIG.
The figure is an enlarged view showing a modified example of the mounting position of the piston and connecting rod, and Figures 9 to 13 show the second embodiment of the present invention, so Figure 9 is a vertical cross-sectional side view, Fig. 10 is a sectional view taken along the line X-X in Fig. 9, Fig. 11 is a plan view of the cylinder head, Fig. 12 is a schematic diagram showing the winding state of the cam chain, and Fig. 13 is a spark plug. is a vertical cross-sectional view of the main parts showing the installation state. ■・・・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・(Multi-cylinder type) internal combustion engine, 2 (2^・2
B・2C・2D)・・・Cylinder, 3・34・・・
・・・・・・・・・・・・・・・・・・・・・・・・Cylinder block, 3a, 34a...Mating surface,
4... Crankshaft, 5... Cylinder head, 7... Piston, 11.
......Connecting rod, 12...
Combustion chamber, 13... recess, 14
......Intake passage, 15...Exhaust passage, 16...Air supply valve, 17.
・・・・・・・・・Exhaust valve, 18・・・・・・・・・
... Valve mechanism, 21... Camshaft,
23, 25...Cam gear, 24, 26...Cam chain, 27...Sprocket, 2
9.42... Head cover, 32... Spark plug, ■4... Center line (of the cylinder), M
・・・・・・Bisector between center lines, C・・・・・・
··cam.

Claims (1)

[Claims] In a multi-cylinder internal combustion engine in which a plurality of cylinders are formed in a single cylinder block, adjacent cylinders are arranged so that their respective center lines form a predetermined angle when viewed from the length direction of the crankshaft. The multi-cylinder cylinders are formed so as to be inclined alternately, and the mating surfaces of each cylinder and a cylinder head attached to the cylinder block are a common plane substantially orthogonal to the bisector of the angle of inclination. type internal combustion engine.