JP2006307844A - V-type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a V-type internal combustion engine capable of preventing formation of condensation in a supply passage, by easily forming the compressed air supply passage to an air-fuel mixture injection valve 30 of respective cylinder head parts from an air compressor 18. <P>SOLUTION: This V-type internal combustion engine 1 is formed by arranging the air-fuel mixture injection valve 30 for directly injecting an air-fuel mixture of fuel and air into combustion chambers 23a and 23b in a cylinder in respective cylinder heads 22a and 22b. The compressed air supply passage to the respective air-fuel mixture injection valves 30 from the air compressor 18 attached to the internal combustion engine, is composed of a common passage 32 arranged in a crankcase 11 and a supply passage 33 arranged by branching off into respective cylinder blocks 21a and 21b. The compressed air supply passage is formed by installing the cylinder blocks 21a and 21b in the crankcase 11, and the formation of condensation is prevented by preventing cooling of compressed air in the compressed air supply passage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a V-type internal combustion engine in which a plurality of cylinders are spaced apart from each other in a V shape and provided on a crankcase, and in particular, an air-fuel mixture injection that directly injects a mixture of fuel and air into a combustion chamber in the cylinder. The present invention relates to a V-type internal combustion engine provided with a valve.

An internal combustion engine used as a power source for a vehicle such as a motorcycle is known in which an air-fuel mixture injection valve for directly injecting an air-fuel mixture into a combustion chamber in a cylinder is disclosed (Patent Document 1). reference.)
This air-fuel mixture injection valve is controlled to open and close according to the combustion operation cycle of the internal combustion engine, mixes the compressed air and fuel supplied from the pneumatic compressor, injects them into the combustion chamber, and operates the internal combustion engine. It is possible to improve the fuel consumption of the internal combustion engine.

Further, as the internal combustion engine, a V-type internal combustion engine in which a plurality of cylinders are separated from each other in a V shape and provided on a crankcase is known, and the internal combustion engine is made compact and the vibration associated with the operation of the internal combustion engine is reduced. Etc. can be realized.
In particular, a V-type internal combustion engine is known as an internal combustion engine having a useful structure in a vehicle such as a motorcycle in which a space for mounting the internal combustion engine is limited.
Japanese Patent Application Laid-Open No. 2004-301113.

The air-fuel mixture injection valve is provided in the cylinder head portion of the internal combustion engine, but how to provide a compressed air supply path from the pneumatic compressor attached to the internal combustion engine to each air-fuel mixture injection valve is a problem.
Specifically, in a V-type internal combustion engine, compressed air must be supplied from the pneumatic compressor to the heads of the cylinders spaced apart in a V-shape, so the compressed air supply path must be routed and branched. For example, the assembly structure of the internal combustion engine becomes complicated based on the setting of the compressed air supply path.

In particular, in a V-type internal combustion engine, unless the length of the compressed air supply path from the pneumatic compressor to the head portion (mixture injection valve) of each cylinder is equalized, the compressed air pressure becomes non-uniform and each mixture injection valve There is a problem that the fuel mixture ratio in the case becomes uneven.
Also, if the compressed air supply path is excessively cooled as the vehicle travels, moisture in the compressed air condenses and condensation occurs in the compressed air supply path, which causes malfunction of the air-fuel mixture injection valve. In addition, there is a problem of causing an operation failure of the internal combustion engine.

  Further, while the compressed air supply path is required not to be excessively cooled, the pneumatic compressor attached to the internal combustion engine is likely to be cooled as the vehicle travels in order to increase the air compression efficiency. There is a need to realize a V-type internal combustion engine that can satisfy the conflicting requirements and solve the above-described problems.

The present invention has been made in view of the above-described conventional circumstances, and the compressed air supply path is devised by arranging the compressed air supply path from the pneumatic compressor attached to the internal combustion engine to each mixture injection valve. It is an object of the present invention to provide a V-type internal combustion engine having a structure that is easy to assemble even if provided.
Another object of the present invention is to provide a V-type internal combustion engine in which the length of the compressed air supply path from the pneumatic compressor to each mixture injection valve is made uniform.

Further, the present invention similarly prevents the compressed air supply path from being excessively cooled even when the internal combustion engine is cooled as the vehicle travels, and prevents the occurrence of condensation in the compressed air supply path. An object of the present invention is to provide a V-type internal combustion engine that can be used.
In addition, the present invention similarly provides a V-type internal combustion engine in which a pneumatic compressor attached to the internal combustion engine is cooled as the vehicle travels, and air compression efficiency by the pneumatic compressor can be increased. It is aimed.

  A V-type internal combustion engine according to the present invention is a V-type internal combustion engine in which a plurality of cylinders are spaced apart from each other in a V shape and provided on a crankcase. An air-fuel mixture injection valve for directly injecting air-fuel mixture is provided, and a part of the compressed air supply path from the pneumatic compressor attached to the internal combustion engine to each air-fuel mixture injection valve is provided as a common path in the crankcase part And

Therefore, by providing a part of the compressed air supply path from the pneumatic compressor to each air-fuel mixture injection valve as a common path in the crankcase part, the compressed air supply path branched to each air-fuel mixture injection valve is integrated as much as possible. The V-type internal combustion engine provided with the compressed air supply path can be assembled simply by assembling the cylinder block to the crankcase.
In the present invention, a part or all of the compressed air supply path from the pneumatic compressor to each air-fuel mixture injection valve can be constituted by an external pipe attached to the internal combustion engine, but it is formed in a crankcase or a cylinder block. It is preferable that the internal pipe line (internal passage) is used, and the internal pipe structure allows the compressed air supply path to be warmed by the operating combustion heat of the internal combustion engine, and this also provides the effect of preventing condensation. .

  Further, in the V-type internal combustion engine according to the present invention, the compressed air supply path from the common path provided in the crankcase portion to each air-fuel mixture injection valve is branched to each cylinder, and each branched compressed air supply path is branched to each cylinder. It is provided along the side wall on the opposite side of the block (preferably provided in the internal passage).

Therefore, each compressed air supply path branched from the common path of the crankcase portion reaches each air-fuel mixture injection valve with a uniform path length, and the compressed air pressure supplied to each air-fuel mixture injection valve is equalized.
Even when the V-type internal combustion engine is mounted on a motorcycle, the compressed air supply path of the cylinder block is shielded by the cylinder block, so that the compressed air supply path is exposed to the traveling wind and cooled. This can also prevent the condensation.

  Furthermore, the V-type internal combustion engine according to the present invention is characterized in that, with the V-type internal combustion engine mounted on a vehicle, the pneumatic compressor is exposed to a front portion in the vehicle traveling direction.

  Therefore, when traveling with the V-type internal combustion engine mounted on a motorcycle, the pneumatic compressor is exposed to the traveling wind and cooled, so that the air compression efficiency of the pneumatic compressor can be increased.

  According to the present invention, since a part of the compressed air supply path from the pneumatic compressor to each air-fuel mixture injection valve is a V-type internal combustion engine provided as a shared path in the crankcase part, the compressed air can be obtained simply by assembling the cylinder block to the crankcase. It is possible to easily assemble a V-type internal combustion engine provided with a supply path, and further, by configuring the common path with an internal passage formed in the crankcase, it is possible to warm the compressed air supply path and obtain a dew condensation prevention effect. it can.

  Further, according to the present invention, the compressed air supply path from the common path provided in the crankcase portion to each mixture injection valve is branched to each cylinder, and each branched compressed air supply path is opposed to each cylinder block. The length of each compressed air supply passage leading to each air-fuel mixture injection valve can be made uniform, and the cylinder block portion can be used even when the V-type internal combustion engine is mounted on a motorcycle. By preventing the compressed air supply path from being cooled by being exposed to the traveling wind, it is possible to obtain a dew condensation prevention effect, and further, by configuring each compressed air supply path with an internal passage formed in the cylinder block, It is possible to obtain a dew condensation prevention effect by warming the compressed air supply path.

  Furthermore, according to the present invention, since the pneumatic compressor is exposed at the front portion in the vehicle traveling direction, the pneumatic compressor can be cooled by being exposed to traveling wind, and the air compression efficiency by the pneumatic compressor can be increased. Can do.

A specific description will be given using an example in which a V-type internal combustion engine according to the present invention is mounted on a motorcycle.
FIG. 6 shows a motorcycle equipped with the V-type internal combustion engine 1 of this example.
This motorcycle has a front wheel 3 pivotally supported at the lower end of a front fork 2 pivotally supported by a vehicle body frame, and a rear wheel at a rear end of a rear fork that is supported by the vehicle body frame so that the front end can swing up and down. 5 is rotatably supported.

A fuel tank 7 attached to the vehicle body frame is provided between the front fork 2 and the seat 6, and a V-type internal combustion engine 1 supported by a hanger 8 constituting the vehicle body frame is provided below the fuel tank 7. It has been. The hanger 8 is provided with a refrigerant radiator 9 for cooling the V-type internal combustion engine 1.
The V-type internal combustion engine 1 has a structure in which a plurality of cylinders (in this example, two cylinders 10a and 10b) are spaced apart from each other in a V shape and are provided on a crankcase 11, and a cylinder positioned in front of the motorcycle in the traveling direction. Exhaust pipes 12a and 12b are drawn backward from the cylinder 10b located at the rear side 10a.

Further, a V-shaped space formed between the cylinders 10a and 10b of the V-type internal combustion engine 1 includes an intake pipe 13 connected to the cylinders 10a and 10b, and nitrogen oxides (NOx) in the exhaust gas. ) Is provided with an exhaust gas recirculation (EGR) control valve 14 that recirculates the exhaust gas to the combustion chamber of the internal combustion engine 1.
Exhaust gas is introduced into the control valve 14 from the exhaust pipe 12b of the rear cylinder 10b through the exhaust introduction pipe 15, and is introduced from the exhaust introduction pipe 15 by controlling the opening and closing of the control valve 14 with a solenoid as is well known. Exhaust gas is supplied to the intake ports of both cylinders 10a and 10b and recirculated to the combustion chamber.

Further, a pneumatic compressor 18 driven by the V-type internal combustion engine 1 is exposed at the front portion of the cylinder 10a located in front of the motorcycle in the traveling direction, and the pneumatic compressor 18 is disposed in the cylinder. In order to directly inject a mixture of fuel and air into the combustion chamber, compressed air is supplied to the mixture injection valves (see FIG. 1) provided in the head portions 19a and 19b of the cylinders 10a and 10b.
That is, the pneumatic compressor 18 takes in and compresses air that has passed through an air filter (not shown), and supplies the compressed air to each mixture injection valve through a supply path that will be described later, and each mixture injection valve is controlled. An appropriate amount of fuel is mixed with compressed air and injected directly into the combustion chamber.

Since the pneumatic compressor 18 is disposed at the front portion of the cylinder 10a positioned forward in the traveling direction of the motorcycle as in this example, the pneumatic compressor 18 is cooled by the traveling wind as the motorcycle travels. That is, when air is compressed by a pneumatic compressor heated to a high temperature, it is difficult to obtain high compression efficiency because the air is also heated, but compared with this, high compression efficiency is achieved by the cooled pneumatic compressor 18. Obtainable.
In the V-type internal combustion engine 1, a V-shaped space formed between the front and rear cylinders 10a and 10b is often used as an auxiliary machine installation place. As described above, the pneumatic compressor 18 is used as the front cylinder. By arranging it at the front part 10a, it is possible to realize a compact V-type internal combustion engine in which the V-shaped space is narrowed.

FIG. 1 shows a V-type internal combustion engine 1 of this example in a side view partially cut in section.
Each cylinder 10a, 10b is provided with cylinder head blocks 22a, 22b at upper ends of cylinder blocks 21a, 21b in which pistons 20a, 20b are slidably accommodated to form combustion chambers 23a, 23b. Each piston 20a, 20b is connected to a crankshaft accommodated in the crankcase 11 by connecting rods 28a, 28b.
Each combustion chamber 23a, 23b has two intake ports 24a, 24b and exhaust ports 25a, 25b. The intake ports 24a, 24b and the exhaust ports 25a, 25b slide on the cylinder head blocks 22a, 22b. It is opened and closed by freely provided intake valves 26a and 26b and exhaust valves 27a and 27b.

  The intake valves 26a and 26b and the exhaust valves 27a and 27b are driven by predetermined operation when the cam mechanisms 29a and 29b provided in the cylinder head blocks 22a and 22b are driven by the operation of the V-type internal combustion engine 1, as is well known. At the exhaust timing, the intake valves 26a and 26b and the exhaust valves 27a and 27b are opened and closed to introduce air into the combustion chambers 23a and 23b from the intake pipe 13 connected to the intake ports 24a and 24b. , 25b, exhaust gas is discharged from the combustion chambers 23a, 23b to the exhaust pipes 12a, 12b.

Exhaust gas is introduced into the control valve 14 of the exhaust gas recirculation device (EGR) from the exhaust pipe 12b through the exhaust introduction pipe 15, and the valve body 14a of the control valve 14 is controlled to open and close, so that the exhaust gas introduced from the exhaust introduction pipe 15 is exhausted. Gas is drawn into the valve chamber 14b and introduced into the branch chamber 16b through the communication pipe 16a. The branch chamber 16b is provided with a pair of one-way valves (reed valves) 16c that prevent backflow to the branch chamber side, and an exhaust supply pipe 17 is connected to each branch valve 16c. The other end of the exhaust supply pipe 17 communicates with a position near the intake ports 24 a and 24 b of the intake pipe 13.
FIG. 4 shows a cross-sectional structure of a portion from the exhaust introduction pipe 15 to the branch chamber 14b as seen from the direction in which the viewpoint is changed by 90 degrees from FIG.

That is, when the control valve 14 is controlled to open and close according to the combustion timing of the internal combustion engine, an appropriate amount of exhaust gas introduced from the exhaust pipe 12b into the branch chamber 16b is prevented from flowing back by the reed valve 16c, and the exhaust supply pipe 17 To the combustion chambers 23a and 23b through the intake ports 24a and 24b.
In an exhaust gas recirculation device (EGR) that recirculates exhaust gas to the combustion chamber and re-combusts, it is preferable that the exhaust gas to be recirculated is hot, but in the rear of the vehicle traveling direction, which is less cooled by the traveling wind of the motorcycle. Since exhaust gas to be recirculated is introduced from the exhaust pipe 12b located, the effect of reducing nitrogen oxide (NOx) can be enhanced.

As shown in FIG. 1, the cylinder head blocks 22a and 22b are provided with an air-fuel mixture injection valve 30 for injecting an air-fuel mixture of fuel and air. It faces the combustion chambers 23a, 23b at the center.
The air-fuel mixture injection valve 30 is controlled by solenoid drive as will be described later, and the compressed air supplied from the pneumatic compressor 18 and the fuel supplied from the fuel tank 7 are directly mixed into the combustion chambers 23a and 23b as an air-fuel mixture. Spray.

The cylinder blocks 21a and 21b are provided on the crankcase 11 so as to be spaced apart from each other in a V shape. The crankcase 11 has a single compressed air supply path (shared path) 32 communicating with the pneumatic compressor 18 as an internal pipe. It is formed as a road.
The other end of the common path 32 is opened at the base end of the V-shaped space formed by the cylinder head blocks 22a and 22b, and each cylinder block 21a, The compressed air supply path 33 and the common path 32 formed as internal pipes in 21b communicate in an airtight manner.
For example, the common path 32 is formed when the crankcase 11 is cast, and the compressed air supply path 33 is formed when the cylinder blocks 21a and 21b are cast.

The compressed air supply path 33 is bifurcated in the vicinity of the mating portion 33a of the cylinder blocks 21a and 21b. Each branched compressed air supply path 33 has a side wall (V-shaped) on the opposite side of each cylinder block 21a and 21b. (Side wall side wall) is extended to the cylinder head.
In FIG. 1, the middle of each compressed air supply path 33 is indicated by a broken line in order to avoid blurring of the drawing.

Accordingly, each compressed air supply passage 33 is provided at a portion facing the V-shaped space where the combustion heat of the internal combustion engine is relatively easily trapped and is not easily cooled by the traveling wind, and thus flows through the compressed air supply passage 33. A situation in which the compressed air is cooled and condensation occurs can be prevented.
In addition, the crankcase 11 can be easily machined by forming a single common path 32 in the crankcase portion, and mixed from the common path 32 through two compressed air supply paths 33 having substantially the same structure. Since the compressed air is supplied to the air injection valve 30, the length of the compressed air supply path from the pneumatic compressor 18 to the air-fuel mixture injection valve 30 of both cylinders is made uniform, and a favorable air-fuel mixture injection operation is made possible. be able to.

  Further, the upper end of each compressed air supply passage 33 is open to the mating surface with the cylinder head block, and each cylinder head block 22a, 22b is mounted on each cylinder block 21a, 21b, thereby allowing each cylinder head block 22a, A compressed air supply path 34 and a compressed air supply path 33 formed as a pipe line 22b communicate with each other in an airtight manner.

FIG. 2 shows a partial cross section of the V-type internal combustion engine 1 along AA in FIG. 1 in order to explain the relationship between the common path 32, the compressed air supply path 33, and the compressed air supply path 34 described above. Is shown.
That is, the pneumatic compressor 18 is assembled by assembling the internal combustion engine 1 such that the cylinder blocks 21a and 21b are assembled on the crankcase 11 and the cylinder head blocks 22a and 22b are assembled on the cylinder blocks 21a and 21b. A compressed air supply path from the cylinder head portion to the air-fuel mixture injection valve 30 is formed by the common path 32, the compressed air supply path 33, and the compressed air supply path 34.
Note that 36 in FIG. 2 is a spark plug provided facing the combustion chamber.

In FIG. 3, the cylinder head portion of the V-type internal combustion engine 1 is shown in cross section in order to explain the structure in which the compressed air supply path 34 reaches the air-fuel mixture injection valve 30.
The compressed air supply passages 34 communicated with the compressed air supply passages 33 of the cylinder blocks 21a and 21b are branched into two lines, one is communicated with an air pressure regulator 38 provided in the cylinder head portion, and the other is mixed gas injection. The valve 30 communicates with the compressed air chamber.
That is, the compressed air led to the compressed air supply path 34 is adjusted to a predetermined air pressure by the air pressure adjuster 38, and the compressed air whose pressure has been adjusted is supplied to the compressed air chamber of the mixture injection valve 30.
In FIG. 3, reference numeral 39 denotes a throttle valve that adjusts the amount of intake air through the intake pipe 13.

FIG. 5 shows a system for supplying compressed air and fuel to the air-fuel mixture injection valve 30, and the air-fuel mixture injection operation by the air-fuel mixture injection valve 30 will be described with reference to FIG.
The air-fuel mixture injection valve 30 includes an air-fuel mixture valve 30a whose lower end faces the combustion chamber 23a (23b) and a fuel valve 30b provided coaxially on the air-fuel mixture valve 30a. By controlling the fuel valve 30b with a solenoid (not shown), an air-fuel mixture in which fuel is mixed with compressed air is directly injected into the combustion chamber 23a (23b).

The air taken in from the air filter 40 provided in the motorcycle is compressed by the pneumatic compressor 18, and the compressed air passes through the compressed air supply path (common path 32, supply path 33, supply path 34) by the air-fuel mixture valve 30 a. It is supplied to the formed compressed air chamber 30c.
The compressed air is guided to the air pressure regulator 38 through the branch path of the supply path 34, and the compressed air adjusted to a predetermined pressure by releasing the excess pressure is supplied to the compressed air chamber 30c.

Here, when the high-pressure air compressed by the pneumatic compressor 18 is cooled, there is a phenomenon in which moisture contained in the compressed air is solidified to cause dew condensation.
On the other hand, the compressed air supply path is formed in the crankcase 11, the cylinder blocks 21a and 21b, and the cylinder head blocks 22a and 22b that can obtain a heating effect by the combustion operation of the internal combustion engine, and further, the influence of cooling by the traveling wind. Since it is formed at a position where it is difficult to receive, condensation is prevented from occurring in the supply path from the pneumatic compressor 18 to the mixture injection valve 30, and compressed air is smoothly supplied to the mixture injection valve 30. .

On the other hand, the fuel pump 42 provided in the motorcycle takes fuel from the fuel tank 7 through the filter 41, and the fuel pumped by the fuel pump 42 is supplied to the fuel chamber 30d formed by the fuel valve 30b.
The fuel branched from the path leading to the fuel injection valve 30 is guided to the fuel pressure regulator 44, and the excess fuel is returned to the fuel tank 7 so that the air pressure is higher than the compressed air chamber 30c and the pressure difference is constant. The fuel whose pressure is adjusted in this way is supplied to the fuel chamber 30d.

When the compressed air is supplied to the compressed air chamber 30c and the fuel is supplied to the fuel chamber 30d in this manner, when the solenoid is energized and the fuel valve 30b is opened, the fuel measured by the fuel chamber 30d is compressed. 30c is injected, and fuel and compressed air are mixed.
Next, when the solenoid is energized and the air-fuel mixture valve 30a is opened, the air-fuel mixture in the compressed air chamber 30c is injected into the combustion chambers 23a and 23b by the pressure, and is ignited and burned by the spark plug 36.

1 is a partial cross-sectional side view of a V-type internal combustion engine according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional front view of the V-type internal combustion engine taken along line AA in FIG. 1. 1 is a cross-sectional plan view of a V-type internal combustion engine according to an embodiment of the present invention. It is sectional drawing which shows the EGR control valve part of the V-type internal combustion engine which concerns on one Embodiment of this invention. 1 is a view showing a system for supplying compressed air and fuel to an air-fuel mixture injection valve of a V-type internal combustion engine according to an embodiment of the present invention. 1 is a side view of a motorcycle equipped with a V-type internal combustion engine according to an embodiment of the present invention.

Explanation of symbols

1: V-type internal combustion engine, 10a, 10b: cylinder,
11: Crankcase, 18: Pneumatic compressor,
21a, 21b: cylinder block, 22a, 22b: cylinder bed block,
23a, 23b: Combustion chamber, 30: Air-fuel mixture injection valve,

Claims (3)

In a V-type internal combustion engine in which a plurality of cylinders are spaced apart from each other in a V shape and provided on a crankcase,
Each cylinder head portion is provided with an air-fuel mixture injection valve that directly injects an air-fuel mixture into the combustion chamber in the cylinder,
A V-type internal combustion engine characterized in that a part of a compressed air supply path from a pneumatic compressor attached to the internal combustion engine to each of the air-fuel mixture injection valves is provided as a common path in a crankcase portion. The V-type internal combustion engine according to claim 1,
The compressed air supply path from the common path provided in the crankcase part to each of the mixture injection valves is branched to each cylinder, and each branched compressed air supply path is along the side wall on the opposite side of each cylinder block. A V-type internal combustion engine provided. The V-type internal combustion engine according to claim 1 or 2,
The V-type internal combustion engine, wherein the pneumatic compressor is exposed and provided in a front portion in the vehicle traveling direction in a state where the V-type internal combustion engine is mounted on the vehicle.

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