JP2003201845A - Multi-cylinder internal combustion engine of compressive ignition type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-cylinder internal combustion engine of compressive ignition type equipped with an improved combustibility, in which the injected fuel to each cylinder is divided into an auxiliary fuel in a minor quantity and a main fuel in a major quantity, the auxiliary fuel is supplied for injection at a timing before the top dead point in the compression stroke, and the main fuel is supplied for injection at a timing after the top dead point in the compression stroke. <P>SOLUTION: During the explosion (expansion) process in each cylinder, part of the combustive (expansion) gas in one cylinder is led to one of the cylinders in compression stroke via a common communication passage 13, and the auxiliary fuel is supplied for injection by an auxiliary fuel injection valve 17 to the led-in combustive (expansion) gas. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression ignition type multi-cylinder internal combustion engine, such as a diesel engine, in which fuel injected and supplied into a cylinder is ignited by compression.

[0002]

2. Description of the Related Art JP-A-2000-310 as a prior art
Japanese Patent Laid-Open No. 150-150 gazette uses a diesel engine as an example of a compression ignition type internal combustion engine of this type to provide a required amount of injected fuel with a small amount of auxiliary fuel in order to obtain a gentle combustion with a small amount of NOx and soot generated. By dividing the fuel and the remaining amount of main fuel and injecting and supplying the auxiliary fuel at a time before the top dead center in the compression stroke, the auxiliary fuel is supplied until it passes the top dead center in the compression stroke. In addition, the hydrocarbon contained in the auxiliary fuel is oxidized to an intermediate oxidation stage, and then the main fuel is injected and supplied at a time after the top dead center in the compression stroke, so that the entire injected fuel is It proposes to ignite in many places at the same time.

In this prior art, the preferable injection amount of the auxiliary fuel is 30% or less of the predetermined injection amount, and the injection timing of the auxiliary fuel is crank angle before the top dead center in the compression stroke. It is preferable to set it within the range of about 50 degrees to 20 degrees.

[0004]

In order to achieve the goal of this prior art, all the auxiliary fuel injected and supplied before the top dead center in the compression stroke is set to the top dead center in the compression stroke. Until then, it is necessary to bring the hydrocarbons contained in the auxiliary fuel into an oxidized state up to an intermediate oxidation stage.

However, in order to make all of the auxiliary fuel in an oxidized state, it is most preferable to make it as fine as possible and mix it with the intake air when injecting and supplying this auxiliary fuel, but a small amount of injected fuel is required. In order to miniaturize, it is necessary to raise the fuel injection pressure considerably, but raising the fuel injection pressure leads to a great improvement in reliability such as pressure resistance of the fuel supply system and performance. There is a problem.

In addition, in a compression ignition type internal combustion engine such as a diesel engine, a cavity is formed in the top surface of the piston so that when the piston rises to near the top dead center in the compression stroke, the cavity in the top surface of the piston is increased. The main fuel is injected into the inside of the piston. However, in this configuration, if the auxiliary fuel is injected and supplied at a time before the top dead center in the compression stroke, the piston does not reach the top dead center at this time. As a result, the auxiliary fuel cannot be injected into the cavity on the top surface of the piston, which increases the proportion of the auxiliary fuel that adheres to the inner surface of the cylinder or the top surface of the piston. Of these, the amount that can be oxidized is reduced, so the amount of auxiliary fuel must be increased by this amount, leading to an increase in fuel consumption. Kalika, with the possible to increase the fuel consumption, wash off is increased by the fuel of the lubricating oil in the cylinder, with the piston baked there is a problem that tends to occur.

The present invention has a technical object to solve the problems of the prior art.

[0008]

In order to achieve this technical object, the first aspect of the present invention is that "injection fuel for each of a plurality of cylinders having a common crankshaft is a small amount of auxiliary fuel, and The main fuel is also divided into a large amount, and the auxiliary fuel is injected and supplied at a time before the top dead center in the compression stroke to pass the top dead center in the compression stroke.
The hydrocarbon contained in the auxiliary fuel is oxidized to an intermediate oxidation stage, and then the main fuel is injected and supplied into the cylinder in each cylinder at a time after the top dead center of the compression stroke. In an ignition-type multi-cylinder internal combustion engine, a mutual communication passage is provided between the respective cylinders, the respective cylinders are communicated with the mutual communication passage through the communication passage, and an opening / closing valve is provided in the communication passage for each cylinder. We installed each on-off valve,
While operating so as to introduce a part of the combustion (expansion) gas in any one cylinder in the explosion (expansion) stroke of each of the cylinders to another one of the cylinders in the compression stroke, A main fuel injection valve for injecting and supplying the main fuel is provided at a cylinder top portion of each cylinder, and an auxiliary fuel injection valve for injecting and supplying the auxiliary fuel is provided at each of the communication passages or the mutual communication passages. It was It is characterized by

According to claim 2 of the present invention, "the injected fuel for each of a plurality of cylinders having a common crankshaft is divided into a small amount of auxiliary fuel and a larger amount of main fuel,
The auxiliary fuel is injected and supplied at a time before the top dead center in the compression stroke to oxidize the hydrocarbons contained in the auxiliary fuel to an intermediate oxidation stage before the top dead center in the compression stroke. In the compression ignition type multi-cylinder internal combustion engine in which the main fuel is injected and supplied into the cylinders in each cylinder at the time when the top dead center of the compression stroke has passed, the cylinders at the tops of the cylinders in the cylinders are While providing a fuel storage chamber communicating with the inside, at the top of the cylinder in each of the cylinders, a fuel injection valve configured to inject the main fuel into the cylinder, and to inject the auxiliary fuel into the fuel storage chamber, Furthermore, a mutual communication passage is provided between the respective cylinders, and in this mutual communication passage,
The fuel storage chamber in each cylinder is communicated with each other via a communication passage,
An on-off valve is provided in the communication passage for each cylinder, and each on-off valve is used to remove a part of combustion (expansion) gas in any one cylinder of the cylinders during the explosion (expansion) stroke. It opens and operates so as to be introduced into another cylinder in the compression stroke. It is characterized by

Furthermore, claim 3 of the present invention is that "in the above-mentioned claim 1 or 2, the mutual communication passage between the respective cylinders is formed for each of a plurality of cylinders." It has a feature.

[0011]

In general, when a mixture of a hydrocarbon fuel and air is burned, radical components such as CH groups and OH groups, which are active intermediate products, are generated, and this active component is generated. While it is carried out by the combustion chain of radical components, it is known that the presence of the above-mentioned active radical component in the mixture of hydrocarbon fuel and air can improve the combustibility of the mixture, resulting in an explosion ( The combustion (expansion) gas in the expansion stroke contains active radical components.

In the structure according to the first aspect, a part of the combustion (expansion) gas in one cylinder of each cylinder during the explosion (expansion) stroke is a radical component active from the communication passage in the one cylinder. After being taken out in a state of including, the fuel is introduced into the other cylinder in the compression stroke at this time through the mutual communication passage and the communication passage in the other one cylinder.

In this way, the auxiliary fuel is injected and supplied from the auxiliary fuel injection valve to the combustion (expansion) gas introduced from one cylinder in the explosion (expansion) stroke to another cylinder in the compression stroke. By doing all of this auxiliary fuel,
Due to the heat of the combustion (expansion) gas and the active radical component contained in the combustion (expansion) gas, the hydrocarbon can be rapidly oxidized to an intermediate oxidation state.

After entering the other cylinder in the compression stroke, the main fuel is injected from the main fuel injection valve into the other cylinder at a time after the top dead center of the compression stroke. By being supplied, the entire fuel injected and supplied to the other cylinder can be simultaneously ignited at a large number of places, and the simultaneous ignition at a large number of places can be performed by the other cylinder. It can be greatly promoted by the active radicals contained in the combustion (expansion) gas introduced into.

As a result, it is possible to surely avoid increasing the pressure of the fuel supply system, and to reduce the amount of auxiliary fuel, so that it is possible to achieve reliable fuel consumption reduction and seizure reduction of the piston. .

According to the first aspect of the present invention, the main fuel injection supply and the auxiliary fuel injection supply are performed by separate fuel injection valves, so that the auxiliary fuel has the same composition as the main fuel. Of course, it is possible to use a fuel having a component different from the main fuel.

Next, in the structure described in claim 2, the main fuel among the fuel injected from the fuel injection valve at the time when the top dead center of the compression stroke has passed in each cylinder is injected and supplied into the cylinder. However, the auxiliary fuel is injected and supplied into the fuel storage chamber.

In this case, since the burned gas at the end of the previous explosion (expansion) stroke is stored in the fuel storage chamber, the auxiliary fuel injected and supplied thereto is ignited. Rather, the heat of the burned gas stored in the fuel storage chamber and the active radical component contained in the burned gas rapidly oxidize hydrocarbons to an intermediate oxidation stage. can do.

Next, the auxiliary fuel in which hydrogen oxide has been oxidized to an intermediate oxidation stage in the fuel storage chamber of each cylinder is supplied from one of the cylinders in the explosion (expansion) stroke. After being taken out together with a part of the fuel (expansion) gas through the communication passage in the one cylinder, the other communication cylinder and the other cylinder are extracted in the other cylinder in the compression stroke at this time. Is introduced through the communication passage in.

After entering the other cylinder during the compression stroke, the main fuel is injected and supplied from the fuel injection valve to the other cylinder at a time after the top dead center of the compression stroke. By doing so, it is possible to simultaneously ignite the entire fuel injected and supplied to the other one cylinder at a large number of places, and simultaneously ignite at a large number of places.
It can be greatly promoted by the active radicals contained in the combustion (expansion) gas introduced into the other one cylinder.

Thus, under the structure in which the auxiliary fuel is injected and supplied and the main fuel is injected and supplied by one fuel injection valve, it is possible to surely avoid increasing the pressure in the fuel supply system, The amount of fuel can be reduced, and reliable fuel efficiency can be achieved.

According to the third aspect of the invention, the combustion (expansion) gas from one cylinder to the other cylinder is alternately reciprocated at short intervals in the mutual communication passage. It is possible to maintain the high temperature in the mutual communication passage by flowing, and to reduce the disappearance of the radical component in the combustion (expansion) gas by maintaining the high temperature. Therefore, there is an advantage that the above-mentioned effect can be promoted. .

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a case where the present invention is applied to a conventionally known four-cycle three-cylinder diesel engine 1 in the first embodiment.

This four-cycle three-cylinder diesel engine 1
Includes a cylinder block 2 and a cylinder head 3 fastened to the upper surface of the cylinder block 2. The first cylinder A1, the second cylinder A2, and the third cylinder A3 share a single crankshaft (not shown).
Are arranged in a line along the crank axis 4.

Each of the three cylinders A1, A2 and A3 has a cylinder 5 provided in the cylinder block 2, a piston 6 which reciprocates in the cylinder 5, and a cylinder head 3 at the top of the cylinder 5. A main fuel injection valve 7 mounted so as to look into the center, two intake ports 8 provided in the cylinder head 3 so as to open at the top of the cylinder 5, and an opening at the top of the cylinder 5 in the cylinder head 3 as well. Two exhaust ports 9 provided to
A cavity 10 is formed in the top surface of the piston 6 to receive the fuel injected from the main fuel injection valve 7.

Further, in each of the cylinders A1, A2 and A3,
An intake valve 11 that opens and closes an opening of each of the intake ports 8 to the top of the cylinder 5 by an intake valve cam shaft (not shown) that rotates in conjunction with a crank shaft, and the exhaust ports 10
An exhaust valve 12 that opens and closes an opening to the top of the cylinder 5 is opened and closed by an exhaust valve cam shaft (not shown) that rotates in conjunction with the crank shaft.

In this case, each cylinder A1, A2, A
As is clear from the stroke diagram shown in FIG. 3, No. 3 is set so that the order of the explosion (expansion) strokes is the repetition of the first cylinder A1-the second cylinder A2-the third cylinder A3.

Further, the main fuel injection valve 7 in each of the cylinders A1, A2, A3 passes through the top dead center of the compression stroke in each cylinder (for example, about 10 after the top dead center of the compression stroke at the crank angle). It is set to perform fuel injection at a timing of 20 degrees.

The cylinder head 3 is provided with the respective cylinders A.
1, A2, A3, a common mutual communication passage 13 is provided so as to extend in the direction of the cylinder row, and the mutual communication passage 13 and the cylinder 5 in each of the cylinders A1, A2, A3 are provided. To communicate with the top of the cylinders via a communication passage 14 provided for each cylinder, and to each of the openings of the cylinders A1, A2, A3 in the communication passage 14 into the cylinder 5.
A poppet-type on-off valve 15 is provided, and each on-off valve 15
Is opened and operated by the electromagnetic opening / closing means 16 controlled by a control circuit (not shown) as follows.

That is, the control circuit receives a signal from a crank angle sensor (not shown) in the diesel engine 1 as an input, and the latter half of the explosion (expansion) stroke in each cylinder A1, A2, A3, During the compression stroke, each on-off valve 15 is configured to open at the same crank angle at the same time for an appropriate time.

An auxiliary fuel injection valve 17 for each of the cylinders A1, A2, A3 is provided in the communication passage 14 in each of the cylinders A1, A2, A3, and
The auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 at the latter half of the explosion (expansion) stroke at A3, that is, at substantially the same time as the opening / closing valves 15 are opened.

The auxiliary fuel may be injected and supplied at a timing that is earlier than the timing at which each of the on-off valves 15 is opened by a crank angle as appropriate.

In this case, each auxiliary fuel injection valve 17
The auxiliary fuel injection amount is set to a small amount of about 30% or less of the required injection fuel amount, and the remaining main fuel is injected and supplied from the main fuel injection valve 7 in a large amount relative to the required injection fuel amount. Is configured to.

In the structure of the first embodiment, the opening / closing valve 15 in the first cylinder A1 is opened for an appropriate time at the latter half of the explosion (expansion) stroke in the first cylinder A1, and at the same time, the compression is performed. By simultaneously opening and closing the on-off valve 15 in the second cylinder A2 during the stroke for an appropriate time, a part of the combustion (expansion) gas during combustion in the first cylinder A1 is changed to the first position as indicated by an arrow A in FIG. After being taken out from the communication passage 14 in the first cylinder A1, the second cylinder 1A2
Is introduced through the mutual communication passage 13 and the communication passage 14 in the second cylinder A2.

At about the same time as or before this, the second
The auxiliary fuel injection valve 17 in the cylinder A2 injects and supplies the auxiliary fuel to the communication passage 14 in the second cylinder A2, so that the auxiliary fuel is supplied into the second cylinder A2 as described above. Combustion (expansion) introduced from
It is mixed with the gas.

As described above, the auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 to the combustion (expansion) gas introduced from the first cylinder A1 in the explosion (expansion) stroke to the second cylinder A2 in the compression stroke. By doing so, all of this auxiliary fuel is
Until the cylinder A2 passes through the top dead center in the compression stroke, the heat of the combustion (expansion) gas and the active radical component contained in the combustion (expansion) gas cause hydrocarbons to undergo an intermediate oxidation step. It can be rapidly oxidized to a state.

When the second cylinder A2 passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7 to the second cylinder A2, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The second cylinder A2 shifts to the explosion (expansion) stroke.

Next, when the second cylinder A2 reaches the latter half of the explosion (expansion) stroke, the opening / closing valve 15 in the second cylinder A2 is opened for an appropriate time, and at the same time, the third cylinder is in the compression stroke. By simultaneously opening and closing the on-off valve 15 in A3 for an appropriate time, a part of the combustion (expansion) gas during combustion in the second cylinder A2 is taken out from the second cylinder A2 as shown by an arrow B in FIG. After being
The communication passage 14 in the third cylinder A3 is connected to the third cylinder A3.
The auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 for the third cylinder A3 into the combustion (expansion) gas introduced into the third cylinder A3 by way of all the auxiliary fuel. During the period until the third cylinder A3 passes through the top dead center in the compression stroke, the hydrocarbon is intermediate due to the heat of the combustion (expansion) gas and the active radical component contained in the combustion (expansion) gas. It can be rapidly oxidized to a state of various oxidation stages.

When the third cylinder A3 passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7 to the third cylinder A3, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The third cylinder A3 shifts to the explosion (expansion) stroke.

Next, when the third cylinder A3 reaches the latter half of the explosion (expansion) stroke, the opening / closing valve 15 in the third cylinder A3 is opened for an appropriate time, and at the same time, the first cylinder in the compression stroke. By simultaneously opening and closing the on-off valve 15 in A1 for an appropriate time, a part of the combustion (expansion) gas during combustion in the third cylinder A3 is taken out from the third cylinder A3 as shown by an arrow C in FIG. After being
The communication passage 14 in the first cylinder A1 is connected to the first cylinder A1.
Auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 for the first cylinder A1 to the combustion (expansion) gas introduced through the first cylinder A1 to introduce all of the auxiliary fuel. Until the first cylinder A1 passes through the top dead center of the compression stroke, the heat of the combustion (expansion) gas and the active radical component contained in the combustion (expansion) gas cause hydrocarbons to be intermediate. It can be rapidly oxidized to a state of various oxidation stages.

When the first cylinder A1 passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7 to the first cylinder A1, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The first cylinder A1 shifts to the explosion (expansion) stroke,
After that, by repeating this, the diesel engine 1 is operated.

In the first embodiment, instead of providing the auxiliary fuel injection valve 17 for each cylinder A1, A2, A3 in the communication passage 14 in each cylinder, mutual communication passages between each cylinder are provided. It may be configured to be provided in 13.

In this case, in the portion between the first cylinder A1 and the second cylinder A2 of the mutual communication passage 13 formed as one as described above, the combustion from the first cylinder A1 to the second cylinder A2 is performed. Since the amount of the (expansion) gas and the amount of the combustion (expansion) gas flowing from the third cylinder A3 to the first cylinder A1 flow, one auxiliary fuel injection valve is provided in this portion and the auxiliary fuel injection valve is It can be used for both the first cylinder A1 and the second cylinder A2. The second cylinder A2 of the mutual communication passage 13
Between the second cylinder A3 and the third cylinder A3, combustion (expansion) gas from the second cylinder A2 toward the third cylinder A3, and the third cylinder A3
Since the amount of the combustion (expansion) gas flows from the first cylinder A1 to the first cylinder A1, one auxiliary fuel injection valve is provided in this portion, and this auxiliary fuel injection valve is connected to the third cylinder A3 and the first cylinder A1.
Can be used for both.

Further, as described above, the mutual communication passage 13 between the respective cylinders has three cylinders A1, A2, A3.
The mutual communication passage 1
Inside 3, the combustion (expansion) gas from the first cylinder A1 toward the second air A2, the combustion (expansion) gas from the second cylinder A2 toward the third cylinder A3, and the third cylinder A3 toward the first cylinder A1. Since the combustion (expansion) gas alternately flows back and forth at short intervals, the inside of the mutual communication passage 13 can be maintained at a high temperature.

Next, FIGS. 4 and 5 show a case in which the present invention is applied to a conventionally known four-cycle four-cylinder diesel engine 1 in the second embodiment.

This four-cylinder diesel engine 1'includes a first cylinder A1 'and a second cylinder A1' having a common crankshaft (not shown).
The cylinder A2 ', the third cylinder A3', and the fourth cylinder A4 'are arranged in a line along the crank axis 4'.

The four cylinders A1 ', A2',
Each of A3 'and A4' has two intake ports 8 including a cylinder, a piston, a main fuel injection valve 7 ', and an intake valve 11.
Also, two exhaust ports 9 having an exhaust valve 12 and the like are provided as in the case of the first embodiment.

As is clear from the stroke diagram shown in FIG. 4, the order of the explosion (expansion) strokes of the cylinders A1 ', A2', A3 'and A4' in the four-cylinder diesel engine 1'is as follows. The first cylinder A1 ', the third cylinder A3', the fourth cylinder A4 ', and the second cylinder A2' are set to be repeated.

The four cylinders A1 ', A2', A3 ',
An intercommunication passage 13 ', which is formed in one line with respect to A4', is provided so as to extend in the direction of the cylinder row.
3'and the cylinders A1 ', A2', A3 ', A4' are communicated with each other through a communication passage 14 'provided for each cylinder.
A poppet-type on-off valve 15 'provided in each communication passage 14'.
In the same manner as the first embodiment, in the latter half of the explosion (expansion) stroke and the latter half of the compression stroke in each cylinder, the crank angle is set to be the same at the same crank angle and opened for an appropriate time. Constitute.

The cylinders A1 ', A2', A
Auxiliary fuel injection valve 17 'for each cylinder is provided in the communication passage 14' in 3 ', A4' so that each cylinder A1 ',
At the latter half of the explosion (expansion) stroke at A2 ', A3', A4 ', that is, at about the same time as the opening of each of the on-off valves 15, or at an earlier crank angle than this. The auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 '.

In the structure of the second embodiment, at the same time as the opening / closing valve 15 'of the first cylinder A1' is opened for an appropriate time in the latter half of the explosion (expansion) stroke of the first cylinder A1 ', At this time, the third cylinder A in the compression stroke
By simultaneously opening and closing the open / close valve 15 in 3'for an appropriate time, a part of the combustion (expansion) gas during combustion in the first cylinder A1 'is discharged to the first cylinder A1' as shown by an arrow D in FIG. The third cylinder A3 'was introduced from this third cylinder A
The combustion (expansion) gas introduced into 3'is supplied to the third cylinder A
The auxiliary fuel is injected and supplied from the auxiliary fuel injection valve 17 'to 3', so that all the auxiliary fuel is rapidly oxidized until the third cylinder A3 'passes through the top dead center of the compression stroke. can do.

When the third cylinder A3 'passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7'to the third cylinder A3', and the main fuel and The auxiliary fuel is simultaneously ignited at a number of places, so that the third cylinder A3 ′ shifts to an explosion (expansion) stroke.

Next, when the third cylinder A3 'is in the latter half of the explosion (expansion) stroke, the on-off valve 15' in the third cylinder A3 'is opened for an appropriate time, and at the same time, during the compression stroke. Open / close valve 15 'in the fourth cylinder A4'
By simultaneously opening for an appropriate time,
A part of the combustion (expansion) gas during combustion in 3 ′ is shown in FIG.
As indicated by an arrow E, the combustion (expansion) gas introduced into the fourth cylinder A4 'and introduced into the fourth cylinder A4' is supplied with auxiliary fuel from the auxiliary fuel injection valve 17 'for the fourth cylinder A4'. Is injected and supplied, all of the auxiliary fuel can be rapidly oxidized until the fourth cylinder A4 'passes through the top dead center of the compression stroke.

When the fourth cylinder A4 'passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7'to the fourth cylinder A4', and the main fuel and Since the auxiliary fuel is simultaneously ignited at a number of places, the fourth cylinder A4 'shifts to an explosion (expansion) stroke.

Next, when the fourth cylinder A4 'is in the latter half of the explosion (expansion) stroke, the on-off valve 15' in the fourth cylinder A4 'is opened for an appropriate time, and at the same time, during the compression stroke. Open / close valve 15 'in the second cylinder A2'
By simultaneously opening for an appropriate time, the fourth cylinder A
Part of the combustion (expansion) gas during combustion in 4 ′ is shown in FIG.
As indicated by the arrow F, the combustion (expansion) gas introduced into the second cylinder A2 'and introduced into the second cylinder A2' is supplied with auxiliary fuel from the auxiliary fuel injection valve 17 'for the second cylinder A2'. Is injected and supplied, all of the auxiliary fuel can be rapidly oxidized until the second cylinder A2 'passes through the top dead center of the compression stroke.

When the second cylinder A2 'passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7'to the second cylinder A2', and the main fuel and The auxiliary fuel is simultaneously ignited at a number of places, so that the second cylinder A2 'shifts to an explosion (expansion) stroke.

Next, when the second cylinder A2 'is in the latter half of the explosion (expansion) stroke, the on-off valve 15' in the second cylinder A2 'is opened for an appropriate time, and at the same time, during the compression stroke. Open / close valve 15 'in the first cylinder A1'
By simultaneously opening for a suitable time, the second cylinder A
Part of the combustion (expansion) gas during combustion in 2 ′ is shown in FIG.
As indicated by an arrow G, the combustion (expansion) gas introduced into the first cylinder A1 'and introduced into the first cylinder A1' is supplied with auxiliary fuel from the auxiliary fuel injection valve 17 'for the first cylinder A1'. Is injected and supplied, all the auxiliary fuel can be rapidly oxidized until the first cylinder A1 'passes through the top dead center of the compression stroke.

When the first cylinder A1 'passes the top dead center of the compression stroke, the main fuel is injected and supplied from the main fuel injection valve 7'to the first cylinder A1', and the main fuel and The auxiliary fuel is simultaneously ignited at a number of places, so that the first cylinder A1 'shifts to the explosion (expansion) stroke, and thereafter, by repeating this, the diesel engine 1'is operated.

In the case of the four-cycle four-cylinder diesel engine 1'according to the second embodiment, the compression stroke in the first cylinder A1 'and the explosion (expansion) stroke in the second cylinder A2 cause the second cylinder A2'. Compression stroke and 4th cylinder A4 '
Explosion (expansion) stroke in the third cylinder A3 'and explosion (expansion) stroke in the first cylinder A1', and compression stroke and third stroke in the fourth cylinder A4 '.
Since the explosion (expansion) stroke in the cylinder A3 ′ is completely the same, a part of the combustion (explosion) gas in one cylinder in the explosion (expansion) stroke of each cylinder is compressed in another cylinder in the compression stroke. The timing of introducing the fuel into the engine and the timing of injecting and supplying the auxiliary fuel at a crank angle, which is most preferable in the prior art, from approximately 50 degrees before the top dead center of the compression stroke to 20 degrees.
It can be set within a range of degrees.

In the second embodiment, too,
Instead of providing the auxiliary fuel injection valve 17 'for each cylinder in the communication passage 14' in each cylinder, the mutual communication passage 1
3'may be provided, and in this case as well,
Similar to the first embodiment, one auxiliary fuel injection valve provided in the mutual communication passage 13 'can be used for two cylinders.

Further, as in the first and second embodiments, the auxiliary fuel is supplied by the auxiliary fuel injection valves 17 and 1 dedicated to the auxiliary fuel.
In the configuration in which the fuel is injected and supplied at 7 ', the fuel having the same component as the main fuel can be used as the auxiliary fuel, and the fuel having the component different from the main fuel can be used.

Furthermore, based on the same idea as described above,
It can be applied to other four-cycle multi-cylinder diesel engines such as two-cylinder or six-cylinder, and compression ignition type four-cycle multi-cylinder internal combustion engines other than diesel engines.

Next, FIGS. 6 and 7 show a case where the third embodiment is applied to a conventionally known four-cycle three-cylinder diesel engine 1 ″.

This three-cylinder diesel engine 1 "is different from the three-cylinder diesel engine 1 in the first embodiment in that the cylinder 5" is provided on the top side surface of the cylinder 5 "in each cylinder A1", A2 ", A3". ″ Fuel storage chamber 1
The point of the configuration in which 8 is formed as a depression. ． In the fuel storage chamber 18, each communication passage 14 ″ communicating with the common communication passage 13 ″ is opened, and a poppet-type on-off valve 15 ″ is provided in this opening. Main fuel for each cylinder And the auxiliary fuel injection supply,
The configuration is such that one porous fuel injection valve 19 provided only substantially at the center of the top of the cylinder 5 ″ is used, and the injection timing of the main fuel and auxiliary fuel by this fuel injection valve 19 is
The injection of the main fuel is indicated by an arrow H in FIG. 7 at a time after the top dead center of the compression stroke in each cylinder (for example, at a timing of 10 to 20 degrees after the top dead center of the compression stroke at the crank angle). 10 "cavity on top of piston 6"
While the injection direction of the auxiliary fuel is set in the direction toward the fuel storage chamber 18, as shown by an arrow J. Other than that, the other configurations are the same. The same parts as those in the first embodiment are indicated by adding "" after the reference numerals.

In the configuration of the third embodiment, the main fuel of the fuel injected from the fuel injection valve 19 at the time when the top dead center of the compression stroke has passed in each cylinder A1 ", A2", A3 ". , The auxiliary fuel is injected and supplied into the fuel storage chamber 18.

In this case, since the burned gas from the previous explosion (expansion) stroke is stored in the fuel storage chamber 18, the auxiliary fuel injected and supplied thereto is ignited. Without changing the heat of the burned gas stored in the fuel storage chamber 18 and the active radical component contained in the burned gas to convert the hydrocarbon into an intermediate oxidation stage. It will be quickly oxidized.

Then, in the first cylinder A1 ″ of each cylinder, the first cylinder A1 ″ is subjected to the latter half of the explosion (expansion) stroke.
At the same time that the open / close valve 15 ″ in 1 ″ is opened for an appropriate time, and at the same time the open / close valve 15 ″ in the second cylinder A2 ″ during the compression stroke is opened for an appropriate time at the same time, the combustion in the first cylinder A1 ″ A part of the combustion (expansion) gas is introduced into the second cylinder A2 ″ during the compression stroke together with the auxiliary fuel oxidized in the fuel storage chamber 18 of the first cylinder A1 ″.

Next, when the second cylinder A2 ″ passes the top dead center of the compression stroke, the main fuel is injected and supplied from the fuel injection valve 19 to the second cylinder A2 ″, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The second cylinder A2 ″ shifts to the explosion (expansion) stroke.

When the second cylinder A2 "is in the latter half of the explosion (expansion) stroke, the on-off valve 15" of the second cylinder A2 "is opened for an appropriate time, and at the same time, during the compression stroke. Open / close valve 15 "in third cylinder A3"
By simultaneously opening for a suitable time, the second cylinder A
Part of the combustion (expansion) gas during combustion in 2 ″ is introduced into the third cylinder A3 ″ during the compression stroke together with the auxiliary fuel that has been oxidized in the fuel storage chamber 18 in the second cylinder A2 ″. .

Next, when the third cylinder A3 ″ passes the top dead center of the compression stroke, the main fuel is injected and supplied from the fuel injection valve 19 to the third cylinder A3 ″, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The third cylinder A3 ″ shifts to the explosion (expansion) stroke.

When the third cylinder A3 ″ is in the latter half of the explosion (expansion) stroke, the on-off valve 15 ″ in the third cylinder A3 ″ is opened for an appropriate time, and at the same time, during the compression stroke. Open / close valve 15 "in the first cylinder A1"
By simultaneously opening for an appropriate time,
Part of the combustion (expansion) gas during combustion in 3 ″ is introduced into the first cylinder A1 ″ during the compression stroke together with the auxiliary fuel oxidized in the fuel storage chamber 18 in the third cylinder A3 ″. .

Next, when the first cylinder A1 ″ passes the top dead center of the compression stroke, the main fuel is injected and supplied from the fuel injection valve 19 to the first cylinder A1 ″, and the main fuel and the auxiliary fuel are supplied. Is ignited in many places at the same time,
The first cylinder A1 ″ shifts to the explosion (expansion) stroke, and thereafter, by repeating this, the diesel engine 1 ″ is operated.

According to the third embodiment, one fuel injection valve 19 can perform main fuel injection supply and auxiliary fuel injection supply.

Further, the third embodiment can be applied to a four-cycle four-cylinder diesel engine based on the same idea as in the second embodiment, and it can be applied to a two-cylinder or six-cylinder engine. The present invention can be applied to other four-cycle multi-cylinder diesel engines and compression ignition type four-cycle multi-cylinder internal combustion engines other than diesel engines.

Although each of the above embodiments has been applied to a four-cycle multi-cylinder internal combustion engine, the present invention is
Needless to say, the present invention can be applied not only to four-cycle but also to two-cycle multi-cylinder internal combustion engine.

[Brief description of drawings]

FIG. 1 is a plan view showing a three-cylinder diesel engine according to a first embodiment.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a stroke diagram of each cylinder in the three-cylinder diesel engine.

FIG. 4 is a plan view showing a four-cylinder diesel engine according to a second embodiment.

FIG. 5 is a stroke diagram of each cylinder in the four-cylinder diesel engine.

FIG. 6 is a plan view showing a three-cylinder diesel engine according to a second embodiment.

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG.

[Explanation of symbols]

1,1 ″ three cylinder diesel engine 1'four cylinder diesel engine A1, A1 ', A1 "first cylinder A2, A2 ', A2 "2nd cylinder A3, A3 ', A3 "3rd cylinder A4 '4th cylinder 2,2 ″ cylinder block 3,3 ″ cylinder head 5,5 ″ cylinder 6,6 ″ piston 7 Main fuel injection valve 11, 11 ', 11 "intake valve 12,12 ', 12 "Exhaust valve 13,13 ', 13 "Mutual communication passage 14,14 ', 14 "communication passage 15,15 ', 15 "on-off valve 17,17 'Auxiliary fuel injection valve 18 Fuel storage chamber 19 Fuel injection valve

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F02B 75/18 F02B 75/18 P F02M 61/14 310 F02M 61/14 310Z

Claims (3)

[Claims] 1. Injection fuel for a plurality of cylinders having a common crankshaft is divided into a small amount of auxiliary fuel and a larger amount of main fuel, and the auxiliary fuel is top dead center in a compression stroke. The hydrocarbon contained in the auxiliary fuel is oxidized to an intermediate oxidation stage before the injection and supply at an earlier timing to pass the top dead center of the compression stroke, and then the top dead center of the compression stroke. In a compression ignition type multi-cylinder internal combustion engine configured to inject and supply the main fuel into the cylinders of each cylinder at a time after, a mutual communication passage is provided between the respective cylinders, and in the mutual communication passage, The cylinders are communicated with each other through a communication passage, and an opening / closing valve is provided in the communication passage for each cylinder. Each opening / closing valve is used for combustion in any one of the cylinders during the explosion (expansion) stroke ( Expansion) part of the gas Is operated so as to be introduced into the other one of the cylinders in the compression stroke, while the main fuel injection valve for injecting and supplying the main fuel is provided at the top of the cylinder in each cylinder. A compression ignition type multi-cylinder internal combustion engine, wherein an auxiliary fuel injection valve for injecting and supplying the auxiliary fuel is provided in the passage or the mutual communication passage. 2. The injected fuel for each of a plurality of cylinders having a common crankshaft is divided into a small amount of auxiliary fuel and a larger amount of main fuel, and the auxiliary fuel is top dead center in a compression stroke. The hydrocarbon contained in the auxiliary fuel is oxidized to an intermediate oxidation stage before the injection and supply at an earlier timing to pass the top dead center of the compression stroke, and then the top dead center of the compression stroke. In a compression ignition type multi-cylinder internal combustion engine configured to inject and supply the main fuel into the cylinders of each cylinder at a time after, while providing a fuel storage chamber communicating with the cylinder at the top of the cylinder of each cylinder, A fuel injection valve for injecting the main fuel into the cylinder and injecting the auxiliary fuel into the fuel storage chamber is provided at the top of the cylinder of each cylinder. An inter-communicating passage is provided between the respective cylinders, the fuel storage chamber in each cylinder is communicated with the inter-communicating passage through the communicating passage, and an on-off valve is provided in the communicating passage for each cylinder. Each on-off valve is configured to introduce a part of the combustion (expansion) gas in any one cylinder of each cylinder during the explosion (expansion) stroke into another cylinder of each cylinder during the compression stroke. A compression ignition type multi-cylinder internal combustion engine, which is operated to open. 3. The compression ignition type multi-cylinder internal combustion engine according to claim 1 or 2, characterized in that the mutual communication passages between the respective cylinders are formed as one for a plurality of cylinders.