JPH0729222Y2 - Intake device for multi-cylinder internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Industrial Field of Application The present invention improves the volumetric efficiency of a multi-cylinder internal combustion engine by controlling the intake pressure fluctuation in the intake system. The present invention relates to the improvement of the intake device designed to achieve the above.

(2) Prior Art In an intake system for a multi-cylinder internal combustion engine, by variably controlling the length and volume of the intake system according to the operating state of the engine,
Resonance effect in which intake pressure fluctuations between cylinders that do not cause intake interference resonate, or negative pressure waves that occur at the start of intake in each cylinder are reflected by the volume expansion part provided in the intake system and returned to the intake port side. Various proposals have already been made to exhibit the inertial effect by utilizing the so as to enhance the volumetric efficiency from low speed to high speed range of the engine.

In such an intake device, a pair of resonance chambers that are respectively communicated with cylinder groups whose intake strokes are not continuous are formed in a volume expansion portion provided in the intake system, and both chambers are communicated with a boundary wall between these chambers, or An on-off valve for shutting off is provided, and the intake system is switched to the resonance supercharging system or the inertia supercharging system by opening / closing control of this on-off valve, and the intermediate portion of the distribution pipe connecting the resonance chamber and the cylinder group is connected via a pipe length switching valve. In order to obtain high volumetric efficiency in a wider operating range by connecting the resonance chamber with each other and changing the length of the distribution pipe, it has already been proposed (for example, Japanese Patent Laid-Open No. 63-
215822).

(3) Problems to be Solved by the Invention However, in the above-mentioned conventional intake device, a high resonance supercharging effect can be obtained when the two resonance chambers are constituted by blocking the communication between the pair of resonance chambers. When the volume of the resonance chamber is determined, when the pair of resonance chambers are communicated with each other to form one system of inertia supercharging system, the volume of the inertia supercharging distribution chamber formed is the volume of the pair of resonance chambers. Because it is uniquely determined as the sum of
There is a problem that the volume is insufficient and a sufficient inertia supercharging effect cannot be obtained. On the other hand, if the volume of the inertial supercharging distribution chamber is sufficiently secured, the volume of the resonance chamber becomes excessive when the resonance supercharging system is formed, and an appropriate resonance supercharging effect and good idle rotation cannot be obtained. There will be problems.

The present invention has been made in view of the above circumstances, and the volume of the resonance chamber for forming the resonance supercharging system and the volume of the inertia supercharging distribution chamber for forming the inertia supercharging system are both optimal. An object is to provide an intake system for a multi-cylinder internal combustion engine that can be set to a value.

B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention, in order to achieve the above object, the inside of the resonance chamber collecting box is divided into a pair of resonance chambers, and each resonance chamber has an upstream side thereof. In the intake passage of a multi-cylinder internal combustion engine, the resonance passage communicating with the outside air, the downstream side of which communicates with a cylinder group whose intake stroke is not continuous via distribution pipes capable of switching the pipe length, respectively, in the resonance chamber collecting box, It is composed of a pair of resonance chambers and a communication chamber adjacent to and in communication with each of the pair of resonance chambers, and an opening / closing valve is provided in a communication section formed in a partition wall between the communication chamber and each of the resonance chambers. In the open state of the on-off valve, one inertia supercharging distribution chamber is formed by the three of the pair of resonance chambers and the communication chamber.
An intermediate portion of the distribution pipe is connected to the communication chamber, and a pipe length switching valve that makes the substantial length of the distribution pipe variable is attached to the connection portion, and the opening / closing valve and the pipe length switching valve are installed in a low speed operation state of the engine. Are both controlled to be in a closed state, the open / close valve is controlled to be in an open state and the pipe length switching valve is controlled to be in a closed state in a medium speed operation state of the engine. Both of the pipe length switching valves are controlled to be in an open state, and the fuel supply means to the multi-cylinder internal combustion engine and the intake system may be of any type.

(2) Operation According to the above configuration, in the low speed operation region of the engine, the communication between the resonance chambers and the communication chambers is blocked by the valve closing control of the opening / closing valve, and the resonance chambers are connected by the valve closing control of the pipe length switching valve. The left and right cylinder groups are connected through the entire length of the distribution pipe, thus forming two resonance supercharging systems in which intake interference does not occur. Further, in the medium speed operation range of the engine, the pair of resonance chambers and the communication chamber are integrally connected by the valve opening control of the opening / closing valve to form a large volume inertial supercharging distribution chamber, and the resonance excess of the two systems is set. The feeding system is canceled and the inertia supercharging system is constructed. Further, in the high speed operation region of the engine, the pipe length switching valve is controlled to be opened so that the intermediate portion of the distribution pipe is short-circuited to the inertia supercharging distribution chamber, thereby forming an inertia supercharging system having a smaller natural frequency.

Then, even if the volume of each resonance chamber is set to a volume at which the optimum resonance supercharging effect is obtained in the low speed operation range of the engine, the volume of the inertia supercharging distribution chamber formed by the valve opening control of the opening / closing valve is By appropriately selecting the volume of the communication chamber, it is possible to set an arbitrary large volume different from the volume of each resonance chamber and also including the volume of each resonance chamber. The volume can be set to a value that provides the optimum inertia supercharging effect in the engine in the high speed operating range, and the natural frequency of such an inertia supercharging system can be accurately set in the medium speed operating range and the high speed operating range. It is possible to control the changeover to, and thereby a high inertia supercharging effect is exhibited in a wide operating range of the engine.

The pair of resonance chambers and the communication chamber are formed in a common resonance chamber assembly box so that the volume of each resonance chamber can be effectively used as a partial volume of the inertial supercharging distribution chamber. By disposing the on-off valve in the collecting box, the size of the intake system becomes compact as a whole.

(3) Embodiment An embodiment in which the present invention is applied to a V-type 6-cylinder internal combustion engine will be described below with reference to the drawings.

1 to 5 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a V type 6 cylinder internal combustion engine equipped with the device of the present invention, and FIG. 2 is a plan view of the cylinder block. FIG. 3 is an enlarged partial plan view taken along the line III-III in FIG. 1, FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, and FIG.
It is sectional drawing which follows the -V line.

In FIGS. 1 and 2, the engine body E of the 6-cylinder internal combustion engine is shown.
Is equipped with a pair of left and right engine blocks Bl, Br which are arranged in a V shape with each other. The left and right engine blocks Bl, Br are respectively joined to the cylinder blocks 1, 1r and their deck surfaces. The left cylinder block 1 has three left cylinders 3l formed in series, and the right cylinder block 1r also has three cylinders 3r.
Are formed in series. The three cylinders 3l on the left side constitute a left cylinder group Cl in which the intake stroke is not continuous, that is, the intake valve 10 described later does not overlap, and the three cylinders on the right side.
3r also constitutes a right-side cylinder group Cr in which the intake stroke is not continuous, that is, the intake valve 10 described later does not overlap.

Pistons 4 are slidably fitted in the left and right cylinders 3l and 3r as usual, and these pistons 4 are interlocked with a crankshaft 6 via a connecting rod 5. Further, the left and right cylinder heads 2l, 2r are respectively provided with a combustion chamber 7 facing the piston 4 and a suction chamber communicating with the combustion chamber 7.
Exhaust ports 8 and 9 are formed, each intake port 8 is provided with an intake valve 10 that opens and closes the port 8, and each exhaust port 9 is provided with an exhaust valve 11 that opens and closes the port 9. To be The intake / exhaust valves 10 and 11 are opened / closed at a predetermined timing by a conventionally known valve operating mechanism 12.

Intake ports 8 of the left and right cylinder heads 2l, 2r
Is connected to an intake system In which will be described in detail later, and a conventionally known exhaust system (not shown) is connected to the plurality of exhaust ports 9 of the left and right cylinder heads 2l and 2r.

Next, the structure of the intake system In will be described in detail with reference to FIGS. 2 to 5. The intake system In is arranged in the V space C between the left and right cylinder blocks 1 and 1r, and the air cleaner Ac
And the intake passage Pi connected to the outlet of this air cleaner Ac.
And a resonance chamber assembly box Bg connected to the downstream end of the intake passage Pi and having a pair of left and right resonance chambers Cr-l, Cr-r and a communication chamber Cs, and the left and right cylinder blocks 1, 1r. Of the left and right resonance chambers Cr-l, Cr-r, which are joined to the end surface where the intake port 8 is opened,
It consists of an intake manifold Mi, which will be described later, that communicates with the right and left cylinder groups Cr and Cl, respectively.

The intake passage Pi is provided with an air cleaner Ac as shown in FIG.
A throttle body 15 is integrally connected with a bolt 16 at the downstream end of an intake passage 14 connected to. The intake passage 14 is formed in a hollow cylindrical shape so as to suck the intake air from the air cleaner Ac, and inside the throttle body 15, a throttle valve 20 controlled to be opened and closed by an operating portion 19 is provided. A resonance chamber collecting box Bg is integrally connected to the downstream end of the throttle body 15 with a bolt 17.

The resonance chamber collecting box Bg is composed of a collecting box body 21 having a substantially rectangular parallelepiped upper surface that is connected to the throttle body 15, and a lid 22 that is hermetically attached to the opening upper surface with a bolt 23. Assembly box body 21
Is integrally formed with an intake manifold Mi described later.

As clearly shown in FIGS. 3 to 5, the resonance chamber collecting box Bg is arranged in parallel with each other by two partition walls 24l, 24r extending along the direction of the crankshaft 6 of the engine, that is, the flow direction of intake air flowing in the box Bg. Left and right resonance chamber C
It is partitioned into a communication chamber Cs located between r-1 and Cr-r and the resonance chambers Cr-1 and Cr-r. The left and right resonance chambers Cr-l, Cr-r are connected at their upstream ends to the downstream ends of a pair of resonance passages 18l, 18r branching left and right from the connecting portion with the throttle body 15, respectively.

The two partition walls 24l and 24r have left and right resonance chambers Cr-l and C, respectively.
On-off valves 25l, 25r are provided for connecting or disconnecting r-r and the communication chamber Cs or for blocking the communication. Ie both partitions 2
Square valve openings 26l, 26r are opened in 4l, 24r, and rotatable valve shafts 27l, 27r inserted along the partition walls 24l, 24r connect the central portions of the valve openings 26l, 26r. Penetrates.
Then, rectangular plate-shaped valve bodies 28l, 28r provided in the valve openings 26l, 26r are fixed to the valve shafts 27l, 27r with screws 30. One ends of the valve shafts 27l, 27r penetrate the rear end wall of the collecting box body 21 and project to the outside, and the projecting ends thereof are
A conventionally known actuator 29 is connected. This actuator 29 is operated and controlled according to the operating state of the engine to open / close the on-off valves 25l, 25r, and closes the on-off valves 25l, 25r during low-speed operation of the engine, and at the medium speed. The open / close valves 25l and 25r are controlled to open during high-speed operation.

Then, the volumes of the left and right resonance chambers Cr-l, Cr-r when the on-off valves 25l, 25r are closed are set to volumes that can obtain an optimum resonance supercharging effect in the low speed operation range of the engine. . Further, the volume of the communication chamber Cs is equal to the open / close valves 25l, 25
When r is controlled to be opened, the left and right resonance chambers Cr-l, Cr-r and the communication chamber Cs are integrally connected to each other, and the inertial supercharging distribution chamber Ch having a large volume shown by the two-dot chain line in FIG. Is formed, the volume of the inertial supercharging distribution chamber Ch is set so that an optimum inertial supercharging effect can be obtained in the high speed operation region in the engine.

The left and right resonance chambers Cr-1 and Cr-r have three left and right exhaust ports 34l and 34r, respectively, formed in the partition walls 24l and 24r along the longitudinal direction thereof. And the left resonance chamber Cr
The three -l exhaust ports 34l communicate with the three cylinders 3r (the intake order is not continuous) of the right cylinder block 1r located on the opposite side of the left resonance chamber Cr-l via an intake manifold Mi described later. Similarly, the three exhaust ports 34r of the right side resonance chamber Cr-r are connected to three cylinders 3l of the left side cylinder block 1 (intake sequence Are not continuous).

The intake manifold Mi has six first to sixth distribution pipes 35 _{1 to} 3 intersecting in an X shape in the center as shown in FIGS.
6 ₆ are integrally juxtaposed in a direction substantially orthogonal to the longitudinal direction of the left and right resonance chambers Cr-l, Cr-r and alternately intersect in opposite directions and extend left and right. Three second,
The fourth and the upstream end of the sixth minute pipe 35 _2, 35 ₄ and 35 ₆ they extend on the opposite side of the resonance chamber Cr-l after passed through respectively with the three exhaust ports 34l of the left resonance chamber Cr-l The downstream ends of the three are connected to the three cylinders 3r of the right cylinder block 1r, respectively, and the remaining upstream ends of every other three first, third and fifth distribution pipes 35 ₁ , 35 ₃ and 35 ₅ are After being connected to the three exhaust ports 34r of the right resonance chamber Cr-r, they extend to the opposite side of the resonance chamber Cr-r, and their downstream ends are connected to the three cylinders 3l of the left cylinder block 1, respectively.

As is clear from FIGS. 4 and 5, the lower surface of the communication chamber Cs located in the center of the resonance chamber collecting box Bg is closed by the _six distribution pipes 35 _{1 to} 356 arranged in parallel, and the resonance on the left side Three distribution pipes extending from chamber Cr-1 35 ₂ , 35 ₄ ,
35 middle part of ₆ is connected by a right lower surface and three branch passages 36 _2, 36 _4, 36 ₆ communicating chamber Cs, 3 distributing pipes 35 _1, 35 extending from the right side of the resonance chamber Cr-r _3, 35
The middle part of ₅ is connected to the lower left side of the communication chamber Cs by three branch passages 36 ₁ , 36 ₃ , 36 ₅ . A left pipe length switching valve 37l is installed in the branch passages 36 ₁ , 36 ₃ , 36 ₅ and a right pipe length switching valve 37r is installed in the branch passages 36 ₂ , 36 ₄ , 36 ₆ .
That is, the pair of left and right valve shafts 38l, 38r rotatably supported by penetrating both sides of the intake manifold Mi are the central portions of the branch passages 36 ₁ , 36 ₃ , 36 ₅ and the branch passages 36 ₂ , 36 ₄ , 36 ₆ , respectively. Valve bodies 39 _{1 to} 39 ₆ formed of an elliptical plate body that crosses the portion and opens and closes the branch passages 36 _{1 to} 36 ₆ at that position are fixed with screws 40. As is clear from FIG. 3, the both valve shafts
The ends of the 38l and 38r protruding from the intake manifold Mi are connected to the actuator 41 to control the opening and closing of the pipe length switching valves 37l and 37r.The pipe length switching valves 37l and 37r are The valve is controlled to be closed, and the valve is controlled to be opened in the high speed operation range.

The reference numeral 42 in FIG. 1 indicates the first to sixth distribution pipes 35 _{1 to} 35 ₆
Fuel injection nozzles provided on the upper wall of the downstream end of the
Reference numerals 43 and 44 in FIG. 4 indicate an EGR gas chamber and a blow-by gas chamber, respectively.

Next, the operation of the embodiment of the present invention will be described.

The actuator 29 is actuated and controlled in accordance with the operating state of the engine. For example, in the low speed operating state, the on-off valves 25l and 25r are controlled to be closed to close the valve ports 26l and 26r, and the left and right resonance chambers Cr-l, Cr -R communication is cut off. Pipe length switching valve
37l, 37r be closed controlled closing the branch passage 36 ₁ to 36 _6, communicating distributing pipes 35 ₁ to 35 ₆ and the communication chamber Cs is cut off. In this state, the resonance passages 18l, 18r for each cylinder group, the left and right resonance chambers Cr-l, Cr-r for each cylinder group, and the left and right distribution pipes 35 ₁ , 35 ₂ , 35 ₃ , for each cylinder group There are two intake systems consisting of 35 ₄ , 35 ₅ , and 35 ₆ , that is, two resonance supercharging systems that do not cause intake interference from each of the three cylinders 3l and 3r to the outlet of the throttle body 15, and The resonance chamber Cr-l, Cr
Since the volume of −r is set so that the natural frequency of the resonance supercharging system substantially coincides with the opening / closing cycle of each intake valve 10 in the low speed rotation range of the engine, the resonance supercharging effect is effectively exhibited. As a result, the volumetric efficiency in the low speed rotation range of the engine is improved. Further, since the volume downstream of the throttle valve 20 is reduced, the response during pressure control is improved, and the idle rotation control is facilitated.

On the other hand, when the engine reaches the medium speed operation state, the on-off valves 25l, 25r are controlled to open, and the left and right resonance chambers Cr-l, Cr-r and the communication chamber Cs are integrated via the valve ports 26l, 26r. Connected to
Forming a large consisting volume of inertia supercharging distribution chamber Ch (see FIG. 4), the chamber Ch is communicated with the common left and right cylinder 3l, the 3r through the entire length of the distributor pipe 35 _{1-35 6} . Then, in this state, the two resonance supercharging systems are canceled, the negative pressure wave generated in the engine intake stroke is reflected and inverted by the large-capacity inertial supercharging distribution chamber Ch, and the positive pressure wave of each cylinder 3l, 3r. is propagated to the intake port 8 is configured inertial supercharging system, yet the negative pressure wave, and positive pressure wave propagated to passage length of is only the length of the distributor pipe 35 _{1-35 6,} in the intake pressure cycle of the engine It is possible to match the opening / closing cycle of the intake valve 10 during high speed rotation.

When the engine reaches the high-speed operation state, the pipe length switching valves 37l and 37r are further controlled to open, and the middle portion of the distribution pipes 35 _{1 to} 35 ₆ has a short branch passage.
It communicates with the communication chamber Cs via 36 _{1 to} 36 ₆ . Simultaneously the substantial length of the distributor pipe 35 _{1-35 6} increases branch passage 36 ₁ to 36 natural frequency of the is reduced inertia supercharging system downstream portion of the connection portion ₆ is further distribution pipes 35 upstream portion of the _{1-35 6} has expanded its volume becomes part of the inertia supercharging distribution chamber Ch, inertia supercharging effect in the high-speed operating range can be more effectively exhibited.

By appropriately setting the volume of the communication chamber Cs, it is possible to arbitrarily secure a large volume of the inertia supercharging distribution chamber Ch necessary to enhance the effect of inertia supercharging in the medium speed and high speed rotation regions of the engine. The volumetric efficiency can be enhanced by effectively exerting the inertia supercharging effect in the operating range.

Further, a pair of resonance chambers Cr-l, Cr-r and a communication chamber Cs are integrally formed in the resonance chamber collecting box Bg, and the partition walls 24l, 24r are provided with open / close valves 25l, 25r. The structure can be simplified and the shape can be made compact.

C. Effect of the Invention As described above, according to the present invention, in the low speed operation range of the engine,
The on-off valve closing control cuts off the communication between each resonance chamber and the communication chamber, and the pipe length switching valve closing control connects each resonance chamber to the left and right cylinder groups through the entire length of the distribution pipe. In this way, two resonance supercharging systems that do not cause intake interference are configured, and in the medium speed operation range of the engine, a pair of resonance chambers and communication chambers are integrated by controlling the opening and closing of the open / close valves. By forming one large-volume inertial supercharging distribution chamber in communication with each other, the resonance supercharging systems of the two systems are canceled to form the inertial supercharging system, and further, in the high-speed operating range of the engine. Since the pipe length switching valve is controlled to open and the intermediate portion of the distribution pipe is short-circuited to the inertia supercharging distribution chamber, an inertia supercharging system having a smaller natural frequency is configured, so that individual resonance Change the chamber volume Even if the volume is set to the optimum resonance supercharging effect in the low speed operation range, the volume of the inertial supercharging distribution chamber formed by the valve opening / closing control of the opening / closing valve is determined by appropriately selecting the volume of the communication chamber. The volume of the inertial supercharging distribution chamber can be set to an arbitrary large volume different from the volume of each resonance chamber and including the volume of each resonance chamber. It can be set to a value that provides the optimum inertia supercharging effect, and the natural frequency of such an inertia supercharging system can be appropriately switched and controlled between the medium speed operating range and the high speed operating range. In a wide operating range of the engine, a high inertia supercharging effect can be obtained and the volumetric efficiency can be improved.

The pair of resonance chambers and the communication chamber are formed in a common resonance chamber assembly box so that the volume of each resonance chamber can be effectively used as a partial volume of the inertial supercharging distribution chamber, and the resonance By disposing the on-off valve in the chamber collection box, the size of the intake system becomes compact as a whole, which can contribute to simplification of the structure and cost reduction.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a V type 6 cylinder internal combustion engine equipped with the device of the present invention, and FIG. 2 is a plan view of the cylinder block. 3 is an enlarged partial plan view taken along line III-III in FIG. 1, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, and FIG.
It is sectional drawing which follows the -V line. Bg …… Resonance chamber assembly box, Cl, Cr …… Cylinder group, C
r-l, Cr-r ... left and right resonance chambers, Cs ... communication chamber, Ch ... inertia supercharging distribution chamber 18l, 18r ... resonance passage, 25l, 25r ... open / close valve, 35 _{1 to} 35 ₆ …
… Distribution pipe, 37l, 37r …… Pipe length switching valve

Claims (1)

[Scope of utility model registration request] 1. A resonance chamber collecting box (Bg) is divided into a pair of resonance chambers (Cr-1, Cr-r), and each resonance chamber (Cr-1, Cr-r) has its upstream side exposed to the outside air. In the resonance passage (18l, 18r) leading to the pipe, distribution pipes (35 _{1 to} 35) that can switch the pipe length on the downstream side to the cylinder group (Cl, Cr) whose intake stroke is not continuous
₆ ) In the intake device of a multi-cylinder internal combustion engine, which communicates with each other separately, the resonance chamber collecting box (Bg) is provided with the pair of resonance chambers (Cr-l, Cr-r) and the pair of resonance chambers. (Cr-l, Cr-r), a communication chamber (Cs) adjacent to and communicating with each other, and a partition wall between the communication chamber (Cs) and the resonance chambers (Cr-l, Cr-r). An on-off valve (25l, 25r) is provided in the communication part formed in (24l, 24r), and when the on-off valve (25l, 25r) is open, the pair of resonance chambers (Cr-l, Cr-r) and One inertial supercharging distribution chamber (Ch) by the three communication chambers (Cs)
Forming a middle portion of the distribution pipe (35 ₁ to 35 ₆₎ connected to said communication chamber (Cs), said distribution pipe (35 to the connecting portion
_{1-35 6)} pipe length switching valve substantial length and variable (37l, 37
r) is installed and the open / close valve (25
l, 25r) and the pipe length switching valve (37l, 37r) are both closed, and the open / close valve (25l, 25r)
r) is opened and the pipe length switching valve (37l, 37r) is controlled to be closed, and the open / close valve (25l, 25r) and pipe length switching valve (37l, 37r) are controlled when the engine is operating at high speed. An intake system for a multi-cylinder internal combustion engine, characterized in that both are controlled to open.