JP2877490B2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fuel cell system corresponding to a cylinder group in which intake strokes are not continuous.
The present invention relates to an intake system for an engine in which a set of independent intake passage groups are respectively assembled to form two systems of intake passages.

[Conventional technology]

2. Description of the Related Art Conventionally, two sets of independent intake passage groups corresponding to a group of cylinders whose intake strokes are not continuous have been gathered to provide two systems of intake air in order to provide an effect such as improvement of charging efficiency by resonance supercharging using a pressure wave of intake air. 2. Description of the Related Art An intake device for an engine having a passage is known. For example, in an intake device disclosed in Japanese Patent Application Laid-Open No. Sho 62-153516, one bank including a group of cylinders whose intake strokes are not continuous and another bank are V-shaped with each other. A surge tank is provided from the two expansion chambers, and an independent intake passage group extending from one bank and an independent intake passage group extending from the other bank are connected to the respective expansion chambers, and at the upstream side of the surge tank, A common intake passage for each bank is provided at an end of each of the enlarged chambers, and a main intake passage is connected to a junction on the upstream side of the two common intake passages. According to this intake device, the cylinders belonging to the same bank do not have adjacent intake strokes, so the range extends from the independent intake passage corresponding to each bank to the confluence on the upstream side of each common intake passage through each expansion chamber. , An intake pressure wave is propagated, and a resonance effect is obtained in a predetermined engine speed range corresponding to the intake passage length in this range.

[Problems to be solved by the invention]

In the device disclosed in the above publication, the intake passage is simply divided into two systems in a range from the independent intake passage to the enlarged chamber and the common intake passage. There is also known a device in which a communication switching means including an opening / closing valve for opening and closing the same is provided so that an effective passage length provided for pressure propagation is made variable so that a resonance effect can be obtained in different rotational speed ranges. In particular, as a structure in which the effective passage length is changed in multiple stages so that a resonance effect can be obtained in various rotational speed ranges, a plurality of communication switching means are provided, for example, at a position near the intake passage downstream (the end of the surge tank). Etc.), a first communication switching means comprising a communication path and an opening / closing valve connected between the two intake paths, and a second communication comprising a communication path and an opening / closing valve connected between the two intake paths on the upstream side thereof. Some of them are provided with switching means.

In the case where a plurality of communication switching means are provided as described above, in the conventional structure in which each communication switching means is individually connected to a different portion of the intake passage, when the open / close valve of each communication switching means is closed, the intake air The connection portion of each communication path to the passage becomes a dead volume for the flow of the intake air, and there is a problem that the dead volume causes a pressure loss and generates a vortex at a plurality of points in the intake passage, thereby increasing the flow resistance of the intake air. Was.

When the communication switching means is connected between the two intake passages, the upstream ends of the individual passages in each of the independent intake passage groups are spaced apart by a predetermined distance in upper and lower enlarged chambers formed by surge tanks extending in the cylinder row direction. In the structure connected every other, a communication path of the communication switching means is connected to one end of each of the enlarged chambers, or the communication switching means is provided in the middle of each common intake passage connected to one end of each of the enlarged chambers. Since the communication passage is connected, when the communication passage is opened and the pressure wave is propagated, there is a difference in a passage length of each cylinder from the independent intake passage to the communication passage through the expansion chamber or the like, and the resonance effect is reduced. There was also a problem that it was likely to be uneven.

In view of such circumstances, the present invention provides an engine which can reduce pressure loss and intake resistance when providing a plurality of communication switching means for switching the communication state between two intake passages in multiple stages. It is an object to provide an intake device. Further, as another object, when a communication switching means is provided to switch a communication state between two intake passages, a difference in a passage length between cylinders occurs when pressure is propagated through the communication passage. To prevent and enhance the resonance effect.

[Means for solving the problem]

According to a first configuration of the present invention, two sets of independent intake passage groups corresponding to a group of cylinders whose intake strokes are not continuous are respectively assembled to form a two-system intake passage.
A first communication switching means including a communication passage communicating the intake passage of the system in the middle of the passage and an opening / closing valve provided in the communication passage; and a bypass of the opening / closing valve to the communication passage of the first communication switching means. And a second communication switching means including a passage connected to the passage and an opening / closing valve provided in the passage.

In this configuration, the communication passage of the first communication switching means is connected between each of the gathering portions of the two intake passages, and the passage of the second communication switching means connected to this communication passage is connected to the gathering portion of the intake passage. It is preferable to be formed in the direction of the upstream side of.

Each of the open / close valves of the first and second communication switching means is operated to open and close in accordance with the engine speed. The two open / close valves are closed in a low speed range and the second communication switching means in a medium speed range. Only the open / close valve is opened, and the two open / close valves are opened in a high speed range.

Further, as another configuration of the present invention, there is provided a two-system intake passage in which two independent intake passage groups each corresponding to a cylinder group whose intake strokes are not continuous are provided.
Communication switching means comprising a communication passage for communicating the intake passages of the system in the middle of the passage and an on-off valve provided in the communication passage; Are connected collectively, and the communication path of the communication switching means is connected to the position of the center point of each collecting portion which is the collection point of the center line of the independent intake passage.

[Action]

According to the first configuration, the communication state between the two intake passages can be switched in multiple stages by the respective communication switching means, and the communication path of the first switching means is directly connected to the intake passage. The number of connection points to the intake passage which causes a pressure loss and an increase in intake resistance is reduced as compared with the case where both intake passages are individually connected.

The communication path of the first communication switching means is connected between the respective collecting parts, and the path of the second communication switching means connected to the communication path is formed toward the upstream side of the collecting part. The second communication switching means is disposed in a space existing near the upstream portion of the collecting section, and this space is effectively used.

Further, according to the above another configuration, in the two systems of intake passages, the passage lengths extending from the independent intake passages to the communication passages via the collecting portion are respectively equalized.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

1 and 2 show the overall structure of an intake device according to an embodiment of the present invention. In the illustrated example, the intake device is applied to a V-type engine. In these figures, reference numeral 1 denotes an engine body of a V-type engine, which is a pair of banks arranged in a V-shape.
It has a cylinder block 2 and a pair of cylinder heads 3 and 4. This engine body 1
It is arranged horizontally in the engine room 6 below the hood 5 at the front of the vehicle, that is, arranged so that the direction of the engine output shaft is in the vehicle width direction.

Each of the banks 1a and 1b is provided with a plurality of cylinders. For example, in the illustrated V-type six-cylinder engine, both banks 1a and 1b are provided.
b is provided with three cylinders. One bank 1a
And the cylinders of the other bank 1b are arranged offset from each other in the engine output axis direction.

An intake manifold 10 includes two independent intake passage groups 11, 12 extending from the banks 1a, 1b, respectively. These two independent intake passage groups 11, 12 are assembled on the upstream side to form two intake manifold groups. Intake collecting portions 13 and 14 are formed. In the illustrated V-type six-cylinder engine, the independent intake passage groups 11, 12 are constituted by three independent intake passages corresponding to the cylinders of the banks 1a, 1b, respectively, and the downstream ends of the respective groups are arranged in the cylinders of the banks 1a, 1b. The heads 3 and 4 are connected to the inner wall surfaces (between banks) and communicate with intake ports formed in the cylinder heads 3 and 4.

Each of the intake collecting portions 13 and 14 does not have a large volume like a surge tank, and each of the independent intake passage groups 11 and 12 is collectively gathered on the upstream side, and a common intake passage 31 for each bank described later. , 32, so that the upstream side is gradually narrowed so as to be directly connected to. These intake collecting portions 13 and 14 are integrally formed so as to vertically overlap with each other via a partition wall, and are arranged on one bank 1 a located on the rear side of the engine room 6. The upstream end of the independent intake passage group 12 extending rearward from the front bank 1b is coupled to the lower intake collecting section 14, and the independent intake passage group 11 extending upward from the rear bank 1a The respective passages are alternately arranged with the respective passages of the independent intake passage group 12 and are bent rearward above the independent intake passage group 12 in a state of intersecting with the passages, and are connected to the upper intake collecting portion 13. .

Each of the intake manifolds 13 and 14 is located forward (inside of the bank) of the spark plug plug hole 15 arranged in the one bank 1a, and is upstream of each of the intake manifolds 13 and 14. Side portions 13a and 14a pass between the two plug holes 15 and are bent rearward in the vehicle width direction.
Attached to the engine body 1 by 16 and an intake pipe 30 for forming a common intake passage described later is connected to this portion.

Each of the intake passage groups 11 and 12, the intake manifolds 13 and 14, and the common intake passages 31 and 32 form two systems of intake passages. Communication switching means for switching the communication state between the two intake passages and changing the effective passage length for resonance is provided for the two intake passages. In this embodiment, in particular, the first communication switching means and the second communication switching means are provided. Means.

The first communication switching means includes a communication passage 21 that connects the two intake passages in the middle of the passage, and an opening / closing valve 22 provided in the communication passage 21. Specifically, a pair of upper and lower short passage portions 21a, 21b protruding in the lateral direction from both intake collecting portions 13, 14 of the intake manifold 10, and a communication hole 21c between these passage portions 21a, 21b. Communication passage for high speed range
An opening / closing valve 22 is provided in the communication hole 21c. The passage portions 21a and 21b of the communication passage 21 are located at a position of a center point O of the intake manifold 13 which is a gathering point of the passage center lines A ₁ , A ₂ and A _{3 in} the independent intake passage group 11 and an independent intake passage group 12.
At the intake center, which is the junction of the passage centerlines B ₁ , B ₂ , B ₃
14 are connected to the position of the center point O ', that is, the center lines of the passage portions 21a and 21b are connected so as to pass through the center points O and O', respectively. A passage 23 is connected to a communication passage 21 of the communication switching means so as to bypass the on-off valve 22, and an on-off valve 24 provided in the passage 23. Specifically, the pair of upper and lower passage portions 21a,
A passage 23 connected to the passage 21b extends rearward (in the direction of the upstream side of the collecting portion) through the space between the plug holes 15, and further bends in the lateral direction.
A communication passage for the medium speed range is formed by a range extending between 23 and a part of the passage portions 21a and 21b, and an opening / closing valve 24 is provided in the middle of the passage portion 23. The opening / closing valves 22, 24 are operated by actuators 25, 26, respectively, and the actuators 25, 26 respond to a negative pressure supplied via, for example, an electromagnetic valve (not shown). Then, by a control signal according to the operating state given to the solenoid valve and the like, both the on-off valves 22 and 24 are closed in a low speed range of the engine, only the on-off valve 24 is opened in a middle speed range, and both open and close valves are opened in a high speed range. The opening / closing valves 22, 24 are opened.

An intake pipe connected to the upstream side of the intake manifold 10
The cylinder 30 integrally includes common intake passages 31 and 32 for the respective cylinders, which communicate with the intake collecting sections 13 and 14, respectively. And this intake pipe 3
Reference numeral 0 indicates that the downstream end of the engine 1 is connected to the intake manifold 10 at the rear, the engine 1 is bent at one side in the vehicle width direction, and the upstream side extends forward. The two common intake passages 31 and 32 of the intake pipe 30 are arranged vertically at the downstream end corresponding to the intake manifolds 13 and 14 of the intake manifold 10, but are arranged side by side as they go upstream. , Are formed in a twisted array.

At the upstream end of the intake pipe 30, the common intake passages 31, 3
2 is connected to a junction portion 33, which is further connected to a throttle body 34 containing a throttle valve 35.
Are connected. The merging portion 33 and the throttle body 34 are located in the vicinity of the space between the banks 1a and 1b, and are connected to the engine hanger 36. The throttle valve 35 is rotatable about a horizontal axis, and rotates in response to an accelerator operation. The merging portion 33 is also provided with a downstream end 37 of an ISC passage that bypasses the throttle valve 35, a purge inlet 38, an EGR inlet 39, a blow-by gas inlet 40, and the like. 41 is an EGR valve and 42 is an EGR passage. The above throttle body 3
An upstream intake pipe (not shown), an air cleaner, and the like are connected to the upstream side of (4).

According to the apparatus of the present embodiment as described above, the effective path length used for pressure propagation for resonance can be switched in three stages, and resonance effects can be obtained in a low speed range, a medium speed range, and a high speed range. .

That is, the cylinders arranged in one bank 1a and the cylinders arranged in the other bank 1b of the V-type engine are configured such that the intake strokes are not continuous, so that the on-off valve 22, When the valve 24 is closed, the pressure wave generated in the cylinder of each bank 1a, 1b
The air is propagated from 12 through the respective intake collecting portions 13 and 14 and the respective common intake passages 31 and 32 to the junction 33 upstream thereof. In this way, the propagation of the pressure wave through a sufficiently long passage to the junction 33 allows a resonance supercharging effect to be obtained in a low-speed region of the engine. When the open / close valve 24 is opened,
The two intake manifolds 13 and 14 are communicated with each other through a medium-speed communication passage composed of a part of the passages 21a and 21b and the passage 23, so that pressure waves propagate through the passage 23. I,
The effective path length of the pressure propagation is shorter than when the on-off valves 22 and 24 are closed, and a resonance supercharging effect is obtained in the middle speed range of the engine. Further, when the opening / closing valve 22 is opened, the intake manifolds 13 and 14 are connected to the passage portions 21a and 21b of the communication passage 21.
In addition, since the effective passage length of the pressure propagation is further shortened due to the short circuit in the communication hole 21c, the resonance supercharging effect can be obtained in the high speed region of the engine.

In order to make such three-stage adjustment possible, the first
The communication switching means and the second communication switching means are provided. The passage configuration of the communication switching means with respect to the intake passage is such that the communication passage 21 of the first switching means is connected to each of the intake manifolds 13 and 14 of the two intake passages. The passage portions 21a and 21b are connected to the passage portions 21a and 21b, and the passage 23 of the second switching means is connected to the passage portions 21a and 21b. That is, the conventional device described in the problem to be solved by the invention is provided separately from the communication path 21 of the first switching means.
The communication path 12 of the second switching means as shown by a two-dot chain line in FIG.
Because the structure 3 is connected to the intake passage, when the open / close valve 22, 124 of each of the communication passages 21, 123 is closed, each of the communication passages 21, 123 opens to the intake passage at a different point as a dead volume. The vortex that disturbs the flow of the intake air at each opening increases the intake air flow resistance and increases the pressure loss due to the dead volume.
On the other hand, as in this embodiment, the passage portion 21 of the first switching means is provided.
When the passage 23 of the second switching means is connected to the passages a and 21b, only the passages 21a and 21b are opened to the intake passage as dead volumes when the on-off valves 22 and 24 are closed. This reduces intake flow resistance and pressure loss.

Further, the two-system intake passage and the first and second
When the communication switching means is provided, the upstream side of the intake collecting portions 13 and 14 has a dead space in the vicinity because the passages are originally shared, so that the second communication switching means Passages 23, from the passage portions 21a, 21b, the intake collecting portions 13, 14
If it is formed toward the rear side, which is the direction of the upstream side, the second communication switching means is compactly provided in the dead space.

In addition, each of the independent intake passage groups 11, 12 is collectively gathered on the upstream side to form intake gathering portions 13, 14, and the communication passage of the communication switching means is located at the position of the signal center point O, O '. The structure in which the passage portions 21a and 21b are connected to each other makes the communication passage (a part of the passage portions 21a and 21b and the passage 23 Communication passage or passage portions 21a, 21b and communication hole 21c
When the pressure wave is propagated through the high-speed communication path 21), the difference in the path length from the independent intake path to the communication path becomes sufficiently small. Further, the communication passage is closed, and the pressure wave flows from the independent intake passage through the collecting portion to the common intake passage 31,3.
Even when the air is propagated to 2, the difference in passage length is sufficiently reduced because the independent intake passage groups 11 and 12 are collectively assembled without having a surge tank. Therefore, in each of these cases, the resonance effect is equally exerted on each cylinder.

In the above embodiment, the present invention is applied to a V-type engine. However, even in the case of an engine other than the V-type engine, two independent intake passage groups corresponding to a group of cylinders whose intake strokes are not continuous are collected and collected. The present invention can be applied if the intake passage of the system is configured.

〔The invention's effect〕

As described above, the first aspect of the present invention provides a first communication switching means including a communication passage that connects two intake passages in the middle of the passage, and an open / close valve provided in the communication passage; Since the communication path of the first communication switching means includes a passage connected to bypass the opening / closing valve and the second communication switching means constituted by an opening / closing valve provided in the passage, resonance is provided. The effective passage length can be varied in multiple stages to provide resonance effects in various operating regions, and only the communication passage of the first switching means is directly connected to the intake passage. The pressure loss and the intake resistance can be reduced by reducing the number of connection points to the intake passage as compared with the case where the means are individually provided. Therefore, the charging efficiency can be effectively increased, and the engine output can be improved.

In this configuration, the communication path of the first communication switching means is connected between each of the two sets of intake passages, and the second communication switching means is connected to the communication path. According to the structure formed in the intake passage toward the upstream side of the gathering portion in the intake passage, the space existing near the upstream portion of the gathering portion is used, and the communication switching means is compactly arranged. This is also advantageous in terms of layout.

According to the third aspect of the present invention, each of the gathering portions of the two intake passages has a structure in which independent intake passage groups are collectively gathered, and each of the gathering portions is a gathering point of the independent intake passage center line. Since the communication path of the communication switching means is connected to the position of the center point, the path lengths extending from the independent intake paths to the communication path via the collecting portion in the two intake paths are equalized. , Can enhance the resonance effect.

[Brief description of the drawings]

FIG. 1 is a plan view of an entire intake device showing one embodiment of the present invention, FIG. 2 is a partially cutaway side view of the device, and FIG. 3 is an enlarged sectional view of a portion where a passage of a communication switching means is connected. FIG. 4 is a schematic diagram showing a passage connection configuration. 1… Engine body, 11,12 …… Independent intake passage group, 13,14
…… Intake collecting part, 21 …… Communication passage, 22 …… On-off valve, 23 ……
Passage, 24 ... On-off valve.

Claims (4)

(57) [Claims] 1. A cylinder corresponding to a group of cylinders whose intake strokes are not continuous.
A set of independent intake passage groups are respectively assembled to form two systems of intake passages, and a communication passage connecting the two systems of intake passages in the middle of the passage and an opening / closing valve provided in the communication passage are formed. First communication switching means,
An engine, comprising: a communication passage connected to the communication switching means so as to bypass the opening / closing valve; and a second communication switching means including an opening / closing valve provided in the passage. Intake device. 2. The communication passage of the first communication switching means is connected between each of the gathering portions of the two systems of intake passages, and the passage of the second communication switching means connected to the communication passage is connected to the collection passage in the intake passage. The intake device for an engine according to claim 1, wherein the intake device is formed toward a direction upstream of the portion. 3. The open / close valves of the first and second communication switching means are opened / closed in accordance with the engine speed. The open / close valves are closed in a low speed range and the open / close valves in a middle speed range. 3. The intake system for an engine according to claim 1, wherein only the open / close valve of the two-communication switching means is opened, and the two open / close valves are opened in a high-speed range. 4. A cylinder corresponding to a group of cylinders whose intake strokes are not continuous.
A pair of independent intake passage groups are provided, each including two systems of intake passages, and a communication passage that connects the two systems of intake passages in the middle of the passage, and an on-off valve provided in the communication passage. A communication switching unit is provided, and each of the two intake passages has a structure in which a group of independent intake passages are collectively gathered, and a position of a center point of each of the aggregates which is a gathering point of the independent intake passage center line. And a communication passage of the communication switching means.