JPH01117918A - Intake device of engine - Google Patents

Abstract

PURPOSE:To improve both the resonating effect and charging efficiency of intake air by forming a resonating annular passage to which intake air ports of two cylinder groups of a multi-cylinder engine are connected on both sides of the passage and connecting intake air supply passages to the opposing approximately middle positions of the passage. CONSTITUTION:Primary and secondary cylinder groups consisting of cylinders wherein intake actions are not executed successively are respectively connected to a pair of banks 1 and 2 of a V-shaped six-cylinder engine, and intake ports 4a to 4f of the cylinders 3a to 3f of the groups are to a resonating annular passage 6. Said annular passage 6 is connected to an upper stream resonance intake passage 7 via an air flow meter 8 and a throttle valve 9. In such constitution the upper stream intake passage 7 is connected to the annular passage 6 at one middle point B thereof where the passage portions 6a and 6b of said passage 6 on the sides of banks 1 and 2 are connected to each other. On the opposite side, a lower stream intake passage 12 is connected to the passage 6 at the other middle point B' where the passage portions 6a and 6b are connected to each other, so communicating said point B' with the upper stream intake passage 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an engine intake H@ that improves intake air filling efficiency by a resonance effect.

(Prior Art) Various engine intake IIIs have been known in the past that improve charging efficiency through the dynamic effect of intake air. For example, in a device disclosed in Japanese Patent Publication No. 60-14169@, in a multi-cylinder engine, two intake passages are connected to each of two groups of cylinders in which the same group includes cylinders whose intake order is not consecutive, and an intake manifold branch is used. is provided with an enlarged chamber (collecting chamber with a large volume) connected to the upstream end of the enlarged chamber, and a resonant passageway extending upstream from the enlarged chamber, and is capable of communicating and disconnecting each of the intake passages to the enlarged chamber, etc. A switching device is provided, and the upstream end of each intake passage is connected to the upstream gathering chamber.

According to this device, when the switching device is in a state where each of the intake passages is cut off from each other, the intake pressure wave that is reversed and reflected in the upstream gathering chamber causes the engine rotation speed to be relatively low. When the inertial supercharging effect is obtained and the switching device communicates with each intake passage, the position of the inverted reflection of the pressure wave is brought closer to the intake port.
The inertial supercharging effect can be obtained in a region where the engine speed is relatively high.

However, according to this intake system, a large volume expansion chamber is provided in the part where the intake manifold branches gather, which results in an increase in the size of the intake system and requires a large installation space when installed in a car. There are some inconveniences.

In addition, in the ■ type engine, for example, JP-A-59-5
As seen in Publication No. 65, an intake manifold having individual curved intake passages corresponding to branch portions and spaces corresponding to enlarged chambers communicating with these individual intake passages is arranged in the space between both banks. By doing so, there is a system that achieves an inertial supercharging effect while reducing the overall size.

However, even with this structure, since the intake manifold located between both banks is provided with an enlarged chamber that communicates with the branch part, it is unavoidable that the intake manifold protrudes upward by an amount of M from the upper end of the bank. The overall height of the engine increases, making it difficult to keep the hood height low when installed in a car.

In other words, with the structure of these conventional devices in which each branch portion of the intake manifold is formed long and connected to the enlarged chamber, there is a limit to compactness (especially reduction in height).

As a means to solve such problems, the expansion chamber described above can be abolished, and, for example, two pipes without an expansion chamber can be installed at each intake port of two cylinder groups in which cylinders whose intake order is not consecutive are in the same group. It is conceivable to connect two intake passages via a short branch pipe, and to converge the two intake passages at an appropriate point on the upstream side so that the pressure waves are inverted and reflected at this section. However, in this case, the quality of the pressure wave propagation path between the intake port and the pressure wave inversion/reflection section varies from cylinder to cylinder. As a result, the above-mentioned difference becomes large and an imbalance occurs in the action of pressure waves on each cylinder, making it difficult to exert a sufficient supercharging effect on each cylinder.

Therefore, in a multi-cylinder engine, the applicant connects each intake port of two groups of cylinders in which the cylinders with different intake orders are in the same group to a common resonance annular passage that does not have an enlarged chamber. We have previously proposed an annular passage in which a passage leading to each intake port of one cylinder group and a passage leading to each intake port of the other cylinder group extend in two directions and are connected to each other on both sides. ing. According to this 5A configuration, a pressure wave that becomes positive pressure at the end of intake is generated near the intake port for each group, and this pressure wave goes around the resonance annular passage and acts on the intake ports of the same cylinder group. A resonance effect is obtained, and interference between the two groups of cylinders that weakens each other's pressure waves is avoided.

However, with this structure, the passage to the intake ports located on the downstream side is longer than the intake ports located on the upstream side in the intake direction, so the intake resistance is relatively large for these intake ports. , which is disadvantageous in terms of air filling efficiency. Therefore, it has been desired to develop a device that can comprehensively improve the air filling amount of the entire engine.

(Object of the Invention) In view of the above circumstances, the present invention makes it possible to reduce the height of the engine by eliminating the need for an expansion chamber, while effectively exhibiting the dynamic effect of the intake air. An object of the present invention is to provide an engine intake device that can improve overall filling efficiency by increasing the amount of air filled into a downstream intake port.

(Structure of the Invention) The present invention provides a multi-cylinder engine in which each intake port of two cylinder groups in which the same group includes cylinders in which the intake order is not consecutive is connected to a common resonance annular passage having no enlarged chamber, This resonance annular passage has an annular shape in which a passage leading to each intake port of one cylinder group and a passage leading to each intake port of the other cylinder group extend in two directions and are interconnected on both sides. Intake air supply passages for supplying intake air are connected to substantially central portions of the continuous portions on both sides.

According to this configuration, since intake air is supplied from both sides of the resonance annular passage, intake resistance to each intake port is reduced.
The air filling amount of the engine as a whole is improved overall.

Moreover, since the intake air supply passage is connected to the approximate center of the part where the passages leading to both groups are connected, that is, the part that becomes a node of pressure fluctuation during resonance, it affects the pressure fluctuation in the passage during resonance. Therefore, a pressure wave that becomes positive pressure at the end of intake is generated near the intake port, and this pressure wave goes around the resonance annular passage and acts on the intake ports of the same cylinder group. A resonance effect can be obtained.

(Embodiment) Fig. 1 shows an embodiment in which the device of the present invention is applied to a V-type six-cylinder engine. three cylinders 3a, 3b
, 3c are provided, and the other bank 2 has numbers 4, 5,
Three cylinders 3d, 3e, and 3f numbered 6 are provided.

The ignition order (intake order) of each cylinder is, for example, No. 1 cylinder 3
a → No. 4 cylinder 3d → No. 2 cylinder 3b-No. 15 cylinder 3 e
-> No. 3 cylinder 3G-) No. 6 cylinder 3f, each cylinder 3a to 3C in one bank 1 constitutes a first cylinder group in which the intake order is not consecutive, and each cylinder 3d to 3d in the other bank '2 3f constitutes a second cylinder group in which the intake order is not consecutive.

Each cylinder 3a to 3f is provided with an intake port 4a to 4f and an exhaust port (not shown), respectively. It opens and closes at predetermined timing.

The intake ports 4a to 4f of each cylinder are connected to a resonance annular passage 6 that does not have an enlarged chamber, and this resonance annular passage 6
is connected to an upstream intake passage (intake air supply passage) 7 through which intake air is introduced via an air flow meter 8 and a throttle valve 9.

The resonance annular passage 6 includes a passage 6a communicating with each intake port 48-4C of the first cylinder group via short branch pipes 10a-10C, and a short branch pipe communicating with each intake port 4d-4f of the second cylinder group. The passages 6b communicating through 10d to 10f extend in two directions, upstream and downstream, and are connected to each other at the end connected to the upstream intake passage 7 and the opposite end. , is circular.

As for the arrangement with respect to the engine body, in the space between both banks 1.2, the passages 6a and 6b forming the resonance annular passage 6 extend parallel to each other along the cylinder arrangement direction, and are mutually arranged on both the front and rear sides of the engine body. Formed by luck. In this case, although not shown, the upstream and downstream portions of the resonance annular passage 6 extending outward from both ends of the engine body are appropriately bent along the engine body to increase the overall height of the engine. The intake system is compactly equipped without the need for

A further feature of the present invention is that the upstream intake passage 7 is connected to a central portion B of a portion where both passages 5a and 5b are connected, and furthermore, on the opposite side, both passages 6a and 6b
A downstream intake passage (intake air supply passage) 12 that communicates this part with the upstream intake passage 7 is also connected to the central portion B' of the continuous portion.

Next, the effects of this device will be explained in Figures 2 and 3.
This will be explained with reference to the figures.

During the intake stroke of each intake port 4a to 4f, intake air is supplied from both sides of the resonance annular passage 6 by the upstream intake passage 7 and the downstream intake passage 12, and each intake port of the same cylinder group has a non-consecutive intake order. Nearby, for example, the first
Near each intake port 4a to 4C of the cylinder group, there is a first
The operation of each cylinder in the cylinder group causes a basic pressure oscillation (line A in FIG. 3) that becomes negative pressure during the respective intake stroke and becomes positive pressure at the end of the intake stroke. The pressure waves generated near this intake port are shown by arrows in Figure 2 (1 air storage 1!1
3a), the pressure propagates in two directions, the upstream side and the downstream side, and propagates around the resonance annular passage 6, and almost goes around the resonance annular passage 6 to connect to the same cylinder group. acts on the intake ports of other cylinders. In this case, the pressure waves circulating in the resonance annular passage 6 are propagated without being reversed.

When the time for the pressure wave to go around the resonance annular passage 6 and the period τ of the above-mentioned basic pressure oscillation coincide with the change in the engine speed, the solid line arrow in FIG. As shown, the pressure wave generated in the first cylinder 3a and propagated through the resonance annular passage 6 overlaps with the pressure wave generated in the second cylinder 3b, and the pressure wave similarly propagated from the second cylinder 3b is transmitted to the third cylinder 3C. The pressure wave propagated from the third cylinder 3C overlaps with the pressure wave generated in the first cylinder 3a. In this way, the pressure waves resonate between the cylinders in the first cylinder group, and the pressure oscillations are strengthened as shown by the line 8 in FIG. The vibration is strengthened (dashed line C). Such a resonance effect increases the filling efficiency of each cylinder.

Moreover, compared to conventional pressure reversal type devices, the length of the communication path between the mountain cylinder groups can be set to be sufficiently longer than the length between the intake ports of adjacent cylinders in the same group, so the pressure wave propagation path can be In addition to reducing the length difference between cylinders, the independence of each cylinder group is maintained, and interference that weakens the pressure waves between cylinders with consecutive intake orders is avoided. The effect is 6 higher than that of the pressure reversal type mentioned above.

Note that the resonance annular passage 6 communicates with the upstream intake passage 7 and the downstream intake passage 12 as described above, but these communicate with the central portions B and B' of the portion where both roads 6a and 6b are connected.
That is, since it is connected to a part that becomes a node of pressure fluctuation during resonance, it does not affect the resonance effect.

The state of this pressure fluctuation will be explained using the graph of FIG. 4. This FIG. 4 shows both roads 6a forming the annular passage 6,
6b, connecting points A and C (Fig. 1) with the branch pipes 10b and 10e communicating with the central cylinders 3b and 3e, respectively, and the central part 8.8' of the part where both roads 5a and 5b are connected. Figure 1) shows changes in the pressure of the intake air in Figure 1), where the pressure corresponding to position and time is three-dimensionally plotted. In the figure, the range where the intake pressure level is greater on the positive pressure side than the reference level indicated by the two-dot chain line 40 is indicated by a thick solid line.

As is clear from this figure, at 8 points or 0 points), cylinders 3a, 3b, 3c (or cylinders 3d, 3e,
3f) The positive pressure wave generated at the end of each intake stroke circulates around the annular passage 6 and moves to other cylinders 3a, 3b, 3 of the same cylinder group.
C (or cylinder 3d.

3e, 3f) on the intake stroke of these cylinders 3a, 3b, 3c (or cylinder 3d).

3e, 3f), the intake pressure at the end of the intake stroke changes to a positive overload compared to the reference level, and a resonant intake supercharging effect is obtained. Cylinders 3a, 3b, 3c (or cylinders 3d, 3e, 3f
) and each cylinder 3d of the other cylinder group,
Since the pressure waves propagated from the cylinders 3e and 3f (or the cylinders 3a, 3b, and 3C) cancel each other out and form pressure fluctuation nodes, the pressure fluctuations are extremely small and are maintained at approximately the reference level. That is, this resonance effect is hardly affected by the connection of both intake passages 7.12.

As described above, according to this device, each of the intake ports 4a to 4
Since intake air is supplied from both sides of f, intake resistance is low on either side of intake ports 4a, 4d, and intake ports 4c, 4f.
Therefore, the air filling III of the entire engine can be improved. Moreover, since the intake passages 7 and 12 are both connected to the portions that become nodes of pressure fluctuation during resonance, they do not affect the resonance effect of the resonance annular passage 6.
Therefore, due to this resonance effect, higher filling efficiency can be obtained than in conventional pressure reversal type devices.

Note that the intake device of the present invention is not limited to the structure shown in FIG. 1; for example, as shown in FIG. 5, the downstream portions of the downstream intake passage 12 and the annular passage 6 are bent upstream. By doing so, the structure of the engine can be made more compact in the longitudinal direction, and as shown in the same figure, the valves 13a and 13b that interlock with each other can be made more compact.
By opening and closing these pulps 13a and 13b, the entire annular passage 6 can be used, and both passages 6a can be used.
, 6b can be used individually.

Furthermore, as shown in Fig. 6, if the number of cylinders 3'a to 3'd is an even number, it can be applied to an in-line engine by dividing it into two groups whose intake order is not consecutive. Furthermore, as shown in the same figure, the portion downstream of the confluence position of the upstream intake passage 7 and the downstream intake passage 12, and the portion between the downstream intake passage 12 and the annular passage 6
A separate throttle valve 9 is installed immediately upstream of the connection part of the
By providing this, the responsiveness of intake air supply during transient periods can be improved by reducing the capacity on the downstream side of the throttle valve 9.

(Effects of the Invention) As described above, the present invention provides an intake system in which each intake port of two cylinder groups in which cylinders whose intake order is not consecutive is connected to a common resonance annular passage. An intake air supply passage is provided for supplying intake air to approximately the center of a portion where the two passages extend in two directions and are connected to each other on the upstream and downstream sides, that is, the portion that becomes a node of pressure fluctuation during resonance. Since it is connected, it is possible to obtain an excellent resonance effect without being affected by the connection of the intake air supply passage, and as a result, the charging efficiency of each cylinder can be improved by the resonance effect despite the compact 54N. can be increased. In addition, since the intake air is supplied from both sides of the annular passage through the intake air supply passage, the intake resistance at each intake port can be reduced, thereby improving the air filling of the entire engine.
1M can be improved comprehensively.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an intake system in an embodiment of the present invention, Fig. 2 is a diagram showing the pressure wave propagation state in the same device, Fig. 3 is a graph showing pressure vibration near the intake port of the same device, FIG. 4 is a graph showing the change in pressure of intake air in the annular passage of the device, and FIGS. 5 and 6 are schematic diagrams of the intake device in other embodiments. 3a to 3C...Each cylinder of the first cylinder group, 3d to 3
f...Each cylinder of the second cylinder group, 4a to 4f...
Intake port, 6... Resonance annular passage, 7... Upstream intake passage (intake air supply passage), 12... Downstream intake passage (intake air supply passage). Patent applicant Mazda 1 Co., Ltd. Agent
People Patent Attorney Etsushi Kotani
Patent Attorney Chief 1) Masamukai Patent Attorney
Yasuo Itaya Figure 1 Figure 2 2 Figure 3 Figure 5

Claims (1)

[Claims] 1. In a multi-cylinder engine, each intake port of two groups of cylinders in which cylinders whose intake order is not consecutive is connected to a common resonant annular passage that does not have an enlarged chamber, and this resonant annular passage is A passage leading to each intake port of one cylinder group and a passage leading to each intake port of the other cylinder group form an annular shape that extends in two directions and is connected to each other on both sides. An intake device for an engine, characterized in that intake air supply passages for supplying intake air are connected to each central portion.