JPS63268918A - Intake device of engine - Google Patents

Abstract

PURPOSE:To improve the charging efficiency by forming an annular passage for resonance which is connected with each intake port. CONSTITUTION:The first group 3a-3c and the second group 3d-3f in which the intake order does not continue are provided and an annular passage 6 connected with each intake port 4a-4f is formed. The passage communicating to the first group cylinders of the annular passage and the passage communicating to the second group cylinders are extended in two directions and connected through communication parts 6a and 6b. The pressure wave having a positive pressure is generated in the vicinity of an intake port in the final period of the intake cycle in each group, and the pressure wave moves in the annular passage and acts onto the intake port in the same group. Therefore, resonance effect can be improved, and the charging efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <FF Field of Application) The present invention relates to an engine intake device that improves the filling efficiency of intake air through a resonance effect.

(Prior Art) Various types of intake systems δ for L-engines have been known in the past, which improve charging efficiency through the dynamic effect of intake air. In a cylinder engine, two intake passages are provided, each connected to two groups of cylinders in which the intake class 1r has discontinuous cylinders in the same group, and each intake passage is connected to the upstream end of an intake manifold branch. A switching device is provided in the enlarged chamber, etc., to enable communication and disconnection of each of the intake passage phases n. The upstream end of each intake passage is connected to the upstream gathering chamber. According to this device, when the switching device is in the state of blocking each intake passage phase U8 listed in F, the intake pressure wave that is reversed and reflected in the upstream gathering chamber causes inertia in a region where the engine speed is relatively low. When the supercharging effect is reduced to 1q and the switching device connects the intake passages, the inverted reflection position of the pressure wave is brought closer to the intake bow 1~, so that the engine speed is relatively high. An inertial supercharging effect can be obtained in this area.

However, according to this intake system, a large volume expansion chamber is provided in the part where the intake manifold bulges gather, which makes the intake system bulky and requires a large installation space when installed in a car. There are some inconveniences.

In addition, in the case of a V-type engine, for example,
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 WI structure, since the intake manifold located between both banks is provided with an enlarged chamber that leads to the branch part, it is unavoidable that the intake manifold protrudes considerably upward from the upper end of the bank. , This increases the overall height of the engine, making it difficult to install it in a car!・It becomes difficult to keep the height low.

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

For this reason, the enlarged chamber is abolished, and, for example, two pipe-shaped intake passages without an enlarged chamber are installed as short branches in each intake port of two groups of cylinders in which the cylinders in which the intake order is not consecutive are in the same group. It is conceivable that the two intake passages of C are connected through a pipe and brought together at an appropriate point on the upstream side, so that the pressure waves are inverted and reflected at this part. However, in this case, there will be a difference in the length of the pressure wave propagation path between the intake port and the pressure wave inversion/reflection part for each cylinder, and if the intake passage is shortened in hopes of achieving a supercharging effect, especially in the high-speed range,
Since the above-mentioned difference becomes relatively large and an imbalance occurs in the action of pressure waves on each cylinder, it becomes difficult to exert sufficient supercharging and effect on each cylinder.

(Object of the Invention) In view of the above circumstances, the present invention makes it possible to effectively exert the dynamic effect of intake air while eliminating the need for an expansion chamber, and in particular,
An object of the present invention is to provide an engine intake device that can generate strong pressure waves and provide a large dynamic effect.

(Structure of the Invention) In a multi-cylinder engine, the device of the present invention has a resonance annular passage connected to each intake port of two cylinder groups in which cylinders in which the intake order is not consecutive are in the same group, and The resonance annular passage has a passage leading to each intake port of one cylinder group and a passage leading to each intake port of the other cylinder group, without having an enlarged chamber. is annular, extending in two directions and connected to the sides on both sides, and communicating portions on both sides are formed independently of the main intake passage.

With this configuration, a pressure wave that becomes positive pressure at the end of the intake stroke is generated near the intake port No. 4 for each of the above groups, and this pressure wave goes around the resonance annular passage almost all the way to the intake port No. 1 of the same cylinder. By acting on the port, a more resonant effect can be obtained. Since the communicating portions on both sides of the resonance annular passage, which serve as the pressure wave propagation path, are formed independently from the first intake passage that supplies intake air, pressure waves are prevented from being attenuated by the intake flow. be done.

(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 3r numbered 6 are provided.

The ignition order (intake order) of each cylinder is, for example, No. 1 cylinder 3
a-94th cylinder 3 d -+ 2nd cylinder 3b- + 5th cylinder 31 + 3rd cylinder 3C → 6th cylinder 3f, and the cylinders 3a to 3C in one bank 1 are the first cylinder group in which the intake order is not consecutive. The cylinders 3d to 3f in the other bank 2 constitute a second cylinder group in which the intake order is not consecutive. Each cylinder 3a-3" is provided with an intake port 4a-4r and an exhaust port 5a-5", respectively, and these intake ports 4a-4f and exhaust port 5a-5r are provided with an intake valve and an exhaust valve (not shown). They are opened and closed at predetermined timings.

The intake ports 4a to 4r of each cylinder are connected to a resonance annular passage 6 that does not have an enlarged chamber.

This resonance annular passage 6 includes a passage communicating with each intake port 48-4C of the first cylinder group via short branch pipes 7a-7C, and a short branch pipe 7d communicating with each intake port 4d-4f of the second cylinder group. The passages communicating through 7f extend on both sides and face each other at both ends, thereby forming an annular shape.

In other words, the resonance annular passage 6 has communication portions 5a and 5b on both sides, which communicate the portions communicating with the intake ports 4a to 4C between the first cylinder groups and the portions communicating with the second cylinder groups 4d to 4, respectively. The length of each of the above-mentioned communicating portions is sufficiently longer than the length between the intake ports of adjacent cylinders in the same cylinder group, so that there is no interference that would weaken the pressure waves between the two cylinder groups. Largely formed.

8 is a main intake passage for supplying intake air, and this main intake passage 8 is divided into a common intake passage 8a that introduces intake air via 1acrina 9, and a branch branch that branches from this common intake passage. The main intake passage 8 is provided with a more flow meter 10 that detects the amount of intake air and a throttle valve 11 that adjusts the amount of intake air in response to accelerator operation.

The downstream ends of the branched intake passages 8b and 8c are connected to the vicinity of the R points where each of the intake ports 1 to 1 and the resonance annular passage 6 come into contact. Therefore, both side communication portions 6a of the resonance annular passage 6,
6b is independent from the main intake passage 8, that is, the main intake passage 8
A resonance annular passage 6 and one intake passage 8 are formed so that the intake air sent from the cylinder is supplied to each cylinder without passing through the communication portions 6a and 6b. Preferably, the length 1-1 of the half circumference of the resonance annular passage 6 is approximately equal to the length L2 of the main intake passage 8 extending over both branch intake passages 8a and 8b. I'll keep it.

The operation of the apparatus of this embodiment will be explained with reference to FIG.

Near each intake port of the same cylinder group where the intake order is not consecutive, for example, each intake port 4a to 4 of the first cylinder group
A basic pressure oscillation (line A in FIG. 2) occurs near C where the pressure becomes negative in the middle of each intake stroke and becomes positive pressure at the end of the intake stroke due to the operation of each cylinder in the first cylinder group. The pressure wave generated near the intake port is divided into both sides and propagates around the resonance annular passage 6, and then goes around the resonance annular passage 6 almost once and reaches the intake ports of other cylinders in the same cylinder group. Use 0. In this case, since the resonance annular passage 6 does not have an enlarged chamber, the pressure wave is propagated without being reversed.

When the pressure wave goes around the resonant annular passage 6 almost once and the period τ of the basic pressure oscillation described above coincides, that is, the entire length L of the resonant annular passage 6 (the length of the branch pipe (equivalent pipe length considering volume etc.) and the above circumference + 111τ
The relationship between
The pressure wave generated in the resonance annular passage 6 overlaps with the pressure wave generated in the second cylinder 3b, and in the same way, the second aroma 83
The pressure wave propagated from 'O' overlaps with the pressure wave propagating to 3 aroma i'23 C, and the pressure wave propagated from No. 3 cylinder 3c
The pressure wave generated in the number cylinder 3a is Φ. In this way, the pressure waves resonate between the cylinder phases U of the first cylinder group, and the pressure oscillations are intensified as shown by line B in Figure 2, and resonance also occurs between the cylinder phases of the second cylinder group. Pressure vibrations are strengthened. Such a resonance effect increases the filling efficiency of each cylinder.

Note that Fig. 2 shows a basic resonance state in which one pressure wave of continuous pressure vibration propagates to the next pressure wave in the same cylinder group.
A resonant state is obtained even when the pressure wave propagates in such a way that it becomes 1, and therefore, the basic resonant state described in ~ is obtained.A resonant state is obtained even when the engine speed is an integral multiple of the engine speed. . However, when the cylinders are divided into two groups, each group generates pressure waves with almost opposite phases, so at even multiples of the rotation speed where the above-mentioned - next resonance is obtained, the pressure waves of both groups are greatly canceled out. Perform the matching action □ 1.
Therefore, what is effective is a rotational speed that is an odd multiple of the rotational speed at which the above-mentioned -order resonance is obtained.

Providing a resonance effect by the pressure waves circulating in the resonance annular passage 6 in this way is advantageous in improving the filling efficiency in the high speed range.

- In other words, if the resonance annular passage 6 is not used, for example, the gathering part of the intake passage leading to each intake port of the first cylinder group and the intake passage leading to each intake port of the second cylinder group is set as a pressure reversal part. When trying to create a dynamic effect using reversed pressure waves, the pressure waves propagate back and forth through the passage between the intake port and the collecting section during a time corresponding to 1/2 of the period of the basic pressure oscillation. When the situation is reached,
The pressure wave reversed from negative pressure to positive pressure at the collecting part and reflected acts on the inner cylinder at the end of the intake stroke, resulting in a dynamic effect of 1q, and the period of pressure oscillation at this time causes the pressure wave in the passage to be reflected. The relationship with length L = (equivalent pipe length) is τ/2 = 2
L −/a ・・・・・・■. Then, Q 'r' where the period τ of the pressure vibration becomes shorter! In order to satisfy this relationship in region ii, it is necessary to set the above passage length to be quite short, but the passage length from the intake port of each cylinder to the passage gathering part is determined by the length between the intake ports of each cylinder. There is a difference in the length of the culm, which shortens the passage length to the collecting part.As the difference becomes relatively large, the imbalance of pressure waves acting on each cylinder increases, reducing the overall charging efficiency. It will be difficult to increase it.

On the other hand, if the resonance annular passage 6 without an enlarged chamber is used as described above, a resonance effect is obtained when the above equation 0 holds, and when comparing the equation 0 and the equation 0, it is found that the pressure vibration If the period τ is the same, the equivalent pipe length of the entire resonance annular passage 6 [is 4 times the blue value pipe length - according to the above formula 0,
Even in the high-speed range, the difference in the pressure wave propagation paths for each cylinder is relatively small, so the unbalance of the pressure waves acting on each cylinder is small. Therefore, even in a high speed range, pressure waves can be applied almost equally to each cylinder, thereby effectively increasing the charging efficiency of each cylinder.

Moreover, especially according to this intake device, the intake air introduced through the main intake passage 8 is transferred to the branch intake passage 8 of the main intake passage 8.
b, 8c are directly supplied to each intake port, and since there is little air flow itself in the communication portions 6a, 6b on both sides of the resonance annular passage 6, the pressure waves propagating through the resonance annular passage 6 are attenuated by the intake flow. is suppressed. Furthermore, the passage diameter, capacity, length, etc. of the communication portions 6a and 6b on both sides can be set to be suitable for the propagation of pressure waves without being subject to restrictions such as securing an intake air introduction section. It becomes possible to strengthen pressure waves. Note that a part of the pressure wave propagating through the resonance annular passage 6 is also transmitted to the branch intake passages 8b and 8c of the main intake passage 8, and these two branch intake passages 8b
, 8G and the resonance annular passage 6 also constitute a pressure wave circulation path, so as mentioned above, the resonance annular passage 6
If the length Ll of approximately half the circumference of the above-mentioned branch intake passages 8b and 8C is made approximately equal, jt vibration will occur between them and the pressure wave will be further strengthened. .

The specific structure of the device of the present invention is not limited to the above-mentioned embodiments, but can be modified in various ways, some examples of which are shown in FIGS. 3 and 4.

In the embodiment shown in FIG. 3, the passage quality of the resonance annular passage 6 is variable. That is, in the communication part 6a on one side between both cylinder groups in the resonance annular passage 6, an nl grid communication 6C is provided which connects the middle of the communication part 6a, and this short-circuit communication part 6c and a part bypassing this are provided. In the state where the short circuit communication part 6C is closed and the detour part is heard, and the short circuit communication part 6
Switching valve 1 that switches between opening C and closing the bypass portion
2. According to this structure, the resonance annular passage 6 is relatively good when the short-circuit communication part 6C is closed,
When the short-circuit communication portion 6C is open, the substantial length of the resonance eleven-shaped passage 6 is shortened. Therefore, a control means (not shown) controls the opening/closing fI of the switching valve 12 according to the engine speed.
By switching the speed, the resonance effect can be enhanced in different rotation speed ranges.

FIG. 4 shows an embodiment in which the present invention is applied to an in-line six-cylinder engine. In this case as well, the intake order of the first to third cylinders 3a! is not consecutive. -3c is the 1st cylinder group,
The 4th to 6th cylinders 3d to 3f whose intake order is not consecutive are the second cylinders.
cylinder group, each intake port 4 of the first cylinder group
Passages leading to a to 4C and each intake port 4 of the second group
d to 4f are extended to both sides, and the respective extending portions are connected to each other, thereby creating communication portions 6a of appropriate lengths on both sides between both cylinder groups, respectively.
A resonance annular passage 6 having a diameter 6b is configured. Also in this case, both branch intake passages 8b, 8 of the main intake passage 8
By connecting the downstream end of c to the vicinity of the intake port,
Communication portions 6 a and 6 b on both sides of the resonance annular passage 6 are formed independently from the main intake passage 8 .

(Effects of the Invention) As described above, in the present invention, each intake passage of two cylinder groups in which cylinders whose intake order is not consecutive is connected to the resonance annular passage, and one cylinder group is connected to the resonance annular passage. The pressure wave that propagates from the intake port of the cylinder and goes around the resonance annular passage acts on the intake ports of the cylinders in the same group, thereby producing a resonance effect. Despite having a compact structure that does not include an expansion chamber, the filling efficiency of each cylinder can be increased by the above-mentioned noise effect. In particular, since the communication portions on both sides between both cylinder groups in the resonance annular passage are formed independently from the intake passage, which supplies intake air, 3i: the pressure waves passing through the resonance annular passage are reduced by the intake flow. This makes it possible to strengthen the pressure waves and further enhance the resonance effect.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an intake system showing one embodiment of the present invention;
The figure shows pressure vibration near the intake port 1, and FIGS. 3 and 4 are schematic diagrams of the intake device showing different embodiments. 38~3C...Each cylinder of the first cylinder group, 3d~3
"...Each cylinder in the second cylinder group, 4a to 4f...
Intake port, 6... Resonance annular passage, 6a, 6b...
- Communication portion between both cylinder groups in resonance annular passage a), 8...main intake passage. Patent applicant Mazda Co., Ltd. Agent
Person Patent Attorney T Kosho Etsushi Dou
Patent Attorney I Chief 1) Masamukai Patent Attorney
Yasuo Itaya 1st Figure 7g Figure 2

Claims (1)

[Claims] 1. A multi-cylinder engine, comprising a resonance annular passage connected to each intake port of two cylinder groups in which cylinders whose intake order is not consecutive are in the same group, and a main intake passage supplying intake air to each cylinder, The resonance annular passage does not have an enlarged chamber, and has a passage leading to each intake port of one cylinder group and a passage leading to each intake port of the other cylinder group, which extend in two directions and are interconnected on both sides. An intake device for an engine, which has a continuous annular shape, and communication portions on both sides thereof are formed independently of a main intake passage.