JPS60132023A - Air intake mechanism for multicylinder engine - Google Patents

Abstract

PURPOSE:To enable the length of an air intake passage to be varied over a wide range by partitioning a surge tank into an inner space and extended parts and rotating a rotary partition member, which connects both parts through a connecting port. CONSTITUTION:Air sucked in from an air cleaner is introduced into a surge tank 6 through an air flow meter and a throttle valve. Then, the air is sucked into each cylinder 9 through each branch passage 10 and intake port 8. When the number of revolution of an engine 1 is low, the connecting part between the inner space 16 and each of the extension parts 13 of the surge tank 6 is positioned at B. When the number of revolution is increased causing a rotary partition member 15 to rotate in the direction of (a), the connecting part is also rotated in the direction of (a), being positioned at B' at the highest condition.

Description

Detailed Description of the Invention -1- (Industrial Application Field) The present invention relates to an intake system for a multi-cylinder engine, in particular an air intake system in which an independent intake passage is provided from a gas tank to each cylinder, and the length of each intake passage is This invention relates to an intake device whose height is variable.

(Prior art) In general, in engines, it is effective to use the so-called intake inertia effect (11) in order to increase intake air filling efficiency and improve output. The effect depends on the relationship between length and engine speed.
There is also a relationship in which the quality of the intake passage that can be effectively obtained becomes shorter as the engine speed increases. Therefore, for example, Utility Model Application Publication No. 56-2023 and Utility Model Application No. 57-2262
As disclosed in Publication No. 9, by making the length of the intake passage variable and changing the length according to the engine speed, it is possible to utilize the intake inertia effect over a wide range from low speeds to high speeds. An intake device has been proposed.

However, the intake device disclosed in these publications is -2
- In both cases, the length of the intake passage is changed by sliding a movable pipe fitted to a fixed pipe in a linear direction, so the device N is large in order to change the length within the required range. In particular, the engine will be installed in a car.
The disadvantage is that it requires a large amount of space when used. Furthermore, in the case of a multi-cylinder engine, an independent intake passage must be provided for each cylinder, and the length of each passage must be made variable. The mechanism becomes complicated.

(Object of the Invention) The present invention is intended to solve the above-mentioned problems regarding an intake system in which the length of the intake passage is variable. The purpose of this invention is to realize an intake device with a small number of parts and a simple drive mechanism.

By the way, the applicant of this application has filed an earlier patent application (Japanese Patent Application No. 1986-4)
No. 8344), he filed an application for an invention related to an engine intake passage that achieves the above-mentioned object - 3 - However, the present invention is a further improvement of this earlier invention, and is a multi-cylinder engine with variable intake passage quality. The purpose of the present invention is to realize an intake system in which intake air flows smoothly and the total height of the engine is not high.

(Structure of the Invention) In order to achieve the above object, the intake system for a multi-cylinder engine according to the present invention is structured as follows.

That is, in an intake system in which a surge tank is provided in the middle of the intake system, and independent intake passages are provided from the surge tank to each cylinder, the extended portions of each intake passage are provided independently on the peripheral wall of the surge tank. The upstream end of each intake passage is connected to the upper part of this extension, and the surge tank defines an internal space and an extension part thereof. A defining rotating member having a communication port that communicates the two is provided. and the rotating member is rotated by a drive mechanism according to the operating state of the engine, and the communication position between the intake passage extension and the internal space of the surge tank is changed, The length of the intake passage downstream of the stirrer tank is configured to vary.

According to such a configuration, the lengths of the plurality of intake passages leading to each cylinder are changed by the rotation of the defining rotating member, resulting in an increase in the size of the entire device, an increase in the number of parts, and furthermore, in the drive mechanism. It becomes possible to vary the length of each intake passage over a wide range without causing complications. In particular, since the extensions provided on the peripheral wall of the surge tank are connected to the intake passages at their upper parts, the intake passages including the extensions do not increase the overall height of the engine and the intake air flows smoothly. It will be composed of

(Example) Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, an intake device 2 installed on one side of the engine 1 is a surge tank into which air is introduced from an air cleaner 3 through an air 70-meter 4 and a thrower 1 through a valve 5. 6, and a plurality of branch pipes 10 branched from the surge tank 6 and sucking air in the tank into each cylinder 9...9 via each intake boat 8...8 in the cylinder 5-head 7. ...10
These constitute an intake system extending from the air cleaner 3 to the plurality of cylinders 9...9.

The surge tank 6 and each branch pipe 1O...1O are formed by an integral casing 11 as shown in FIGS. 2 and 3, and the casing 11 is fixed to one side of the cylinder head 7. Each branch pipe 1O...1O
and each intake port 8 . . . 8 are connected to form substantially linear intake passages 12 . . . 12 extending from the surge tank 6 to each cylinder 9 . Also,
The above-mentioned intake passages 12 are provided on the peripheral wall of the surge tank 6.
12 extension parts 13...13 are provided (pulled).These extension parts 13...13 are provided independently by partition walls 17I...14 erected on the inner surface of the casing 11. , are connected linearly to the upstream ends of the intake passages 12 . . . 12 in the upper part of the surge tank 6, respectively, as shown in FIG. In other words, it is formed in a spiral shape so as to extend downwardly from the upper part of the surge tank 6 through the outer part and then to the center part of the tank 6 from the inner side.

On the other hand, in the central part of the surge tank 6, the above-mentioned extension parts 13...13 in the peripheral wall part and a space inside thereof are defined.
A hollow cylindrical defining rotating portion vJ15 is provided.

This rotating member 15 is connected to an intake system in which one end of the rotating member 15 is opened as shown in FIG. A bearing 22 is connected to the side cover 21, which is connected to the upstream part of the side cover 21, and is pivotally supported by the casing 11 via a bearing 19 at the end thereof, and the other end is fixed to the casing 11 by bolts 20...20. is pivoted through the
It is rotatable within the surge tank 6.

Each of the above-mentioned extension portions 13 and 13 attached to the rotating member 15 is
... 13 and the internal space 16, a plurality of communication ports 23...23 are provided (pulled) on the circumferential surface defining the inner space 16 and the communication ports 23...2.
3, the internal space 16 and each extension portion 13...13 are communicated with each other.

= 7 - Furthermore, as shown in FIG. 4, a drive mechanism 24 for rotating the defining rotating parts 4, 115 is provided outside one end of the surge tank 6. , an input gear 26 fixed to a shaft part 25 integral with the rotating part (215) protruding from the side cover 21 to the outside, an arcuate gear 27 meshed with the input gear 26, and the arcuate gear 27. and a diaphragm 29 that is driven via a lever 28, and exhaust pressure is introduced into the diaphragm 29 from an exhaust passage (not shown) of the engine 1.

Here, since the exhaust pressure is high when the engine rotates at high speeds and becomes low when the engine speeds are low, the arcuate gear 27 and the input gear 26 rotate in the direction a from the illustrated positions as the engine speed increases. Accordingly, the rotating member 15 also rotates in the direction a shown in FIG.

In this embodiment, as shown in FIG. 2, there are two centrally located extensions 13.
A spare space 30 is provided in the 13 spaces, and the space 3O and the internal space 16 of the rotating member 15 are communicated through a communication port 31.

This space 30 is used, for example, to uniformly recirculate exhaust gas to each cylinder 9...9 when recirculating exhaust gas, or to obtain stable intake negative pressure for various control purposes. It will be done. In addition, as shown in Fig. 3, each branch pipe 1O.
. . 32 are installed above 1O, and the fuel 1 supplied through the fuel supply pipe 33 is injected into each intake passage 12 .
It is designed to inject into each of the 2 parts. Furthermore, the casing 11 and the rotating member 15 are configured so that they can be easily assembled by inserting the rotating member 15 with the side cover 21 removed.

With the above configuration, when the engine 1 is operating, the air taken in from the air cleaner 3 shown in FIG. 1O... 1O and intake ports 8... 9 - Introduced into the internal space 16 of the rotating member 15, and distributed to each extension portion 13...13 from the communication ports 23...23 formed on the circumferential surface of the member 15. . After passing through each extension part 13...13 in a spiral shape, each cylinder passes through the intake passage 12...12 consisting of the branch pipe 10...10 and the intake port 8...8. This leads to 9...9. In that case, each of the above extension parts 13...13
Since they are provided independently by the partition walls 14...14, air flows from the communication ports 23...23) to the extension portion 13.
. . 13 is branched from the large volume internal space 16 in the surge tank 6 at the communication portion B (see Fig. 3), and from the communication portion B to the extension portions 13 . . . 13 and the intake air. The connecting portions A with the passages 12...12 are passed through independent passages until reaching each cylinder 9...9.

However, when the rotation speed of the engine 1 is low and the exhaust pressure introduced into the diaphragm 29 of the drive mechanism 2/I shown in FIG. 4 is low, the defining rotating member 15 is in the position shown in FIG. 3. The internal space 16 of the surge tank 6 and each extension part 13.
...The communication part B with 13 is also in the position shown in Figure 10, but from this state the engine speed is -F
When the exhaust pressure introduced into the two dye hair 7 flams increases, the rotary member 15 is rotated in the direction a via the gears 27 and 26 in the drive mechanism 24, so that the communication portion B The motor also moves in the direction a, and reaches the position indicated by the symbol B', for example, when the engine speed is at its highest. In other words, the extensions 13...13 expand and contract between the positions B and B' due to changes in engine speed, and the surge tank downstream of the extensions 13...13 and the intake passages 12...12 The length of the independent passages will change. As a result, if the above length is always changed to the optimum length for each engine speed, the intake inertia effect can be effectively utilized in a wide engine operating range from low to high speeds. You will be able to do that.

By the way, according to the second paragraph, since the length of the spiral extensions 13...13 is changed by the rotation of the defining rotation member 15, the entire intake device 2 can be changed. The length of the extension parts 13...13 can be varied within a large range (dimension between positions B and B') without increasing the size, and one rotating member 15 can be driven. Since the lengths of the plurality of extension parts 13 . . . 13 can be changed all at once by pressing the button, the drive mechanism 24 and the entire device can be simply constructed with fewer parts.

In particular, since each of the extension parts 13...13 is wound downward and the connection part A with each intake passage 12...12 is provided in the upper part of the surge tank 6, as shown in FIG. The intake passages 12...12 (branch pipes 1O...10) and extensions 13...13 are connected in a straight line to the intake ports 8...8 which are inclined diagonally upward as shown in FIG. Also, the position of the upper end of the surge tank 6 does not become too high, and therefore, the overall height of the engine 1 does not need to be increased, and a passage through which intake air flows smoothly can be formed.

Furthermore, since the surge tank 6 is located below the intake passages 12...12, a wide space C is secured above the passages 12...12 in a range below the upper end of the engine. Therefore, it becomes possible to install the fuel injection nozzles 32-12-...32 above the intake passages 12...12 using the space C as shown in FIG. The fuel 1 injection nozzle is designed to be installed in the intake passage for ease of assembly and prevention of clogging.
It is desirable to install it on the F side.

As shown in FIG. 5, if the downstream edge 23a' of the connecting port 23' is shaped to smoothly continue with the extension part 13', the rotating member 15' Moving member 115'
It is possible to reduce the resistance when air flows out from the internal space 16' to each extension part 13'...13', and for the same purpose, as shown in FIG.
The cross-sectional shape of the partition portion 231]' between 3' and 23' may be rounded on the inside.

(Effects of the Invention) As described above, according to the present invention, in an intake system for a multi-cylinder engine in which the length of the intake passage is variable, the length of the intake passage can be varied over a wide range. Together as we can,
It is compact and simply configured, and it is possible to form an intake passage through which intake air flows smoothly without increasing the overall height of the engine. As a result, as this type of intake device with a variable length of the intake passage, an intake device suitable for automobile engines and the like will be put into practical use.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view showing the entire intake system, FIG. Fig. 4 is a rear view showing the drive mechanism; Fig. 5 is a longitudinal sectional front view of main parts showing another embodiment around the communication port; Fig. 6 is a longitudinal sectional front view taken along the line
The figure is a cross-sectional plan view of the main part taken along the line Vl--Vl in Fig. 5. DESCRIPTION OF SYMBOLS 1... Engine, 2... Intake system, 6... Surge tank, 9... Cylinder, 12... Intake passage, 13...
- Extension portion, 15... Defining rotating member, 16... Internal space, 23... Communication port, 24... Drive mechanism. Applicant Toyo Kogyo Co., Ltd. -14- Figure 5 Figure 6 5b 1AC

Claims (1)

[Claims] (1) A pilot tank is provided in the middle of the intake system, and the sword
An intake system for a multi-cylinder engine in which independent intake passages are provided from a surge tank to each cylinder, wherein extensions of each of the intake passages are formed independently in the vertical direction on a peripheral wall of the surge tank, and The flow ends of each of the above-mentioned intake passages are connected to the upper part of each extension, and the internal space of the surge tank and each of the above-mentioned extensions are defined so that they communicate with each other through a communication port, and the flow ends of each of the intake passages are connected to the upper part of each extension. A defining rotary member is provided that changes the length of the intake passage downstream of one nouge tank by rotating to change the position of the communication port, and the defining rotary member is rotated according to the operating state of the engine. An intake system for a multi-cylinder engine characterized by being equipped with a rotating drive mechanism.