JPH0318659Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an engine intake system, and particularly to an engine intake system that utilizes a resonance effect to improve charging efficiency.

[Prior Art] Conventionally, a partition wall has been provided which includes two groups of intake system collecting parts in which cylinders having non-consecutive firing orders are collected, and a resonant intake passage formed upstream of the collecting part, and partitions the upstream resonant intake passage. A hole is opened in the middle of the engine, and a valve is installed to open and close this hole.It closes when the engine is running at low speeds and opens at high speeds to create a resonance effect that corresponds to the engine speed. An engine intake system in which the communication length of an intake passage is varied has been proposed (Japanese Patent Laid-Open No. 148025/1983).

However, in the conventional engine intake system described above, the communication length of the upstream resonant intake passage is simply switched in two stages depending on the high or low engine speed, so an effective resonance effect can be obtained at medium speeds. Therefore, there was a problem in that it was not possible to effectively respond to engine operating conditions where the speed changes over a very wide range from low to high speed.

Of course, if multiple holes are provided in the partition wall and an on-off valve is provided for each hole, the communication length can be changed in multiple stages, but this would require a large number of on-off valves and would be difficult to control. It becomes complicated and costs increase.

[Purpose of the invention] The purpose of the invention is to provide an engine intake device that can change the communication length of the upstream resonant intake passage in multiple stages or continuously using a single valve and actuator. It is.

[Structure of the invention] For this reason, the invention provides a circular hole in the partition wall of the upstream resonant intake passage, and a disc-shaped valve body having a communication port offset with respect to the center of rotation is provided in this hole. By rotating this valve body around an axis passing through the center of rotation, the communication length can be switched in multiple stages.

[Effects of the invention] According to the invention, it is possible to control the communication length state in multiple stages with a single valve device, and it is possible to obtain a resonance effect over a wide operating range of the engine.
It is possible to improve the output by improving the filling efficiency.

[Embodiments] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

As shown in FIG. 1, first and second intake manifolds M1 and M2, which form intake passages for cylinders in which the firing order is not consecutive, are connected to a box-shaped surge tank 1.
It communicates with first and second surge tank chambers 3 and 4, respectively, which are formed by dividing the inside of the chamber into two equal parts by a partition wall 2.
Each inlet 3i of the first and second surge tank chambers 3 and 4,
4i are formed on both sides of the partition wall 2,
They communicate with first and second resonant intake passages 5 and 6, respectively. The first and second resonant intake passages 5 and 6 extend independently and in parallel, and throttle valves 7 and 8 are provided on the upstream side to control the amount of intake air according to the load. Downstream of these throttle valves 7, 8, the first and second resonant intake passages 5, 6 are circular-shaped intake passages that surround and accommodate a disc-shaped valve body 9, as shown in FIG. They are coupled by a communication portion 10 so as to be able to communicate with each other.

The disc-shaped valve body 9 is supported at its center by a rotating shaft 11 that extends in a direction perpendicular to the first and second resonant intake passages 5 and 6, and has bearings 12 and 13 at both ends.
One end of the rotary shaft 11 rotatably supported by the rotary shaft 11 extends outward and is mechanically connected to, for example, a diaphragm type actuator 15 via a drive lever 14 . The disc-shaped valve body 9 has a rotating shaft 11.
A communication port 16 is formed that opens at a position eccentric to the engine rotation speed, and the actuator 15 moves this communication port 16 to three positions in total with a phase difference of 90 degrees, as shown in FIG. 3, depending on the engine speed. A, B, C
The disk-shaped valve body 9 is driven so as to be positioned at .

Now, as shown in FIG.
Defined as the length to the communication port 16, by switching the communication port 16 to positions A, B, and C,
The communication length is a→b→c (a>b>
c).

FIG. 4 schematically shows the relationship between the engine rotational speed and the output shaft torques TA, TB, and TC obtained when the communication port 16 is held at each position A, B, and C, respectively.

As is generally known, the communication length required to obtain a resonance effect is long at low rotation speeds.
It becomes shorter at high speeds. As clearly shown in Fig. 4, at position A where the communication length is the longest, a sufficiently high output shaft torque TA is obtained at low rotations compared to other positions B and C. When the rotation speed is medium, the output shaft torque TB at position B is the highest, and at high speed, the output shaft torque TC at position C, where the communication length is the shortest, is the highest.

Therefore, when the engine speed changes from low to medium to high, the communication port 16 of the disc-shaped valve body 11
By sequentially switching the position of A→B→C, high output shaft torque can be obtained. In other words, the resonance effect that can improve the filling rate can be ensured over a wide range from low speed to high speed, depending on the engine speed.

As described above, in the present invention, multistage communication lengths can be ensured with a single valve device.

In addition, in the above embodiment, the valve body is disk-shaped,
Although communication ports were provided at eccentric positions, for example, the first,
The partition wall that partitions the second resonant intake passages 5 and 6 is shaped like a disk, and for example, three communication ports are formed eccentrically from the center position in this disk portion, and these communication ports are opened sequentially according to the engine speed. It goes without saying that a fan-shaped valve body that is open (the other two are closed) may be used.

[Brief explanation of drawings]

FIG. 1 is an explanatory plan view of the main parts of an engine intake system according to an embodiment of the present invention, and FIG.
3 is an enlarged sectional explanatory view of the valve body portion, and FIG. 4 is a graph showing the relationship between engine rotational speed and output shaft torque obtained at each position of the communication port. M1, M2...first and second intake manifolds,
3, 4... 1st, 2nd surge tank chamber, 5, 6...
...first and second resonant intake passages, 9...disk-shaped valve body,
15... Actuator, 16... Communication port.

Claims (1)

[Claims for Utility Model Registration] An intake system comprising two groups of intake system collection parts in which cylinders with non-consecutive firing orders are collected, and a resonant intake passage on the upstream side of the collection part, and a communication length of the upstream resonant intake passage. In an engine that changes the temperature, the upstream resonant intake passages are arranged in parallel and close to each other, a communication part is provided between the two passages, an on-off valve is provided that rotates around the center of this communication part, and the on-off valve is An intake device for an engine, characterized in that a communication port is provided so that the communication position of both passages can be switched in multiple stages according to rotation.