JPS60169627A - Suction device of engine - Google Patents

Abstract

PURPOSE:To improve charging efficiency with the aid of resonance effect produced within a total operation range, by a method wherein a suction pipe is divided into 2 parts at its middle part, an enlarged chamber is disposed to the downstream of each of the branched pipes, a short-circuiting valve is located to each of a partition and a communicating part between the two enlarged chambers, and operation of the valves are controlled. CONSTITUTION:A suction pipe 5, located to the downstream of an air cleaner 2, is divided into 2 parts at its middle part by means of a partition 8, enlarged chambers 101 and 102 are respectively located to the downstream of the branched suction pipes, and branch pipes 71-76, extending to each cylinder, are branched from the enlarged chambers. A short-circuit valve 122 is located to the partition 8, a short-circuit valve 121 is attached to a partition part through the medium of which the two enlarged chambers 101 and 102 positioned adjacent to each other, and operation, responding to an operation state, of each of the valves is controlled by a controller 13. This enables the length of a resonnance passage to be switched in a 3-stage, and produces a resonnance effect about within a whole operation range, resulting in the possibility to improve charging efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine, and particularly to an intake system that utilizes resonance effects to improve intake air filling efficiency.

(Prior art) Improving the filling efficiency of intake air is effective in increasing engine output, but in recent years, attempts have been made to utilize the dynamic effect of intake air to improve this filling efficiency. It is being The dynamic effects of this intake include a pulsation effect that utilizes the pulsation of the intake air within the intake passage, an inertial effect that utilizes the kinetic energy of the intake air, and vibrations of the intake air within the intake system. There is a resonance effect that utilizes the resonance of the engine, but when the resonance effect is utilized in a multi-cylinder engine, the intake system is usually configured as follows.

That is, in order to avoid interference of intake air vibration between cylinders, the cylinders are grouped into groups whose intake order is not consecutive, and the intake passages are made to correspond to each cylinder group!
It branches into several branch passages, and each of the branch passages has an intake expansion chamber acting as a resonance chamber on the downstream side thereof. This intake expansion chamber is connected to a plurality of cylinders of a corresponding cylinder group through independent intake passages.

In such a configuration, an independent intake system is formed for each cylinder group from the branch part of each branch passage to the plurality of cylinders via the intake expansion chamber and the independent intake passage, and each intake system is connected to the eleventh branch. A certain natural frequency is determined by the length and diameter of the passage, the volume of the intake expansion chamber, and the length and diameter of the independent intake passage. 11.1 The vibration of the intake air passing through the system resonated with this intake system.
A large positive pressure wave is generated, and this positive pressure wave causes the action of pushing intake air into the cylinder.

However, since the vibration of the intake air passing through the intake system is induced based on the intake action of each cylinder, its frequency changes depending on the engine rotational speed. Therefore, the noise caused by intake vibration in the intake system can only be obtained at a certain engine speed or within a limited range around this engine speed. For example, in an automobile engine. In the case of an engine that is operated in a wide range from low speed to high speed, it is not possible to obtain a resonance effect over the entire operating range.

L for resonance effect! To solve the above-mentioned problems [7-C], for example, there is an air intake device disclosed in Japanese Utility Model Application Laid-open No. 58-178421. This is done by dividing a plurality of cylinders into groups for each cylinder whose intake strokes do not overlap, as shown in FIG. Both resonance passages A and BJ: communicate the downstream intake manifold parts (intake expansion chambers) C and D with each other via an auxiliary resonance passage E of a required length, and A passage opening/closing valve F is installed to open and close the passage. According to this intake system, two independent intake systems are formed for each cylinder group, and the resonance point of intake vibration for both intake systems is located at the on-off valve [
It will change depending on whether it is opened or closed. Therefore, the resonance effect can be obtained over a wider range of engine speeds than when there is only one resonance point.

However, in this intake system, since the auxiliary resonance passage E is formed in a state that projects outside separately from the resonance passages A and B that constitute the intake passage and the intake manifold portion C21), The entire engine becomes bulky, making it difficult to store it in a single engine room with limited space, especially in the case of an automobile engine. Furthermore, since the resonance point is simply switched to two stages by the switch N1 of the on-off valve F, the operating range in which the resonance effect can be obtained is not sufficiently expanded.

Historically, with the above configuration, the intake manifold sections C and D are divided for each cylinder group, resulting in poor distribution of intake air to each cylinder.
The pressure inside D becomes uneven and the so-called pumping loss increases, and at low loads when the intake air filling amount for each IC is small, the output decrease due to the increase in pumping is more than -V due to the increase in output due to the resonance effect. become.

(Object of the Invention) The present invention utilizes the resonance effect to increase the -C intake air filling amount.
[NO] - This is a one-engine intake system designed to solve the following problems, and the intake H1r can be configured compactly, and the resonance effect can be utilized in a wider range of engine operating ranges. Sea urchin Juru.

It also prevents a decrease in output due to deterioration of intake air distribution or increase in pumping loss that occurs at low loads. shall be.

(Structure of the Invention) To achieve the first objective, an engine intake system according to the present invention is structured as follows.

That is, there are two branch passages in which the intake passage is branched at a predetermined branch part, intake expansion chambers each provided downstream of both branch passages and each having a required volume, and the intake expansion chambers and the intake order. Two independent intake systems are constituted by independent intake passages that connect a plurality of discontinuous cylinders, a first passage that short-circuits both the intake expansion chambers, and the branch section and the intake expansion chamber. and a second passage that short-circuits both branch passages between the first and second passages. A first valve and a second valve are provided to open and close the second passage, respectively. And this first one. By controlling the second valve to close according to the engine speed, the length of the portion of the above-mentioned two branch passages that acts as a resonant passage can be switched to three stages, and when the load is low, the first valve The two intake expansion chambers are constructed so as to communicate with each other.

According to such a configuration, the branch passage that constitutes the intake passage acts as a resonant passage, so that there is no air outside the intake passage.
There is no need to step up the auxiliary resonance passages as in the conventional example, and therefore the intake system or the entire engine can be constructed compactly.

In addition, by switching the resonance point into three stages as described above, the resonance effect can be utilized in a wider range of L engine operating ranges, and at low loads, the two intake expansion chambers are communicated with each cylinder. Improved distribution of air intake to
Furthermore, by equalizing the pressure in both chambers, a decrease in output due to pumping loss is prevented, and output performance at low loads is also improved.

(Example) Hereinafter, embodiments of the present invention will be explained based on the drawings. .

As shown in FIG. 2, this embodiment is applied to an in-line six-cylinder I engine, and the engine 1 has an air cleaner 2.
An intake device 4 extending from six cylinders 31 to 36 is provided. This first step! '
- The surge tank 6 is connected to each of the above-mentioned cylinders 31 to 36, and is composed of the same number of i7 intake passages 71 to 76 as the number of cylinders covered. A partition wall 8 is provided inside, and the partition wall 8 separates the downstream portion of the main intake passage 5 from the first. 2nd branch passage 91.92
The inside of the surge tank 6 is divided into both branch passages 91.
92, the first. Second intake expansion chamber 1
0+, 102. Here, the first intake expansion chamber 101 is connected to the first to third cylinders 31 to 33 via the first to third cylinders 1'/intake passages 71 to 73, and
The intake expansion chamber 102 includes fourth to sixth independent intake passages 74 to 76.
(It will be connected to the 4th to 6th cylinders 34 to 36, but within the two cylinder groups of the 1st to 3rd cylinders 31 to 33 and the 4th to 6th cylinders 34 to 36, The intake order of each cylinder is not consecutive.

However, the first. Second intake expansion chamber 1
01 and 102, there is a first passage 111 that directly communicates the two parts 101 and 102, and the passage 111 is opened.
A closing valve 11 and a valve 121 are provided in the partition wall 8 (J), and a second branch passage 91 and a second branch passage 92 are connected to each other at an intermediate portion in a portion that partitions the first and second branch passages 9+ and 92. A passage 112 and a second valve 122 for opening and closing the passage 112 are provided.

And 1.1 D, 1st. The second balzo 12+, 122 is
The first . Opening/closing control is performed via the second P output regulators 14+ and 142, and this control device 13 receives signals such as a signal C from a rotational speed sensor 15 that detects the rotational speed of the engine 1, and negative signals that detect the load. The signal d from the Xun sensor 16 is input, and the first and second valves 121 are
, 122 is designed to open and close 1, where,
-1 The first engine according to the operating condition of engine 1. 2nd barzo 1
The opening/closing control of 21° 122 is performed as shown in FIG.

That is, the operating range is divided into a high load range and a low load range, and in the high load range, the low speed range T is further divided according to the rotation speed.
, Medium-low speed range ■, Medium IT! It is divided into four regions: l speed range ■ and ^ far range IV, and low speed range l (・ indicates the 1st and 2nd valves 12
1. Close both valves 122 and close the first valve 1 in the medium and low speed range ■.
21, close the second valve 122 by 11'', and listen to the first valve 121 in the medium and high speed range (even if the second valve 122 is closed, it will not work), and then again in the high speed range IV. Close both the first and second valves 121 and 122.
;1, ta, i1 (in the negative range V, the first valve 121
(The second valve 122 may be closed)
Control it like this.

Note that, as shown in FIG. 2. Directly upstream of the connection to the intake expansion chambers 10+ and 102, there is a first
．． A second slot 1 to a valve 18+, 182 are provided, respectively. Although not shown, each independent intake passage 7t"
-7e are each equipped with a fuel injection valve.

According to the above configuration, when the engine 1 is operating, the IC intake air drawn into the main intake passage 5 from the air cleaner 2 is transferred to the branch part At a5, the intake air branches into the first and second branch passages 91 and 92, and the intake air that flows into the first branch passage 91 flows through the passage 91, the first intake expansion chamber 101, and the first to third independent intake passages 71. ~ 73 through the first intake system Y1 consisting of the first ~
The intake air that has flowed into the third cylinders 31 to 33 and the 12-branch passage 92 is transferred to the second intake air, which is formed by the passage 92, the second intake expansion chamber 102, and the fourth and sixth independent passages 74 to 76. It flows into the fourth and sixth cylinders 34 to 36 through the system Y2.

However, both intake systems Y1. Intake expansion chamber 1 located in Y2
A first passage 111 that directly communicates between the first valve 121 and the first passage 111 that directly communicates the first valve 121 and the first passage 111 that connects the first passage 102 and 2nd branch passage 91.92
The second passage 112 that communicates with the second pulp 122 J:
In the closed state, both intake systems Y1. Y2 is the first to third cylinders 31 to 3 from the branching part X.
The entire range from the 3rd and 4th cylinders to the 6th cylinders 34 to 36 is already in an independent state, and the 1st... 2nd branch passage 91.9
2, its entire length acts as a bellows tube in which the intake vibration resonates. However, when the second balzo 122 listens, both intake systems Y1. Y'2 is independent only on the downstream side of the second passage 112; : state (, 1st ° 2nd branch passage 9
As a 1.92 resonance tube (! 1 The river part is shortened,
When the Iζ first valve 121 opens, both intake systems Y1. Y2
Only the downstream side of the intake expansion chambers 101 and 102 becomes independent, and the first and second branch passages 91 and 92 no longer function as resonance chambers. Therefore, 1. 2nd valve 1
21, 122 open jHj According to the state number J, the frequency of 114 at which the intake air resonates, in other words, the resonance of the intake air, the JζC filling efficiency, or the 1 engine rotational speed when the output torque of the engine 1 increases changes 4. It turns out. That is, as shown in FIG. When both the second valves 121 and 122 are closed, as shown by curve (1), a peak of output 1 - l q occurs in the low speed range l (at this time, in the high speed range I
(secondary peak P4 occurs at V), first valve 1
21 and the second pulp 122 is closed, a peak P2 of output torque occurs in the medium and low speed range ■ as shown by curve (2), and when the first valve 121 is ff1J, a peak P2 of output torque occurs in the medium and low speed range ■. A peak P3 of output torque is likely to occur in region (■).

However, C1 above 1. The second valves 12+ and 122 control the engine 1 by output signals a and b from the control device 13.
The opening/closing is controlled as shown in FIG. 3 according to the operating range. In other words, when the rotational speed is in the low speed range ■ in the high load range, the first. When the second valves 121 and 122 are closed and the speed is in the medium and low speed range ■, the first valve 121 is idle and the second pulp 1
22 is open and the first valve 121 is opened when the medium speed is 17AUl, and when the high speed is Iv, both valves 1 are opened.
21° and 122 are closed again. (As a result, the output of the engine 1 in the high load range is 1 to 100 mph.) - The input curve (1) to (1) in Fig. 4 for changes in engine speed is
3) will change according to the curve (4) connecting the four beaks P1 to P1]4, and as a result, the output will increase in substantially the entire rotation range of the engine 1.

On the other hand, in the low negative range V, the first valve 121 is closed regardless of the rotation speed, and the first valve 121 is closed regardless of the rotation speed. WI2 intake expansion chamber 10 +
, ' 102 are always in communication and in the IC state.

Therefore, intake air freely flows into each cylinder 31 to 3G from both chambers 10t, 102, and the distribution 4Q of the intake air is improved, and the II force in the cylinders 10't, 102 is made uniform. As a result, the pumping loss in each cylinder 31 to 36 is reduced, and the output reduction due to the pumping loss at low load exceeds the output increase due to the resonance effect. This prevents the negative effect of a decrease in

FIG. 5 shows an embodiment in which the present invention is applied to a V-type six-cylinder engine, and in this actual example, the first to third cylinders 31' to 33' in the engine 1' A surge tank 6' is arranged between the first bank 11' which has the right side and the second bank 12' which has the fourth to sixth cylinders 34' to 36'. Cylinders 31' to 33' are connected to one end of the surge tank 6' and extend into both banks 11' and 12' on both sides of the surge tank 6'.
and independent branch passages 71' leading to 34' and 36', respectively.
~73' and 74'-76' are installed, respectively. Also in this embodiment, ■first intake passage 5'
A partition wall 8' is provided which cuts the inside of the surge tank 6' in the direction of the crankshaft from the middle part of the main intake passage 5'. 92'
and the first branching passage downstream of both branch passages 91' and 92'.
．． Second intake expansion chambers 101' and 102' are formed. In addition, a first passage 111' that directly communicates both the intake expansion chambers 101', 1(')2' and the passage 111' is opened in the center of the surge tank 6' that connects to the partition wall 8'.
A first valve 121' for closing is provided, and a partition wall 8
The part that partitions the second branch passages 9+' and 92' includes a second passage 112' that directly communicates the two passages 9+' and 92', and a second passage 112' that opens and closes the passage 112'. Two valves 122' are installed, and the opening and closing of the first and second valves 12+' and 122' are controlled according to the operating state of the engine 1', as in the embodiment 1-. .

Therefore, in this embodiment, even more so than d5, a resonance effect is obtained over substantially the entire range of engine speed in a high load range, and the charging efficiency or output is increased. In particular, in this embodiment, C represents the first and second intake expansion chambers 1.
Since the first passage 111' that communicates the C 1st pulp 121' in the low p loading area is installed in the center of the surge tank 6', the first passage 111' that communicates the C 1st pulp 121' with The distribution of intake air to 31' and -36' is further improved.

(Effects of the Invention) As described above, according to the present invention, in an engine in which the intake air filling efficiency is reduced by utilizing the resonance effect of the intake system, the branch passage constituting the intake passage. Since the resonator is made to act as a resonance pipe whose resonance point changes, the intake device can be constructed more compactly than when a resonance passage is provided separately from the intake passage. Further, by changing the resonance point in three stages, the resonance effect is utilized in a wider range of engine operating ranges, and the output is improved in substantially all engine operating ranges. Furthermore, by installing multiple independent intake systems to take advantage of the resonance effect, deterioration of intake air distribution, increase in pumping loss, and associated decrease in output at low loads are prevented, and the system is good even at low loads. This results in 19 output characteristics. In this way, an intake system is realized which is particularly suitable for motor vehicle engines.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of an engine showing a conventional example, FIG. 2 is a schematic plan view showing an embodiment of the present invention, FIG. 3 is a graph showing a control area in this embodiment, and FIG. 4 is a graph showing the embodiment of the present invention. FIG. 5 is a schematic plan view showing another embodiment of the present invention. 1.1'...Engine, 31-36.31'-36'
...Cylinder, 5.5'...Intake passage (main intake passage),
71~7e, 71'~76'...Independent intake passage, 9+
, 92.97', 92'...branch passage, 101,1
02,101', 102'...Intake expansion chamber, 11+
, 11+'...first passage, 112.112'...second passage, 1:ll'+, 121'...first pulp, 1
22.122'...Second valve. Applicant: Toyo Kogyo Co., Ltd. Figure 3 Figure 4

Claims (1)

[Claims] (1) The intake passage is branched into two branch passages at a predetermined branching part, and an intake expansion chamber is provided on the downstream side of both branch passages, and the intake order is not continuous from the intake expansion chamber. This is a carrot intake system in which a plurality of cylinders are each provided with independent intake passages, and the two intake expansion chambers are short-circuited. A second passage short-circuiting both branch passages is provided, and first and second valves are provided to open and close the first and second passages, respectively.
A one-engine intake system in which a second valve is controlled to open and close depending on the operating state of the engine.