JPH08526Y2 - Intake system structure of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an intake system structure of an internal combustion engine (hereinafter referred to as "engine" if necessary) mounted on, for example, an automobile.

[Prior Art] Conventionally, an engine mounted in an automobile or the like is provided with a variable displacement resonator branched from a part of an intake passage of the engine to obtain a resonance supercharging effect adapted to the rotational state of the engine. Is being done.

[Problems to be solved by the invention] By the way, when performing resonance supercharging using a resonator,
As a measure against noise, in general, the relationship between the intake passage diameter and the connection passage diameter to the intake passage of the resonator is set so that the intake passage diameter is larger than the connection passage diameter. Few.

Further, even in an intake system that has a large resonance effect without the air cleaner provided in the intake passage, there is a problem that a peak (peak) resonance gain cannot be obtained by connecting the air cleaner.

On the other hand, in general, from the Helmholtz resonator theory,
It is known that the resonance (resonance) frequency can be changed by changing any of the tank volume, the outlet passage diameter, and the outlet passage length of the resonator. Therefore, the tank volume of the resonator, the outlet passage diameter, and the outlet passage length. It is conceivable that the resonance frequency is changed by changing any one of the above to adjust so that the optimum resonance state can be exerted in each case even when the engine speed changes.

That is, as shown in FIG. 2, a variable volume type resonator 5 is provided via a connection passage 4 branched from a part of an intake passage 3 that communicates the air cleaner 1 and the engine 2.
Inside the resonator 5, there is provided a movable partition member (hereinafter referred to as "piston" if necessary) 8 that slides in the resonator 5 by a screw rod 9, and the screw rod 9 is rotated by a motor 10.
The piston 8 is moved in the axial direction of the screw rod 9. As a result, the volume of the one-side chamber A communicating with the intake passage 3 side is changed and the volume of the intake passage 3 including the resonator 5 is variably adjusted. On the other hand, the chamber B on the other side of the piston 8 is open to the atmosphere through the opening 5a.

Then, by the above adjustment, the resonance frequency of the intake passage is changed according to the engine rotation state, so that the resonance supercharging effect optimal for the intake system is obtained. Also, the resonator 5
In order to change the volume of the intake air passage 3, the air flow sensor (AFS) 7 is provided immediately downstream of the air cleaner 1 in the air cleaner 1, and the potentiometer 11 for measuring the movement of the piston 8 is provided in the resonator 5. This is performed by detecting the amount of air inside, detecting the position of the piston 8, and moving the motor 10 and operating the piston 8 by an electronic control unit (ECU) not shown.

By the way, in the variable volume type resonator 5 as described above, since the air flow sensor 7 is located upstream of the branch point 3a of the resonator 5, when the piston 8 moves, the amount of air detected by the air flow sensor 7 (air cleaner The amount Q of air taken in from 1) differs from the actual amount Qa of cylinder intake air of the engine.

That is, as shown in FIG. 2, when the piston 8 moves and the inside of the resonator 5 expands, a part of the air amount Q ΔQ
Is sucked into the resonator 5, and the actual cylinder intake air amount Qa is the air amount Q detected by the air flow sensor 7 minus the air amount ΔQ absorbed in the resonator 5, that is, Qa = Q− When ΔQ is reached and the piston 8 moves and the inside of the resonator 5 contracts, the air amount ΔQ is discharged from the inside of the resonator 5 and the actual cylinder intake air amount Qa
Is the sum of the air amount Q detected by the air flow sensor 7 and the air amount ΔQ discharged from the resonator 5, that is, Qa = Q + ΔQ.

Therefore, there is a problem in that the amount of intake air to the cylinder cannot be correctly measured by AFS7. In order to solve such a problem, it is necessary to estimate the inflow air amount ΔQ of the resonator from the position of the piston 8 and correct the measured value.

For this correction, for example, the output of the potentiometer for piston position control is A / D converted for each SGT (that is, for each engine revolution by the crank angle sensor), and the A
DAN, which is the basis of the / N data (AFS7 per inhalation cycle
There is a means for correcting the amount of air that passes through the following.

That is, The A / D resolution of the piston position is 10.24l / [(4/5) × 256] = 0.05l / bit ΔX is the difference between A / D values for each SGT. DAN resolution is 0.0064LPS / LSB k is a constant. To do.

However, as a result of such correction, although it was confirmed that the correction has an effect, the following problems remain.

In other words, since ΔX has only I2 to 3 digits, 8bitA /
The resolution is poor with D conversion. There is a phase difference between the error and the correction, and the constant k differs depending on the piston position. Furthermore, Qa <-
It does not hold when ΔQ and AFS cannot handle backflow.

The present invention has been made in view of these problems,
A variable volume resonator capable of exhibiting an optimum resonance state in each case according to a change in engine speed,
It is possible to eliminate the difference between the air detection amount by the air flow sensor and the actual cylinder intake amount of the engine due to the movement of the movable partition member (piston) by a simple structure without using a complicated correction means. An object is to provide an intake system structure.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the intake system structure of an internal combustion engine of the present invention has an intake air amount in the intake system of the internal combustion engine, in the middle of communicating from the air cleaner to the combustion chamber of the internal combustion engine. Is provided with an air passage for detecting an air flow sensor, and a variable volume type resonator is provided so as to branch from an intake passage portion on the downstream side of the air flow sensor arrangement portion, and the resonator is provided by a movable partition member. The chamber has two partitioned chambers, and the movable partition member is configured to move so that the volume of one chamber communicating with the intake passage portion is made variable, and the other chamber of the resonator is It is characterized in that it communicates with an intake passage portion on the downstream side of the air flow sensor arrangement portion and on the upstream side of the branch portion to the resonator. It

[Operation] In the above-described intake system structure of the internal combustion engine of the present invention, the volume of one chamber of the resonator is changed by moving the movable partition member, and the resonance supercharging effect corresponding to each engine speed is obtained. You will get it. At this time, the volume of one chamber changes with the movement of the movable partition member,
A part of the amount of air passing through the air flow sensor is sucked or discharged into one chamber, and the cylinder intake amount of the engine tends to change with respect to the amount of air passing through the air flow sensor. Accordingly, the volume of the other chamber changes opposite to the volume of one chamber,
A corresponding amount of air is sucked or discharged from the other chamber to the intake passage portion on the downstream side of the air flow sensor installation portion and on the upstream side of the branch portion to the resonator. Are offset.

[Embodiment] An intake system structure of an internal combustion engine as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of the intake system structure of the internal combustion engine of the present invention. During,
The same reference numerals as those in FIG. 2 indicate almost the same parts.

First, the structure of the intake system structure of the internal combustion engine will be described. As shown in FIG. 1, an air cleaner 1 and an engine 2 are provided.
A variable volume type resonator 5 is provided in a portion of the intake passage 3 that communicates with the, and is branched from a part of the intake passage 3 via a connection passage 4.

A throttle valve 6 is provided in the intake passage 3, and an air flow sensor (AFS) 7 is provided immediately downstream of the air cleaner 1.

The variable volume type resonator 5 is provided with a slidable movable partition member (piston) 8 and a screw rod 9 for moving the variable partition member 5 inside, and a motor 10 for rotating the screw rod 9 is provided outside the resonator 5. It is provided.

The operation of the motor 10 is controlled by an electronic control unit (ECU) (not shown) according to the rotation state of the engine,
The screw rod 9 is rotationally driven by the motor 10, whereby the piston 8 is moved in the axial direction of the screw rod 9, and the volume divided into two by the piston 8 in the chamber A, that is, the side communicating with the intake passage 3. Is configured so that the internal volume of the resonator is adjusted. Therefore, the volume of the intake passage 3 of the engine is adjusted so that the resonance supercharging effect adapted to the rotational state of the engine can be obtained.

Further, the resonator 5 is provided with a potentiometer 11 for measuring the position of the piston 8, piston position information is sent to the ECU, and feedback control is performed so as to bring the piston 8 to a predetermined position. And
The opening 5a of the chamber B on the other side divided into two by the piston 8 of the resonator 5 is connected by a scavenging pipe 12 between the downstream side of the air flow sensor (AFS) 7 in the intake passage 3 and the branch point 3a of the resonator. There is.

Next, the operation of the intake system structure of the internal combustion engine will be described. Although the intake state changes according to the change of the engine speed, the internal volume of the one side chamber A of the resonator is changed according to the change of the engine speed. Adjust. At this time, based on the position of the piston 8 detected by the potentiometer 11, the ECU (not shown) feedback-controls the motor 10 to move the piston 8 while rotating the screw rod 9 to adjust the internal volume of the one side chamber A. To do.

As a result, the resonance frequency of the intake passage 3 is changed to obtain the optimum supercharging effect that resonates with the pulsation of the air flow according to the engine speed.

Further, the other chamber B of the resonator 5 is not opened to the atmosphere, but is communicated through the scavenging pipe 12 between the downstream side of the AFS 7 in the intake passage 3 and the upstream side of the resonator branch point 3a. 5. When air enters and leaves the one side chamber A of 5, the air amount ΔQ ′ of the same amount as the inflow and outflow amount ΔQ of AFS7 in the intake passage 3 from the other side chamber B.
To and from the branch point 3a.

That is, as shown in FIG. 1, when the air amount ΔQ enters the one side chamber A, at the same time, the air amount ΔQ
Air having an air amount ΔQ ′ equal to Q is discharged from the other chamber B to the intake passage 3.

In addition, the air amount Δ from the inside of the chamber A on one side to the intake passage 3 is increased.
When the air of Q is discharged, at the same time, the air of the air amount ΔQ ′ equal to this air amount ΔQ enters the other chamber B.

Therefore, the cylinder intake air amount Qa to the engine becomes Qa = Q−ΔQ + ΔQ ′ = Q or Qa = Q + ΔQ−ΔQ ′ = Q, and the intake air amount Q and the cylinder intake air amount Qa that have passed through the AFS7.
And match (or almost match).

Therefore, the relationship between the air amount Q measured by the AFS7 and the cylinder intake air amount Qa is always equal to each other without being influenced by the air amount ΔQ flowing into the resonator 5.

Therefore, there is no need to correct the data of AFS7, and the problem that the resolution at the time of A / D conversion related to this data correction is deteriorated and the constant k needs to be changed for each piston position and AFS7 However, the problem of not being able to deal with reverse flow is solved, and through AFS7, engine control can always be performed with a predetermined accuracy.

[Advantages of the Invention] As described above in detail, according to the intake system structure of the internal combustion engine of the present invention, the variable volume type resonator branched from a part of the intake passage is divided into two chambers by the movable partition member. Of these, the chamber on the other side, which is not communicated with the intake passage side through the connection passage, is communicated between the air flow sensor downstream side of the intake passage and the upstream side of the resonator branch point, so that it is downstream from the branch point. The intake air amount into the cylinder of the engine on the side is not affected by the volume change of the resonator, and the air amount flowing through the air flow sensor and the intake air amount into the cylinder are always equal. Therefore, it is no longer necessary to correct the detected value of the air flow sensor as in the past, and complicated calculation for this data correction, deterioration of resolution during A / D conversion, change of constant k, and backflow of the air flow sensor. Various problems such as handling are solved, and it becomes possible to always perform engine control with predetermined accuracy through the air flow sensor.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an intake system structure of an internal combustion engine as an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing an intake system structure of an internal combustion engine as a conventional example. 1 ... Air cleaner, 2 ... Internal combustion engine (engine), 3
...... Intake passage, 3a ...... Branch point of connection passage, 4 ... Connection passage, 5 ... Resonator, 5a ... Opening, 6 ... Throttle valve, 7 ... Air flow sensor, 8 ... Movable partition member ( Piston), 9 …… Screw rod, 10 …… Motor, 11 ……
Potentiometer, 12 ... Scavenger pipe, A ... One side chamber, B ... Other side chamber, Q ... Air amount in intake passage,
Qa ... intake amount into cylinder, ΔQ ... inflow air amount into resonator (one side chamber) or outflow air amount from resonator (one side chamber), ΔQ ′ ... outflow air amount from other side chamber or other Amount of air flowing into the side chamber.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Hiroshi Higuchi, No. 1, Uzumasa Tatsumi-cho, Ukyo-ku, Kyoto City, Kyoto Prefecture Mitsubishi Motors Engineering Co., Ltd. Kyoto Office (56) Reference JP-A-61-226517 (JP, A)

Claims (1)

[Scope of utility model registration request] In an intake system of an internal combustion engine, an intake passage is provided with an air flow sensor for detecting an intake air amount, which is provided on the way from an air cleaner to a combustion chamber of the internal combustion engine. A variable-volume type resonator is provided so as to branch from a downstream intake passage portion, and the resonator has two chambers partitioned by a movable partition member, and the movable partition member is moved to move the intake passage. An intake passage portion configured to change the volume of one chamber communicating with the portion, and the other chamber of the resonator downstream of the air flow sensor arrangement portion and upstream of a branch portion to the resonator. An intake system structure for an internal combustion engine, which is characterized in that