JP2008309091A - Intake pipe length switching mechanism of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake pipe length switching mechanism of an internal combustion engine capable of smoothly switching an intake pipe length while securing excellent sealability. <P>SOLUTION: In the slide type intake pipe length switching mechanism, one of confronting opening end parts of a movable pipe 31 and a second fixed pipe 21 is provided with a funneled end part 22 expanding toward another opening end part and the other opening end part is attached with an elastic seal member 32 composed of an inside lip 32i extending out toward inside of the funneled end part 22 and an outside lip 32o extending out toward outside of the funneled end part 32. In the intake pipe length switch mechanism of the internal combustion engine, a cut-out 32a for communicating an in-lip space 37 formed by being surrounded by the funneled end part 22, the inside lip 32i and the outside lip 32o with an external space outside of the in-lip space when the funneled end part 22 and the elastic seal member 32 contact is formed for the funneled end part 22 or the elastic seal member 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake pipe length switching mechanism that switches the intake pipe length in accordance with the operating state of the internal combustion engine.

  In an intake system for an internal combustion engine, by switching the intake pipe length between long and short according to the low and high engine speeds, the inertia supercharging effect in intake is obtained both during medium and low speed running and at high speed running. An intake pipe length switching mechanism that has been proposed has already been proposed (see, for example, Patent Document 1).

  In the intake pipe length switching mechanism disclosed in Patent Document 1, a slider, which is a movable pipe, is slidably fitted on a guide pipe extending at an end of a primary intake pipe, and the secondary intake pipe is A funnel-shaped guide ring is fixed to the end, and the opening end of the slider and the opening end of the guide ring face each other in the surge tank.

  The opening end of the slider tapers to a taper and abuts so as to be inserted into the funnel-shaped guide ring to seal the inside of the intake pipe. However, the annular abutting seal portion is single and reliably seals. For this purpose, the opening end portion having the taper taper surface of the slider must be inserted deeply into the guide ring. Then, a large frictional resistance is generated at this time, and the intake pipe length cannot be switched smoothly. .

  Accordingly, the end of the movable intake pipe is a funnel-shaped opening end, and the cylindrical seal is provided with a cylindrical first lip and a second lip extending in the seal radial direction at the opening end of the fixed intake pipe abutting on the end. (For example, refer to Patent Document 2).

JP-A-2-252918 Japanese Patent No. 3235436

  In the intake pipe length switching mechanism disclosed in Patent Document 2, when the funnel-shaped opening end of the movable intake pipe comes into contact with the cylindrical seal of the fixed intake pipe, the first lip of the cylindrical seal has a funnel-shaped opening. The second lip is in contact with the inside of the end portion, the second lip is in contact with the outside of the funnel-shaped opening end portion, the annular contact seal portion is doubled inside and outside, and the cylindrical seal is inserted into the funnel-shaped opening end portion. There is no need for sealing.

  However, also in Patent Document 2, when the first lip and the second lip of the cylindrical seal of the fixed intake pipe come into contact with the funnel-shaped opening end of the movable intake pipe, the opening end, the first lip, and the first lip Since the space inside the lip surrounded by the two lips is closed, the first lip and the second lip act like a suction cup and become resistance when the funnel-shaped opening ends are separated. It becomes difficult to separate and the intake pipe length cannot be switched smoothly.

  The present invention has been made in view of the above points, and the object of the present invention is to provide an intake pipe length switching mechanism for an internal combustion engine that can ensure high sealing performance and can smoothly switch the intake pipe length. .

  In order to achieve the above object, the invention according to claim 1 is characterized in that the first fixed pipe and the first fixed pipe are slidably fitted and moved forward and backward with respect to the first fixed pipe to expand and contract the pipe length. An intake passage of an internal combustion engine is configured to include the movable pipe that is configured to be connected to and communicate with a first opening end of the movable pipe that comes into contact with the extension of the length of the movable pipe as the movable pipe advances. In a sliding-type intake pipe length switching mechanism in which an intake pipe length is switched by contact / separation with the second fixed pipe as the pipe advances and retreats, one open end of the open end portions of the movable pipe and the second fixed pipe facing each other The part is formed with a funnel-shaped end portion that expands toward the other, and the other opening end portion has an inner lip extending toward the inside of the funnel-shaped end portion and an outer side of the funnel-shaped end portion. An elastic seal member with an outer lip extending toward the When the funnel-shaped end portion and the elastic seal member abut, the lip inner space formed by the funnel-shaped end portion, the inner lip, and the outer lip is formed outside the lip inner space. A notch communicating with the space serves as an intake pipe length switching mechanism of the internal combustion engine formed in the funnel-shaped end portion or the elastic seal member.

  According to a second aspect of the present invention, in the intake pipe length switching mechanism of the internal combustion engine according to the first aspect, the funnel-shaped end portion communicates with an intake port of a cylinder head and opens into the intake chamber. The elastic seal member is formed on the contact surface of the funnel-shaped end portion with which the inner lip contacts or the inner lip.

  According to a third aspect of the present invention, in the intake pipe length switching mechanism of the internal combustion engine according to the first or second aspect, the funnel-shaped end portion is provided in the second fixed pipe.

  According to the intake pipe length switching mechanism of the internal combustion engine according to claim 1, when the other elastic seal member comes into contact with one funnel-shaped end portion of the opening end portions of the movable tube and the second fixed tube facing each other, the elastic seal The inner lip of the member is in contact with the inside of the funnel-shaped end, the outer lip is in contact with the outside of the funnel-shaped end, the annular abutment seal is doubled inside and outside, one forms a full seal, and the other cuts Sealing performance can be ensured by making a substantially all-round seal excluding the notch.

  When the funnel-shaped end and the elastic seal member abut, the lip inner space formed by the funnel-shaped end, the inner lip and the outer lip is communicated with the outer space outside the lip inner space. Since the notch is formed in the funnel-shaped end or the elastic seal member, when the funnel-shaped end and the elastic seal member are separated, the inner space of the lip communicates with the outer space through the notch. The lip and the outer lip do not act like a suction cup, can be separated without resistance, and the intake pipe length can be switched smoothly.

  According to the intake pipe length switching mechanism of the internal combustion engine according to claim 2, the funnel-shaped end portion communicates with the intake port of the cylinder head and opens into the intake chamber, and the notch of the funnel-shaped end portion is an elastic seal member It is formed on the contact surface of the funnel-shaped end that contacts the inner lip or the elastic seal member, so that the inner space of the lip communicates with the outer space by the notch to invalidate the suction cup action and the cylinder via the notch. A negative pressure also acts on the inner space of the lip communicating with the head, so that the outer lip is more and more pressed against the funnel-shaped end portion to maintain a higher sealing performance.

  According to the intake pipe length switching mechanism of the internal combustion engine according to claim 3, since the funnel-shaped end portion is provided in the second fixed pipe and not in the movable pipe, an increase in the weight of the movable pipe can be avoided, and the movable pipe The force required for the sliding movement can be reduced, and the movable tube can be smoothly advanced and retracted with a small inertia force.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The internal combustion engine E of the present embodiment is a four-stroke in-line four-cylinder internal combustion engine mounted on an automobile.
FIG. 1 and FIG. 2 are perspective views showing the main part of the intake device 1 provided on the side wall of the cylinder head of the internal combustion engine E. An intake pipe length switching mechanism 10 is shown.

  The intake chamber 3 has a structure in which a bottom cover 5 closes an opening opened below a rectangular parallelepiped housing case 4, and four primary-side intake pipes 2 arranged in series from the bottom cover 5. The both ends of the primary side intake pipe 2 are opened into the intake chamber 3, and the intake chamber 3 reaches the air cleaner through the throttle body via the intake port (not shown).

  Between the upper wall of the housing case 4 and the side wall of the cylinder head, an intake manifold 7M in which four secondary intake pipes 7 are integrated in parallel is interposed. Although not shown, 7 communicates with the intake port of each cylinder of the cylinder head.

The bottom lid 5 has a rectangular inner surface 5s with the housing case 4 that bulges downward, and an expanded pipe 2e that communicates with the primary intake pipe 2 on the bulged bottom wall. A cylindrical first fixed tube 11 protrudes upward.
The four first fixed pipes 11 arranged in series have their lower base ends formed integrally with the first base plate 12 and connected to each other.
The first base plate 12 is fastened and fixed to the four corners of the bottom lid 5 by bolts 13.

On the other hand, a cylindrical second fixed pipe 21 communicating with the secondary intake pipe 7 protrudes downward on the upper wall of the housing case 4, and the four second fixed pipes 21 arranged in series are They are connected together.
A funnel-shaped end portion 23 having a funnel-like curved opening surface is fixed to the lower ends of the four second fixed pipes 21, and the four funnel-shaped end portions 22 are second base plates extending in a flange shape. 23 are connected together.

  The first base plate 12 on the lower side and the second base plate 23 on the upper side are parallel to each other, and five stud bolts 25 are interposed between the two. The four in the intake chamber 3 are arranged in series on the lower side. The first fixed pipes 11 and the four second fixed pipes 21 arranged in series on the upper side are coaxially positioned with a certain distance therebetween.

  A movable tube 13 is externally fitted to each of the four first fixed tubes 11 arranged on the lower side so as to be slidable in the axial direction (vertical direction). The four movable tubes 31 are connected to each other by a connecting portion 31c. They are connected and integrated, and move up and down all at once.

The connecting portions 31c on both sides except the center bulge sideways and are respectively penetrated by two stud bolts 25 so that the four movable tubes 31 can always move up and down while maintaining their postures.
A seal ring 33 is fitted in the vicinity of the lower end of the inner peripheral surface of the movable tube 31, and the seal ring 33 is in sliding contact with the first fixed tube 11 to close the gap between the first fixed tube 11 and the movable tube 31. It is out.

The movable tube 31 advances and retreats with respect to the first fixed tube 11 to expand and contract the tube length.
That is, when the movable tube 31 is retracted (lowered), the first fixed tube 11 is entirely accommodated inside to reduce the tube length (see FIG. 1), and when it moves forward (up), the movable tube 31 protrudes from the first fixed tube 11 and extends the tube length. (See FIG. 2).

An annular elastic seal member 32, which is an elastic member, is fitted to the upper opening end of the movable tube 31, and the funnel-shaped end portion 22 is formed at the lower end of the second fixed tube 21 to which the elastic seal member 32 faces. Is provided.
Therefore, when the movable tube 31 moves forward (ascends), the elastic seal member 32 at the upper open end of the movable tube 31 comes into contact with the funnel-shaped end portion 22 of the second fixed tube 12, and the first fixed tube 11 and the first fixed tube 11 2 The movable tube 31 communicates with the fixed tube 21 (see FIGS. 2 and 4).

  Here, the funnel-shaped end portion 22 at the lower end of the second fixed tube 21 has groove-shaped notches 22a directed obliquely upward on the upper small-diameter inner peripheral surface of the opening curved surface, as shown in FIG. One is formed on the curved surface.

  As shown in FIG. 4, the annular elastic seal member 32 at the upper opening end of one movable tube 31 has an inner lip 32 i and a funnel-shaped end 22 extending substantially upward toward the inside of the funnel-shaped end 22. And an outer lip 32o extending obliquely upward toward the outer side.

  When the elastic seal member 32 comes into contact with the funnel-shaped end portion 22, as shown in FIGS. 5 and 6, the inner lip 32i of the elastic seal member 32 is located on the inner surface of the small diameter on the upper side of the open curved surface of the funnel-shaped end portion 22. The outer lip 32o is elastically deformed so as to slidably contact and warp inward, and the outer lip 32o is elastically deformed so as to slidably contact the lower large-diameter development surface of the opening curved surface of the funnel-shaped end portion 22 and warp outward.

  Therefore, an inner lip space 37 surrounded by the inner lip 32i, the outer lip 32o, and the funnel-shaped end portion 22 which are elastically deformed by sliding contact with the opening curved surface of the funnel-shaped end portion 22 is formed.

  The notch 22a formed on the opening curved surface of the funnel-shaped end portion 22 is formed on the upper small-diameter inner peripheral surface of the opening curved surface with which the inner lip 32i of the elastic seal member 32 abuts, as shown in FIG. In addition, when the elastic seal member 32 comes into contact with the funnel-shaped end portion 22, the lip inner space 37 communicates with the inside of the funnel-shaped end portion 22, that is, the inside of the second fixed tube 21 by the notch 22 a.

With reference to FIGS. 1 and 2, the rotation operation shaft 41 faces the casing case 4 along the four movable tubes 31 in the direction of arrangement of the four movable tubes 31 arranged in series. It is installed between the side walls and is rotatably supported.
The end portion of the rotation operating shaft 41 penetrating one side wall is interlocked with the output shaft of the electric motor 40, and the rotation operating shaft 41 is rotated by the drive of the electric motor 40.

Protrusions 35 and 36 are provided at both ends of the four movable tubes 31 connected in series.
And the bifurcated clamping piece of the front-end | tip of the rocking | fluctuating arms 42 and 43 to which the base end part was fixed to the both ends vicinity of the rotation action | operation axis | shaft 41 has pinched the protrusions 35 and 36 slidably, respectively.

  Therefore, when the electric motor 40 is driven and the rotary operation shaft 41 is rotated, the swing arms 42 and 43 are swung up and down integrally, and the protrusions 35 sandwiched by the sandwiching pieces of the swing arms 42 and 43, The four movable tubes 31 can be moved up and down via 36.

  Referring to FIG. 2 showing the state in which the four movable tubes 31 are raised, the first fixed plates 11 and 11 at both ends are buffered on the upper surface of the first base plate 12 around the base end portion connected to the first base plate 12. A material 50 is sandwiched between fixing plates 51 and fixed by fastening bolts 13.

  The semicircular arc-shaped cushioning material 50 has an inner peripheral edge in contact with the outer peripheral surface of the proximal end portion of the first fixed tube 11, but the inner peripheral edge of the semicircular arc-shaped fixing plate 51 extends from the outer peripheral surface of the first fixed tube 11. The shock-absorbing material 50 is exposed in an arc shape at a certain distance, and the exposed portions of the shock-absorbing material 50 around the first fixed tube 11 are opposed to the lower opening end of the movable tube 31 (FIG. 2). For example, a buffering effect can be obtained at the time of contact.

  As described above, the intake pipe length switching mechanism 10 advances (raises) the four movable pipes 31 when the engine speed is low, and moves the elastic seal member 32 at the upper open end of the four movable pipes 31 to the first position. 2 The movable pipe 31 communicates with the first fixed pipe 11 and the second fixed pipe 21 in contact with the funnel-shaped end portion 22 of the fixed pipe 12 so that the primary intake pipe and the intake port communicate with each other. The effective intake pipe length is made long so that the inertia supercharging effect at low engine speed can be obtained. On the other hand, when the engine speed becomes high, the electric motor 40 drives to move the four movable pipes 31 backward (down) ), The communication between the first fixed pipe 11 and the second fixed pipe 21 is opened in the intake chamber 3, and the effective intake pipe length is switched to a short length from the secondary intake pipe to the intake port. Also, an inertial supercharging effect can be obtained.

  When the intake pipe length is switched, the contact of the lower end of the second fixed pipe 21 with the funnel-shaped end portion 22 due to the advance of the movable pipe 31 driven by the electric motor 40 is buffered by the intervention of the elastic seal member 32, and the movable pipe 31. The contact with the first base plate 12 on the side of the first fixed tube 11 due to the retreat of the first position is buffered by the interposition of the cushioning material 50, and the generation of abnormal noise and wear can be prevented.

When the elastic seal member 32 is brought into contact with the funnel-shaped end portion 22 by the advance of the movable tube 31, the inner lip 32i and the outer lip 32o of the elastic seal member 32 are open curved surfaces of the funnel-shaped end portion 22 as described above. (See FIGS. 5 and 6), the annular contact seal portion is doubled inside and outside. A contact seal portion formed by one outer lip 32o seals the entire circumference of the funnel-shaped end portion 22.
The contact seal portion by the other inner lip 32i seals substantially the entire circumference of the funnel-shaped end portion 22 excluding the notch 22a.

The notch 22a formed in the funnel-shaped end 22 that opens into the intake chamber 3 and communicates with the intake port via the second fixed pipe 21 and the secondary-side intake pipe 7 A lip inner space 37 formed by being surrounded by the lip 32i and the outer lip 32o communicates with the intake port to apply a negative pressure to the lip inner space 37 so that the outer lip 32o is increasingly pressed against the funnel-shaped end.
As a result, it is possible to prevent deterioration of the sealing performance due to the formation of the notch 22a and to maintain the sealing performance high.

  Further, when the elastic seal member 32 comes into contact with the funnel-shaped end portion 22 by the advance of the movable tube 31, the lip inner space 37 communicates with the outer space (the inner space of the second fixed tube 21) through the notch 22a. Therefore, the inner lip 32i and the outer lip 32o do not stick to the funnel-shaped end portion 22 like a suction cup, so there is no resistance when the elastic seal member 32 is separated from the funnel-shaped end portion 22 and the intake pipe length is switched. Can be performed smoothly.

The funnel-shaped end portion 22 is provided on the second fixed tube 21 and is not provided on the movable tube 31 side, so that an increase in the weight of the movable tube 31 can be avoided and the force necessary for sliding the movable tube 31 is reduced. The movable tube 31 can be smoothly advanced and retracted with a small inertia force.
The impact force associated with the contact of the movable tube 31 is small, the generation of abnormal noise and wear can be further suppressed, and an electric motor that is small and light can be used.

In the above embodiment, the notch 22a is formed in the upper small-diameter inner peripheral surface with which the inner lip 32i abuts out of the open curved surface of the funnel-shaped end portion 22. However, in the embodiment shown in FIG. A groove-shaped notch 60a is formed on the lower large-diameter developing surface with which the outer lip 32o abuts in the curved open surface of the end 60.
In FIG. 7, the movable tube and the elastic seal member are the same as those in the above embodiment, and the same reference numerals are used.

  When the elastic seal member 32 comes into contact with the funnel-shaped end portion 60 by the advancement of the movable tube 31, the inner lip 65 communicates with the outer space (the inner space of the intake chamber 3) through the notch 60a. 32i and the outer lip 32o do not stick to the funnel-shaped end portion 22 like a suction cup. Therefore, there is no resistance when the elastic seal member 32 is separated from the funnel-shaped end portion 60, and the intake pipe length is smoothly switched. be able to.

Further, the notch may be formed in the elastic seal member instead of the funnel-shaped end portion.
For example, in the example shown in FIG. 8, a notch 75 is formed in a part of the inner lip 72i out of the outer lip 72o and the inner lip 72i of the elastic seal member 72 that contacts the funnel-shaped end portion 70 without a notch. Yes.
In this example, the same effect as that of the embodiment shown in FIG. 6 can be obtained.

Alternatively, as in the example shown in FIG. 9, a notch 85 is formed in a part of the outer lip 82o among the outer lip 82o and the inner lip 82i of the elastic seal member 82 that abuts the funnel-shaped end 80 having no notch. May be.
In this case, the same effect as that of the embodiment shown in FIG. 7 can be obtained.

  Contrary to the above embodiment, a funnel-shaped end portion having a notch is formed on the movable tube side, and an elastic seal member having an inner lip and an outer lip is provided on the second fixed tube side. It may be.

FIG. 3 is a perspective view showing an intake pipe length switching mechanism that is configured inside by removing a part of an intake chamber of an intake device provided on a side wall of a cylinder head of an internal combustion engine according to an embodiment of the present invention. It is the same perspective view which shows the state which the movable pipe advanced and raised. It is a perspective view of the funnel-shaped end part of the lower end of the 2nd fixed pipe. FIG. 6 is a partial cross-sectional view of the intake pipe length switching mechanism in a state where the movable pipe is retracted and lowered. FIG. 6 is a partial cross-sectional view of the intake pipe length switching mechanism in a state where the movable pipe moves forward and rises. It is the principal part enlarged view. It is a principal part enlarged view of the intake pipe length switching mechanism of another embodiment. It is a principal part enlarged view of the intake pipe length switching mechanism of another embodiment. It is a principal part enlarged view of the intake pipe length switching mechanism of another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Intake device, 2 ... Primary side intake pipe, 3 ... Intake chamber, 4 ... Housing case, 5 ... Bottom cover body, 7M ... Intake manifold, 7 ... Secondary side intake pipe,
10 ... Intake pipe length switching mechanism, 11 ... First fixed pipe, 12 ... First base plate, 13 ... Bolt,
21 ... Second fixed tube, 22 ... Funnel-shaped end, 22a ... Notch, 23 ... Second base plate, 25 ... Stud bolt,
31 ... movable tube, 31c ... coupling part, 32 ... elastic seal member, 32i ... inner lip, 32o ... outer lip, 33 ... seal ring, 35, 36 ... projection, 37 ... space in lip,
40 ... Electric motor, 41 ... Rotating shaft, 42,43 ... Oscillating arm,
50 ... cushioning material, 51 ... fixed plate,
60 ... Funnel-shaped end, 60a ... Notch, 65 ... Space in the lip.
70 ... Funnel-shaped end, 72 ... Elastic seal member, 72i ... Inner lip, 75 ... Notch,
80: funnel-shaped end portion, 82: elastic sealing member, 82o: outer lip, 85: notch.

Claims (3)

A first fixed pipe, a movable pipe that is slidably fitted to the first fixed pipe and is moved forward and backward with respect to the first fixed pipe to expand and contract the pipe length, and the extension of the pipe length as the movable pipe advances. An intake passage of the internal combustion engine is configured to include a second fixed pipe that is in contact with and communicates with one open end of the movable pipe, and intake air is brought into contact with and separated from the second fixed pipe as the movable pipe advances and retreats. In the slide type intake pipe length switching mechanism where the pipe length is switched,
One opening end of the opening ends of the movable tube and the second fixed tube facing each other is formed with a funnel-shaped end that expands toward the other, and the other opening end has the funnel-shaped end. An elastic seal member is attached comprising an inner lip extending towards the inside of the shaped end and an outer lip extending towards the outside of the funnel shaped end;
When the funnel-shaped end portion and the elastic seal member abut, the lip inner space formed by the funnel-shaped end portion, the inner lip, and the outer lip is formed outside the lip inner space. An intake pipe length switching mechanism for an internal combustion engine, wherein a notch communicating with a space is formed in the funnel-shaped end portion or the elastic seal member. The funnel-shaped end communicates with the intake port of the cylinder head and opens into the intake chamber.
2. The intake pipe length switching mechanism for an internal combustion engine according to claim 1, wherein the notch is formed in a contact surface of the funnel-shaped end portion with which the inner lip of the elastic seal member contacts or the inner lip.   The intake pipe length switching mechanism for an internal combustion engine according to claim 1 or 2, wherein the funnel-shaped end portion is provided in the second fixed pipe.

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