JP2008309090A - 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 free from generation of noise and abrasion when switching an intake pipe length. <P>SOLUTION: In the slide type intake pipe length switching mechanism 10, an intake passage of the internal combustion engine consists of a movable pipe 31 for moving back and forth for the first fixed pipe 11 by slidably fitting to the first fixed pipe 11 and a second fixed pipe 21 for contacting and communicating with an opening end part of the movable pipe 32 by extension of a pipe length accompanying a forward movement of the movable pipe 31 and the intake pipe length is switched by connection or disconnection of the second fixed pipe 21 along with the back-and-forth movement of the movable pipe 31. In the intake pipe length switching mechanism of the internal combustion engine, a buffer material 50 is arranged at least at one of confronting contact surfaces of the first fixed pipe 11 side and the movable pipe 31 side. <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).

JP-A-2-252918

  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 portion 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.

When the slider moves forward and backward with respect to the guide pipe by the actuator to expand and contract the pipe length, and the slider open end abuts the funnel-shaped guide ring by the advance of the slider, it is effective to communicate from the primary intake pipe to the intake port The intake pipe length is long.
On the other hand, when the slider moves backward with respect to the guide pipe, the communication between the primary side intake pipe and the secondary side intake pipe is released, the guide ring is opened to the surge tank, and the effective intake pipe length is drawn from the secondary side intake pipe. Short to port.

An elastic member is usually attached to one open end of the slider that comes into contact with the funnel-shaped guide ring because it needs to have a sealing function. It also has an action.
However, when the slider moves backward away from the guide ring, there is nothing equivalent to a cushioning material between the slider and the portion corresponding to the fixed side stopper of the primary side intake pipe.

Therefore, when the intake pipe length is switched from long to short, there is a possibility that abnormal noise or wear may occur due to the contact of the slider.
In particular, when a metal material is used for the slider and the stopper, the occurrence of abnormal noise and wear is remarkable.

  The present invention has been made in view of the above points, and its object is to provide an intake pipe length switching mechanism for an internal combustion engine that does not generate abnormal noise or wear when the intake pipe length is switched.

  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 slide-type intake pipe length switching mechanism in which the intake pipe length is switched by contact and separation with the second fixed pipe as the pipe advances and retreats, at least of the contact surfaces facing each other on the first fixed pipe side and the movable pipe side An intake pipe length switching mechanism for an internal combustion engine in which a cushioning material is disposed on one side.

  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 cushioning material is disposed only on the contact surface on the first fixed pipe side.

  According to a third aspect of the present invention, in the intake pipe length switching mechanism of the internal combustion engine according to the second aspect, the internal combustion engine is a multi-cylinder internal combustion engine, and the first fixed pipe, the second fixed pipe, One set of movable pipes is provided, and the plurality of first fixed pipes are integrally coupled by a base plate, and the plurality of movable pipes are connected to each other and integrated with each corresponding first fixed pipe. It is slidably fitted externally, and the cushioning material is arranged on the contact surfaces around the two fixed tubes located at both ends of the base plate.

According to the intake pipe length switching mechanism of the internal combustion engine according to claim 1, the buffer material is disposed on at least one of the contact surfaces facing each other on the first fixed pipe side and the movable pipe side. Since the cushioning material is interposed at the time of contact with the first fixed pipe side, it is possible to prevent abnormal noise and wear.
Note that the abutting with the second fixed pipe by the advancement of the movable pipe has a buffering effect because at least one of the opening end portions that abut each other has a sealing function and an elastic material is used.

  According to the intake pipe length switching mechanism of the internal combustion engine according to claim 2, since the buffer material is disposed only on the contact surface on the first fixed pipe side, an increase in the weight of the movable pipe can be avoided, and the sliding of the movable pipe Therefore, the movable tube can be smoothly advanced and retracted with a small inertia force.

  According to the intake pipe length switching mechanism of the internal combustion engine according to claim 3, the internal combustion engine is a multi-cylinder internal combustion engine, and each cylinder is provided with one set of a first fixed pipe, a second fixed pipe, and a movable pipe, The plurality of first fixed pipes are integrally coupled by a base plate, the plurality of movable pipes are connected to each other and integrated, and are slidably fitted to the corresponding first fixed pipes, and the cushioning material is provided on the base plate. Since it is arranged on the contact surface around each of the two fixed pipes located at both ends, when the integrally connected movable pipes are retracted, the movable pipes at both ends absorb the impact force with the buffer material between the base plates. Since the other inner movable pipes do not come into direct contact with the base plate due to the presence of cushioning materials at both ends, it is possible to prevent the generation of noise and wear without placing cushioning materials around all the fixed pipes of the base plate. Can .

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 is not shown, but reaches the air cleaner through the throttle body via the intake port.

  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, and each secondary intake pipe is inserted. 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 22 having a curved opening surface formed in a funnel shape 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).

A rotating operation shaft 41 is provided between the opposing side walls of the housing case 4 along the four movable tubes 31 in the direction of arrangement of the four movable tubes 31 arranged in series. Has been.
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.

FIG. 3 is a perspective view showing an extracted portion between the lower first base plate 12 and the upper second base plate 23 connected in parallel to each other by five stud bolts 25.
FIG. 3 shows a state in which the four movable tubes 31 are raised, on the upper surface of the first base plate 12 around the base end portion connected to the first base plate 12 in the first fixed tubes 11 and 11 at both ends. The buffer material 50 is sandwiched and fixed between the fixed plates 51.

  The buffer material 50 is made of an elastic member such as hydrogenated nitrile rubber (H-NBR), for example, and is arranged on the upper surface of the first base plate 12 in a semicircular shape so as to surround the outer peripheral surface of the first fixed tube 11 about half. A fixing plate 51 having a similar semicircular arc shape is overlaid thereon, and the mounting portion 50a of the cushioning material 50, the mounting portion 51a of the fixing plate 51 and the first base plate 12 projecting outwardly at three locations are connected to the bolt 13 Passes through and is screwed and fastened to the bottom lid 5 of the intake chamber 3 so that the buffer plate 50 is clamped by the fixing plate 51 and fixed to the first base plate 12.

  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 a circular arc 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. 4). reference).

  Therefore, when the rotary operation shaft 41 is rotated by driving the electric motor 40 and the swing arms 42 and 43 swing downward and the four movable tubes 31 are retracted (lowered), the movable tubes 31 and 31 on both ends are moved. The lower opening end abuts against the buffer members 50 and 50 fixed to the first base plate 12 (see FIG. 5), and the two inner movable tubes 31 and 31 are interposed between the first base plate 12 and the buffer members 50 and 50 at both ends. Since no shock absorbing material is disposed around all four first fixed pipes 11 of the first base plate 12, it is possible to prevent abnormal noise and wear and save members.

  2 and 4, when the rotary operation shaft 41 is rotated by the drive of the electric motor 40 and the swing arms 42 and 43 swing upward and the four movable tubes 31 are advanced (raised). As described above, the elastic seal members 32 at the upper open ends of the four movable tubes 31 come into contact with the funnel-shaped end portion 22 of the second fixed tube 12, so that noise and wear are caused by the buffering effect due to the elasticity of the elastic seal members 32. Occurrence is prevented.

  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 communication is effective from the primary intake pipe to the intake port. The intake pipe length is made long so that an inertia supercharging effect at a low engine speed can be obtained. On the other hand, when the engine speed becomes high, the four movable pipes 31 are retracted (lowered) by driving the electric motor 40. 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, even at a high engine speed. An inertial supercharging effect can be obtained.

  When the intake pipe length is switched, the contact with the second fixed pipe 21 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 second is caused by the backward movement of the movable pipe 31. The contact with the first base plate 12 on the side of the one fixed tube 11 is buffered by the interposition of the buffer material 50, so that abnormal noise and wear can be prevented.

Since the buffer material 50 is fixed to the first base plate 12 on the first fixed tube 11 side and is not attached to the movable tube 31, an increase in the weight of the movable tube 31 can be avoided, and the force required for sliding the movable tube 11 And the movable tube 31 can be advanced and retracted smoothly with a small inertia force.
Therefore, 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 buffer material 50 is fixed to the first base plate 12 with the fixing plate 51 sandwiched therebetween. However, as shown in FIG. The buffer material 60 may be fixed to the upper surface of the first base plate 12 around the tubes 11 by baking.
Since no fixed plate is used, the weight can be further reduced.
In FIG. 6, the same members as those in the above embodiment are denoted by the same reference numerals except for the cushioning material 60.

Further, instead of providing a buffer material on the first base plate 12 on the first fixed tube 11 side, a buffer material 70 may be attached to the lower opening end of the movable tube 31 by baking or the like, as shown in FIG. Good.
At that time, the cushioning material 70 is attached only to the movable tubes 31, 31 at both ends of the four movable tubes 31, so that the weight can be reduced as much as possible.
In FIG. 7, the same reference numerals are used for the same members as in the above-described embodiment except for the cushioning material 70.

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. FIG. 5 is a perspective view of an intake pipe length switching mechanism in a state where a movable pipe moves forward and rises. 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. 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. It is a perspective view of the intake pipe length switching mechanism of another embodiment. FIG. 6 is a perspective view of an intake pipe length switching mechanism according to 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 ... 2nd fixed pipe, 22 ... Funnel-shaped end, 24 ... 2nd base plate, 25 ... Stud bolt, 31 ... Movable pipe, 31c ... Connection part, 32 ... Elastic seal member, 33 ... Seal ring, 35, 36 ... Projection, 40 ... Electric motor, 41 ... Rotating shaft, 42,43 ... Oscillating arm,
50 ... cushioning material, 51 ... fixed plate,
60 ... cushioning material,
70 ... cushioning material.

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,
An intake pipe length switching mechanism for an internal combustion engine, wherein a cushioning material is disposed on at least one of the opposing contact surfaces of the first fixed pipe side and the movable pipe side.   2. The intake pipe length switching mechanism for an internal combustion engine according to claim 1, wherein the cushioning material is disposed only on the contact surface on the first fixed pipe side. The internal combustion engine is a multi-cylinder internal combustion engine;
Each cylinder is provided with one set of the first fixed pipe, the second fixed pipe, and the movable pipe,
The plurality of first fixed pipes are coupled together by a base plate,
The plurality of movable tubes are connected and integrated with each other and slidably fitted to the corresponding first fixed tubes,
3. The intake pipe length switching mechanism for an internal combustion engine according to claim 2, wherein the cushioning material is disposed on contact surfaces around two fixed pipes positioned at both ends of the base plate.

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