JPH08338251A - Inlet pipe length variable mechanism - Google Patents

Abstract

PURPOSE: To provide an inlet pipe length variable mechanism in which the reduction in controllability and output caused by generation of short-circuit air flow can be prevented. CONSTITUTION: This mechanism has an auxiliary port 25 and a curved inlet pipe 23 one of which is fitted to the other in such a manner as to be capable of sliding to form mutually communicating first and second inlet passages R1, R2, and a seal ring 32 supported on one of the opposed wall surfaces in the mutual superposed part of the auxiliary port 24 and the curved inlet pipe 23 is in contact with the other opposed wall surface. Otherwise, the seal ring 32 may be arranged on the inner wall of the auxiliary port 24 forming the outside pipe, of the auxiliary port 24 and the curved inlet pipe 23, and have a ring form laid along the outer circumferential form of the curved inlet pipe 23 so that the inner circumferential surface of the seal ring 32 makes contact with the curved inlet pipe 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable intake pipe length mechanism for an internal combustion engine, and more particularly to a variable intake valve length in an intake passage constituting member of an intake system by varying the amount of overlap between the first and second intake passage pipes. The present invention relates to a mechanism for varying the intake pipe length in a variable portion.

[0002]

2. Description of the Related Art An intake system of an internal combustion engine connects an intake port of the engine with an air cleaner having an air intake port so as to connect an air cleaner, an intake pipe, a throttle body for adjusting an intake amount, and intake pulsations of other cylinders. It is configured by sequentially connecting interfering surge tanks and intake system constituent members such as an intake manifold that branches intake air into each cylinder.

The intake passage length is determined by connecting these respective intake system constituent members to each other, and the length is constant.

By the way, it is known that the volumetric efficiency of the engine changes depending on the engine speed and the length of the intake pipe, which is considered to be due to the pulsation effect and the inertial effect of the intake pipe. Here, the pulsating effect is caused by the fact that the negative pressure wave generated in the intake port at the time of opening the intake valve reciprocates between this intake port and the atmospheric pressure equivalent part side of the intake pipe and then returns as a positive pressure wave. The inertial effect is caused by the inertia shown by the flow of the air column in the intake pipe.

In either case, it is possible to expect the action of pushing the intake air into the cylinder, and this makes it possible to improve the volumetric efficiency.

Furthermore, in a multi-cylinder engine, intake interference may occur between the intake passages of the cylinders, and in order to prevent this, the intake passages of the cylinders are branched to each other until a large capacity surge tank or the like is reached. Has been done. Here, intake interference is
A negative pressure wave generated when the intake valve opens opens through the intake passage and reaches the intake port of another cylinder just before the intake valve closes,
This is a phenomenon that reduces the volumetric efficiency of the cylinder.

In this way, the intake system of the engine is provided with the intake pipe variable mechanism which can positively utilize the intake pulsation in order to prevent intake interference and improve the engine volume efficiency.

For example, as shown in FIG. 9, the intake passage forming member of the engine 1 has intake air inertia tubes 2a extending from the respective cylinders,
2b and 2c and straight tubes 3a, 3b and 3c at the tips of these
(Not shown), a surge tank 4 accommodating these straight pipes 3a, 3b, 3c, an atmosphere open pipe 6 extending from a part of the surge tank 4 and communicating with the tank inner chamber 5, and a straight pipe Three
It is composed of extension pipes 7a, 7b and 7c (not shown) which are fitted onto a, 3b and 3c.

Here, a sliding actuator (not shown) is connected to the extension pipes 7a, 7b, 7c, and the extension pipes 7a, 7b, 7c slide by this actuator, whereby the passages of the straight pipes 3a, 3b, 3c. Length of each extension pipe 7
a, 7b, 7c can be increased or decreased by dL, and as a result,
The intake path length Li of each cylinder is adjusted to be increased or decreased.

Here, the lengths of the straight pipes 3a, 3b, 3c are set so that the intake path length Li capable of positively utilizing the intake inertia and the intake pulsation in the maximum output generation region can be secured.
As a result, when the engine 1 is in the rotation speed range when the maximum output is generated, the length dL secured by each extension pipe 7a, 7b, 7c
Is zero and is in the rotation speed range at the time of maximum torque generation, the extension pipes 7a, 7b, 7c are set to increase the intake passage length Li.
The length dL secured by is controlled as large as possible.

An intake air inertial pipe provided with such an intake pipe variable mechanism is disclosed in Japanese Utility Model Publication No. 59-7537.

[0012]

By the way, in the intake pipe variable mechanism as shown in FIG. 9, the straight pipes 3a, 3b, 3c are provided.
A gap is provided between the extension pipes 7a, 7b, and 7c that are fitted over them and in order to reduce mutual sliding resistance.

Therefore, the air flow r may flow due to a short circuit through the gap. In such a case, when the short-circuited air flow r flows into the straight pipes 3a, 3b, 3c, the substantial intake path length Li is shortened.

As a result, when the short-circuit air flow r is generated, the intake inertia efficiency is reduced when the maximum torque is generated, the controllability and the output are reduced, which is a problem.

An object of the present invention is to provide an intake pipe length varying mechanism capable of preventing a decrease in controllability due to the occurrence of a short circuit air flow.

[0016]

In order to achieve the above-mentioned object, the invention of claim 1 is such that one side is slidably fitted to the other side and the first and second intake passages are formed to communicate with each other. The first and second intake passage pipes are provided, and the seal ring supported by one of the opposing wall faces of the overlapping portions of the first and second intake passage pipes is in contact with the other opposing wall face. .

According to a second aspect of the present invention, the seal ring forms an outer pipe of the first and second intake passage pipes.
It is characterized in that it is provided on the inner wall of the intake passage pipe, and the inner peripheral surface of the seal ring has a ring shape along the outer peripheral shape of the second intake passage pipe so as to abut against the second intake passage pipe.

In a third aspect of the present invention, the seal ring forms a second inner pipe of the first and second intake passage pipes.
It is arranged on the outer wall of the intake passage pipe, and the outer peripheral surface of the seal ring has a ring shape along the inner peripheral shape of the first intake passage pipe so as to abut against the inner peripheral wall of the first intake passage pipe. And

According to a fourth aspect of the present invention, the seal ring is
It is characterized in that it is held in a concave portion provided at the tip end portion of the first passage on the side of the second passage.

A fifth aspect of the present invention is characterized in that a gap is provided between the annular lower wall of the recess and the seal ring.

According to a sixth aspect of the present invention, a flange portion formed at the tip of the first intake passage pipe on the side of the second passage and a passage-direction cross-section overlapping the tip end surface of the flange portion in the second passage direction are opposite. An L-shaped L-shaped tip member is provided, and the recess is formed by fixing the flange portion and the L-shaped tip member with a screw.

According to a seventh aspect of the invention, the axial position of the second passage is variably set in the first intake passage pipe so that the first intake passage pipe slides with respect to the second intake passage pipe. It is characterized in that a variable mechanism is provided.

According to an eighth aspect of the present invention, one end communicates with the combustion chamber and the other end communicates with the surge tank, and the other end has an arcuate longitudinal cross section, and the other end of the intake pipe. Formed on the auxiliary port that is slidably fitted to the other end so as to be able to rotate around the arc center of the, and a tip portion that is located on the inner wall of the auxiliary port and on the other end side of the intake pipe. And a seal ring fitted into the recess and having an inner peripheral surface in contact with the other end of the intake pipe.

The invention according to claim 9 is characterized in that the other end of the intake pipe is accommodated in a substantially semicircular casing centered on the center of the arc.

[0025]

According to the first aspect of the present invention, the first and second intake passage pipes, one of which is slidably fitted to the other and have the first and second intake passages communicating with each other, are provided, and are relatively arranged. Since the seal ring supported by one of the facing wall surfaces in the overlapping portions of the sliding first and second intake passage pipes abuts the other facing wall surface, the seal ring here is the first and second intake air pipes. The gap between the overlapping portions of the passage pipe is sealed to prevent the occurrence of short-circuit air flow.

According to the invention of claim 2, the seal ring is the first,
The outer peripheral shape of the second intake passage pipe is arranged on the inner wall of the first intake passage pipe that forms the outer pipe of the second intake passage pipe, and the inner peripheral surface of the seal ring contacts the second intake passage pipe. The seal ring provided on the inner wall of the first intake passage pipe seals the gap between the second intake passage pipe and the first intake passage pipe, and prevents the occurrence of short-circuit airflow.

According to the invention of claim 3, the seal ring is first,
The first intake passage pipe is provided on the outer wall of the second intake passage pipe forming the inner pipe of the second intake passage pipe so that the outer peripheral surface of the seal ring contacts the inner peripheral wall of the first intake passage pipe. Since it has a ring shape along the inner peripheral shape, the seal ring provided on the outer wall of the second intake passage pipe here seals the gap with the first intake passage pipe and prevents the occurrence of a short-circuit air flow.

According to the fourth aspect of the invention, since the seal ring is held in the recess provided in the tip end of the first passage on the side of the second passage, the seal ring held in the recess is the first and the first. 2 The gap between the overlapping portions of the intake pipe is sealed to prevent the occurrence of short-circuit air flow.

According to the fifth aspect of the present invention, since a gap is provided between the annular lower wall of the recess and the seal ring, the seal ring here can move within the gap, and the first and second intake passage pipes can be moved to each other. It is possible to seal the gap between the overlapping portions and to absorb the fitting deviation between the first and second intake passage pipes.

According to a sixth aspect of the present invention, a flange portion formed at the tip of the first intake passage pipe on the second passage side and a passage-direction cross section overlapping the tip end surface of the flange portion in the second passage direction have an inverted L shape. Since the concave portion is formed by fixing the flange portion and the L-shaped tip member with a screw, before connecting the flange portion and the L-shaped tip member with a screw. A seal ring can be arranged in the portion corresponding to the recess.

According to a seventh aspect of the invention, a variable mechanism for variably setting the axial position of the second passage is provided in the first intake passage pipe so that the first intake passage pipe slides with respect to the second intake passage pipe. Since it is provided, the variable mechanism here easily moves the first and second intake passage pipes relative to each other.

According to the invention of claim 8, one end communicates with the combustion chamber and the other end communicates with the surge tank, and the other end has an arcuate longitudinal cross-section, and the other end of the intake pipe. Is formed on the inner wall of the auxiliary port and on the other end side of the intake pipe so as to be slidably fitted to the other end so as to be rotated around the arc center of A recess,
Since there is a seal ring fitted in the recess and the inner peripheral surface of which is in contact with the other end side of the intake pipe, the seal ring here seals the gap between the overlapping portions of the auxiliary port and the intake pipe, and the short-circuit air flow. Prevent the occurrence of.

According to the ninth aspect of the invention, since the other end of the intake pipe is housed in a casing having a substantially semicircular shape centered on the arc center, it is possible to prevent the casing from interfering with the auxiliary port.

[0034]

1 shows an intake pipe length varying mechanism A as an embodiment of the present invention.

This intake pipe length varying mechanism A is mounted on an in-line four-cylinder engine (hereinafter simply referred to as engine) 10.

Here, in the engine 10, an intake manifold 12 and an exhaust manifold (not shown) are integrally connected to the left and right walls of the cylinder head 11. Each tip of the intake manifold 12 is branched and formed until it reaches the surge tank 13 having a large capacity, thereby preventing intake interference occurring between the intake passages of each cylinder.

The surge tank 13 has an intake port 211 formed in the upper portion thereof, and the intake port 211 communicates with an air cleaner 17 via a throttle body 14 and an intake pipe 16.

Here, the throttle body 14 is a cylindrical body made of aluminum die-cast, and a throttle valve 18 for variably adjusting the intake air amount is arranged inside thereof.

The throttle valve 18 is a link 18
1 is connected to a throttle actuator (not shown).

Here, the air cleaner 17, the intake pipe 16,
By sequentially connecting the respective intake system constituent members such as the throttle body 14, the surge tank 13, the intake manifold 12 and the intake port 19, the total intake pipe length L _T which is the total intake path of the engine 10 is determined, and the length thereof is determined. It is variably adjusted only in the surge tank 13 part.

As shown in FIGS. 1, 2, 5, and 6, the surge tank 13 has a capacity capable of interfering with the intake pulsation of each cylinder, and particularly accommodates the main part of the intake pipe length varying mechanism A.

That is, the surge tank 13 comprises a semicircular semicircular portion 20 and a lid-shaped lid-shaped portion 21 integrally connected to the semicircular portion 20 to form a casing 131 for sealing the housing chamber 22.

The lid 21 has a suction port 211 formed on the upper side wall thereof, and as shown in FIG.
11 is provided with an inclined convex portion 212 that reduces the convex amount as the distance from 11 increases, and four openings 213 are formed in the lower portion,
The intake manifolds 12 are connected to the outside of these openings, and the curved intake pipes 23 having a circular arc-shaped cross section are connected to the inside (see FIG. 2).

Further, the lid-shaped portion 21 pivotally supports the rotary shaft 25 of the auxiliary port 24 at an intermediate position in the height direction thereof. As shown in FIG. 6, the rotary shaft 25 is pivotally attached at its left and right ends to the lid-shaped portion 21 via bearings 26, and two at each of two points from the center thereof.
The two arms 27 are integrally connected, and the pivot ends of the two arms 27 are integrally connected to the auxiliary port 24. A direct-current motor 29, which is an actuator for varying the intake pipe length, is connected to one end of the rotary shaft 25 via a reduction mechanism not shown. The DC motor 29 is driven by the controller 30 so that the auxiliary port 24 slides with respect to the curved intake pipe 23. The controller 30 drives the auxiliary port 24 and variably sets the auxiliary port 24 in accordance with the engine speed so as to hold the auxiliary port 24 at a predetermined position in the axial direction position of the second passage R2 formed by the curved intake pipe 23.

Four curved intake pipes 23 are arranged side by side, and each curved intake pipe 23 has an arcuate cross section in the longitudinal direction.
The center of the arc is formed to coincide with the center of the rotary shaft 25. Here, the curved intake pipe 23 has a tip opening 23.
1 is arranged at a substantially middle position in the height direction of the accommodation chamber 22,
As a result, the tip opening 23 is directly fed from the suction port 211.
When the intake air is introduced into 1, the intake pipe length in the surge tank 13 can be maintained at the shortest L _S b, that is, the total intake pipe length L _T of the engine can be minimized, and the intake inertia at the maximum output of the engine can be obtained. It is set to ensure the action.

On the other hand, the auxiliary port 24 is provided for each curved intake pipe 23.
The first passage R1 is formed to have an inner diameter that fits over the first passage R1 and communicates with the second passage R2. Here, the four auxiliary ports 24 juxtaposed in the lateral direction are integrated by a connecting portion 28. In particular, each auxiliary port 24 has an arcuate cross-section in the longitudinal direction, and the arc center thereof coincides with the center of the rotary shaft 25. Therefore, when the auxiliary port 24 swings around the rotation shaft 25, the inner wall of the auxiliary port 24 and the outer wall of the curved intake pipe 23 do not interfere with each other, and a predetermined interval t (see FIG. 3) can be maintained.

Here, the auxiliary port 24 is connected to the curved intake pipe 23.
In the state in which it is further projected to the maximum extent (the position shown by the solid line in FIG. 2), the tip opening 24 of the auxiliary port 24 is drawn from the suction port 211.
When the intake air is introduced into 2, the intake pipe length in the surge tank 13 can be maintained at the longest L _S 2 + L _S b, that is, the total intake pipe length L _T of the engine can be made the longest, and the maximum engine torque can be obtained. It is set to ensure the intake inertia action.

Here, as shown in FIG. 4, the auxiliary port 2
A concave portion 31 is formed on the inner wall of the intake pipe 23 on the other end side thereof, and the inner peripheral surface of the seal ring 32 fitted in the concave portion 31 has the other end side of the intake pipe 23. Abut.

The seal ring 32 may be made of a material having a low friction coefficient, and is made of Teflon resin here.
The seal ring 32 may be made of other resin or metal having a low friction coefficient. This seal ring 32 is shown in FIG.
As shown by the two-dot chain line, the inner peripheral surface is formed as a substantially rectangular annular body and contacts the outer peripheral wall of the curved intake pipe 23.

The recess 31 has a flange portion 241 formed at the tip of the auxiliary port 24 on the curved intake pipe 23 side and an L-shaped cross-section in the passage direction overlapping the tip end surface of the flange portion 241 in the second passage R2 direction. It is formed by tightening and fixing the V-shaped tip member 33 with the screw 34. In this case, before the flange portion 241 and the L-shaped tip member 33 are integrated, the seal ring 32 is interposed therebetween, and then the L-shaped tip member 33 is fastened to the flange portion 241 by the screw 34. The seal ring 32 can be easily attached.

Here, the seal ring 32 is the auxiliary port 2
4 and the curved intake pipe 23 can be sealed at the gap t between the overlapping portions. In particular, here, a gap t1 is provided between the annular lower wall 311 of the recess 31 and the seal ring 32, and the seal ring 32 can move within the gap t1. Therefore, it is possible to absorb the misalignment between the auxiliary port 24 and the curved intake pipe 23,
Along with being able to prevent a decrease in controllability due to the occurrence of short-circuit airflow. The assembling accuracy of the first and second intake passage pipes may be relatively low. The cost can be reduced.

In the above description, the recess 31 is formed by fastening the flange 241 and the L-shaped tip member 33 with the screw 34, but instead of this, as shown in FIG. Annular projection 2 of port 24
The recess 31a may be formed so as to be located on the inner wall of 42 and on the other end side of the curved intake pipe 23. In this case, the device can be simplified.

In the intake pipe length varying mechanism A described above, the seal ring is supported on the inner wall of the auxiliary port 24 which is the first intake passage pipe, and the seal ring 32 is provided on the outer peripheral wall of the curved intake pipe 23 serving as the second intake passage pipe. The inner peripheral surface was in contact.

Instead of this, as a modification of the intake pipe length varying mechanism A, the seal ring 32 is supported on the outer peripheral wall of the curved intake pipe 23 as the second intake passage pipe, and the auxiliary port 24 which is the first intake passage pipe. You may employ | adopt the structure which a seal ring contacts the inner wall of.

Also in this case, similarly to the device of FIG. 1, the seal ring 32 can seal the gap t between the overlapping portions of the auxiliary port 24 and the curved intake pipe 23.

Further, in the above-described variable intake pipe length mechanism A, the auxiliary port 24, which is the first intake passage pipe, is slidable on the outer peripheral wall of the curved intake pipe 23 serving as the second intake passage pipe on the fixed side. It was fitted out.

As a modified example of the intake pipe length varying mechanism A which is replaced with this, an auxiliary port 24 is provided on the lid portion 21 as a second intake passage pipe.
May be fixed, and the curved intake pipe 23 as the first intake passage pipe, which is the movable side, may be inserted into the auxiliary port 24.

Also in this case, as in the apparatus of FIG. 1, the seal ring 32 supported by one of the two members is connected to the auxiliary port 24.
The gap t between the curved intake pipe 23 can be sealed.

[0059]

According to the first aspect of the present invention, there is provided the first and second intake passage pipes, one of which is slidably fitted to the other and the first and second intake passages are formed to communicate with each other. Since the seal ring supported by one of the facing wall surfaces of the overlapping portions of the first and second intake passage pipes that are slidingly abutted against the other facing wall surface, the seal ring here is the first and second 2 The gap between the overlapping portions of the intake pipe is sealed to prevent the occurrence of short-circuit air flow. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow.

According to the invention of claim 2, the seal ring is first,
The outer peripheral shape of the second intake passage pipe is arranged on the inner wall of the first intake passage pipe that forms the outer pipe of the second intake passage pipe, and the inner peripheral surface of the seal ring contacts the second intake passage pipe. The seal ring provided on the inner wall of the first intake passage pipe seals the gap between the second intake passage pipe and the first intake passage pipe, and prevents the occurrence of short-circuit airflow. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow.

According to the invention of claim 3, the seal ring is first,
The first intake passage pipe is provided on the outer wall of the second intake passage pipe forming the inner pipe of the second intake passage pipe so that the outer peripheral surface of the seal ring contacts the inner peripheral wall of the first intake passage pipe. Since it has a ring shape along the inner peripheral shape, the seal ring provided on the outer wall of the second intake passage pipe here seals the gap with the first intake passage pipe and prevents the occurrence of a short-circuit air flow. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow.

According to the fourth aspect of the invention, since the seal ring is held in the recess provided in the tip end of the first passage on the second passage side, the seal ring held in the recess is the first and the first. 2 The gap between the overlapping portions of the intake pipe is sealed to prevent the occurrence of short-circuit air flow. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow.

According to the fifth aspect of the invention, since a gap is provided between the annular lower wall of the recess and the seal ring, the seal ring here can move within the gap, and the first and second intake passage pipes can be moved to each other. It is possible to seal the gap between the overlapping portions and to absorb the fitting deviation between the first and second intake passage pipes. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow, and the assembly accuracy of the first and second intake passage pipes may be relatively low, so that the cost can be reduced.

According to the sixth aspect of the present invention, the flange portion formed at the tip of the first intake passage pipe on the second passage side and the passage-direction cross-section overlapping the tip end surface of the flange portion in the second passage direction have an inverted L shape. Since the concave portion is formed by fixing the flange portion and the L-shaped tip member with a screw, before connecting the flange portion and the L-shaped tip member with a screw. A seal ring can be arranged in the portion corresponding to the recess. Therefore, the work of fitting the seal ring into the recess is facilitated and the workability is improved.

According to the invention of claim 7, a variable mechanism for variably setting the axial position of the second passage is provided in the first intake passage pipe so that the first intake passage pipe slides with respect to the second intake passage pipe. Since it is provided, the variable mechanism here easily moves the first and second intake passage pipes relative to each other. Therefore, the device can be easily created.

According to the invention of claim 8, one end communicates with the combustion chamber and the other end communicates with the surge tank, and the other end has an arcuate longitudinal cross section, and the other end of the intake pipe. Is formed on the inner wall of the auxiliary port and on the other end side of the intake pipe so as to be slidably fitted to the other end so as to be rotated around the arc center of A recess,
Since there is a seal ring fitted in the recess and the inner peripheral surface of which is in contact with the other end side of the intake pipe, the seal ring here seals the gap between the overlapping portions of the auxiliary port and the intake pipe, and the short-circuit air flow. Prevent the occurrence of. Therefore, it is possible to prevent the controllability and the output from decreasing due to the occurrence of the short-circuit airflow.

According to the invention of claim 9, the other end of the intake pipe is housed in a substantially semicircular casing centered on the center of the arc, so that the casing can be prevented from interfering with the auxiliary port. Therefore, it is possible to easily manufacture a device that can prevent the controllability and the output from decreasing due to the occurrence of the short-circuit air flow.

[Brief description of drawings]

FIG. 1 is a partially cutaway schematic side view of an engine intake system equipped with an intake pipe length varying mechanism as one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a surge tank used in the intake pipe length varying mechanism of FIG.

FIG. 3 is an enlarged cutaway sectional view of a portion S in FIG.

FIG. 4 is an enlarged cutaway sectional view of a seal ring portion used in the intake pipe length varying mechanism of FIG.

5 is a partially cutaway schematic plan view of the engine intake system of FIG. 1. FIG.

6 is a cross-sectional view taken along the line BB of FIG.

7 is a sectional view taken along line AA of FIG.

8 is an enlarged cutaway sectional view of a seal ring used in a modification of the intake pipe length varying mechanism of FIG.

FIG. 9 is a schematic cutaway side sectional view of a conventional device. 10 Engine 11 Cylinder Head 12 Intake Manifold 13 Surge Tank 131 Casing 14 Throttle Body 17 Air Cleaner 20 Semi-Circular Part 21 Lid Model Part 211 Intake Port 213 Opening 22 Storage Room 23 Curved Intake Pipe 24 Auxiliary Port 241 Flange 25 Rotating Shaft 27 Arm 29 DC motor 31 Recess 32 Seal ring 33 L-shaped tip member 34 Screw t Gap between overlapping parts t1 Gap between annular lower wall and seal ring R1 First intake passage R2 Second intake passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirofumi Higashi 5-3-8 Shiba, Minato-ku, Tokyo ・ Inside Mitsubishi Motors Corporation

Claims (9)

[Claims] 1. A first and a second intake passages, wherein first and second intake passage pipes are formed, one of which is slidably fitted to the other to form first and second intake passages communicating with each other. An intake pipe length varying mechanism, wherein a seal ring supported by one of the facing wall surfaces of the overlapping portions of the tubes abuts on the other facing wall surface. 2. The seal ring is provided on an inner wall of a first intake passage pipe forming an outer pipe of the first and second intake passage pipes, and an inner peripheral surface of the seal ring is the second intake pipe. 2. The intake pipe length varying mechanism according to claim 1, wherein the intake pipe length varying mechanism has a ring shape along the outer peripheral shape of the second intake passage pipe so as to come into contact with the passage pipe. 3. The seal ring is provided on an outer wall of a second intake passage pipe forming an inner pipe of the first and second intake passage pipes, and an outer peripheral surface of the seal ring is the first intake passage. The intake pipe length varying mechanism according to claim 1, wherein the first intake passage pipe has a ring shape along the inner peripheral shape of the first intake passage pipe so as to come into contact with the inner peripheral wall of the pipe. 4. The intake pipe length varying mechanism according to claim 1, wherein the seal ring is held in a recess provided in a tip end portion of the first passage on the second passage side. 5. The variable intake pipe length mechanism according to claim 4, wherein a gap is provided between the annular lower wall of the recess and the seal ring. 6. An L-shaped cross-section in a passage direction overlapping with a flange portion formed at a tip of the first intake passage pipe on the side of the second passage and an end surface of the flange portion in the second passage direction having an inverted L shape. The intake pipe length varying mechanism according to claim 2, further comprising a character-shaped tip member, wherein the recess is formed by fixing the flange portion and the L-shaped tip member with a screw. 7. A variable mechanism for variably setting an axial position of the second passage so that the first intake passage pipe slides with respect to the second intake passage pipe. The variable intake pipe length mechanism according to claim 1, wherein the variable intake pipe length mechanism is provided. 8. An intake pipe having one end communicating with a combustion chamber and the other end communicating with a surge tank, and the other end having an arcuate cross section in the longitudinal direction, and an arc center of the other end of the intake pipe. An auxiliary port that is slidably fitted to the other end so as to be pivoted to, and a recessed portion formed on the inner wall of the auxiliary port and located at the other end side of the intake pipe, An intake pipe length varying mechanism, comprising: a seal ring fitted in the recess and having an inner peripheral surface in contact with the other end of the intake pipe. 9. The intake pipe length varying mechanism according to claim 6, wherein the other end of the intake pipe is housed in a substantially semicircular casing centered on the arc center.