JP3265950B2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake device for an engine,
In particular, the present invention relates to an intake system of an engine in which the amount of superposition of a fixed intake pipe and a movable intake pipe in an intake path constituting member of an intake system is varied to vary the substantial length of the intake path.

[0002]

2. Description of the Related Art An intake system of an internal combustion engine is for allowing intake air from an intake port on an air cleaner side to flow into an intake port of the engine, and is usually provided with an air cleaner, an intake pipe, and a throttle body provided with a throttle valve for adjusting an intake amount. And an intake system component such as a surge tank that interferes with intake pulsation of another cylinder and an intake manifold that branches intake air into each cylinder. These intake system components are sequentially connected to each other to determine an intake path length, and the length is usually constant.

[0003] Incidentally, it is known that the volume efficiency of an engine changes according to the engine speed and the length of the intake pipe, which is considered to be due to the pulsation effect and the inertia effect of the intake pipe. Here, the pulsation effect is caused by a negative pressure wave generated at the intake port at the time of opening of the intake valve returning as a positive pressure wave after reciprocating between the intake port and the surge tank. This is caused by inertia shown by the flow of the air column in the intake pipe. In any case, the effect of pushing the intake air into the cylinder can be expected, and thereby the volume efficiency can be improved.

Further, in a multi-cylinder engine, there is a possibility that intake interference may occur between intake passages of the respective cylinders. In order to prevent this, the intake passages of the respective cylinders are branched from each other until they reach a large capacity surge tank or the like. Have been. Here, the intake interference is
The negative pressure wave generated when the intake valve was opened passed through the intake path, and reached the intake port of another cylinder just before the intake valve closed,
This is a phenomenon that reduces the volumetric efficiency of the cylinder. As described above, in setting the intake system of the engine, an intake pipe suitable for preventing intake interference and improving the engine volumetric efficiency is set. In particular, an intake pipe variable mechanism capable of positively utilizing intake pulsation is provided. Proposed.

[0005] For example, as shown in FIG.
Inertia pipe 2 whose intake path member extends from each cylinder
a, 2b, 2c and straight pipes 3a, 3b,
3c (not shown), a surge tank 4 for accommodating these straight pipes 3a, 3b, 3c, an atmosphere opening pipe 6 extending from a part of the surge tank 4 and communicating with the tank inner chamber 5, Extension tubes 7a, 7b, 7c which are fitted over the tubes 3a, 3b, 3c
(Not shown). Here, the extension pipes 7a, 7
A sliding actuator (not shown) is connected to the extension pipes 7a, 7b, and 7c.
By sliding the 7c, the passage length of the straight pipes 3a, 3b, 3c can be adjusted by the extension pipes 7a, 7b, 7c by dL. As a result, the substantial intake branch path length L _{T of} each cylinder is obtained.
Has been adjusted.

Here, the lengths of the straight pipes 3a, 3b, 3c are set so as to ensure the intake branch path length in which the intake inertia and intake pulsation can be positively used in the maximum output generation range.
Accordingly, when the engine 1 is in the high rotation speed range when the maximum output is generated, the length d secured by each of the extension pipes 7a, 7b, 7c
The L to zero, whereas, when in the rotational speed range of the maximum torque generation, the extension tube 7a, 7b, the length dL of 7c to secure retained maximally increasing hold the branch intake path length L _T Like that. However, in the variable intake pipe mechanism as shown in FIG. 24, the airflow r is short-circuited through the gap t between the straight pipes 3a, 3b, 3c and the extension pipes 7a, 7b, 7c externally fitted thereto. May be. In such a case, when the short-circuited airflow r flows into the straight pipes 3a, 3b, 3c,
It reduced substantial intake branch path length L _T, reduces the intake inertia efficiency in the maximum torque generation or the like, controllability and output is decreased, and has a problem.

[0007] An intake inertia pipe provided with such an intake pipe variable mechanism is disclosed in Japanese Utility Model Publication No. 59-7537. Such an intake system of an engine in order to solve the problem of air flow r is shorted substantial branch intake path length L _T to shorten it has been proposed by the present inventors through the gap t. 25 and 26, the surge tank 9, the throttle body 10 and the air cleaner 37 are connected to the upstream end of the intake pipe variable device 8, and the intake manifold is connected to the downstream end of the intake pipe variable device 8. 12 are connected.

Here, the air cleaner 37, the intake pipe 13,
Each intake system component such as a throttle body 10, a surge tank 9, an intake manifold variable device 8, an intake manifold 12, and an intake port (not shown) determines the total intake pipe length L. In particular, the intake manifold variable device 8 The length L is variably adjusted. That is,
The variable intake pipe line device 8 fixes the fixed intake pipe 14 to the lid-shaped casing 15, and integrally connects the movable intake pipe 16 to the drive shaft 18 pivotally supported by the lid-shaped casing 15 via the arm 117. Note that a semicircular casing 19 is superimposed on the lid-shaped casing 15, and the housing casing 20 is formed by both casings.
Is formed.

A DC motor (not shown) is connected to one end of the drive shaft 18. The DC motor drives the arcuate movable intake pipe 16 to slide with respect to the arcuate fixed intake pipe 14. In particular, the center of the arc of each movable intake pipe 16 is
Coincides with the center of 8. For this reason, when the movable intake pipe 16 swings about the center of the drive shaft 18, the inner wall of the movable intake pipe 16 and the outer wall of the fixed intake pipe 14 do not interfere with each other, and a predetermined interval t (FIG.
6) to reduce the sliding resistance. In particular, as shown in FIG. 26, a seal ring 21 is supported on the inner wall at the rear end of the movable intake pipe 16, and the inner peripheral surface of the seal ring 21 contacts the outer wall of the fixed intake pipe 14 to block the interval t. The short circuit of the intake path is prevented. Also in this case, in a state where the movable intake pipe 16 is made to protrude from the fixed intake pipe 14 to the maximum, the tip end opening 242 of the auxiliary port 24 is
Is set so that the intake pipe length in the casings 15 and 19 can be maintained to be the longest (L1 + L2), and the inertia action of the intake air can be ensured in a low engine speed range (for example, at idle). .

[0010]

By the way, in the intake device for an engine as shown in FIG. 25, the inner peripheral surface of the seal ring 21 of the movable intake pipe 16 is always in close contact with the outer wall of the fixed intake pipe 14. As a result, a large sliding resistance occurs, which leads to an increase in the size of the drive actuator, and the responsiveness also decreases. Therefore, the inner peripheral surface of the seal ring 21 that blocks the interval t is often set to be relatively rough in contact with the outer wall of the fixed intake pipe 14, and as a result, the action of preventing the seal ring 21 from short-circuiting the intake path. Cannot be fully extracted, which is a problem.

Particularly, in a low rotation range where the engine is idling, the movable intake pipe 16 protrudes as much as possible from the movable intake pipe 16 and the overlapped portion of both pipes is small, and as a result, the inner peripheral surface of the seal ring 21 is reduced. A short-circuit flow is likely to flow through a small gap between the suction pipe 14 and the outer wall of the fixed intake pipe 14, whereby the length of the intake pipe in the accommodation room becomes the longest (L1 + L2), and the case where the short-circuit flow shortens the intake path length L. As a result, hunting occurs, and as a result, the intake inertia effect becomes unstable in a low rotation range such as an idle operation range of the engine, and rotation in the low rotation range becomes unstable. An object of the present invention is to eliminate sliding resistance between a movable intake pipe and a fixed intake pipe when the engine is in a low rotation range, and to reliably generate a short-circuit airflow between the movable intake pipe and the fixed intake pipe. To
An object of the present invention is to provide an intake device for an engine that can stably obtain an intake inertia effect in a low rotation speed region such as an idle operation region of the engine.

[0012]

In order to achieve the above object, according to the present invention, at least a part of an intake passage is formed by fitting to an upstream end of a fixed intake pipe communicating with an engine combustion chamber. A movable intake pipe movable between a longest intake passage position where the overlap length with the fixed intake pipe is the shortest and a shortest intake passage position where the overlap length is the longest; An intake system for an engine, comprising: an elastic seal ring mounted on one of the fixed intake pipes and hermetically contacting at least the other intake pipe when the movable intake pipe is at the longest intake passage position. smell
The other of the movable intake pipe or the fixed intake pipe
One intake pipe on the surface of the intake pipe facing one intake pipe
Form an annular protrusion to reduce the gap between the wall and the elastic
The diameter of the body seal ring is about the same as the diameter of the part other than the annular protrusion
Or between the annular protrusion and a diameter other than the annular protrusion
The movable intake pipe is positioned at the longest intake passage position.
The annular protrusion and the elastic seal ring
And air-tightly contact with each other.

[0013]

According to a third aspect of the present invention, in the intake system for an engine according to the first aspect , when the movable intake pipe moves from the longest intake passage position to the shortest intake passage position, the elastic seal ring is attached to the other end. A sliding contact surface having a substantially constant diameter is provided on the other intake pipe so as to be slidably contacted with the intake pipe of the above.

According to a third aspect of the present invention, in the intake device for an engine according to the second aspect, the diameter of the annular projection is gradually increased from the diameter of the sliding contact surface to the annular projection. The elastic seal ring is in airtight contact with the tapered portion when the movable intake pipe is at the longest intake passage position.

[0016] The invention of claim 4, claims 1 to 3
In the intake system for an engine described in the above, an annular projection is located on the space side of the intake pipe formed by the movable intake pipe and the fixed intake pipe, and is provided outside the intake pipe formed by the movable intake pipe and the fixed intake pipe. The elastic seal ring is located on the space side.

[0017] The invention of claim 5, claims 1 to 4
In the above described intake system for an engine, an annular projection is formed on an outer surface of the fixed intake pipe, and the movable intake pipe is fitted to the fixed intake pipe.

According to a sixth aspect of the present invention, in the intake system for an engine according to the fifth aspect , an elastic seal ring is fitted to an axial end of the movable intake pipe.

[0019] The invention of claim 7, claim 1 to claim 3
In the intake device for an engine described above, an annular protrusion is formed on an inner surface of the movable intake pipe, and the movable intake pipe is fitted around a fixed intake pipe.

The invention according to claim 8 is the invention according to claims 1 to 7.
The above described intake system for an engine is characterized in that the fixed intake pipe is formed as an arcuate intake pipe, and the movable intake pipe is formed as an arcuate intake pipe which rotates around the arc center of the fixed intake pipe.

According to the ninth aspect of the present invention, there are provided the first to eighth aspects.
In the intake system for an engine described above, an upstream end of the fixed intake pipe is located in an intake container through which intake air is conducted via an air cleaner, and the movable intake pipe moves in the intake container, The combustion chamber is configured to be supplied with intake air that has passed through the air cleaner.

According to a tenth aspect of the present invention, at least a part of the intake passage is formed by fitting to the upstream end of the fixed intake pipe communicating with the engine combustion chamber, and the overlap length with the fixed intake pipe is minimized. A movable intake pipe movable between a longest intake passage position and a shortest intake passage position where the overlap length is the longest, and a space of one of the movable intake pipes or one of the fixed intake pipes located outside the movable intake pipe; An elastic seal ring that is held in the part and slides against the other intake pipe located on the inner side, wherein the seal ring has a plurality of contact parts with at least one intake pipe and a contact part with the other intake pipe. There is a feature that the contact portion of the elastic seal ring is switched by a pressure difference between the inside and outside of the intake pipe so as to be movable in the space of the one intake pipe.

According to an eleventh aspect of the present invention, in the intake system for an engine according to the tenth aspect , the elastic seal ring has an X-shaped cross section, and the diagonal projections are fixed and movable intake pipes, respectively. And the contact portion of the elastic seal ring is switched by a pressure difference between the inside and outside of the intake pipes.

According to a twelfth aspect of the present invention, in the intake system for an engine according to the tenth aspect , the elastic seal ring has one end of either side wall in the space of the one intake pipe. And the contact portion is switched by the pressure difference between the inside and outside of the intake pipe, and is always in sliding contact with the other intake pipe.

According to a thirteenth aspect of the present invention, at least a part of the intake passage is formed by fitting to the upstream end of the fixed intake pipe communicating with the engine combustion chamber, and the overlap length with the fixed intake pipe is minimized. A movable intake pipe that can move between the longest intake passage position and the shortest intake passage position where the overlap length is the longest, and is supported by one of the movable intake pipes or one of the fixed intake pipes located outside the movable intake pipe. An elastic seal ring slidably in contact with the other intake pipe located on the inner side; and a movable intake pipe and a fixed intake pipe formed on one of the intake pipes on a surface opposite to a sliding contact surface of the elastic seal ring. And an outside air flow passage for applying air pressure outside the intake pipe constituted by

According to a fourteenth aspect of the present invention, in the intake system for an engine according to the tenth to thirteenth aspects, the fixed intake pipe rotates about an arc center of the fixed intake pipe and the movable intake pipe rotates about an arc center of the fixed intake pipe. It is characterized by being formed by a circular arc-shaped intake pipe.

According to a fifteenth aspect of the present invention, in the intake system for an engine according to the tenth to fourteenth aspects, the upstream end of the fixed intake pipe is located in an intake container through which intake air is conducted through an air cleaner. Preferably, the movable intake pipe moves within the intake container, and intake air that has passed through the air cleaner is supplied to a combustion chamber of the engine.

According to a sixteenth aspect of the present invention, at least a part of the intake passage is formed by fitting to the upstream end of the fixed intake pipe communicating with the engine combustion chamber, and the overlap length with the fixed intake pipe is minimized. A movable intake pipe that can move between a longest intake passage position and a shortest intake passage position where the overlap length is the longest, and is mounted on one of the movable intake pipes or the fixed intake pipe, and is mounted on the other intake pipe. The seal ring slidingly contacting the intake pipe and the other intake pipe axis at a portion slidingly contacting the elastic seal ring when the movable intake pipe is at the longest intake passage position are formed linearly. I do.

According to a seventeenth aspect of the present invention, in the intake system for an engine according to the sixteenth aspect , the elastic seal ring slides on the other intake pipe at a plurality of positions in the axial direction.

[0030]

FIG. 1 shows an intake system for an engine according to an embodiment of the present invention. The intake device of this engine is mounted on an in-line four-cylinder engine (hereinafter simply referred to as engine) 30. Here, the engine 30 has its cylinder head 3
An intake manifold 32 and an exhaust manifold (not shown) are integrally connected to the left and right walls of the device 1. Each end of the intake manifold 32 passes through a variable intake path length mechanism A accommodating a first fixed intake pipe 43 and a movable intake pipe 42, a second fixed intake pipe 33, and a surge tank 3.
4 sequentially.

As shown in FIGS. 1 and 2, the surge tank 3
4 has a suction port 341 formed in the upper part thereof,
An air cleaner 37 communicates with 41 via a throttle body 35 and an intake pipe 36. The surge tank 34 has a suction port 341 formed in the side wall of the upstream portion, and has a slope protrusion 342 that reduces the protrusion amount as the distance from the suction port 341 increases, as shown in FIG. Four openings 343 are formed, and each of the intake manifold extension portions 33 is formed to extend through these openings. The end of the intake manifold extension 33 is connected to the intake port 401 in the lid type casing 40 of the intake pipe length varying mechanism A. Here, the throttle body 35 is a cylindrical body made of aluminum die-cast, and a throttle valve 3 for variably adjusting the intake air amount is provided therein.
8 are provided.

The throttle valve 38 has a link 38
1 is connected to a throttle actuator (not shown). Here, the respective intake system components such as the air cleaner 37, the intake pipe 36, the throttle body 35, the surge tank 34, the intake manifold extension 33, the variable intake pipe length mechanism A, the intake manifold 32, and the intake port 29 are sequentially connected. All intake pipe length L _I that is in the intake path the entire length of the engine 30 is determined by Rukoto, its length intake conduit length varying mechanism a
Is variably adjusted only by. As shown in FIGS. 1 to 3, the variable intake path length mechanism A forms an outer frame with a bowl-shaped semicircular casing 39 and a lid-shaped lid-shaped casing 40 integrally connected thereto, and inside these casings. The accommodation room 41 is sealed. The semicircular casing 39 has a bowl shape so as not to interfere with a movable intake pipe 42 described later, and a flange 391 which is overlapped with the lid type casing 40 and is bolted is formed on a peripheral edge thereof.

On the other hand, as shown in FIGS. 4 and 5, the lid-type casing 40 has a substantially rectangular dish-like shape having a central projection 402, and its peripheral edge is superimposed on the semicircular casing 39, and is bolted. The formed flange 403 is formed. The lid-type casing 40 has four suction ports 401 formed on an upstream side wall, and an actuator shaft 44 for swinging the movable suction pipe 42 is pivotally supported at an intermediate position in the height direction (vertical direction in the drawing),
Four downstream openings 408 are formed on the downstream side wall. Four fixed intake pipes 43 are integrally arranged side by side at each downstream opening 408 of the lid type casing 40, and each fixed intake pipe 43 is formed to have an arc-shaped cross section in the longitudinal direction. Is formed so as to coincide with the center line L0.

The curved space 4 which forms a main part of the accommodation room 41
11 is formed between the central projection 402 of the lid-shaped casing 40 and the inner wall of the semicircular casing 39, and this curved space 411 is formed.
Inside, the movable intake pipe 42 fitted to the fixed intake pipe 43 can rotate around the center line L0. In particular, here, the movable intake pipe 42
Is rotated about the center line L0, the lid-shaped casing 40
The volume of the curved space 411 is reduced within a range that does not interfere with the central projection 402 and the inner wall of the semicircular casing 39, thereby reducing the volume of the intake passage on the downstream side of the throttle valve 38 and accompanying the opening and closing operation of the throttle valve. The responsiveness of engine speed fluctuations has been improved.

As shown in FIG.
The left and right ends thereof are covered with a lid type casing 4 via a bearing 45.
The two arms 27 on the left and right sides are integrally connected to two points from the left and right ends. Here, 4 corresponding to each cylinder
The four movable intake pipes 42 are arranged in parallel in the cylinder direction and are integrally connected to each other, and the rotating ends of each of the two arms 27 are integrally connected to the left and right ends of the four movable intake pipes 42. Here, the lid-type casing 40 has a long trough 404 formed in the center of the center protrusion 402, and the actuator shaft 44 is accommodated in the lower wall side of the trough 404. Further, upright walls 405 are formed at the left and right ends of the central projection 402, respectively, and a vertical groove 407 is formed between the upright wall 405 and the side wall 406 of the lid type casing 40. This flute 4
Reference numeral 07 denotes left and right 2 rotating around the actuator shaft 44.
The book arm 27 can be accommodated without interference.

A DC motor 28, which is an actuator for varying the length of the intake pipe, is connected to one end of the actuator shaft 44 via a speed reduction mechanism (not shown). This DC motor 28
Is driven by the controller 49 so that the movable intake pipe 42 slides with respect to the fixed intake pipe 43. Controller 49
Drives the movable intake pipe 42 externally fitted to the fixed intake pipe 43, and drives the movable intake pipe 42 to be held at a predetermined position in the axial direction of the second passage R2 formed by the fixed intake pipe 43. Here, the fixed intake pipe 43 has its tip opening 431.
Is disposed at a substantially intermediate position in the height direction of the storage chamber 41, whereby the front end opening 431 is directly provided from the suction port 401.
When allowed to flow into the intake, the can hold intake pipe length of the intake conduit length varying mechanism in A the shortest LA, i.e., the most can be shortened branch intake path length L _T of the engine, the intake pulsation at the maximum output of the engine It is set so that the action can be secured.

On the other hand, the movable intake pipe 42 is formed to have an inner diameter fitted to each of the first fixed intake pipes 43 and forms a first passage R1 communicating with the second passage R2. Here, the four movable intake pipes 42 arranged in parallel in the cylinder direction corresponding to the respective cylinders and fixed to each other are formed to have an arc-shaped longitudinal cross-sectional shape, and the center of the arc is the actuator shaft 4.
4 coincides with the center line L0. Therefore, the four movable intake pipes 42 can be simultaneously swung about the actuator shaft 44. As shown in FIG. 3, the movable intake pipe 42 has a maximum intake passage position P1 at which the movable intake pipe 42 projects maximum from the fixed intake pipe 43.
At the position (indicated by the solid line in FIG. 3), when the intake air flows into the funnel-shaped tip opening 421 of the movable intake pipe 42, the intake branch path length in the intake pipe length variable mechanism A is the longest (LA + LM). , And the intake branch path length L _{T obtained} by adding the intake path lengths of the intake manifold 32 and the intake port 29 to this.
Is set to be the longest, and the intake inertia action in a low rotation range such as when the engine is idling can be secured.

As shown in FIG. 3, the suction port 401 of the lid-type casing 40 is formed by a cylindrical seal 45 that is fitted and inserted into the lid-type casing 40 integrally. The inner annular end 451 of the tubular seal 45 is pressed against the funnel-shaped tip opening 422 of the movable intake pipe 42 to seal the accommodation chamber 41 and the inside of the intake passage. As shown in FIGS. 13 and 14A and 14B, a concave portion 423 as a space is formed at the rear end of the movable intake pipe 42, and a seal ring 46 is fitted into the same. Here, in particular, the fixed intake pipe 4 of the movable intake pipe 42
A flange portion 421 formed at the end on the third side;
The L-shaped tip member 47 having an L-shaped cross-section in the passage direction overlapping with the tip surface of the second passage R2 in the direction of the second passage R2 is formed by tightening with a screw 48. In this case, before the flange portion 421 and the L-shaped tip member 47 are integrated, the seal ring 46 is interposed between them, and the L-shaped tip member 47 is fastened to the flange portion 421 with the screw 48 thereon. And the attachment of the seal ring 46 can be facilitated.

In the above description, the concave portion 423 is formed by tightening and fixing the flange portion 421 and the L-shaped tip member 47 with the screw 48. Alternatively, FIGS. ), The recess 423 may be formed directly on the inner wall of the rear end of the movable intake pipe 42.
In this case, the device can be simplified. On the other hand, the fixed intake pipe 4
An annular protruding portion 432 is formed at the tip of 3, and the diameter gradually changes from the small diameter portion 433 to the annular protruding portion 432 at a continuous portion between the annular protruding portion 432 and the small diameter portion 433 forming a sliding contact surface. A tapered portion 434 is provided.

Therefore, the elastic seal ring 32 can be slidably contacted with the outer peripheral surface of the small-diameter portion 433 of the other fixed intake pipe 43, can slide smoothly, reduce the sliding resistance, and reduce the sliding resistance. Responsiveness can be secured. Further, only when the movable intake pipe is at the longest intake passage position P1, the seal ring 46 can abut the tapered portion 434 in an airtight manner, and can reliably seal the gap between both intake pipes. A stable intake inertia effect can be obtained. Further, the accuracy error between the movable intake pipe 42 and the fixed intake pipe 43 can be absorbed, and the controllability can be prevented from deteriorating due to the generation of short-circuit airflow. 1st, 2nd
The assembly accuracy of the intake pipe may be relatively low. Cost can be reduced. The seal ring 46 may be formed of a material having a low coefficient of friction, and is formed of NBR resin here.
The seal ring 46 may be made of Teflon resin or metal having a low coefficient of friction.

This seal ring 46 is shown in FIGS.
As shown in (a) and (b), the cross section is X-shaped. Here, projections m1 and m2 that are diagonal to each other are fitted into the concave portion 423 on the movable intake pipe 42 side, and the annular projections 432 are in contact with the projections n1 and n2. Here, when the inside of the intake pipe is at a negative pressure and the outside of the intake pipe is at a positive pressure, the projection m2 is pressed against the side wall of the recess 423, and the projection n1 is pressed against the annular projection 432, and the seal ring 46 reliably exhibits a sealing action. . On the other hand, when the pressure inside the intake pipe is positive and the pressure outside the intake pipe is negative, the projection m1
The protrusions n2 are pressed against the annular protrusions 432 respectively on the side walls of the seal 23, and the seal ring 46 surely exhibits a sealing action. For this reason, the projections n1 and n2 and the projections m1 and m2, which are diagonal to each other, of the seal ring 46 having an X-shaped cross section can enhance the sealing action due to the pressure difference between the inside and outside of the intake pipes, and the overlapping portions of both intake pipes Can be more reliably sealed, the occurrence of short-circuit airflow can be prevented, and the intake inertia effect can be stably obtained.

The seal ring 46 fitted in the recess 423 of the movable intake pipe 42 has an X-shaped cross section. Instead, as shown in FIGS. 15 and 16A and 16B. Alternatively, a W-shaped seal ring 46a may be used.

In this case, projections m1 and m2, which are diagonal to each other, are fitted into the recess 423 of the movable intake pipe 42, and the projections n1 and n2 abut on the annular projection 432. Here, when the pressure inside the intake pipe is negative and the pressure outside the intake pipe is positive, the protrusion m2 is
The protrusions n1 and n2 are pressed against the annular protrusions 432 on the side walls of the third member 3, respectively, and the seal ring 46 reliably exhibits a sealing action. On the other hand, when the pressure inside the intake pipe is positive and the pressure outside the intake pipe is negative, the protrusion m1 is pressed against the side wall of the concave portion 423, and the protrusions n1 and n2 are pressed against the annular protrusion 432. Show. Therefore, the cross section W
Diagonal protrusions n of the U-shaped seal ring 46a
1, n2 and the projections m1 and m2 can enhance the sealing action by the pressure difference between the inside and outside of the intake pipes, more reliably seal the gap between the overlapping portions of both intake pipes, and prevent the generation of short-circuit airflow. A stable intake inertia effect can be obtained.

When such an intake system of the engine is driven, the controller 49 controls the movable intake pipe 42 through the DC motor 46 in a low rotation range including the idle operation of the engine.
Is driven around an actuator shaft 44 to move the movable intake pipe 42
To the longest intake passage position P1. In this case, the funnel-shaped tip end opening 422 of the movable intake pipe 42 is pressed against the cylindrical seal 45, and the seal ring 46 can reliably seal between the movable intake pipe 42 and the annular projection 432, and the housing chamber 41 side and the intake passage The inside can be sealed. When the intake air flows from the surge tank 34 side, the intake branch path length in the intake pipe length variable mechanism A can be maintained at LA + LM, and the flow path of the intake manifold extension 33 (shown by hatching in FIG. 3). ) Is continuously applied. That is, if where the flow path length of the intake manifold 32 and the intake port 29 and LP, substantial branch intake path length L _T of each cylinder (= LA + L
M + LB + LP) can be maximized, and the inertia of the intake air can be sufficiently secured in a low rotation range such as when the engine is idling. In addition, the volume of the intake chamber 41 downstream of the throttle valve 38 does not include the volume of the housing chamber 41, and the throttle valve The responsiveness of engine rotation fluctuation due to the opening and closing operation of the engine can be improved, and the engine rotation in a low rotation range can be stabilized.

On the other hand, when the engine reaches the high rotation range, the controller 49 controls the movable intake pipe 42 via the DC motor 46.
Is driven around an actuator shaft 44 to move the movable intake pipe 42
Is moved to the shortest intake passage position P0.
In this case, the seal ring 46 can smoothly slide on the outer peripheral surface of the small-diameter portion 433 of the fixed intake pipe 43, and the rotation resistance at that time is relatively small, and a switching operation with good responsiveness can be performed. Substantial intake branch path length L of each cylinder in this high rotation range
_T (= LA + LP) is maintained at the shortest length, and it is possible to secure the intake pulse operation for the maximum output of the engine, thereby contributing to the improvement of the output. FIG. 23 shows a characteristic of the torque T according to the engine speed Ne when the engine 30 to which the present invention is applied is driven.

Here, the symbol は indicates the characteristics of the base engine, the symbol △ indicates the characteristics of the engine having a gap between both intake pipes, and the symbol x indicates the characteristics of the engine to which the invention is applied.
Here, the movable intake pipe 42 is held at the shortest intake passage position P0 on the low rotation side with the engine rotation speed set to a threshold of 5000 rpm, and the movable intake pipe 4 is held in the high rotation range exceeding 5000 rpm.
2 is held at the longest intake passage position P1. In this case, in the device of the present invention indicated by the symbol x, the torque value in the entire rotation range clearly increases from the torque values indicated by the other symbols ○ and の た め, particularly because the sealing property between the two intake pipes is good. The engine output has been improved. As described above, in the variable intake pipe length mechanism A, the seal ring 4 is provided on the inner wall of the movable intake pipe 42.
6 is supported, and the inner peripheral surface of the seal ring 46 is in contact with the outer peripheral wall of the fixed intake pipe 43.

Instead of this, as a modified example of the variable intake pipe length mechanism A, a seal ring 46 is provided on the outer peripheral wall of the fixed intake pipe 43.
And a configuration in which a seal ring abuts on the inner wall of the movable intake pipe 42 may be adopted. In such a case as well, the seal ring 46 can seal the gap between the overlapping portions of the movable intake pipe 42 and the fixed intake pipe 43, similarly to the apparatus of FIG. Further, in the above-described variable intake pipe length mechanism A, the movable intake pipe 42 is slidably fitted on the outer peripheral wall of the fixed intake pipe 43. May be adopted. Also in this case, FIG.
As in the case of the device described above, the seal ring 46 supported by one of the two members can seal the gap between the movable intake pipe 42 and the fixed intake pipe 43.

In the above description, both the fixed intake pipe 43 and the movable intake pipe 42 are formed to have an arc-shaped cross section in the longitudinal direction, and the center of the arc coincides with the center line L 0 of the actuator shaft 44. For this reason, as shown in FIG.
Abuts on the outer peripheral surface of the radiation L, which extends from the center line L0.
As shown by the alternate long and short dash line L2, the seal ring 4
6b is inclined and comes into contact with the outer peripheral wall of the fixed intake pipe 43, so that a perfect circular contact is not made. As a result, there is a possibility that the sealing performance may be deteriorated. In order to eliminate this problem, a fixed intake pipe 43a shown in FIG. 17 may be used instead of the fixed intake pipe 43 of the intake device of the engine shown in FIG.

In this case, the distal end e of the fixed intake pipe 43a is formed in a straight tubular shape unlike the other parts. When the seal ring 46b abuts on the straight distal end portion e, the seal ring 46b can abut on the outer peripheral wall of the fixed intake pipe 43 in a perfect circular shape, and as a result, it is possible to prevent a decrease in sealing performance. In addition,
Here, the above-mentioned annular protruding portion 432 may be formed in a straight tubular shape by expanding the straight distal end portion e of the fixed intake pipe 43a, and in this case also, sufficient sealing performance can be secured. As described above, in the variable intake pipe length mechanism A, a concave portion 423 is formed in the inner wall of the movable intake pipe 42, the seal ring 46 is fitted therein, and the inner peripheral surface of the seal ring 46 is attached to the outer peripheral wall of the fixed intake pipe 43. Was in contact. Instead of this, a configuration as shown in FIG. 19 may be adopted as a modified example of the intake pipe length variable mechanism A.

The movable intake pipe 42c used in the modified example of the variable intake pipe length mechanism A shown in FIG. 19 has a recess 423c formed at the overlapping end with the fixed intake pipe 43c.
A through hole g is formed in the low wall f, and a seal ring 46c having a U-shaped cross section is fitted in the concave portion 423c. here,
When the inside of the intake pipe has a negative pressure and the outside of the intake pipe has a positive pressure, which is the mode requiring the highest sealing performance, the concave portion 42 on the movable intake pipe 42 side is used.
Positive pressure is applied to 3 via a through hole g, and a U-shaped seal ring 46c is pressed against the outer peripheral wall of the fixed intake pipe 43, so that sealing can be reliably performed. Further, as a modified example of the intake pipe length variable mechanism A, a configuration as shown in FIGS. 20 to 22 may be adopted.

Here, the movable intake pipes 42d and 42e used in the modified example of the intake pipe length variable mechanism A shown in FIGS. 20 and 21 are provided with an annular locking portion 4 at the overlapped end with the fixed intake pipes 43d and 43e.
24, and an elastic seal ring 46d,
46e is externally fitted and adhered. In these cases, when the movable intake pipe 42 is moved to the longest intake passage position P1, the inner peripheral surfaces of the seal rings 46d and 46e abut on the annular projection 432 of the fixed intake pipe 43 and the tapered portion 434 in front of the fixed intake pipe 43. Sealability can be secured. Further, in the case of the variation example of the variable intake pipe length mechanism A shown in FIG. To form

In this case, when the movable intake pipe 42f is moved to the longest intake passage position P1, the outer peripheral surface of the seal ring 46f comes into contact with the inner bulging portion 424 of the movable intake pipe 42, and the sealing performance between the inside and outside of the intake pipe can be secured. Also in each of these modified examples, the seal rings 46c to 46f can smoothly slide on the outer peripheral surface of the fixed intake pipe 43 or the inner peripheral surface of the movable intake pipe 42, and the movable intake pipe 42f is moved to the longest intake passage position P1. , Each of the seal rings 46c to 46f can secure the sealing property between the inside and outside of the intake pipe. As described above, the intake device of each engine shown in FIG. 1 and the modification thereof reliably seals the gap between the overlapping portions of both intake system pipes only when the movable intake pipe 42 is at the longest intake passage position P1. When the movable intake pipe 42 is at a position other than the longest intake passage position P1, the gap between the overlapping portions of the two intake system pipes is sealed. Roughness can be maintained, sliding resistance can be reduced, and responsiveness of the intake pipe length variable mechanism A can be ensured.

In particular, an annular protruding portion 432 for reducing the gap between one of the movable or fixed intake pipes and one of the intake pipe walls is formed on the surface of the other intake pipe facing the one intake pipe. May be set to a value approximately equal to the diameter other than the annular protrusion 432 or a value between the diameter of the annular protrusion 432 and the diameter other than the annular protrusion. In this case, when the movable intake pipe 4 is at the longest intake passage position P1, the annular projection 432 is
As a result, the gap between the two intake pipes can be reliably sealed only when the movable intake pipe is at the longest intake passage position, and the intake inertia effect in a low rotation range. Is obtained stably.

In particular, the movable intake pipe is located at the longest intake passage position P1.
The sliding contact surface having a substantially constant diameter on the other intake pipe so that the seal ring 46 comes into sliding contact with the other intake pipe loosely when moving from the position to the shortest intake passage position P0 side.
May be provided continuously. In this case, when the movable intake pipe is at the longest intake passage position P1, the gap between the two intake system pipes can be reliably sealed. When the movable intake pipe is at a position other than the longest intake passage position, the gap between the two intake system pipes is closed. Roughness can be maintained, sliding resistance can be reduced, and responsiveness of the variable intake mechanism can be ensured. In particular, a tapered portion 434 whose diameter gradually changes from the diameter of the sliding contact surface to the annular projecting portion may be provided at a portion of the annular projecting portion 432 connected to the sliding contact surface. in this case,
When the movable intake pipe 42 is at the longest intake passage position P1, the seal ring 46 can abut the tapered portion 434 in an airtight manner, and as a result, the elastic seal ring has the entire outer circumference including the annular projection of the other intake pipe. Sliding on the surface can be performed smoothly, sliding resistance can be reduced and responsiveness of the variable intake mechanism can be secured.

In particular, the annular projection 432 is located on the side of the space inside the intake pipe formed by the movable intake pipe 42 and the fixed intake pipe 43, and the outer space side of the intake pipe formed by the movable intake pipe and the fixed intake pipe. The seal ring 46 may be located at the position. In this case, the seal ring 46 is connected to the annular protrusion 43 of the other intake pipe.
2 can smoothly contact and secure airtightness. In particular,
An annular protrusion 432 is formed on the outer surface of the fixed intake pipe 43,
When the movable intake pipe 42 is externally fitted to the fixed intake pipe, the movable intake pipe can abut the annular projection 432 at the longest intake passage position P1 where the overlap length of the movable intake pipe with the fixed intake pipe is the shortest, Airtightness can be ensured.

In particular, when the seal ring 46 is fitted to the end of the movable intake pipe 42 in the axial direction, the seal ring 46 can abut on the annular protrusion on the outer surface of the fixed intake pipe, thereby ensuring airtightness. In particular, an annular protrusion may be formed on the inner surface of the movable intake pipe 42, and the movable intake pipe 42 may be fitted over the fixed intake pipe. In this case, the movable intake pipe 42 is located at the longest intake passage position where the overlapping length of the movable intake pipe 42 with the fixed intake pipe 43 is the shortest.
The annular projection on the inner surface can smoothly contact the seal ring provided on the fixed intake pipe 42, and airtightness can be secured. In particular, when the fixed intake pipe 43 is formed as an arcuate intake pipe and the movable intake pipe 42 is formed as an arcuate intake pipe rotating around the arc center L0 of the fixed intake pipe 43, the movable intake pipe 42 is formed as a fixed intake pipe. It can be smoothly rotated in a state where it is fitted to the outside.

In particular, the upstream end of the fixed intake pipe is located in an intake vessel 40 through which intake air is conducted via an air cleaner 37, and the movable intake pipe 42 moves in the intake vessel 40, and the combustion chamber of the engine 30 May be supplied with air that has passed through the air cleaner 37. In this case, regardless of the airtightness of the movable intake pipe 42 and the fixed intake pipe, the intake air from the air cleaner is reliably sealed from the outside by the intake container 40 and supplied to the combustion chamber. Next, the intake device of each engine of FIG. 1 and its modification includes a movable intake pipe 42 and a fixed intake pipe 4.
When the contact portion of the seal ring 46 located at the overlapping portion of the three receives a pressure difference between the inside and outside of the intake pipes, one of the plurality of contact portions of the seal ring 46 surely becomes the other. Contact the contact part of the intake pipe. Therefore, the gap between the overlapping portions of the two intake system pipes can be reliably sealed, the occurrence of short-circuit airflow can be prevented, and the intake inertia effect can be stably obtained.

In particular, the seal ring 46 has an X-shaped cross section, and projections m1, m2, n1, and n2 that are diagonal to each other.
May contact the fixed and movable intake pipes 43 and 42, respectively, and the contact portion of the seal ring 46 may be switched by a pressure difference between the inside and outside of the intake pipes. In this case, the abutting portions of the seal ring 46 having an X-shaped cross section are formed so that one of the plurality of abutting portions of the seal ring 46 is reliably connected to the other intake pipe by a pressure difference between the inside and outside of the intake pipes. Can contact the contact part of
The gap between the overlapping portions of the two intake system pipes can be more reliably sealed, the occurrence of short-circuit airflow can be prevented, and the intake inertia effect can be stably obtained.

In particular, in the seal ring 46, both ends of the seal ring abut on one of the side walls on both sides in the space of one of the intake pipes, and the contact portion is switched by a pressure difference between the inside and outside of the intake pipe. You may make it always slidably contact an intake pipe. In this case, a seal ring 46 fitted in the space of one of the intake pipes can abut one of its fitting portions to one of the side walls in the space, and the overlapping portion of the two intake system pipes by the seal ring 46. Can be more reliably sealed, the occurrence of short-circuit airflow can be prevented, and the intake inertia effect can be stably obtained.

Next, in the intake device of each engine shown in FIG. 1 and its modification, the outside air flow passage g as a tube passage for applying the air pressure outside the intake pipe to the surface opposite to the sliding contact surface of the seal ring 46a. Opposite. For this reason, the air pressure outside the intake pipe is applied to the surface opposite to the sliding contact surface of the seal ring 46a through the external air flow passage g, and the contact portion of the seal ring located at the overlapping portion of the two intake system pipes. Can reliably contact the contact portion of the other intake pipe, can reliably seal the gap between the overlapping portions of both intake pipes, prevent the occurrence of short-circuit airflow, and obtain a stable intake inertia effect . In particular, when the fixed intake pipe 43 is formed as an arc-shaped intake pipe and the movable intake pipe 42 is formed as an arc-shaped intake pipe that rotates around the arc center L0 of the fixed intake pipe, the movable intake pipe 42 is fixed. It can be smoothly rotated in a state of being fitted to the intake pipe 43 outside.

In particular, the upstream end of the fixed intake pipe 43 is connected to the intake containers 39 and 40 through which the intake air is conducted through the air cleaner 37.
The movable intake pipe 42 is located inside the intake vessels 39 and 4.
The engine may move so as to move within zero, and supply the intake air that has passed through the air cleaner to the combustion chamber of the engine 30.
In this case, the intake air from the air cleaner 37 is supplied to the movable intake pipe 4.
Regardless of the airtightness of the fixed intake pipe 43 and the fixed intake pipe 43, the air is reliably sealed from the outside by the intake container portion and supplied to the combustion chamber.
Next, the intake device of each engine in FIG.
When the movable intake pipe 42 is at the longest intake passage position P1, the axis of the fixed intake pipe 43a at a portion that slides on the seal ring 46b is formed linearly (see the distal end e). Therefore, when the movable intake pipe 42 is at the longest intake passage position P1, the inclination of the seal ring 46b when the seal ring 46b comes into sliding contact with the linear distal end portion e can be eliminated,
It can reliably seal the gap between the overlapping parts of both intake system pipes,
The generation of short-circuit airflow is prevented, and the intake inertia effect can be stably obtained.

In particular, the seal ring 46b may slide on the other intake pipe at a plurality of positions in the axial direction. In this case, the movable intake pipe 42 is located at the longest intake passage position P.
When the value is 1, the seal ring 46b slides on the other linear end portion e where the inclination due to the seal ring 46 sliding on the other curved intake pipe is likely to occur. The inclination of 46b can be reliably eliminated, and the gap between the overlapping portions of both intake system pipes can be reliably sealed.

[0063]

According to the first aspect of the present invention, there is provided a movable intake pipe movable between a longest intake passage position where the overlap length with the fixed intake pipe is the shortest and a shortest intake passage position where the overlap length is the longest. And an elastic seal ring attached to one of the movable or fixed intake pipes and hermetically contacting at least the other intake pipe when the movable intake pipe is at the longest intake passage position. For this reason, only when the movable intake pipe is at the longest intake passage position, the gap between the overlapping portions of the two intake pipes can be reliably sealed, and the occurrence of short-circuit airflow is prevented,
When the intake air inertia effect is obtained stably and the movable intake pipe is located at a position other than the longest intake passage position, the seal of the gap between the overlapping portions of both intake pipes can be roughly held to reduce sliding resistance, and variable Responsiveness of the intake mechanism can be ensured.

A tenth aspect of the present invention is a movable intake pipe which can move between a longest intake passage position where the overlap length with the fixed intake pipe is the shortest and a shortest intake passage position where the overlap length is the longest, An elastic seal ring held in a space portion of one of the movable intake pipes or the fixed intake pipe, which is located outside of the movable intake pipe or the fixed intake pipe, wherein the seal ring has a plurality of contact portions with at least one of the intake pipes; A contact portion is also provided on the intake pipe. Therefore, when a pressure difference between the inside and outside of the two intake pipes is received, one of the plurality of contact sections of the elastic seal ring surely comes into contact with the contact section of the other intake pipe. The gap between the overlapping portions can be reliably sealed, the occurrence of short-circuit airflow can be prevented, and the inertia effect of the intake air can be stably obtained.

A thirteenth aspect of the present invention is a movable intake pipe movable between a longest intake passage position where the overlap length with the fixed intake pipe is the shortest and a shortest intake passage position where the overlap length is the longest, An elastic seal ring that is supported by one of the movable or fixed intake pipes located outside and is in sliding contact with the other intake pipe located inside; and a sliding contact surface formed on one of the intake pipes with the elastic seal ring An external air flow passage for applying air pressure outside the intake pipe constituted by a movable intake pipe and a fixed intake pipe is provided on the surface opposite to the intake pipe. For this reason, air pressure outside the intake pipe is applied to the surface opposite to the sliding contact surface of the elastic seal ring through the external air flow passage, and the elastic seal ring located at the overlapping portion of the two intake system pipes is pressed. The contact portion is reliably brought into contact with the contact portion of the other intake pipe, whereby the gap between the overlapping portions can be reliably sealed, short-circuit airflow can be prevented, and the intake inertia effect can be stably obtained.

According to a sixteenth aspect of the present invention, the arc center of the fixed intake pipe is located between the longest intake passage position where the overlap length with the fixed intake pipe is the shortest and the shortest intake passage position where the overlap length is the longest. An arc-shaped movable intake pipe that rotates around the center, a seal ring that is mounted on one of the movable or fixed intake pipes and slides on the other intake pipe, and the movable intake pipe is in the longest intake passage position. Sometimes, the axis of the other intake pipe at the portion that comes into sliding contact with the elastic seal ring is formed in a straight line.
For this reason, when the movable intake pipe is at the longest intake passage position, the elastic seal ring comes into sliding contact with the other linear intake pipe, and the inclination of the elastic seal ring is eliminated, so that the two intake system pipes are separated from each other. The gap in the overlapped portion can be reliably sealed, the generation of short-circuit airflow is prevented, and the intake inertia effect can be stably obtained.

[Brief description of the drawings]

FIG. 1 is a partially cut-away schematic side view of an intake device for an engine as one embodiment of the present invention.

FIG. 2 is a partially cutaway schematic plan view of the intake device of FIG. 1;

FIG. 3 is an enlarged cutaway sectional view of a variable intake pipe length mechanism of the intake device of FIG. 1;

4 is an enlarged plan view of a lid type casing of the variable intake pipe length mechanism of the intake device of FIG. 1;

FIG. 5 is a side view of a lid type casing of the intake pipe length variable mechanism of the intake device of FIG. 4;

FIG. 6 is a side view of the lid-type casing in a direction indicated by an arrow E in FIG. 5;

FIG. 7 is a side view of the lid-type casing in the direction of arrow F in FIG. 5;

FIG. 8 is a sectional view taken along line DD of FIG. 4;

FIG. 9 is a sectional view taken along line AA of FIG. 4;

FIG. 10 is a sectional view taken along line BB of FIG. 4;

FIG. 11 is a sectional view taken along line GG of FIG. 5;

FIG. 12 is a sectional view taken along line CC of FIG. 4;

FIG. 13 is an explanatory view of a seal of a movable and fixed intake pipe in the variable intake pipe length mechanism of the intake apparatus of FIG. 1;

14A and 14B are explanatory views of a seal of a movable and fixed intake pipe in the variable intake pipe length mechanism of the intake apparatus of FIG. 13, wherein FIG. 14A shows a case where a negative pressure is applied to the intake path and FIG. Is shown.

FIG. 15 is an explanatory view of a seal of a movable and fixed intake pipe in a variable intake pipe length mechanism in a modification of the intake apparatus of FIG. 1;

16A and 16B are explanatory diagrams of seals of a movable and fixed intake pipe in the variable intake pipe length mechanism of the intake apparatus of FIG. 15, wherein FIG. 16A shows a case where the intake path has a negative pressure and FIG. Is shown.

FIG. 17 is a cross-sectional view of a movable and fixed intake pipe overlapping portion in a variable intake pipe length mechanism used in a modification of the intake device of FIG. 1;

FIG. 18 is a view for explaining a problem of a overlapping portion of a movable and fixed intake pipe in the variable intake pipe length mechanism in a modified example of the intake apparatus of FIG. 17;

FIG. 19 is an enlarged view of a seal ring of a movable and fixed intake pipe overlapping portion in a variable intake pipe length mechanism used in a modified example of the intake apparatus of FIG. 1;

FIG. 20 is an enlarged view of a seal ring of an overlapped portion of a movable and fixed intake pipe in a variable intake pipe length mechanism used in a modification of the intake apparatus of FIG. 1;

21 is an enlarged view of a seal ring of a movable and fixed intake pipe overlapped portion in a variable intake pipe length mechanism used in a modified example of the intake apparatus of FIG. 1;

FIG. 22 is an enlarged view of the seal ring of the overlapping portion of the movable and fixed intake pipe in the variable intake pipe length mechanism used in the modified example of the intake apparatus of FIG. 1;

FIG. 23 is a comparison diagram of engine speed-torque characteristics of the intake device of FIG. 1 and a conventional device.

FIG. 24 is an overall configuration diagram of a conventional intake device.

FIG. 25 is a cross-sectional view of a movable and fixed intake pipe in a variable intake pipe length mechanism of a conventional intake device.

FIG. 26 is an enlarged sectional view of a portion S in FIG. 24;

[Explanation of symbols]

27 Arm 28 DC motor 29 Intake port 30 Engine 31 Cylinder head 32 Intake manifold 33 Intake manifold extension 34 Surge tank 35 Throttle body 37 Air cleaner 39 Semicircular casing 40 Lid casing 401 Inlet 408 Downstream port 41 Storage chamber 42, 42c, 42d, 42e Movable intake pipe 423, 423c recess 424 Internal bulging part 43, 43d, 43e, 43f Fixed intake pipe 432 Annular projection 434 Tapered part 44 Actuator shaft 46, 46c, 46d, 46e, 46f Seal ring g Flow passage t Gap between overlapping portions m1, m2 Projection n1, n2 Projection A Intake pipe length variable mechanism R1 First intake passage R2 Second intake passage P0 Shortest intake passage position P1 Longest intake passage position LA Fixed intake pipe length LB Extension tube length LM Movable Tracheal length L _T branch intake path length

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shiro Kumagai 5-33-8 Shiba, Minato-ku, Tokyo / Inside Mitsubishi Motors Corporation (72) Inventor Hirofumi Higashi 5-33-8 Shiba, Minato-ku, Tokyo No. Mitsubishi Motors Corporation (72) Inventor Hiroyuki Kiuchi 4-21-1, Shimomaruko, Ota-ku, Tokyo, Mitsubishi Motors Engineering Co., Ltd. (56) References JP-A-8-338251 (JP, A (58) Field surveyed (Int.Cl. ⁷ , DB name) F02B 27/02

Claims (17)

(57) [Claims] 1. A longest intake passage position which is fitted to an upstream end of a fixed intake pipe communicating with an engine combustion chamber to form at least a part of an intake passage and has a shortest overlap length with the fixed intake pipe. A movable intake pipe that can move between the shortest intake passage position where the overlap length is the longest, and a movable intake pipe attached to one of the movable intake pipe or the fixed intake pipe, and at least the movable intake pipe is the longest. in an intake device for an engine provided with the other contact with rubber seal ring hermetically the intake pipe when it is in the intake passage position, other intake of the moving intake pipes or the stationary intake pipe
One intake pipe wall is provided on the surface of the pipe facing one intake pipe.
An annular projection is formed to reduce the gap between
The diameter of the ring is the same as the diameter of the ring
Is the value between the annular protrusion and the diameter other than the annular protrusion.
And the movable intake pipe is at the longest intake passage position
When the annular protrusion and the elastic seal ring
An air intake device for an engine, wherein the air contact is made airtight . 2. The intake system for an engine according to claim 1, wherein when the movable intake pipe moves from the longest intake passage position to the shortest intake passage position, the elastic seal ring loosens toward the other intake pipe. An intake device for an engine, wherein a sliding surface having a substantially constant diameter is provided on the other intake pipe so as to be in sliding contact with the annular protrusion. 3. The intake device for an engine according to claim 2, wherein a portion of the annular projection that is continuous with the sliding contact surface has a tapered portion whose diameter gradually changes from the sliding contact surface diameter to the annular projection. Wherein the elastic seal ring is in airtight contact with the tapered portion when the movable intake pipe is at the longest intake passage position. 4. A suction device according to claim 1 or claim 3 wherein the engine is located the annular projection into the intake pipe space side formed by the stationary intake pipe and the moving intake pipes, and the moving intake pipes An intake device for an engine, wherein an elastic seal ring is located on an outer space side of an intake pipe formed by a fixed intake pipe. 5. The intake apparatus according to claim 1 to claim 4, wherein the engine, the annular projecting portion to the stationary intake pipe outer surface is formed, characterized in that the moving intake pipes are fitted to the stationary intake pipe Engine intake device. 6. An intake system for an engine according to claim 5 , wherein an elastic seal ring is fitted to an axial end of said movable intake pipe. 7. The intake apparatus according to claim 1 to claim 3, wherein the engine, and wherein the annular projection is formed on the movable intake pipe surface, the movable intake pipe is fitted to the stationary intake pipe Engine intake system to be used. 8. The air intake device of claim 1 to claim 7, wherein the engine, arcuate intake pipe above stationary intake pipe arcuate intake pipe, the moving intake pipes to rotate about the arc center of the stationary intake pipe An intake device for an engine, wherein the intake device is formed as: 9. The intake device according to claim 1 to claim 8, wherein the engine, the upstream end of the stationary intake pipe is located in the intake container is conducted intake through the air cleaner, the moving intake pipes An intake device for an engine, wherein the intake device moves within the intake container, and the intake air passing through the air cleaner is supplied to a combustion chamber of the engine. 10. A longest intake passage position which is fitted to an upstream end of a fixed intake pipe communicating with an engine combustion chamber to form at least a part of an intake passage and has a shortest overlap length with the fixed intake pipe. A movable intake pipe movable between the shortest intake passage position where the overlap length is the longest, and the movable intake pipe is held in a space of one of the movable intake pipes or one of the fixed intake pipes located outside, and An elastic seal ring slidably in contact with the other intake pipe located on the inner side, wherein the seal ring has a plurality of contact portions on at least one intake pipe and a contact portion on the other intake pipe. An aspirating device for an engine, wherein the abutting portion of the elastic seal ring is switched by a pressure difference between the inside and outside of the two intake pipes. 11. The intake system for an engine according to claim 10 , wherein said elastic seal ring has an X-shaped cross section, and projections which are diagonal to each other contact said fixed and movable intake pipes, respectively. An intake device for an engine, wherein a contact portion of the elastic seal ring is switched by a pressure difference between the inside and outside of the pipe. 12. The intake system for an engine according to claim 10 , wherein both ends of the elastic seal ring abut on one of side walls in both sides of the space of the one intake pipe. An aspirating device for an engine, wherein a contact portion is switched by a pressure difference between the inside and the outside, and the sliding portion is always in sliding contact with the other intake pipe. 13. A longest intake passage position which is fitted to an upstream end of a fixed intake pipe communicating with an engine combustion chamber to form at least a part of an intake passage and has a shortest overlap length with the fixed intake pipe. A movable intake pipe that can move between the shortest intake passage position where the overlap length is the longest, and one of the movable intake pipes or the fixed intake pipe that is supported by one of the externally located intake pipes, And a movable intake pipe and a fixed intake pipe formed on the one intake pipe and on a surface opposite to the sliding contact surface of the elastic seal ring. An intake device for an engine, comprising: an external air flow passage for applying air pressure outside an intake pipe. 14. An intake device according to claim 10 or claim 13, wherein the engine, arcuate intake pipe above stationary intake pipe arcuate intake pipe, the moving intake pipes to rotate about the arc center of the stationary intake pipe An intake device for an engine, characterized by being formed by: 15. The intake apparatus according to claim 10 or claim 14, wherein the engine, the upstream end of the stationary intake pipe is located in the intake vessel inlet through the air cleaner is conducted, the moving intake The pipe moves within the intake vessel,
An intake device for an engine, wherein intake air passing through the air cleaner is supplied to a combustion chamber of the engine. 16. A longest intake passage position which is fitted to an upstream end of a fixed intake pipe communicating with an engine combustion chamber to form at least a part of an intake passage and has a shortest overlap length with the fixed intake pipe. A movable intake pipe movable between the shortest intake passage position where the overlap length is the longest, and one of the movable intake pipe or the fixed intake pipe mounted on the movable intake pipe or the fixed intake pipe, and slidably contacts the other intake pipe. An intake system for an engine, wherein the seal ring and the other intake pipe axis at a portion in sliding contact with the elastic seal ring when the movable intake pipe is at the longest intake passage position are linearly formed. . 17. An intake system for an engine according to claim 16 , wherein said elastic seal ring is in sliding contact with the other intake pipe at a plurality of positions in the axial direction.