JP2000008865A - Variable intake device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain a desired intake inertia effect by separating air- tightly adjacent extension parts into each other, while suppressing an increase of slide resistance when a surge tank is rotated. SOLUTION: In this device, length of an intake passage in the downstream of a surge tank is formed variable in accordance with rotation of the surge tank 30. Here, an annular groove is provided respectively in an outer peripheral location of the surge tank opposed to an internal periphery of each axial direction partition part 24, a seal member having a notched part is respectively fit mounted in each annular groove, an outer peripheral surface of the seal member is slide abutted to the internal periphery of each axial direction partition wall part, also a lock part locking each notched part in the peripheral direction in the vicinity of a communication port 35 of the surge tank is provided in each annular groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable intake device for an engine that utilizes the inertial effect of intake air.

[0002]

2. Description of the Related Art Conventionally, in order to improve the engine output by increasing the charging efficiency of the intake air in the entire range from the low speed range to the high speed range of the engine speed, the length of the intake passage is changed to change the entire engine speed. It is known to use the inertial effect of intake air. As a variable intake device for this type of engine, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 60-224923.

This variable intake device is provided with a bottomed cylindrical surge tank rotatably disposed in an intake system of an engine, the inside of which is communicated with the outside air. The surge tank rotatably supports the surge tank. An intake manifold covering the outer periphery, a branch intake passage provided in the intake manifold downstream of the surge tank and connected to each cylinder of the engine, and an axial partition formed in the intake manifold are provided around the surge tank. An extension that forms part of each branch intake passage, a communication port that is formed in the peripheral wall of the surge tank and communicates with each extension and the inside of the surge tank, and between the inner circumference of each axial partition and the outer circumference of the surge tank. A ring-shaped seal member provided in each of the first and second airtight seals to hermetically separate the extension portions adjacent to each other in the axial direction, and to rotate the surge tank according to the engine speed. The downstream side of the intake passage length of the surge tank in which a variable.

[0004]

The effect of the inertia of the intake air is that during the intake stroke of the engine, a negative pressure generated in the combustion chamber due to the lowering of the piston generates a pressure wave by the opening operation of the intake valve. Is propagated as a negative pressure wave in the intake passage at the speed of sound, reflected on the surge tank wall surface to become a positive pressure wave, and returned to the combustion chamber during the opening period of the intake valve. In the above-described conventional apparatus, the length of the extension portion is made variable by rotating the surge tank, so that the positive pressure wave is returned to the combustion chamber during the opening period of the intake valve over the entire engine speed range.

The above-mentioned inertial effect is obtained by the pressure wave propagating in the intake passage without being disturbed or greatly attenuated. A sealing member made of a material such as Teflon is fitted into an annular groove formed on the inner peripheral surface of each axial partition of the intake manifold, and the inner peripheral surface of the sealing member slides on the outer peripheral surface of the surge tank. By doing so, adjacent extension portions are air-tightly separated to suppress the disturbance and attenuation of the pressure wave in the extension portions, and to suppress an increase in sliding resistance when the surge tank rotates.

However, in the above-described conventional apparatus, the inner peripheral surface of the seal member fitted into the annular groove formed on the inner periphery of each axial partition wall is brought into sliding contact with the outer peripheral surface of the surge tank. Therefore, since the diameter of the seal member is increased, the opening amount of the notch (the opposing gap at both ends of the seal member) cannot be reduced. The seal member is fitted in the annular groove without any restriction on its circumferential position, so that the position of the cutout portion can change in the circumferential direction with the rotation of the surge tank. As a result, the adjacent extension portions in the middle of the intake passage on the downstream side of the surge tank communicate with each other through the notch portion, and the pressure wave is disturbed or attenuated in the extension portion, and the desired intake inertia effect is obtained. There was a problem that can not be obtained.

Accordingly, the present invention provides a variable intake device for an engine in which a desired intake inertia effect is obtained by airtightly separating adjacent extensions while suppressing an increase in sliding resistance during rotation of a surge tank. That is the subject.

[0008]

The technical means taken to solve the above-mentioned problem is a bottomed cylindrical surge tank which is rotatably disposed in an intake system of an engine and the inside of which is communicated with outside air. An intake manifold that rotatably supports the surge tank and covers the outer periphery of the surge tank, and a branch intake passage provided in the intake manifold downstream of the surge tank and connected to each cylinder of the engine,
An extension part which is provided axially separated around the surge tank by an axial partition part formed in the intake manifold and forms a part of each of the branch intake passages, and is formed on a peripheral wall of the surge tank. A communication port that communicates the inside of each of the extension portions with the inside of the surge tank, and the extension portions that are provided between the inner periphery of each of the axial partition walls and the outer periphery of the surge tank and are adjacent to each other in the axial direction in an airtight manner. A ring-shaped sealing member for isolating, and a variable intake device for an engine that varies a length of an intake passage downstream of the surge tank in accordance with rotation of the surge tank. An annular groove is provided at an outer peripheral portion of the surge tank opposed to each other, and the seal member having a notch is fitted into each annular groove, and an outer peripheral surface of the seal member is formed inside the axial partition wall portion. With sliding contact on said is that the provided locking portions for locking the respective notch in the circumferential direction in the vicinity of the communication port in each annular groove.

According to the above means, the outer peripheral surface of the seal member is fitted by fitting the seal members having the cutouts into the annular grooves respectively provided in the outer peripheral portion of the surge tank facing the inner periphery of each axial partition. Are slid in contact with the inner periphery of each axial partition, so that the sliding contact reduces the diameter of the seal member, reduces the opening amount of the notch (the opposing gap at both ends of the seal member), and reduces the notch. The circumferential position of the portion is restricted to the vicinity of the communication port by the locking portion. For this reason, the notch is prevented from being located in the middle of the intake passage on the downstream side of the surge tank in a state of being greatly opened, and the adjacent extension portions are air-tightly isolated by the seal member, so that the desired intake inertia effect is obtained. Is obtained favorably.

In the above-mentioned means, it is preferable that the locking portion is provided in an opening area in a circumferential direction of the communication port.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a variable intake device for an engine according to the present invention will be described below with reference to the drawings.

1 to 3, reference numeral 10 denotes a four-cylinder engine. A combustion chamber 15 is formed between a cylinder block 12 in which a cylinder 13 in which a piston 14 reciprocates is formed and a head of the piston 14. It has a cylinder head 11. The cylinder head 11 has an intake port 11 a and an exhaust port 1, one end of which opens into the combustion chamber 15.
1b is formed, and each intake port 11a and exhaust port 11b are opened and closed by an intake valve and an exhaust valve (not shown). An intake manifold 20 having independent intake pipes 21 connected to the other ends of the respective intake ports 11a on the outlet side thereof is fixed to the cylinder head 11. An air cleaner 25 is provided at the tip of a collective intake passage communicating with the inlet side of the intake manifold 20, and an air flow meter 26 is provided downstream thereof. A throttle valve 27 is provided downstream of the air flow meter 26, and a surge tank 30 is rotatably provided downstream of the throttle valve 27.

As shown in FIG. 2, the surge tank 30 has a bottomed cylindrical shape with one end opened, and extends axially into the cylindrical portion of the intake manifold 20. Intake manifold 20
A worm wheel 40 to be described later is provided at one end of the cylindrical portion.
A case 36 that accommodates the like is fixed, and a shaft 32 formed at the bottom of one end of the surge tank 30 is rotatably supported by the case 36 via a bearing 34. At the other end of the cylindrical portion of the intake manifold 20 (the inlet side of the intake manifold 20), an inner flange having a plurality of communication holes is formed, and a shaft portion 31 formed at the other end of the surge tank 30 is formed.
Is rotatably supported on the inner flange via a bearing 33, and the internal space of the surge tank 30 is communicated with the collective intake passage through a communication hole. The shaft portion 31 is integrally connected to the cylindrical portion of the surge tank 30 by a plurality of connection portions (not shown) formed radially at the other end opening of the surge tank 30.

In the cylindrical portion of the intake manifold 20, an extension 23 having one end connected to a branch passage 22 in the independent intake pipe 21 is formed in a spiral shape so as to wind inward around the surge tank 30. Have been. The extension 23 is shown in FIG.
In the radial direction of the surge tank 30, as shown in FIG.
0, and the outside is defined by an outer wall 20a and a partition wall 20b that are gently connected to the independent intake pipe 21. The cylindrical portion of the intake manifold 20 is formed with an axial partition 24 that partitions the extending portion 23 in the axial direction. As shown in FIG.
0a is provided.

As shown in FIG. 7, a ring-shaped seal member 50 made of Teflon or the like having a notched portion 50a is fitted in each annular groove 30a. Seal member 5
In the state in which the surge tank 30 is disposed in the intake manifold 20, the outer diameter is larger than the inner peripheral diameter of the axial partition wall portion 24 in a state where the surge tank 30 is fitted in the annular groove 30a. The outer peripheral surface of the sealing member 50 is slidably contacted with the inner peripheral surface of the axial partition wall portion 24 in an airtight manner, and the notch 50
(The opposing gap at both ends of the seal member) is reduced.

The cylindrical portion of the surge tank 30 located between the axial partition portions 24 is provided with a communication port 35 for communicating the internal space of the surge tank 30 and the extension 23 at the same position in the circumferential direction. Have been. As shown in FIGS. 4, 6 and 7, each annular groove 30 a radially protrudes into a circumferential opening area of the communication port 35, and its circumferential end face is formed by a notch of the seal member 50. A locking portion 37 is formed parallel to the end surface of the first portion 50a. Thereby, the end face of the cutout portion 50a of the seal member 50 is locked to the circumferential end face of the locking portion 37, so that the movement of the seal member 50 in the circumferential direction within the annular groove 30a is restricted, and the cutout portion 50a is Communication port 3 always
5 is located in the vicinity.

In the case 36, as shown in FIG. 1, the shaft portion 32 projects through a seal member 43.
A worm wheel 40 is fixed to the outer periphery of 2.
A worm gear 41 fixed to an output shaft of an electric motor 42 meshes with the worm wheel 40, and the surge tank 30 is rotated by the rotation of the electric motor 42. A known angle sensor 44 such as a potentiometer is provided at the tip of the shaft portion 32, and a detection signal of the angle sensor 44 is sent to a controller 45. The rotation of the electric motor 42 is controlled by the operating state of the engine. Controller 4 according to (engine speed, etc.)
5 is controlled.

In the above configuration, during operation of the engine 10, the intake air is supplied to the air cleaner 25 and the air flow meter 26.
And, it is introduced into the internal space of the surge tank 30 through the throttle valve 27, and is guided from the communication port 35 to each combustion chamber 15 through the extension 23 and the branch passage 22. At this time, when the piston 14 starts to descend from the top dead center, a negative pressure wave is generated, and this negative pressure wave propagates upstream through each intake port 11a, the branch passage 22 and the extension portion 23, and passes through the communication port 35. The gas enters the surge tank 30 and is reflected on the wall surface of the surge tank 30 so that the polarity is inverted. In addition, the gas propagates to the combustion chamber 15 to cause an inertia effect of the intake air, thereby improving the charging efficiency. Here, in order to change the length of the intake passage on the downstream side of the surge tank 30 according to the rotation speed of the engine 10, the surge tank 30 is moved to the low speed position LO as shown in FIG.
Electric motor 4 so as to be located between
The rotation is controlled by 2. As a result, the inertia effect of the intake air can be used in the entire range of the engine speed from the low speed range to the high speed range, and the charging efficiency of the intake air is increased, and the engine output is improved.

In this embodiment, the surge tank 30
The seal member 50 is fitted in the annular groove 30a, and the surge tank 30 is arranged in the intake manifold 20 so that the diameter of the seal member 50 is reduced and the amount of opening of the cutout 50a (opposing gaps at both ends of the seal member). Is reduced, the notch 50
Communication between adjacent extension portions 23 via a is prevented. Further, in the present embodiment, the surge tank 30
The notch 50 of the seal member 50 is
a is always located in the opening area of the communication port 35 in the circumferential direction. Therefore, for example, the gap 5 between the adjacent extension portions 23 is notched.
0a, the communication point is the extension portion 23
Tank 3 which communicates with each other through each communication port 35
Since the pressure wave is close to the internal space 0, the above-mentioned pressure wave is not greatly disturbed or attenuated, and the above-described desired intake inertia effect can be stably used.

[0020]

As described above, according to the present invention, the seal members having the notches are respectively fitted in the annular grooves provided on the outer peripheral portion of the surge tank facing the inner periphery of each axial partition. Since the outer peripheral surface of the seal member is slid in contact with the inner periphery of each axial partition, the diameter of the seal member is reduced by this slid contact, and the opening amount of the notch (the opposing gap at both ends of the seal member) is reduced. At the same time, the circumferential position of the notch is restricted to the vicinity of the communication port by the locking portion. For this reason, it is possible to prevent the notch portion from being located in the middle of the intake passage on the downstream side of the surge tank in a state of being greatly opened, and for example, to communicate between adjacent intake passages on the downstream side of the surge tank via the notch portion. Even if it does, since the notch is located close to the internal space of the surge tank where each intake passage communicates with each other via each communication port, the pressure wave is prevented from being greatly disturbed or attenuated, and the desired intake air is prevented. The inertia effect can be obtained satisfactorily and stably.

[Brief description of the drawings]

FIG. 1 is an external view of an engine provided with a variable intake device according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 showing one embodiment of the variable intake device for the engine according to the present invention.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along the line CC of FIG. 2;

FIG. 5 is an enlarged view of a part D in FIG. 2;

FIG. 6 is an enlarged view of a portion E in FIG. 4;

FIG. 7 is a top view of the seal member and the locking portion shown in FIG. 6;

[Explanation of symbols]

 Reference Signs List 10 engine 11 cylinder head 20 intake manifold 21 independent intake pipe 22 branch passage 23 extension 24 axial partition wall 30 surge tank 30a annular groove 31, 32 shaft 35 communication port 36 case 37 locking part 40 worm wheel 41 worm gear 42 electric Motor 50 Seal member 50a Notch

Claims (2)

[Claims] 1. A surge tank having a bottomed cylindrical shape rotatably disposed in an intake system of an engine and having an interior communicating with outside air, rotatably supporting the surge tank, and covering an outer periphery of the surge tank. An intake manifold, a branch intake passage provided in the intake manifold downstream of the surge tank and connected to each cylinder of the engine, and an axial partition formed in the intake manifold are arranged around the surge tank. An extension part that is provided separately from each other in the direction and constitutes a part of each of the branch intake passages; a communication port formed on a peripheral wall of the surge tank and communicating with each of the extension parts and the inside of the surge tank; A ring-shaped seal member provided between the inner periphery of the axial partition and the outer periphery of the surge tank to seal between the extensions adjacent to each other in the axial direction; In the variable intake device for an engine, wherein the length of the intake passage on the downstream side of the surge tank is varied according to the rotation of the surge tank, annular grooves are respectively formed on outer peripheral portions of the surge tank facing the inner periphery of each of the axial partition portions. A seal member having a notch is fitted into each of the annular grooves to bring the outer peripheral surface of the seal member into sliding contact with the inner periphery of each of the axial partition walls, and to communicate with each of the annular grooves. A variable intake device for an engine, further comprising: a locking portion that locks each of the cutout portions in a circumferential direction near a mouth. 2. The variable intake device for an engine according to claim 1, wherein the locking portion is provided in a circumferential opening area of the communication port.