JP3030378B2 - Variable engine intake pipe length - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for varying the length of an intake pipe of an engine, and more particularly, to first and second components in an intake path constituting member of an intake system.
The present invention relates to a variable intake pipe length device for an engine including a component for varying the amount of polymerization of intake pipes to each other to vary the intake path length.

[0002]

2. Description of the Related Art An intake system of an engine communicates between an intake port of the engine and an air intake of an air cleaner, and interferes with an air cleaner, an intake pipe, a throttle body for adjusting an intake amount, and intake pulsation of another cylinder. It is configured by sequentially connecting intake system components such as a surge tank and an intake manifold for branching intake air to each cylinder. These intake system components are connected to each other to determine an intake path length, and the length is basically 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 returns as a positive pressure wave after the positive pressure wave generated in the intake port at the time of closing the intake valve reciprocates (twice) between the intake port and the portion corresponding to the atmospheric pressure of the intake pipe. The inertia effect is caused by the 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. 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, the intake system of the engine is provided with the intake pipe variable mechanism capable of positively utilizing the intake pulsation in order to prevent intake interference and improve engine volumetric efficiency.

For example, in the engine 1 shown in FIG. 9, the intake system extends from a plurality of intake path constituting members, that is, from the combustion chamber 2 and the intake port 3 of each cylinder, and the other end is connected to the surge tank 4.
Manifolds (only one cylinder is shown) serving as a first intake passage pipe communicating with the intake manifold, a surge tank 4 accommodating a protruding pipe 501 at a tip end of the intake manifold 5, and a protrusion in the surge tank 4 A curved pipe 9 as a second intake passage pipe formed with one end opening 7 opened at a position facing the other end opening 6 of the pipe 501 and the other end opening 8 protruding outside from the surge tank and communicating with the inside again; One end includes a surge tank 4 and the other end includes an intake pipe 11 that communicates with an air cleaner 10. Here, a throttle valve 17 is mounted on each intake manifold 5 so as to be rotatable. These intake system components are connected to each other to determine the total intake path length, and the length is basically constant.

Here, a straight portion 901 is formed at the lower end of the curved tube 9, and the extension tube 12 is fitted on the straight portion 901. The extension tube 12 is provided with a drive device 13 having a leaf-shaped opening 121 formed at the end thereof, and bringing the opening 121 into and out of contact with the opening 502 on the other end opening 6 side of the protruding tube 501. The driving device 13 and the straight portions 901 and 9
The extension tube 12 fitted to the outside 01 forms a trombone mechanism.

The drive unit 13 includes a first link 14a pin-connected to the outer peripheral wall of the extension pipe 12, a second link 14b pin-connected to the other end of the first link 14a, and a second link 1
A drive shaft 14c is integrally connected to the pivot end of the drive shaft 4b, and a DC motor 15 is connected to the drive shaft 14c via a speed reducer (not shown). The DC motor 15 is connected to a controller 16. The controller 16 drives the extension pipe 12 in accordance with the engine speed, and controls the approach / separation of the gap X between the opening 121 at the tip and the opening 502 of the protruding pipe 501.

Here, when the engine 1 is in the rotation range when the maximum output is generated, the controller 16 reduces the gap X between the opening 121 of the extension pipe 12 and the opening 502 of the protruding pipe 501 in order to shorten the total intake pipe length. , The entire air flow in the surge tank 4 is led directly from the inlet 111 on the intake pipe 11 side to the other end opening 6 of the opening 502, and the effective intake pipe length is kept at the minimum value Lso, so that the maximum output is generated. To ensure the pulsation effect of the intake pipe in the rotation range at. On the other hand, when the engine 1 is in the rotation range at the time of the generation of the maximum torque, the opening 121 of the extension pipe 12 and the opening 502 of the protruding pipe 501 are brought into contact with each other to increase the total intake pipe length. Is guided from the inflow port 111 to the other end opening 6 via the curved pipe 9 to maintain the effective intake pipe length at the maximum value Ls, thereby ensuring the pulsating effect of the intake pipe in the rotation range when the maximum torque is generated.

The effective intake pipe length in the surge tank 4 has a maximum value of Ls and a minimum value of Lso. To secure an intermediate value between them, a part of the airflow is led to the opening 6 at the other end, and From the other end opening 8 to the other end opening 6 through the curved tube 9. In this case, the ratio of the air flow rate between the other end opening 8 and the other end opening 6 is achieved by adjusting the gap X to increase or decrease.

Here, as shown in FIG. 8, when the gap X is increased or decreased, the effective intake pipe length in the surge tank 4 is increased or decreased between the maximum value Ls and the minimum value Lso, and the gap X becomes zero. When the near small gap region Xs is reached, the effective intake pipe length sharply increases, the rate of change of the effective intake pipe length per unit gap rapidly increases,
The pressure loss μ indicated by the broken line is also rapidly increasing.

If the gap X is in the small gap area Xs in FIG. 8, the opening area of the flow path through which the air flows flows is obtained by multiplying the circumference of the two-dot chain line by the gap X as shown in FIG. The outer peripheral length (circumferential length of the two-dot chain line) is larger than the opening area. That is, m (= A) obtained by dividing the channel cross-sectional area A by the perimeter S
/ S) is the fluid average depth, and the pressure loss is inversely proportional to the fluid average depth m. For this reason, here, the fluid average depth m is small, the pressure loss μ is large, and this causes a sudden increase in intake flow resistance. Incidentally, such an intake device for an engine is disclosed in Japanese Utility Model Laid-Open No. 61-32521.

[0012]

As described above, the effective intake pipe length in the surge tank 4 is set to the maximum value Ls and the minimum value Lso.
, The gap X is particularly small in the small gap region Xs
, The flow resistance of the airflow is large and the pressure loss μ increases rapidly, causing pulsation of the airflow. In addition, when the gap is in the small gap region Xs, the change rate of the effective intake pipe length per unit gap change is sharply increased, and the controllability is apt to be reduced. An object of the present invention is to provide a variable intake pipe length device for an engine with good controllability.

[0013]

In order to achieve the above-mentioned object, a first aspect of the present invention is a first intake passage pipe having one end communicating with a combustion chamber and the other end communicating with a surge tank, and one end having the surge tank. A second intake passage pipe having an opening at a position opposite to the other end opening of the first intake passage pipe and having the other end communicated with the intake passage in the surge tank or on the upstream side of the surge tank; It is provided at one of the other end opening of the intake passage and the one end opening of the second intake passage tube, extends toward the other opening so as to be fitted to the other, and has a front end edge inclined with respect to the axis. The first intake passage pipe or the second intake passage pipe, wherein the flange and the other opening are fitted over the entire circumference thereof. On the other hand, the mating with the opening is released As is the manner obtained, characterized in that the movable mechanism to variably set the axial position of the contrast aperture or other opening at.

According to a second aspect of the present invention, the intake passage pipe having the flange portion is located inside, and is fitted to the other intake passage pipe.

According to a third aspect of the present invention, the intake pipe having the flange is the first intake pipe.

The invention according to a fourth aspect is characterized in that the position of the second intake passage pipe in the axial direction is variable by the movable mechanism.

According to a fifth aspect of the present invention, the intake pipe having the flange is the second intake pipe.

The invention according to claim 6 is characterized in that the position of the first intake passage pipe in the axial direction is variable by the movable mechanism.

[0019]

According to the first aspect of the present invention, a first intake passage pipe having one end communicating with the combustion chamber and the other end communicating with the surge tank, and one end opening at a position opposite to the other end opening of the first intake passage pipe in the surge tank. And a second intake passage pipe having the other end communicated with the intake passage in the surge tank or on the upstream side of the surge tank.
A flange portion is provided at one of the openings at one end of the intake passage tube, and the flange portion extends toward the other opening so as to be fitted to the other, and its leading edge is inclined with respect to the axis. The first intake passage pipe or the second intake passage pipe is provided with a movable mechanism, and the first intake passage pipe or the second intake passage pipe is fitted with the flange and the other opening over the entire circumference. The position of the one opening or the other opening in the axial direction is variably set so as to obtain a mode in which the fitting is released. Therefore, the rate of change of the effective intake pipe length per unit gap change in the small gap region becomes relatively small.

According to a second aspect of the present invention, the intake passage tube having the flange portion is fitted inside the other intake passage tube, and also in this case, the effective intake pipe length per unit gap change in the small gap region. The rate of change is relatively small.

According to the third aspect of the present invention, the intake passage pipe having the flange portion is the first intake passage pipe, and also in this case, the rate of change of the effective intake pipe length per unit gap change in the small gap area is relatively small. .

According to the fourth aspect of the present invention, since the position of the second intake passage pipe in the axial direction is made variable by the movable mechanism, the rate of change of the effective intake pipe length per unit gap change in the small gap area is also relatively small. Become smaller.

According to a fifth aspect of the present invention, the intake passage pipe having the flange portion is the second intake passage pipe, and also in this case, the rate of change of the effective intake pipe length per unit gap change in the small gap area is relatively small. .

According to a sixth aspect of the present invention, the position of the first intake passage in the axial direction is made variable by the movable mechanism.
In the small gap region, the change rate of the effective intake pipe length per unit gap change becomes relatively small.

[0025]

FIG. 1 shows an engine intake pipe length varying device A as an embodiment of the present invention.

The variable intake pipe length device A has a larger number of identical members than the variable intake pipe length device A of the engine shown in FIG. 9 except for the fact that the pipe components in the surge tank 4a are partially different. Here, the same members are denoted by the same reference numerals, and redundant description will be omitted.

The variable intake pipe length device A is mounted on an in-line four-cylinder engine (hereinafter simply referred to as an engine) 1. The intake system of the engine 1 includes an air cleaner 10, an intake pipe 11, a surge tank 4a, and an intake manifold with a throttle valve 17. The total intake pipe length, which is the total length of the intake path of the engine 10, is determined by sequentially connecting the intake system components such as the pipe 5 and the intake port 3, and the length is the maximum value Ls and the minimum value in the surge tank 4a. The value is increased or decreased within the range of the value Lso. FIG.
As shown in FIG. 4 to FIG. 4, the surge tank 4a has a capacity capable of interfering with the intake pulsation of each cylinder, and particularly accommodates a main portion of the variable intake pipe length device A of the engine.

The surge tank 4a accommodates a projecting pipe 501 at the tip of the intake manifold 5, and furthermore, the projecting pipe 501
A curved pipe 9 as a second intake passage pipe formed with one end opening 7 opened at a position opposed to the other end opening 6 and another end opening 8 projecting outside from the surge tank and communicating with the inside again; Has an inflow port 111 at one end of the intake pipe 11 communicating with the air cleaner 10. Here, the extension tube 12 is fitted to the straight portion 901 at the lower end of the curved tube 9. Extension tube 12
The driving device 13 is mounted on the, and the flared opening 121 at the end thereof and the opening 502 on the other end opening 6 side of the protruding pipe 501 are operated to approach and separate. The opening portion 502 of the protruding tube 501 has a base portion integrally connected to an inner peripheral wall thereof, and a flange portion 18 protruding from the inclined opening 6a cut and inclined.

The outer diameter D1 of the flange 18 is smaller than the inner diameter d1 of the extension tube 12 (see FIG. 3), so that both can be fitted smoothly.

Here, when the opening 121 of the extension pipe 12 is at the retreat position E1 where it is most retracted, as shown in FIG. 1 and FIG.
Are set so as to be apart from the gap Q2. On the other hand, when the opening 121 of the extension tube 12 is at the most protruding position E2, the inclined opening 6a of the flange 18 is set to be completely covered by the opening 121 of the extension tube 12, as shown in FIG. Is done.

Here, the drive device 13, the straight portion 901 and the extension tube 12 constitute a trombone mechanism.

The driving device 13 includes a first link 14a and a second link 14a.
A link 14b, a drive shaft 14c integrally connected to the second link 14b, and a DC motor 15;
5 is connected to the controller 16a. Controller 1
6a drives the extension pipe 12 in accordance with the engine speed, and the opening 121 at the tip thereof and the opening 50 of the protruding pipe 501.
2 is controlled. Here, when the engine 1 is in the rotation range when the maximum output is generated, the controller 16a separates the gap between the opening 121 of the extension pipe 12 and the opening 502 of the protruding pipe 501 in order to shorten the total intake pipe length, The inclined opening 6a of the flange portion 18 is fully opened, and all the airflow in the surge tank 4 is directly guided from the inflow port 111 to the inclined opening 6a.
The effective intake pipe length is kept at the minimum value Lso, and the pulsation effect of the intake pipe in the rotation range when the maximum output is generated is secured.

At this time, as shown in FIG.
2 is large, the opening area of the flow path through which the air flow flows is the area of the circle of the two-dot chain line e, and the outer peripheral length (the circumferential length of the two-dot chain line circle e) is small for the opening area. Is small,
The pressure loss μ is low (see FIG. 7). On the other hand, when the engine 1 is in the rotation range when the maximum torque is generated, the opening 121 of the extension pipe 12 reaches the protruding position E2 where the opening 121 of the extension pipe 12 protrudes most so as to increase the total intake pipe length, and as shown in FIG. The inclined opening 6 a of the portion 18 is completely covered by the opening 121 of the extension tube 12. Here, all of the airflow in the surge tank 4 is the inlet 1
From 11, it is guided to the flange portion 18 side through the curved pipe 9, holds the effective intake pipe length at the maximum value Ls, and secures the pulsation effect of the intake pipe in the rotation range when the maximum torque is generated.

At this time, the inclined opening 6a is completely covered,
There is no inflow airflow from the inclined opening 6a, and as shown in FIG. 7, the intake air flow resistance is smaller and the pressure loss μ is relatively lower than in the case of the device of FIG. Next, when the engine 1 is in the rotation range when the intermediate output is generated, the controller 16a sets a gap between the opening 121 of the extension pipe 12 and the opening 502 of the protruding pipe 501 in order to set the total intake pipe length to the intermediate length. Move closer to the specified amount. At this time, as shown in FIGS. 3 and 6, the inclined opening 6a of the flange portion 18 forms a crescent shape when viewed from the bottom, and the surge tank 4
A part of the airflow in the air is sucked through the crescent-shaped inclined opening 6a,
The remaining portion is sucked through the curved tube 9.

As a result, the effective intake pipe length is maintained at an intermediate value between the minimum value Lso and the maximum value Ls, and the pulsating effect of the intake pipe in the intermediate rotation range can be ensured. At this time, as shown in FIG. 6, the gap is located between Q1 and Q2,
The opening area of the flow path through which the air flow flows is the area of the curved crescent shape indicated by the two-dot chain line f in FIG. 6A, and the outer peripheral length (the outer peripheral length of the curved crescent shape f indicated by the two-dot chain line) for the opening area ) Is small. That is, the average fluid depth m (= A / S) obtained by dividing the flow path cross-sectional area A by the peripheral length S is relatively large, and the pressure loss is relatively small. For this reason, the pressure loss μ is relatively small here,
The intake flow resistance is relatively small (see the broken line in FIG. 7).

In particular, at this time, even if the gap Q reaches the small gap area q close to zero, the rate of change of the effective intake pipe length per unit gap is maintained similarly to outside this area, and the controllability decreases. Can be prevented. In the above-described variable intake pipe length device A, the intake manifold 5 that is the first intake passage pipe has the flange portion 18,
The extension pipe 12 on the side of the curved pipe 9 as an intake passage pipe was fitted outside. Instead of this, as a modified example of the variable intake pipe length mechanism A, the extension pipe as the second intake path pipe is provided with a flange, and the extension pipe of the intake manifold as the first intake path pipe is fitted to the outside. A configuration may be adopted. In this case, the same operation and effect as those of the apparatus shown in FIG. 1 can be obtained.

[0037]

According to the first aspect of the present invention, a first intake passage pipe having one end communicating with the combustion chamber and the other end communicating with the surge tank, and one end facing the other end opening of the first intake passage pipe in the surge tank. And a second intake passage pipe having the other end communicated with the intake passage in the surge tank or on the upstream side of the surge tank, and in particular, the other end opening of the first intake passage or one end of the second intake passage pipe A flange portion is provided in one of the openings, the flange portion extends toward the other opening so as to be fitted to the other, and is formed so that a leading edge thereof is inclined with respect to the axis, A movable mechanism is provided, whereby the first intake passage pipe or the second intake passage pipe is configured such that the flange and the other opening are fitted over the entire circumference thereof, and the fitting between the flange and the other opening is released. So that The axial position of the mouth or other opening to variably set. For this reason, the change rate of the effective intake pipe length per unit gap change in the small gap region becomes relatively small,
Controllability is improved.

According to a second aspect of the present invention, the intake passage tube having the flange portion is fitted inside the other intake passage tube, and also in this case, the effective intake pipe length per unit gap change in the small gap region. The rate of change is relatively small, and controllability is further improved.

According to a third aspect of the present invention, the intake passage pipe having the flange portion is the first intake passage pipe, and also in this case, the change rate of the effective intake pipe length per unit gap change in the small gap region becomes relatively small. , Controllability is improved.

According to the fourth aspect of the present invention, since the position of the second intake passage pipe in the axial direction is made variable by the movable mechanism, the rate of change of the effective intake pipe length per unit gap change in the small gap area is relatively small. It is smaller and controllability is improved.

According to a fifth aspect of the present invention, the intake passage pipe having the flange portion is the second intake passage pipe, and also in this case, the change rate of the effective intake pipe length per unit gap change in the small gap area becomes relatively small. , Controllability is improved.

According to the sixth aspect of the present invention, the position of the first intake passage in the axial direction is made variable by the movable mechanism.
In the small gap region, the change rate of the effective intake pipe length per unit gap change becomes relatively small, and controllability is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a variable intake pipe length device of an engine as one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the trombone mechanism of the variable intake pipe length device of FIG. 1 when it is fully opened.

FIG. 3 is an enlarged cross-sectional view of the trombone mechanism of the variable intake pipe length device of FIG. 1 at an intermediate opening.

FIG. 4 is an enlarged sectional view of the trombone mechanism of the variable intake pipe length device of FIG. 1 when fully closed.

FIG. 5 is a diagram illustrating flow resistance characteristics when the trombone mechanism of the intake pipe length varying device in FIG. 1 is fully opened.

FIG. 6 is a view for explaining flow resistance characteristics of the trombone mechanism of the variable intake pipe length device of FIG. 1 at an intermediate opening degree;
(A) is a bottom view and (b) is a side view.

FIG. 7 is a characteristic diagram of an effective intake pipe length and a gap of the intake pipe length variable device of FIG. 1;

FIG. 8 is a characteristic diagram of an effective intake pipe length and a gap of a conventional intake pipe length variable device.

FIG. 9 is an overall configuration diagram of a conventional variable intake pipe length device.

FIG. 10 is a view for explaining flow resistance characteristics in the vicinity of a fully closed trombone mechanism of a conventional intake pipe length varying device. DESCRIPTION OF SYMBOLS 1 Engine 4a Surge tank 5 Intake manifold 501 Protruding pipe 502 Opening 6a Inclined opening 7 One end opening 9 Curved pipe 10 Air cleaner 11 Intake pipe 111 Inflow port 12 Extension pipe 121 Opening 13 Drive unit 18 Flange part A Variable intake pipe length device Ls Maximum value Lso Minimum value Q1 gap Q2 gap

Continuation of the front page (56) References JP-A 4-27122 (JP, U) JP-A 4-6537 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02B 27 / 02

Claims (6)

(57) [Claims] A first intake passage pipe having one end communicating with the combustion chamber and the other end communicating with the surge tank; one end opening at a position opposite to the other end opening of the first intake passage pipe in the surge tank; A second intake passage pipe having an end communicating with the intake passage in the surge tank or on the upstream side of the surge tank, and one of an opening at the other end of the first intake passage and an opening at one end of the second intake passage pipe; A flange portion provided on one side and extending toward the other opening so as to be fitted to the other side, and having a leading edge formed so as to be inclined with respect to an axis; (2) In the intake passage pipe, the flange and the other opening are fitted over the entire circumference thereof, and the fitting between the flange and the other opening is released. The axis of the opening or the other opening A variable intake pipe length device for an engine, comprising a movable mechanism for variably setting a direction position. 2. The variable intake pipe length of an engine according to claim 1, wherein the intake pipe having the flange portion is located inside and is fitted to the other intake pipe. 3. The variable intake pipe length of an engine according to claim 1, wherein the intake pipe having the flange is the first intake pipe. 4. The variable intake pipe length mechanism according to claim 1, wherein the position of the second intake passage pipe in the axial direction is variable by the movable mechanism. 5. The variable intake pipe length of an engine according to claim 1, wherein the intake pipe having the flange is the second intake pipe. 6. The intake pipe length varying mechanism according to claim 1, wherein said first intake passage pipe is configured such that the position in the axial direction is variable by said movable mechanism.