JPH0649891Y2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine intake device.

(Prior Art) Conventionally, in an engine for an automobile, from the viewpoint of enhancing intake charging efficiency and improving engine output, for example, pressure generated in an intake pipe as disclosed in Japanese Patent Laid-Open No. 56-115819. A dynamic supercharging system that uses vibration (pressure wave) to supercharge intake air is used.

By the way, there are roughly two types of methods of utilizing the pressure wave of the intake air in the dynamic supercharging method. One of these methods is called the intake inertia effect, in which the pressure wave (negative pressure wave) generated by opening and closing the intake valve travels back up in the intake passage and reverses in the volume of the surge tank. Then, after becoming a positive pressure wave, this positive pressure wave is transmitted to the downstream side in the intake passage and reaches the intake port portion at the end of the intake stroke to perform supercharging action. That is, in this case, the pressure wave reciprocates in the same intake passage.

Another method is called an inter-cylinder interference effect, in which the intake passages connected to the two cylinders are connected to each other, and the pressure wave generated in one intake passage (in this case, , The pressure wave of positive pressure generated by the inertia of the intake valve itself when the intake valve is closed, and a part of the combustion gas in the combustion chamber flows back into the intake passage when the intake valve is closed to compress the intake air (There is a positive pressure wave) that is transmitted to the other intake passage to perform supercharging at the end of the intake stroke of the cylinder. That is, in this case, the pressure wave propagates from one intake passage to the other intake passage.

Therefore, in order to obtain the intake inertia effect or the inter-cylinder interference effect by using the surge tank as the intake reversal portion or the transmission portion to obtain a high level of dynamic supercharging, the surge tank satisfies the following conditions. Such a configuration is required. That is, first, as the first condition, both the original function of the surge tank, that is, the function of increasing the intake volume increasing response at the time of acceleration due to intake air retention and the function of reversing the pressure wave of intake air due to the intake inertia are made compatible. From the viewpoint of having a relatively large volume, the second condition is that the diffusion attenuation of the pressure wave in the surge tank is suppressed and the surge tank is effectively used as a pressure wave transmission unit between the cylinders. This means that the surge tank volume is set to be relatively small in terms of functioning.
That is, the surge tank is required to satisfy the trade-off condition.

However, since the conventional surge tank has a configuration in which the intake passage is simply connected to the surge tank as disclosed in the above-described known example, the capacity of the surge tank is unique depending on the distance between the intake passages. If the interval is increased, the surge tank capacity is increased accordingly. That is, it is hard to say that the conventional surge tank has a surge tank structure in consideration of the improvement of the dynamic supercharging efficiency as described above.

Further, depending on the engine model, two intake passages are provided for each cylinder, and only one of the intake passages is opened to the surge tank, and the other intake passage is not opened to the surge tank, and is close to the surge tank. Some of them have an intake passage configuration in which they are arranged through, but in this case, unless the relative arrangement of the two intake passages is sufficiently taken into consideration, the surge tank and the above two intake passages are simply arranged vertically. Since they are arranged in a stack, the height of the intake system including them becomes high, which may cause a problem such as an increase in the overall height of the engine.

(Purpose of the Invention) The present invention is intended to solve the problems pointed out in the above-mentioned prior art, in which an intake passage that does not open to the surge tank and an intake passage that opens to the surge tank are arranged close to each other. The purpose of the intake device is to achieve both improvement of dynamic supercharging of intake air and securing of an appropriate capacity of a surge tank without causing an increase in overall height of the engine.

(Means for Achieving the Purpose) As a means for achieving the above object, at least a pair of first intake passages are made to penetrate through the surge tank in an independent state, while at least a pair of In the intake system for an engine, wherein a second intake passage is opened in the surge tank, the pair of first
The penetration position of the intake passage with respect to the surge tank is set to a position deviated upward or downward from the vertical center position of the surge tank, and at the lateral position of the penetration part of the pair of first intake passages. A volume portion of the surge tank is extended, and the opening positions of the pair of second intake passages to the surge tank are both offset in the up-down direction of the surge tank in a direction opposite to the first intake passage. It is characterized by that.

(Operation) According to the present invention, the following operations can be obtained by the above means.

(1) At least a pair of second openings that open into the surge tank
Since the opening position of the intake passage is biased in the vertical direction of the surge tank with respect to at least the pair of first intake passages penetrating the surge tank, it extends to the side of the first intake passage. The installed surge tank volume portion is deviated in the vertical direction of the surge tank with respect to the pair of second intake passages and deviates from the straight line connecting the openings of the pair of second intake passages. Therefore, the extended portions located on the sides of the pair of first intake passages hardly contribute as a pressure wave transmission portion of the inter-cylinder interference that occurs between the second intake passages, so that the entire surge tank is The volume of the capacity that functions as a pressure wave transmission part becomes smaller, and the diffusion attenuation of the pressure wave in the surge tank is suppressed as much as possible by this substantial volume reduction, resulting in a high level of inter-cylinder interference effect. Is realized.

(2) When the intake inertia action is performed in each of the second intake passages by using the surge tank as the pressure wave reversal unit, the pressure inertia has a directional transmission in the intake inertia action as in the case of the inter-cylinder interference action. Therefore, the full capacity of the surge tank including the portion extending to the side of the first intake passage functions as a reversal portion of the pressure wave, and thus a high level intake inertia effect is realized.

(3) The surge tank volume required for the surge tank to exert its original function, that is, the function of improving intake responsiveness during acceleration by accumulating intake air is as much as that of the surge tank on the side of the first intake passage. By extending the volume portion, it is easily ensured without increasing the height of the intake system.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

Structure FIG. 1 shows a main part of an intake system of a two-rotor rotary piston engine 1 for an automobile equipped with an intake device according to an embodiment of the present invention. In FIG. 1, reference numeral 2 is an intake manifold. The intake manifold 2 is curved so that the upstream side flange 61 and the downstream side flange 62 are orthogonal to each other, and is fastened and fixed to the side surface of the engine 1 with the upstream side flange 61 facing upward. ing. An intake passage block 3 described later is connected to the upstream side flange 61 of the intake manifold 2, and a surge tank block 4, a throttle body 5 and an intake pipe 6 described later are sequentially connected to the upstream side of the intake passage block 3. , These make up a series of intake systems.

The intake passage block 3 is composed of passages that are curved in two directions, that is, the vertical direction and the horizontal direction, as shown in FIGS. 1 and 2, and is provided in a first cylinder (not shown) of the engine 1. It has a first intake passage group 10 connected to it and a second intake passage group 20 connected to a second cylinder (not shown). The two intake passage groups 10 and 20 have the same passage configuration, and sandwich a control valve 7 which will be described later and which is arranged on the axis Lo of the intake passage block 3 as shown in FIG. Are arranged in line symmetrically on both sides.

That is, the first intake passage group 10 has two independent intake passages, that is, a first independent intake passage 11 that functions as a high load intake passage and a second independent intake passage 14 that functions as a low load intake passage. In addition, the second intake passage group 20 also has a first independent intake passage 21 that also functions as a high load intake passage and a second independent intake passage 24 that functions as a low load intake passage.

The two independent intake passages 11, 14 of the first intake passage group 10
And the two independent intake passages 21 and 24 of the second intake passage group 20 are throttle valves 71 and 72 (throttles corresponding to the independent intake passages 21 and 24) provided in the throttle body 5 as shown in FIG. (The valve is not shown in the figure), so that when the engine is under low load, it is the same as the second independent intake passage 14
Only 24 is opened, and it is the same as the first independent intake passage 11 for high load.
21 are blocked, and when the engine is under heavy load,
In addition to the second independent intake passages 14 and 24, the first independent intake passages 11 and 21 for high load are opened at the same time.

Hereinafter, the individual intake passages 10, 20 of the intake passage block 3 will be described.
The specific passage configuration of the above will be described in detail by taking the two independent intake passages 11 and 14 on the first intake passage group 10 side as an example.

The first independent intake passage 11 has an upstream passage portion 12 located upstream of the intake air and a downstream passage portion 13 located downstream of the intake air. Of the two intake passage portions 12 and 13, first, the passage structure of the downstream passage portion 13 is set as follows.

That is, the downstream passage portion 13 extends from the downstream end 13b that opens onto the downstream flange 64 that abuts the upstream flange 61 of the intake manifold 2 to the upstream end 13a that is connected to the control valve 7 described later. It will be extended. In this case, in the up-down direction, as shown in FIG. 1, first, it rises obliquely upward from its downstream end 13b, then curves toward the engine 1 side and extends on the engine 1 in a substantially horizontal direction for control. It is curved so as to reach the valve 7 side.

Further, in the plane direction, as shown in FIG. 2, it first extends outward (in a direction away from the axis Lo) from its downstream end 13b, and then largely bends inward (direction closer to the axis Lo). The upstream end 13a is connected to the control valve 7 so as to be orthogonal to its axis (same as the axis Lo of the intake passage block 3). The upstream end 13a of the downstream side passage portion 13 is connected to the first independent intake air on the side of the second intake passage group 20 through the second valve passage 44 (described later) of the control valve 7 as shown in FIG. It is opposed to the downstream passage portion 23 of the passage 21.

On the other hand, the upstream side passage portion 12 includes the upstream side flange 63 arranged substantially horizontally and the downstream side passage portion 13 and the upstream end 13a thereof.
It is arranged so as to straddle a position slightly downstream, and its passage configuration is set as follows.

That is, when the upstream passage portion 12 is extended from the upstream end 12a toward the downstream end 12b, first, in the vertical direction, as shown in FIG. 1, it extends downward from the upstream flange 63. After coming out, it is largely curved toward the downstream passage portion 13 side, and after extending as it is in the substantially horizontal direction above the engine 1, it is connected to the downstream passage portion 13 from its side. In the plane direction, as shown in FIG. 2, the center point P ₁ of the upstream end 12a of the upstream passage portion 12 and its downstream end 12b
Is curved so as to bulge in a substantially arcuate shape outside the straight line L ₁ connecting the confluence point Q ₁ with the downstream passage portion 13 (the direction away from the axis Lo).

If the upstream passage 12 is configured in this way, the above-mentioned junction Q ₁
The passage direction line of the upstream passage portion 12 and the downstream passage portion 13 in
The intersection angle α ₁ formed with the passage direction line (for the sake of convenience, described on the second intake passage group 20 side) is, for example, when the passage direction line of the upstream passage portion 12 matches the straight line L ₁ or the straight line L _{1. It} is always smaller than that when curved inward of ₁ (that is, in the direction approaching the axis Lo) (that is, the first independent intake passage).
11 will be greatly bent at the confluence Q _1. )

On the other hand, the second independent intake passage 14 has, similarly to the first independent intake passage 11, an upstream passage portion 15 located on the intake upstream side and a downstream passage portion 16 located on the intake downstream side. ing.
Of the two intake passage portions 15, 16, the passage structure of the downstream passage portion 16 is set as follows.

That is, the downstream passage portion 16 extends from the downstream end 16b opening on the downstream flange 64 that abuts the upstream flange 61 of the intake manifold 2 toward the upstream end 16a connected to the control valve 7. To be done. In this case, first, in the up-down direction, as shown in FIG. 1, after rising upward from the downstream end 12b, the curve is curved toward the engine 1 side, and on the engine 1 and above the first side. The control valve 7 extends in a substantially horizontal direction at a position substantially the same as the downstream passage portion 13 of the independent intake passage 11.
It is curved so as to reach the side.

Further, in the plane direction, as shown in FIG. 2, the first independent intake passage 11 is temporarily extended outside from the downstream end 16b inside the downstream passage portion 13 and along the downstream passage portion 13. After putting it out, it bends largely inward and its upstream end
16a is connected to the control valve 7 so as to be orthogonal to its axis. Then, the upstream end 12a of the downstream passage portion 16
6 is made to face the downstream side passage portion 26 of the second independent intake passage 24 on the side of the second intake passage group 20 via the first valve passage 43 (described later) of the control valve 7 as shown in FIG. ing.

On the other hand, the upstream passage portion 15 includes an upstream flange 63 arranged substantially horizontally and the downstream passage portion 16 and an upstream end 16a thereof.
It is arranged so as to straddle a position slightly downstream, and its passage configuration is set as follows.

That is, when the downstream passage 16 is extended from the upstream end 16a toward the downstream end 16b, first, in the vertical direction, as shown in FIG. After extending, it is greatly curved so as to bypass the lower side of the downstream side passage portion 13 of the first independent intake passage 11 so as to closely approach,
It is connected to the upstream passage portion 15 from the side thereof. Further, in the plane direction, as shown in FIG.
The center point P ₂ of the upstream end 15a of the upstream passage portion 15 and the confluence point Q _{2 of the} downstream end 15b and the downstream passage portion 16 inside the upstream passage portion 12 of the independent intake passage 11 Straight line L
₂ bulges outward in a substantially arcuate shape, and the upstream side passage portion 12
It is curved so as to follow.

If the upstream passage portion 15 is configured in this way, the above-mentioned joining point Q ₂
The passage direction line of the upstream side passage portion 15 and the downstream side passage portion 16 in
The intersection angle α ₂ formed by the straight line L ₂ is the same as that on the side of the first independent intake passage 11 when the straight line L ₂ is aligned with the straight line L ₂ of the upstream passage portion 15, for example. _It is always smaller than when curved inward of ₂ .

Further, when the first independent intake passage 11 and the second independent intake passage 14 are arranged side by side in the horizontal direction at substantially the same height as described above, it is possible to arrange the first independent intake passage 11 and the second independent intake passage 14 in the vertical direction in comparison with the case where they are arranged in the vertical direction. Since the height can be suppressed, as shown in FIG. 1, the intake system is provided in a relatively narrow space between the upper surface of the engine 1 and the bonnet line 1 located thereabove, and the required passage length is sufficient. It can be provided in a secured state.

The control valve 7 is connected to the axis Lo of the intake passage block 3 as described above.
As shown in FIG. 5, it has a bottomed cylindrical case body 41 integrally formed with each of the independent intake passages 11, 14, 21, and 24. , Each independent intake passage
On the way of 11,14,21,24, that is, each downstream side passage section 13,16,23,
The upstream ends of 26 are opened on the peripheral wall 41a of the case body 41, respectively. The case main body 41 and the end face plate 45 that closes the open end of the case main body 41 constitute a closed cylindrical valve case 40. The sliding contact is rotatably fitted.

The valve body 42 is integrally formed of a synthetic resin material in a substantially shaft shape, and the front rotary shaft 57 and the rear rotary shaft 58 are respectively provided on the boss portions 59 and 60 which are provided at both ends of the shaft center portion thereof so as to project. It is provided. The rear rotation shaft 58 is rotatably supported on the bottom wall 41b of the case body 41 of the valve case 40, and the front rotation shaft 57 is rotatably supported on the end plate 45, so that the valve body 42 slides in the inner space 56. It is possible to rotate in close contact. The actuator 30 is connected to the outer end of the front rotary shaft 57 via a lever mechanism 46.

In addition, the valve body 42 has an internal space 56 in the valve case 40.
Each of the above-mentioned downstream side passage portions 13, 16, 23, 2 in the state of being inserted into the inside
First position at the upstream end of 6 and the corresponding position in the direction of rotation.
The valve passage 43 and the second valve passage 44 are formed so as to penetrate in the radial direction. Then, using the actuator 30, the valve body
By rotating 42, the two downstream passage portions 13 and 16 on the first intake passage group 10 side and the two downstream passage portions 23 and 26 on the second intake passage group 20 side face each other. It is designed to be in communication (hereinafter referred to as valve opening position) or to be cut off from communication (hereinafter referred to as valve closing position). Specifically, it is set to the valve closing position during low speed operation of the engine and opened during high speed operation. It is set to the valve position.

Further, as shown in FIGS. 5 and 6, the valve body 42 has recesses 47 and 49 formed by axially recessing around the boss portions 59 and 60 at both axial ends thereof. Then, between the concave portions 47, 49 and the inner surface of the end face plate 45 and the inner surface of the bottom plate 41a of the case body 41, which are opposed to the concave portions 47, 49, volume portions 51, 53 having appropriate volumes are formed.

Further, at the axially intermediate portion of the valve element 42, the first valve passage is also provided.
In a portion located between 43 and the second valve passage 44, a concave portion which is divided in the circumferential direction by a rib 50 extending in the radial direction as shown in FIGS. 5 and 7 and which opens on the outer peripheral surface of the valve body 42. 48,48 ... are formed. The concave portions 48, 48 ... Form a volume 52 with the inner surface of the peripheral wall 41a of the case body 41 of the valve case 40 facing the concave portions 48.

Further, a cone spring 54 is fitted between the boss portion 59 of the valve body 42 and the end face plate 45 to constantly urge the valve body 42 toward the other boss portion 60 side. In the arrangement direction of the cone spring 54, the end portion on the small diameter side is on the valve body 42 side,
It is set so that the end on the large diameter side is located on the end face plate 45 side.

The surge tank block 4 includes, as shown in FIGS. 1, 3 and 4, a first intake air intake passage 35 connected to the first independent intake air passage 11 of the first intake air passage group 10, and A second intake introduction passage 36 connected to the first independent intake passage 21 of the second intake passage group 20 and a third intake introduction passage connected to the second independent intake passage 14 of the first intake passage group 10. 37 and the second above
Fourth connected to the second independent intake passage 24 of the intake passage group 20
Passage part 32 composed of four air introduction paths of intake air introduction path 38
And the surge tank 31 provided at the upstream end of the passage 32.
And have. And this surge tank block 4
Is attached to the intake passage block 3 side by fastening a downstream flange 66 provided on the passage portion 32 side to the upstream flange 63 of the intake passage block 3.

Further, the passage portion 32 of the surge tank block 4 is curved as shown in FIG.
Are arranged in proximity to the upper side of the intake passage block 3. In this case, in the surge tank 31 portion, as shown in FIGS. 3 and 4, the upstream ends of the third intake air introduction passage 37 and the fourth intake air introduction passage 38 are respectively the volume chambers 33 of the surge tank 31.
Although it is open inside, the first intake air intake passage 35 and the second intake air intake passage 36 extend to the upstream side flange 65 without being opened and the first port 39A and the second port 39B on the upstream side flange 65.
Are in communication with each other.

That is, in this embodiment, the first intake air intake passage 35 and the second intake air passage 35
2 of the intake air intake passages 36 correspond to the first intake air passage in the scope of the utility model registration claim, and two intake intake passages 37 and 4 of the utility model registration are in the scope of the utility model registration claim. Corresponds to the second intake passage.

Further, the third intake air intake passage 37 and the fourth intake air intake passage 38 are
The surge tank 31 communicates with the third port 39C on the upstream side flange 65 via the volume chamber 33. Further, the throttle body 5 is connected to the upstream side flange 65, and the ports 39A, 39B, 39C are provided in the throttle body 5 so as to correspond to the ports 39A, 39B, 39C.
It is opened and closed by 1,72.

Specifically, in a low load range where the engine load is equal to or lower than a preset load, only the third port 39C is opened in response to the increase in the load and the first port 39A and the second port 39B are kept closed. To be done. In the high load range where the engine load exceeds the above set load, the first and second ports 39A, 39B are gradually opened in association with the opening operation of the third port 39C, and in the full load state, the three ports 39A, 39A, All 39B and 39C are fully opened.

The throttle body 5 is, as shown in FIG.
It has a conventionally well-known structure, and each of the ports 39A,
Independent passage parts 73 and 74 (port 39
The independent passages corresponding to C are omitted in the drawing), and communicate with each other at the merging portion 75 on the rear side of the throttle valves 71 and 72 respectively provided therein. In this embodiment, the merging portion 75 is made to function as a pressure wave inversion portion or a transmission portion as described later.

Furthermore, in this embodiment, the present invention is applied to
As shown in the figure, the first intake air intake passage 35 and the second intake air intake passage 36
And the volume chamber of the surge tank 31
The third intake air intake passage 37 and the fourth intake air intake air passage 38 are arranged in the upper part of the inside 33, and the first intake air intake air passage 35 and the second intake air intake air passage 38 are connected to each other.
It is arranged so as to be located below the first intake air intake passage 35 and the second intake air intake passage 36 in the left-right direction below 36. The third of the volume chambers 33
The upper portions of the intake air intake passage 37 and the fourth intake air intake passage 38 are extension chambers 33a and 33b, respectively, and the space between the third intake air intake passage 37 and the fourth intake air intake passage 38 is a central chamber 33C. Furthermore, the surge tank 31 located below the central chamber 33C
Both sides of the bottom wall portion 31a are formed into smooth curved surfaces along the mouth end shapes of the third intake air intake passage 37 and the fourth intake air intake passage 38.

Operation and Action Next, the operation and action of the intake device having the above-described configuration will be described.

In this engine 1, depending on the engine load, the first
The intake air is introduced into each of the two cylinders by selectively using the independent intake passages 11 and 21 and the second independent intake passages 14 and 24, respectively, and the operation of the engine is continued. Due to supercharging, intake charging efficiency is improved,
Higher engine output is realized.

Dynamic supercharging is performed in various modes depending on the operating state of the engine as follows.

I: Low load area When the engine load is low, each intake passage group 10, 20
The independent intake passages 11 and 21 are closed, and only two passages of the respective second independent intake passages 14 and 24 contribute to intake air introduction.

Ia: Low load / low speed region At low load / low speed of the engine, the control valve 7 is set to the closed position, and in the volume chamber 33 of the surge tank 31, the second independent intake passages 14, 24 are provided. Downstream passageway 16,26
A third intake air intake path 37 and a fourth intake air intake path 38, which are respectively connected to each other, communicate with each other. Therefore, the volume chamber 33 is used as a pressure wave reversal portion to perform dynamic supercharging by the intake inertia in each of the second independent intake passages 14 and 24, and at the same time, the volume chamber 33 is used as a pressure wave transmission portion. Each second independent intake passage 14,2
Dynamic supercharging due to inter-cylinder interference is performed across four intervals.

In this case, in the present embodiment, the present invention is applied so that the volume chamber 33 of the surge tank 31 is not limited to the central chamber portion 33C located between the third intake introduction passage 37 and the intake introduction passage 38.
Extension chambers 33 extended above these
Since it is composed of a and 33b, it is possible to secure a sufficient volume of the volume chamber 33, so that the inversion action of the pressure wave in the volume chamber 33 is efficiently and surely performed, and a high level is achieved. Dynamic supercharging due to the intake inertia effect is obtained.

Further, the central chamber 33C, which serves as a pressure wave transmitting portion in the inter-cylinder interference, is formed to be relatively narrow and has two extension chambers 33a, 33b.
Is a position largely deviated from the line connecting the third intake air introduction path 37 and the fourth intake air introduction path 38, and it hardly functions as a pressure wave transmission part in the inter-cylinder interference, and the lower surface side of the central chamber part 33C is pressure liquid. Is a curved surface suitable for smoothly transmitting from one intake introduction path to the other intake introduction path side, the diffusion and transmission resistance of the pressure wave in the volume chamber 33 are small, and a cylinder of such a high level. Interference effect will be obtained. That is, the surge tank 31 of this embodiment
It can be said that the above configuration is suitable for achieving both the intake inertia and the inter-cylinder interference performed by using the volume chamber 33 of the surge tank 31.

I-b: At low load / high speed In the low load / high speed region of the engine, the control valve 7 is set to the open position, so that the second independent intake passages 14,24 of the respective intake passage groups 10,20 are Are opposed to each other via the control valve 7. Therefore, in this operating region, dynamic supercharging is performed by the inter-cylinder interference effect via the downstream side passage portions 16 and 26 of the respective second independent intake passages 14 and 24. In this case as well, in each of the second independent intake passages 14 and 24, an intake inertia effect can be obtained via the surge tank 31, but in this case, since the passage length does not match the engine speed, It hardly contributes to supercharging.

II: High load region In the high load region of the engine, each of the intake passage groups 10 and 20 has two independent intake passages 11 and 14 and 21 and 24, and intake is introduced through both passages.

II-a: At high load / low speed At high load / low speed, the control valve 7 is set to the closed position, and each of the first independent intake passages 11 and 21 has the throttle body 5
Communicate with each other, and each second independent intake passage 14,2
4 communicates with the surge tank 33. Therefore, the inter-cylinder interference action does not occur via the control valve 7, and the surge tank
Dynamic supercharging is performed by an intake inertia effect or an inter-cylinder interference effect in which the pressure wave inversion portion or transmission portion is the 31 and the throttle body 5.

That is, on the side of the first independent intake passages 11 and 21, since the first independent intake passages 11 and 21 communicate with each other at the confluence portion 75 of the throttle body 5, the throttle body 5 is reversed in pressure wave. A dynamic supercharging is performed by the intake inertia effect and the inter-cylinder interference effect as the section and the transmission section. On the other hand, on the side of each of the second independent intake passages 14 and 24, these second
Since the independent intake passages 14 and 24 communicate with each other in the surge tank 31, the surge tank 31 is used as an inversion portion and a transmission portion of the pressure wave to perform dynamic supercharging by the intake inertia effect and the inter-cylinder interference effect. .

II-b: At high load / high speed At high load / high speed, since the control valve 7 is in the open position, the control valve 7 is connected to the downstream passage portion 13 of the first independent intake passage 11 on the first intake passage group 10 side. Downstream passage portion 16 of the second independent intake passage 14
Respectively communicate with the downstream side passage portion 23 of the first independent intake passage 21 and the downstream side passage portion 26 of the second independent intake passage 24 on the side of the second intake passage group 20 through the control valve 7 so as to face each other. is doing.

For this reason, the control valve 7 is used as a pressure wave transmitting portion, and the downstream side passage portions 13 and 23 of the first independent intake passages 11 and 21 on the side of the intake passage groups 10 and 20 and the intake passage groups 10 and 20 side. Dynamic supercharging is performed by the inter-cylinder interference effect between the downstream side passage portions 16 and 26 of the second independent intake passages 14 and 24, respectively. In this case, the intake inertias that are separately performed in the independent intake passages 11, 14, 21, and 24 hardly contribute to the dynamic supercharging.

As described above, in the intake system of this embodiment, the dynamic supercharging by the inter-cylinder interference effect is performed by using the control valve 7 as a pressure wave transmitting portion at high load / high speed and low load / high speed. However, in this embodiment, the upstream side passage portions 12, 15, 22, 25 of the independent intake passages 11, 14, 21, 24 are respectively connected to the upper end portions P ₁ , P ₂ and the downstream passage portions thereof. Since it is curved so as to bulge into a substantially arc shape outside the straight lines L ₁ and L ₂ connecting the confluence points Q ₁ and Q ₂ with ₁₃ , 15, 23 and 25, the confluence points Q ₁ and
The crossing angles α ₁ , α ₂ between the upstream passages 12, 15, 22, 25 and the downstream passages 13, 15, 23, 25 at Q ₂ are as small as possible, and both passages are large. You will have a bend.

Therefore, each downstream side passage portion, for example, two downstream side passage portions 13 and 16 on the side of the first intake passage group 10 propagate from the downstream side to the upstream side, and further through the control valve 7 to the second intake passage portion. Passage group
Immediately before a part of the pressure wave propagating to the two downstream passage portions 23 and 26 on the 20 side reaches the control valve 7, they are dispersed and propagated from the confluence points Q ₁ and Q ₂ to the corresponding upstream passage portions 12 and 15 side. It will be suppressed as much as possible.

Therefore, for example, compared with the case where a large amount of the pressure wave is dispersively propagated from the downstream side passage portion to the upstream side passage portion side, the interference between the pressure wave and the intake flow flowing in the direction opposite to this (interference passage length ) Is reduced as much as possible, the intake resistance is reduced accordingly, and the intake charging efficiency is improved. Further, the attenuation of the pressure wave propagating from the downstream side passage portion of one intake passage group to the other downstream side passage portion is suppressed as much as possible because the dispersion propagation of the pressure wave to the upstream side passage portion is reduced. , Dynamic supercharging due to high level inter-cylinder interference effect is realized.

Further, in this embodiment, since the volume portions 51, 52, 53 are formed between the valve body 42 and the valve case 40 as described above, the abnormal noise from the control valve 7 is caused by the following reasons. The occurrence will be effectively prevented. That is, when the control valve 7 is in the closed position, the downstream passage portions 13, 16, 23, 26 are closed by the outer peripheral surface 42a of the valve body 42, respectively. However, since the intake negative pressure of the engine is acting in each of the downstream side passage portions 13, 16, 23, 26, this intake negative pressure is generated by the outer peripheral surface 42a of the valve body 42 and the case body of the valve case 40. It penetrates into the inner space 56 through the sliding surface of the inner peripheral surface 41b of 41,
The inside of the internal chamber 56 has a negative pressure. On the other hand, the atmospheric pressure is applied to the end surface of the front rotary shaft 57 protruding to the outside. Therefore, due to the pressure difference between the atmospheric pressure and the negative pressure in the internal cavity 56, the valve element 42 is pressed toward the rear rotary shaft 58 side (that is, the pressing biasing direction of the internal cavity 54). Is urged in the same direction). If the valve body 42 continues to be pressed to one side as it is, no problem will occur, but since the intake negative pressure pulsates, the valve body 42 changes its axial direction due to the change in the balance state due to the pulsation of the intake negative pressure. The valve case
A striking sound is generated between 40 and the valve body 42.

However, in this embodiment, since the volume portions 51, 52, and 53 are provided at both ends of the valve body 42 and the central portion in the axial direction, respectively, the negative pressure pulsation in the internal cavity 56 is It is suppressed as much as possible by the volume effect of the volume parts 51, 52, 53, the axial movement of the valve body 42 is prevented, and the valve case 40 and the valve body 42 are prevented.
It is possible to effectively prevent the generation of abnormal noise due to the impact sound during the period.

In addition, in this embodiment, a recess is formed in the axial center of the valve element 42.
When the volume 52 is formed by 48, 48 ..., Since the rib 50 is formed between the recesses 48, 48 .., the heat shrinkage during manufacturing is prevented and the accuracy is improved. There is an advantage that cracking due to deformation (particularly heat shrinkage) can be prevented, and is particularly remarkable when the valve body 42 is made of synthetic resin as in this embodiment.

Further, a cone spring 54 is provided between the valve body 42 and the end plate 45.
Is provided, the movement of the valve body 42 due to the pulsation of the intake negative pressure is suppressed, and the valve case 40 or the valve body 42 is suppressed.
The manufacturing error can be easily absorbed, and proper operation of the control valve 7 can be ensured.

(Effect of the Invention) The present invention allows at least a pair of first intake passages to penetrate through a surge tank independently of each other.
In an intake device for an engine, wherein at least a pair of second intake passages are opened in the surge tank,
The penetration position of the pair of first intake passages with respect to the surge tank is set to a position deviated upward or downward from the vertical center position of the surge tank, and the penetration portion of the pair of first intake passages. Of the surge tank, and the opening positions of the pair of second intake passages to the surge tank are opposite to those of the first intake passage in the vertical direction of the surge tank. It is characterized by being displaced in the direction.

Therefore, according to the engine intake system of the present invention, (1) the portion of the surge tank extending laterally of the first intake passage constitutes a part of the surge tank capacity. , A deviation in the vertical direction of the surge tank with respect to a straight line connecting the openings of the pair of second intake passages, and hardly contributes as a pressure wave transmission portion of inter-cylinder interference performed between the second intake passages. Therefore, the ratio of the volume portion functioning as the pressure wave transmission portion to the entire volume of the surge tank is reduced by the volume of the extended portion, and the diffusion attenuation of the pressure wave in the surge tank is suppressed as much as possible,
A high-level inter-cylinder interference effect is realized. (2) When the intake inertia action is performed by using the surge tank as the pressure wave reversal section in each of the second intake passages, the pressure is reduced as in the case of inter-cylinder interference. Since the wave transmission does not have directionality, the entire capacity of the surge tank including the portion extending laterally of the first intake passage functions as a pressure wave reversal portion, and a high level intake inertia effect can be realized. (3) The surge tank volume necessary for the surge tank to exert its original function, that is, the function of improving intake responsiveness during acceleration by accumulating intake air, is the surge tank volume on the side of the first intake passage. Can be easily realized without increasing the height of the intake system, and the like, so that without increasing the total height of the engine,
There is a practical effect that both improvement of the dynamic supercharging of intake air and securing of an appropriate capacity of the surge tank can be achieved at the same time.

[Brief description of drawings]

FIG. 1 is a side view of a main part of an intake device for an engine according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a vertical sectional view taken along the line III-III of FIG. FIG. 4 is an IV-IV arrow view of FIG. 1, FIG. 5 is an enlarged vertical sectional view of the control valve shown in FIG. 1, and FIG. 6 is a VI-VI vertical sectional view of FIG. Figure 7 is VII in Figure 5
-VII is a vertical sectional view, and FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 1 …… Engine 2 …… Intake manifold 3 …… Intake passage block 4 …… Surge tank block 5 …… Throttle body 6 …… Intake pipe 7 …… Control valve 10,20 …… Intake passage 11,21 …… First Independent intake passage 12,15,22,25 …… Upstream passage 13,16,23,26 …… Downstream passage 17,27 …… Merge point 31 …… Surge tank 35 to 38 …… Intake introduction passage 40 …… Valve case 41 …… Case body 42 …… Valve body 43,44 …… Valve passage 47〜49 …… Concave 50 …… Rib 51〜53 …… Volume part

Claims (1)

[Scope of utility model registration request] 1. An engine in which at least a pair of first intake passages are penetrated in a surge tank in an independent state from each other while at least a pair of second intake passages are opened in the surge tank. In the intake device, a penetration position of the pair of first intake passages with respect to the surge tank is set to a position displaced upward or downward from a vertical center position of the surge tank,
A volume portion of the surge tank extends at a side position of a penetrating portion of the pair of first intake passages, and the opening positions of the pair of second intake passages to the surge tank are both provided in the surge tank. An intake system for an engine, wherein the intake system is biased in a direction opposite to the first intake passage in the vertical direction of the.