JPH02102324A - Suction device for multiple cylinder engine equipped with supercharger - Google Patents

Abstract

PURPOSE:To obtain a good resonance effect constantly by disposing a suction bypass passage provided for by-passing a supercharger to make aperture parts to suction collecting passages close to each other, and disposing a relief valve at this bypass passage for opening both aperture parts simultaneously. CONSTITUTION:A supercharger 15 is disposed on the side of an engine main body 1 of a type V engine, and a throttle body 20 is connected with its downstream side by a connecting tube 21. An air flow sensor 14 is connected with the throttle body 20 by a duct 22. The connecting tube 21 is also connected with the downstream side end of an intake manifold 12 by a bypass passage tube 27, while the other end of the bypass passage tube 27 is connected with a connecting tube 28 including two separate passages 28a, 28b connected with right and left suction collecting passages 36, 37 respectively, and a valve body 20 (relief valve 50) having a negative pressure operation type actuator 29 is provided at its connection part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-cylinder engine with a supercharger, and particularly to an intake system for a multi-cylinder engine that uses both resonance supercharging and supercharging by a supercharger.

(Prior Art) Engines have been known that perform supercharging by utilizing the dynamic effect of intake air in order to increase the charging efficiency of the engine. This type of supercharging usually utilizes the so-called inertia effect of intake air, and as is well known, the negative pressure generated when the intake valve opens is converted into positive pressure in the upstream volume section. Invert and shift so that this positive pressure wave forces the intake air.

In addition, Japanese Patent Publication No. 14169/1983 states that the natural frequency of intake pressure vibration is variable to obtain a supercharging effect over a wide rotation range, so that the intake valve opening timings do not overlap with each other (that is, the ignition timings are adjacent to each other). For each group of cylinders (not connected together), multiple spaces are provided where the ends of the independent intake passages (manifold branches) of each cylinder gather, and each resonant passage is connected to the second flow of these spaces. At the same time, a switching valve is provided to freely switch the plurality of spaces to communicate with each other and disconnect them from each other, and in the high speed range, the switching valve is opened to perform inertia supercharging using the communicating rain space as a volume part, and in the low speed range, the switching valve is opened. A system is described in which supercharging is performed using pressure waves that are closed and reversed upstream of each resonant passage.

Furthermore, the following intake device that performs supercharging by more actively utilizing the resonance effect of intake pressure vibration has already been proposed.

This intake system divides all cylinders into multiple groups, with cylinders with non-adjacent ignition timings as one group.
A compact collection passage without an enlarged part is provided for each group to collect the independent intake passages of each cylinder, and the collection passages are communicated with each other upstream, and according to this,
A large supercharging effect can be obtained in the synchronized rotation range due to the resonance of pressure waves generated by opening and closing the intake ports of each cylinder.

In particular, in the case of this resonant supercharging type intake system, there is no need to make the independent intake passages of each cylinder long, and each collective passage has a small diameter so as not to attenuate pressure waves. The system becomes compact, and in particular, in a V-type engine, the intake manifold can be disposed in the space between the banks, and the entire intake system can be configured compactly.

In an intake manifold having a surge tank portion with a large capacity, it is difficult to fit the intake manifold compactly between the V banks like this. Conventionally, for example, Japanese Patent Application Laid-Open No. 59-565
Although there have been attempts to compactly arrange an intake manifold between the banks of a V-type engine as described in the above publication, all of them have problems such as a complicated structure.

By the way, as a method of supercharging an engine, in addition to the above-mentioned supercharging that utilizes the dynamic effect of intake air, a well-known method is mechanical supercharging as described in Japanese Patent Application Laid-open No. 178730/1983. There is a supercharger, and it is being considered to use this supercharger in conjunction with resonance supercharging. However, in the case of a mechanical turbocharger, as described in the above publication, a bypass passage is provided to bypass the turbocharger, and this bypass passage is opened and closed by a control valve (relief valve). Controlling the boost pressure should be done. Therefore, the applicant first decided to install a supercharger in the intake passage that constitutes the resonance system.
We proposed a system in which the downstream end of a bypass passage that bypasses a supercharger is connected to the downstream end of a resonant intake passage (collection passage) (Japanese Patent Application No. 63-61144).

However, in an intake system in which the downstream end of the bypass passage is connected to the downstream end of the collecting passage in this way, the plurality of collecting passages are connected to each other by a separate long communication passage at the downstream end to improve the tuned rotation range of the resonance system. When an attempt is made to set the engine speed to the low speed side, this communication passage becomes short-circuited by the bypass passage, and a problem arises in that the engine output cannot be improved at the low speed side as expected.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and provides that the intake and joint passages constituting the resonance system are connected over a short distance by a bypass passage that bypasses the supercharger, resulting in synchronized rotation of the resonance effect. The purpose is to prevent the range from shifting to the high rotation side.

(Structure of the Invention) The intake system for a supercharged multi-cylinder engine of the present invention collects the independent intake passages of each cylinder into respective intake joint passages for each group in which the ignition order is not consecutive, and the intake joint passages. In an intake system for a supercharged multi-cylinder engine with a supercharger arranged in the second stream, an intake bypass having one end opening upstream of the curved supercharger and the other end opening into the respective intake joint passages. A passage is arranged so that each opening to each intake bypass passage is close to each other, and a single relief valve is arranged in the intake bypass passage to simultaneously open both openings in a specific operating range. .

(Function) The pressure waves generated in the intake joint passages of each group by opening and closing the intake ports of each cylinder become pressure waves with large amplitude in the tuned rotation range specific to the resonance system, and supercharging is performed by the action of the pressure waves. It's hard. Additionally, by adding the action of the upstream supercharger to this, even greater supercharging can be obtained over a wide rotation range.

A relief valve provided at an opening on the side of the intake bypass passage that bypasses the supercharger opens in a specific operating range to form a flow of intake air that does not go through the supercharger. At this time, the respective intake passages communicate through the respective openings, but since these openings are narrowed by the relief valves, the communication passages do not become sufficient to substantially short-circuit the intake passages. Therefore, the problem that the tuned rotation range of the resonance system shifts to the high speed side due to opening of the relief valve does not occur.

(Example) Examples will be described below based on the drawings.

FIG. 1 is an overall view of an embodiment of the present invention applied to a V-type six-cylinder engine.

In this embodiment, the engine body I includes a cylinder block 2 formed in which three cylinders with different firing orders are divided into left and right banks and lined up in a row in the direction of the output shaft, and a cylinder block 2 in which three cylinders with non-consecutive firing orders are arranged in a line in the direction of the output shaft. It consists of fixed cylinder heads 3, 4, head covers 5, 6 that cover the top of each cylinder head 3, 4, and an oil pan 7 that covers the bottom of the cylinder block 2 from below, and has a V-shaped cross section as a whole. has been done. A generator and other auxiliary equipment 8, 9, 10 are arranged on both sides of the bottom of the engine body I, and a compactly formed intake manifold I2 is arranged between the left and right banks at the top of the engine body I. has been done.

An engine body 1 is vertically mounted in the center of an engine room 11 of an automobile. And Ennon Room 11
An air cleaner 13 is disposed at the left side of the engine body 1 when viewed from the front side, and an air flow sensor 14 for detecting the amount of intake air is disposed behind the air cleaner 13 and above the left side bank cover 5. is arranged and connected to the air cleaner 13. In addition, the engine body 1
On the other hand, a supercharger (mechanical supercharger) 15 is disposed on the right side opposite to the air cleaner I3, and a supercharger (mechanical supercharger) 15 is disposed on the side of the engine room 11 on the same side as the supercharger 15 and forward of the supercharger I5. An intake air cooler I7 is connected to the supercharger 15 by an air pipe 16. A communication pipe 18 is disposed between the intake air cooler 17 and the front end of the intake manifold 12 disposed between the banks.

Behind the supercharger 15, a throttle valve I9 is located above the head cover 6 on the right bank.
A throttle body 20 is installed, and this is connected to the supercharger 15 by a connecting pipe 2I.

Further, the air flow sensor 14 and the throttle body 20 located on the opposite side of the engine room with the engine body 1 in between are connected by a duct 22. This duct 22 extends rearward from both sides above the engine main body 1,
It is arranged along the gap between the engine body 1 and the dash panel 23 at the rear of the engine room, and constitutes an intake passage that communicates the air flow sensor I4 and the throttle body 20.

The air flow sensor I4 and the throttle body 20 are located just inside the left and right suspension towers 24.25.
It is located above the rad cover to the left and right. The air cleaner 13, supercharger 15, and intake air cooler 17 are connected to the left and right suspension towers 24. , 25, and is located in front of them, with a shape that juts out to the left and right. The air intake port 26 of the air cleaner I3 extends inwardly and upwardly from the front side, and opens forward into the upper part of the engine room 11 in front of the engine body 1.

The connecting pipe 21 connecting the throttle body 20 and the supercharger 15 is also connected to the downstream end of the intake manifold 12 by a bypass passage pipe 27. This bypass passage pipe 27 is connected to the rad cover to the right side.
6 and extends between the banks, and is connected to a connecting pipe 28 that is connected to a portion of the downstream end of the intake manifold 12. A valve body 30 equipped with a negative pressure responsive actuator 29 is interposed in the connecting portion thereof. Further, a negative pressure responsive actuator 32 for driving the Nyatter valve in each branch pipe section 31 is disposed at the downstream end of the intake manifold 12, and above the engine body 1, these two actuators 29 Three-way solenoid valves 33 and 34 for selectively introducing negative pressure or atmospheric pressure for operation are provided at .32.

Next, the detailed structure of the intake manifold 12 will be explained with reference to FIGS. 2 to 5.

Figures 2 and 3 show the above intake manifold 12.
FIG. 2 is a plan view and a front view of FIG. Further, FIG. 4 is a sectional view taken along the line AA in FIG. 2, and FIG. 5 is a sectional view taken along the line BB in FIG.

The intake manifold I2 includes independent intake passages 35 each composed of six branch pipe sections 31 corresponding to each cylinder of the left and right banks of the V-type engine, and left and right intake passages that collect these independent intake passages 35 for each bank. Kaai passage 3
6.37. Each intake joint passage 36, 37 is compactly formed so as not to become an enlarged part in order to perform supercharging by utilizing the resonance effect of the intake system, and is formed in an axial direction corresponding to the left and right banks. The intake manifolds 12 are offset by a predetermined amount and extend adjacent to each other in the longitudinal direction of the intake manifold 12. And each intake passage 36.
The independent intake passages 35 of each bank are connected to openings 38 formed in the side wall of the bank 37 at intervals in the longitudinal direction.

Each intake passage 36, 37 has an inlet opening 36a, 37a at its front end. These inlet openings 3
6a and 37a are located above the front end of the intake manifold 12, and each intake joint passage 36, 37 extends horizontally rearward from these inlet openings 36a and 37a, and is located at the most upstream side in each intake gathering portion 3637. Almost directly above the opening 38 of the independent intake passage 35, the step portions 36b and 37b are curved downward. And this stepped portion 36b
, 37b, the most downstream opening 38
It extends straight to the rear position. The stepped portion 36
b, 37b are located directly downstream of the opening 38, which is located in the most downstream direction, so that the intake air flows through these stepped portions 36b, 37b.
It is deflected downward at b.

The inlet openings 36a, 3 of each intake passageway 36.37
6b is connected to the intake air cooler I through the communication pipe 18 described above.
7 is connected. The communication passage formed inside the communication pipe 18 is divided into two at the connection portion with each intake joint passage 36, 37, and is gathered into one on the upstream side to communicate with the intake air cooler 17. As a result, the left and right intake passages 3
6.37 communicate with each other on the upstream side.

A substantially rectangular opening 39.40 is formed at the bottom of the downstream end of each intake joint passage 36.37, and these openings 39.40 are interconnected by a lower communication passage 41. As shown in FIG. 6, this downstream communication passage 41 utilizes the space created between the intake joint passage 36 and the left and right independent intake passages 31 below '37 between the left and right banks, and is curved. It is integrally formed at the bottom of the intake manifold 12 so as to extend largely toward the front side along the connecting passages 36 and 37. In this way, the downstream sides of the left and right intake joint passages 36 and 37 communicate with each other, and because this downstream side communication passage is long, the natural frequency of the intake system becomes small, and the supercharging effect due to resonance is reduced in the low rotation range. increases. In order to prevent water and oil from accumulating at the bottom of the downstream communicating path 41, drain ports 42 are provided on the left and right sides toward the connecting portions with the respective banks.

At the lower front side of the intake manifold I2 located between the left and right banks, adjacent to the downstream communication passage 41, and also between the left and right intake joint passages 35 below each intake collecting portion 36. A sealed vacuum chamber 43 shown in FIG. This vacuum chamber 43 stores the operating negative pressure of the actuator 32 that drives the shutter valve 44 provided in each independent intake passage 35, the actuator 29 that drives the relief valve in the valve body 30, and the like,
Intake negative pressure from the left and right independent intake passages 35 is introduced and stored through the check valve 45.

-I- The shutter valve 44 is provided to prevent intake air from blowing back at low speeds and low loads. At low speeds and low loads, the negative pressure stored in the vacuum chamber 43 is guided to the acticoator 32 via the three-way solenoid valve 34, and when the actuator 32 operates, each shutter valve 44 is set to a predetermined position. It can be closed to the opening degree. FIG. 8 shows the operating range of the shutter valve.

At the front end of the intake manifold I2, the inlet openings 36a and 37a of the intake joint passages 36 and 37 are provided.
A cooling water passage 46 is formed at a position directly below. The cooling water passage 46 opens at one end in the center of the front end surface of the intake manifold 12, extends downward, bifurcates into two, and opens at a connecting portion with the left and right banks. Cooling water enters through the upper opening and flows downward to be directed to each bank.

Bypass openings 47 and 4.8 are provided in the earthen walls at the downstream ends of the left and right intake joint passages 36.37, respectively, and the connecting pipe 28 is connected to the upper surface of the intake manifold 12 where these openings 47.48 are located. ing. The connecting pipe 28 forms two independent passages 28a and 28b that communicate with the left and right intake passages 3637, respectively, and is reversed to the front side above the intake manifold 12, and the valve body 30 is attached to the tip thereof. Connected horizontally. A horizontal artificial pipe section 49 is formed on the side corresponding to the right bank in the valve body 30, and the bypass passage pipe 27 is connected to this inlet pipe section 49. A passage 27a in the bypass passage pipe 27 and a passage 2 in the connecting pipe 28
8a and 28b constitute an intake bypass passage that bypasses the supercharger I5.

A relief valve 50 connected to a negative pressure responsive actuator 29 is provided within the valve body 30, as shown in FIG. As shown in FIG.
/cm) or more, it opens to relieve the supercharging pressure, and also opens at low load (for example, when the intake negative pressure is 100 mm1 (g or less)) to bypass the superchurner 15 and allow intake air to flow. This prevents overcharging during high loads and reduces pump loss during low loads.

The detailed structure of the relief valve 50 is shown in FIG. The two passages 28a and 28b communicating with each intake joint passage 36 and 37 are connected to the partition wall 28c of the connecting pipe 28.
The tip openings 28d and 28e are formed close to each other and narrowed. A valve body 30 is connected to the end 28f of the connecting pipe where these are opened. The valve body 30 has a single communication hole 51 that communicates with both the openings 28d and 28e of the connecting pipe 28.
A valve seat 52 is attached to the communication hole 51. The relief valve 50 is connected to the diaphragm 53 of the actuator 29, and opens and closes the communication hole by negative pressure operation. When the relief valve 50 is closed, a slight gap is created between the relief valve 50 and the partition wall 28c. This gap ensures the sealing performance when the relief valve 50 is seated, and allows the single relief valve 50 to simultaneously open and close both openings 28d and 28e.

When the relief valve 50 opens, each intake passage 36.
The two passages 28a, 28b that communicate with 37 communicate with each other at the tip openings 28d, 28e. However, since these passages 28a and 28b are narrowed at the openings 28d and 28e and are also throttled by the relief valve 50, a communication state that substantially short-circuits both intake passages does not occur.

In addition, in this embodiment, since the air cleaner 13 is disposed on one side of The Suspension Tower in the engine room 11 as described above, an air cleaner with a sufficiently large capacity is used, and the cold air from the front is removed. Air can be introduced to improve filling efficiency.

The intake air cooler 17 is also located at the front of the engine room 11 on the opposite side of the air cleaner 13, so
You can use the sufficient space to install a large one and use the cold air from the front to increase the cooling effect.

The throttle body 20 must be placed close to the passenger compartment in order to operate the throttle valve 19 with an accelerator wire or the like, and the supercharger 15 is required to be installed downstream of the throttle body 20. Since the supercharger 15 is located on the opposite side of the air cleaner 13, the throttle body 20 can be located behind the supercharger 15 and sufficiently close to the passenger compartment. Since the duct 22 can be connected to the air cleaner 13 side by a gently curved duct 22, an intake system can be obtained that can be sufficiently accommodated within the bonnet line even if a sharp bend that increases intake resistance is made.

Further, since the intake air cooler 17 and the inlet opening 36a37a of the intake joint passage 36,37 are connected by the communication pipe I8 so as to introduce intake air into the intake manifold 12 from the front side, it is possible to obtain a resonance effect. While ensuring the length of the branched passage portion, the overall length of the communication passage can be suppressed from increasing and the discharge resistance of the supercharger 15 can be reduced.

Also, from the air cleaner 13 to the supercharger 15
Since the intake passage is long, the attenuation of the pulsating waves transmitted upstream from the supercharger 15 is increased, so the intake flow noise leaking outside via the air cleaner 13 is reduced. Moreover, since the second flow of the supercharter I5 is throttled by the throttle valve I9,
Particularly at low loads, the effect of attenuating intake flow noise becomes greater.

Therefore, there is no need to particularly increase the volume of the air cleaner in order to reduce intake air flow noise.

Further, since the throttle valve 19 is provided upstream of the supercharger 15, when the gloss valve 44 of each independent intake passage 35 is closed in a low load region, the load applied to the supercharger 15 is reduced. Fuel efficiency can be improved accordingly.

Moreover, the bypass pipe 27 that constitutes the intake bypass passage is
Since it is provided at almost the shortest distance from the direct second flow of the supercharger 15 to the right side, across the upper part of the rad cover 6, to the valve body 30 between the banks of the engine body 1, it reduces the intake resistance of the intake bypass passage. Filling efficiency under load can be increased. Since this bypass pipe has a relatively small diameter, it does not add much to the height of the engine.

The downstream side communication passage 41 of the left and right intake joint passages is formed integrally between the independent intake passages 35 at the lower part of the intake manifold 12 by utilizing the space between the banks as described above, so that it curves toward the front side. Therefore, not only a compact intake system is obtained, but also the rigidity of the lower part of the intake manifold 12 including the independent intake passage 35 and the communication passage 41 is increased.

In addition, each intake joint passage 36, 37 is provided with stepped portions 36b, 37b for deflecting the intake air flow immediately upstream of the opening 38 of the independent intake passage 35 that opens at the most upstream side. Since the flow velocity of the intake air flowing in is suppressed and the flow is changed downward, the phenomenon that the intake air flows straight due to a large inertial force and is biased toward the independent intake passage 35 that opens at the rear end is alleviated. Further, by providing the stepped portions 36b and 37b, a space is secured for providing the cooling water passage 46 at the front end of the intake manifold I2.

The valve body 30 is horizontally connected to the front inverted portion of the connecting pipe 28 above the rear end of the intake manifold 12, and the bypass passage pipe 27 is connected to the horizontally formed inlet pipe portion 49. The space between the banks can be used effectively, and the intake bypass system, as well as the entire intake system, can be made compact.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented in various other forms.

(Effects of the Invention) Since the present invention is configured as described above, the intake bypass passage can be controlled with a single relief valve without hindering the setting of the resonance effect on the low rotation side of the intake system. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is an overall view of an embodiment of the present invention, FIG. 2 is a plan view of an intake manifold in the same embodiment, FIG. 3 is a front view of the same, and FIG. 4 is a sectional view taken along line A-A in FIG. Figure 5 is the same B
-B sectional view, FIG. 6 is a schematic diagram explaining the structure of the intake manifold in the same embodiment, FIG. 7 is a detailed view of the main part of the same embodiment, and FIGS. 8 and 9 are shutter valves in the same embodiment. and a control area diagram of a relief valve. 1. Live pipe, 30: Road, 5 Engine, 12: Intake manifold, supercharger, 2
7: Bypass passage pipe, 28: Connection 28c: Partition wall, 28d
, 28e: Opening, valve body 36. 37: Intake collective passage 0: Relief valve.

Claims (1)

[Claims] (1) A multi-cylinder engine with a supercharger in which the independent intake passages of each cylinder are assembled into a respective intake common passage for each group with a non-consecutive ignition order, and a supercharger is arranged upstream of the intake common passage. In the intake device, an intake bypass passage whose one end opens upstream of the supercharger and the other end opens into each of the intake air collection passages is arranged such that each opening to each of the air intake air collection passages is close to each other, An intake system for a multi-cylinder engine with a supercharger, characterized in that the intake bypass passage is provided with a single relief valve that simultaneously opens each of the openings in a specific operating range.