JPH0729245Y2 - V-type engine negative pressure extraction structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a negative pressure extracting structure for extracting an operating intake negative pressure for various negative pressure responsive actuators in a V-type engine.

(Prior Art) In an engine equipped with a supercharger or an engine that performs supercharging by utilizing the dynamic effect of intake air, the overlap between intake and exhaust is increased to scavenge the combustion chamber at supercharging pressure to prevent knocking. Improving performance is traditionally done. In that case, if the overlap is large, blowback will occur at low load, so a shutter valve is provided in the independent intake passage of each cylinder downstream of the intake passage, and these shutter valves are closed by a negative pressure responsive actuator at low load. Something like that is proposed. Further, as described in Japanese Patent Publication No. 56-10451, in an engine having a mechanical supercharger provided downstream of a throttle valve, a secondary valve closed at idle in each independent intake passage downstream of the supercharger ( It has also been proposed to provide a shutter valve) to suppress pressure fluctuations downstream of the supercharger during idling and stabilize idling rotation.

By the way, the engine is provided with various devices driven by a negative pressure responsive actuator that utilizes negative intake pressure. The intake negative pressure for operating these actuators is usually introduced from the common intake passage downstream of the throttle valve or the negative pressure outlet provided in the surge tank. However, in the case where a shutter valve that closes when the load is low is provided in each independent intake passage downstream of the common intake passage, the negative pressure in the common intake passage located upstream of the shutter valve or the surge tank does not become so large. However, if the negative pressure outlet is provided at this position, there arises a problem that a sufficient negative pressure for operating various actuators cannot be obtained.

Therefore, the present applicant previously proposed that an intake negative pressure outlet for various negative pressure utilization means is provided in an independent intake passage downstream of the second throttle valve (shutter valve) (Japanese Patent Application No. 62- 30795
2).

However, in the case of a V-type engine, particularly in the case of a V-type engine in which the intake collecting passages are arranged between the banks, the independent intake passages corresponding to the cylinders of the left and right banks are provided in the narrow space between the banks, so that each shutter valve When an intake negative pressure is taken out from the downstream independent intake passage, there is a problem that it is difficult to compactly arrange a vacuum chamber for storing the negative pressure.

(Purpose of the Invention) The present invention has been made in view of the above problems.
In a type engine, it is an object to secure a sufficiently high negative pressure for operating a negative pressure responsive actuator and to form a vacuum chamber compact for that purpose.

(Structure of the Invention) In the present invention, the space below the intake collecting passage arranged between the banks of the V-type engine extracts and stores the high intake negative pressure generated in the independent intake passage downstream of the shutter valve of each cylinder. It has been found that it can be effectively used as a vacuum chamber of, and its structure is as follows. That is, in the negative pressure extraction structure of the V-type engine according to the present invention, the intake collecting passage is arranged between the banks, and the shutter valve that closes at a low load is provided in the independent intake passage of each cylinder branched from the intake collecting passage. In the interposed V-type engine, a vacuum chamber communicating with the independent intake passage downstream of the shutter valve is provided in an interbank space located between the independent intake passages below the intake collecting passage, and an actuator is provided via the vacuum chamber. The feature is that the intake negative pressure for operation is taken out.

(Function) The vacuum chamber can be formed compactly by being provided between the left and right independent intake passages below the intake collecting passages arranged between the banks, and can communicate with the adjacent independent intake passages downstream of the shutter valve. As a result, a sufficiently high intake negative pressure can be secured.

(Example) Hereinafter, an example will be described with reference to the drawings.

FIG. 1 is an overall view of an embodiment of the present invention applied to a V-type 6 cylinder engine.

In this embodiment, the engine body 1 is a cylinder block 2 formed so that three cylinders whose ignition order is not continuous are divided into left and right banks and arranged in a line in the output shaft direction.
And cylinder heads 3 and 4 respectively fixed to the left and right upper portions of the cylinder block, head covers 5 and 6 that cover the upper portions of the cylinder heads 3 and 4, and an oil pan 7 that covers the bottom portion of the cylinder block 2 from below. , Has a V-shaped cross section as a whole. Then, generators and other auxiliary machines 8, 9, 10 are arranged on both sides of the lower part of the engine body 1, and
A compact intake manifold 12 is arranged between the left and right banks above the engine body 1.

The engine body 1 is mounted vertically in the center of the engine room 11 of the automobile. An air cleaner 13 is disposed in the front part of the engine room 11 at a position on the left side of the engine body 1 when viewed from the front side, and behind the air cleaner 13.
An air flow sensor 14 for detecting the amount of intake air is provided above the head cover 5 of the left bank and is provided with the air cleaner.
It is linked to 13. A supercharger (mechanical supercharger) 15 is disposed on the right side of the engine body 1 opposite to the air cleaner 13, and the engine room 11 on the same side as the supercharger 15 and in front of the supercharger 15. An intake air cooler 17 connected to the supercharger 15 by an air pipe 16 is arranged on the side portion. A communication pipe 18 is arranged between the intake cooler 17 and the front end of the intake manifold 12 arranged between the banks.

Behind the supercharger 15, a throttle body 20 equipped with a throttle valve 19 is disposed above the head cover 6 of the right bank, and is connected to the supercharger 15 by a communication pipe 21.

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 interposed therebetween.
Are connected by a duct 22. This duct 22
An intake passage that extends rearward from both sides above the engine body 1 and is arranged along the gap between the engine body 1 and the dash panel 23 at the rear of the engine room to communicate the air flow sensor 14 and the throttle body 20 is doing.

The air flow sensor 14 and the throttle body 20 are located just inside the left and right suspension towers 24, 25 and above the left and right head covers. And air cleaner
The 13 and the supercharger 15 and the intake air cooler 17 are located in front of the left and right suspension towers 24 and 25, and are shaped to project left and right. The air intake port 26 of the air cleaner 13 extends from the front side toward the inside and upward, and is opened forward in the upper part of the engine room 11 in front of the engine body 1.

A connecting pipe 21 that connects the throttle body 20 and the supercharger 15 is also connected to a downstream end of the intake manifold 12 by a bypass passage pipe 27. The bypass passage pipe 27 extends above the right head cover 6 to extend between the banks, and is connected to a communication pipe 28 connected to an upper portion of a downstream end of the intake manifold 12. Then, a negative pressure responsive actuator is connected to these connecting portions.
A valve body 30 with 29 is interposed. Also,
At the downstream end of the intake manifold 12, a negative pressure responsive actuator 32 for driving the shutter valve in each branch pipe portion 31 is arranged, and above the engine body 1,
Three-way solenoid valves 33, 34 for selectively introducing a negative pressure for operation or atmospheric pressure are arranged in both actuators 29, 32.

As shown in FIG. 2, the intake manifold 12 includes each independent intake passage 35 formed by six branch pipe portions 31 corresponding to each cylinder of the left and right banks of the V-type engine, and these independent intake passages 35 for each bank. The left and right intake air collecting passages 36, 37 are provided to collect the air. Each intake collecting passage 36, 37 is formed compact so as not to become a substantially enlarged portion in order to perform supercharging by utilizing the resonance effect of the intake system,
The intake manifolds 12 are offset by a predetermined amount in the axial direction corresponding to the left and right banks and are adjacent to each other and extend in the longitudinal direction of the intake manifold 12.

Each intake air collecting passage 36, 37 is connected to the intake air cooler 17 by the communication pipe 18 described above. The communication passage formed inside the communication pipe 18 is divided into two at a connection portion with the intake air collection passages 36 and 37, and is collected on the upstream side to communicate with the intake air cooler 17. As a result, the left and right intake air collecting passages 36, 37 communicate with each other on the upstream side.

Below the intake manifold 12 located between the left and right banks, as shown in FIG. 2, the lower side is covered with a cover plate 38 between the left and right independent intake passages 35 below the intake collecting portions 36, 37. A closed vacuum chamber 39 is formed. This vacuum chamber 39 has an independent intake passage
An actuator 32 for driving a shutter valve 40 provided in 35, an actuator 29 for driving a relief valve in the valve body 30, and the like for accumulating operating negative pressure, and a negative pressure outlet provided with a check valve 41.
The intake negative pressure is introduced from the independent intake passage 35 downstream of the shutter valves 40 of all the left and right cylinders via 42 to be stored. Since the intake negative pressure downstream of the shutter valves 40 of all cylinders is introduced into the vacuum chamber 38, a stable and high operating negative pressure can be secured.

The shutter valve 40 is provided to prevent the blowback of intake air at low speed and low load. At low speed and low load, the negative pressure stored in the vacuum chamber 38 is guided to the actuator 32 via the three-way solenoid valve 34, and the shutter valve 40 is closed to a predetermined opening by operating the actuator 32. To be FIG. 3 shows the operating region of the shutter valve.

Further, in this embodiment, since the air cleaner 13 is arranged on one side of the front of the suspension tower in the engine room 11 as described above, an air cleaner having a sufficiently large capacity is used, and cool air from the front is also used. It can be introduced to improve the filling efficiency.

Since the intake air cooler 17 is also arranged in the front part of the engine room 11 on the opposite side of the air cleaner 13, a large one is installed by utilizing sufficient space, and the cooling effect is obtained by the cool air from the front. Can be raised.

The throttle body 20 must be arranged in a position 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 provided downstream of the throttle body 20. Since the supercharger 15 is arranged on the opposite side of the air cleaner 13 as shown in the above, it is possible to arrange the throttle body 20 at a position rearward of the supercharger 15 and sufficiently close to the passenger compartment, and further, at the rear. Since the duct 22 that gently curves can be connected to the air cleaner 13 side, an intake system can be obtained that can be sufficiently accommodated in the bonnet line without forming a sharp bend that increases intake resistance.

Further, the intake cooler 17 and the intake collecting passages 36, 3 are arranged to introduce intake air from the front side into the intake manifold 12.
Since the 7 are connected by the communication pipe 18, the length of the branched passage portion for obtaining the resonance effect is secured, while suppressing the increase of the length of the communication passage as a whole, the supercharger 15
The discharge resistance of can be reduced.

Also, due to the long intake passage from the air cleaner 13 to the supercharger 15,
Because the attenuation of the pulsating wave transmitted from 15 to the upstream side becomes large,
The intake flow noise that leaks outside through the air cleaner 13 is reduced. Moreover, since the upstream side of the supercharger 15 is throttled by the throttle valve 19, the effect of damping the intake flow noise becomes large especially when the load is low. Therefore, it is not necessary to particularly increase the volume of the air cleaner in order to reduce the intake flow noise.

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

Further, the bypass pipe 27 that constitutes the intake bypass passage is provided immediately upstream of the supercharger 15 from the right side head cover 6
The valve body 30 between the banks of the engine body 1 is provided at the shortest distance across the upper part of the engine main body 1, so that the intake resistance of the intake bypass passage can be reduced and the charging efficiency at low load can be improved. Since this bypass pipe has a relatively small diameter, it does not significantly increase the height of the engine.

The valve body 30 is horizontally connected to the forward reversal portion of the connection pipe 28 above the rear end of the intake manifold 12, and the bypass passage pipe 27 is connected sideways, so that the space between the banks can be effectively used. , The intake bypass system and thus the entire intake system can be made compact.

The present invention is not limited to the above embodiment, but can be implemented in various other modes.

(Effect of the Invention) Since the present invention is configured as described above, it is necessary to secure a sufficiently high negative pressure for operating the negative pressure responsive actuator in the V-type engine and to form the vacuum chamber compactly. it can.

[Brief description of drawings]

FIG. 1 is an overall view of an embodiment of the present invention, FIG. 2 is a sectional view of an essential part of the embodiment, and FIG. 3 is a control area diagram of a shutter valve in the embodiment. 1: engine, 12: intake manifold, 32: actuator, 35: independent intake passage, 36, 37: intake collecting passage, 39: vacuum chamber, 40: shutter valve, 42: negative pressure outlet.

Claims (1)

[Scope of utility model registration request] 1. A V-type engine in which an intake collecting passage is arranged between banks, and a shutter valve which is closed at a low load is provided in an independent intake passage of each cylinder branched from the intake collecting passage. A vacuum chamber communicating with the independent intake passage downstream of the shutter valve is provided in the inter-bank space located between the independent intake passages below the passage, and intake negative pressure for actuator operation is taken out through the vacuum chamber. Negative pressure extraction structure for V type engine.