JPH04303124A - Intake device for engine with mechanical supercharger - Google Patents

Abstract

PURPOSE:Not to cause the lowering of engine output during a supercharging process and to effectively reduce noise generated in an intake passage by driving a supercharger in an engine with a mechanical supercharger. CONSTITUTION:In the intake device A of an engine E with a mechanical supercharger, a supercharger bypass passage 25 and an inter cooler bypass passage 28 are united in a body as a common passage 29 on an upstream side in the direction of an air flow, and the common passage 29 is provided with a common passage switching valve 31 to open and close the common passage 29 and a resonator 32 communicating with the common passage 29 on the downstream side of the valve 31. It is preferable for an enclosure member 32 surrounding a supercharger 19 to function as the resonator, and moreover it is more preferable for the enclosure member 32 to surround the common passage 29. In addition to that, the engine E is a V-type engine, and the supercharger 19 and the resonator 32 are provided between V-banks.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a mechanical supercharged engine.

0002

BACKGROUND OF THE INVENTION Engine intake systems equipped with a mechanical supercharger consisting of a Roots-type or vane-type volumetric compressor are known from the prior art. However, when a mechanical turbocharger is installed in the intake system, the vibration of the turbocharger or the pulsation of the discharge pressure causes air column vibration in the air in the intake passage, which causes a problem such as the generation of harsh noise. There is. Particularly when the load is low, engine noise is reduced, so there is a problem in that the noise generated from the intake passage becomes more apparent.

[0003] Furthermore, when a Roots-type or vane-type compressor is used as a supercharger, the discharge pressure at low rotation speeds is relatively low, so there is a problem that the low-speed torque of the engine cannot be sufficiently increased. . Therefore, a solution could be to use an internal compression type Lysholm compressor with high discharge pressure as a supercharger, but since the Lysholm compressor has high discharge pressure and extremely high rotational speed (for example, ma
x35000r. p. m. ), the noise generated from the intake system becomes particularly loud. Furthermore, if the turbocharger is equipped with an electromagnetic clutch and the electromagnetic clutch is disengaged during low loads that do not require supercharging, it will be possible to prevent noise from the intake system at least during low loads, but as a turbocharger When a Lysholm type compressor is used, the rotational speed is very high, so the electromagnetic clutch wears out or breaks quickly.

[0004] Therefore, an intake system has been proposed in which a resonator (resonator) is connected to the intake passage downstream of the supercharger to reduce the noise caused by the supercharger by resonance absorption (for example, (Refer to Publication No.-165929).

[0005]

[Problems to be Solved by the Invention] However, in conventional intake systems in which a resonator is connected to the intake passage downstream of the supercharger, the capacity of the resonator must be increased considerably in order to reduce air column vibration at a predetermined frequency. Since this setting has to be made, there is a problem that the dead volume of the intake passage downstream of the supercharger increases, leading to a decrease in engine output.

The present invention was made in order to solve the above-mentioned conventional problems, and it is possible to improve the performance of a mechanically supercharged engine without causing a decrease in engine output during supercharging.
An object of the present invention is to provide an intake device that can effectively reduce noise generated from an intake passage when a supercharger is driven.

[0007]

[Means for Solving the Problem] In order to achieve the above object, a first invention provides a supercharger that bypasses the supercharger while a mechanical supercharger and an intercooler are interposed in the intake passage. In an engine with a mechanical supercharger, the engine is equipped with a bypass passage, a supercharger bypass passage opening/closing valve that is interposed in the supercharger bypass passage and opens at low load, and an intercooler bypass passage that bypasses the intercooler. The feeder bypass passage and the intercooler bypass passage are unified as a common passage on the upstream side in the air flow direction, and a common passage opening/closing valve is provided to open and close this common passage, and a common passage is provided downstream of the common passage opening/closing valve. An intake device for a mechanical supercharged engine is provided, which is characterized by being provided with a communicating resonator.

[0008] A second invention is the intake system for a mechanical supercharged engine according to the first invention, in which the resonator comprises:
An intake device for a mechanical supercharged engine is provided, characterized in that it is formed by communicating an enclosure member surrounding a supercharger main body with a common passage downstream of a common passage opening/closing valve.

[0009] A third invention is an intake system for a mechanical supercharged engine according to the second invention, characterized in that at least the common passage is surrounded by an enclosure member together with the supercharger. Provides an intake system for a supercharged engine.

[0010] A fourth invention is an intake system for a mechanical supercharged engine according to the first to third inventions, wherein the engine is a V-type engine, and the supercharger and resonator are arranged between the V banks. An intake device for an engine with a mechanical supercharger is provided.

[0011]

[Examples] Examples of the present invention will be explained in detail below. As shown in FIG. 3, the 6-cylinder V-type engine E is provided with first and second banks P and Q that are longitudinal in the cylinder arrangement direction, and on the first bank P side, the first and second banks are arranged in order from the front side. Third,
The fifth cylinders #1, #3, #5 are arranged, and the second, fourth, and sixth cylinders #2, #5 are arranged in order from the front side on the second bank Q side.
4, #6 are arranged. The first cylinder head 2 is fastened to the upper surface of the cylinder block 1 of the engine E on the first bank P side, and the second cylinder head 3 is fastened to the upper surface of the second bank Q side. An oil pan 4 is attached to the lower surface of.

In each cylinder #1 to #6, when the intake valve 5 is opened, a mixture is drawn into the combustion chamber 7 from the intake port 6, and after this mixture is compressed by the piston 8. The combustion gas is ignited and combusted by a spark plug (not shown), and when the exhaust valve 9 is opened, the combustion gas is discharged to the exhaust port 10. Note that the air-fuel mixture is formed by injecting fuel from the injector 11 into the air in the intake port 6. Such a process is continuously repeated, and the piston 8 reciprocates in the direction of the cylinder axis.
3 rotational motion.

An intake system A is provided to supply air to the engine E, and the main intake system of this intake system A will be explained below. As schematically shown in FIG. 1, the intake device A is provided with a collective intake passage 16, and in this collective intake passage 16, air cleaners 17 for removing dust from the air are installed sequentially from the upstream side when viewed in the intake flow direction. and a throttle valve 1 that opens and closes in conjunction with the accelerator pedal.
8, a mechanical supercharger 19 using a Lysholm compressor to be described later, and an intercooler 21 that cools air whose temperature has increased due to supercharging.
The downstream end of the collective intake passage 16 on the downstream side of the surge tank 2 cancels out the intake pulsation generated by the air flow.
Connected to 2. And in the surge tank 22,
Independent intake passages 23 each have a downstream end connected to the intake port 6 of the corresponding cylinder.

Although shown schematically in FIG. 1, the intake system downstream of the intercooler 21 is actually divided into a first bank P side and a second bank Q side. Specifically, as shown in FIG. 2, on the downstream side of the intercooler 21, the collective intake passage 16 is divided into a collective intake passage 16 on the first bank P side and a collective intake passage 16 on the second bank Q side. , collective intake passages 16, 1 on the first and second banks P and Q sides
The downstream ends of 6 are connected to surge tanks 22 and 22 on the first and second banks P and Q sides, respectively. The surge tank 22 on the first bank P side is connected to independent intake passages 23 that supply air to the first, third, and fifth cylinders #1, #3, and #5, respectively, and the second bank Q side surge tank 22
are connected to independent intake passages 23 that supply air to the second, fourth, and sixth cylinders #2, #4, and #6, respectively. Note that the intercooler bypass passage 28, which will be described later, is also divided into a first bank P side and a second bank Q side. However, the intake system on the first bank P side and the second bank Q
Since the intake systems on the side have substantially the same configuration, the first bank P side and the second bank Q side will be described below without distinction.

The bypass intake system of intake device A will be explained below. As shown in FIG. 1 again, in the collective intake passage 16,
A supercharger bypass passage 25 is provided that connects the B1 position downstream of the supercharger 19 and the B2 position upstream of the supercharger 19. A passage opening/closing valve 26 is provided. The supercharger bypass passage opening/closing valve 26 is driven by an actuator 27. Here, the turbocharger bypass passage opening/closing valve 26 is opened at a predetermined low load, and at this time, a part of the air downstream of the turbocharger 19 is transferred to the turbocharger bypass passage 25.
The inside flows from the B1 side to the B2 side and is returned to the collective intake passage 16 upstream of the supercharger 19. In this case, air pressure is not increased downstream of the supercharger 19, so supercharging is not performed.

Further, an intercooler bypass passage 28 is provided which connects the above-mentioned position B1 of the collective intake passage 16 and the position B4 downstream of the intercooler 21. here,
Supercharger bypass passage 25 and intercooler bypass passage 2
8 is unified in the portion between the B1 position and the B3 position to form a common passage 29. And common passage 2
A common passage opening/closing valve 31 for opening and closing the common passage opening/closing valve 9 is interposed at a position slightly closer to B3 than the B1 position. Here, when the supercharger bypass passage opening/closing valve 26 is opened, this common passage opening/closing valve 31 is also opened, and the air which is not supercharged and whose temperature has not increased is bypassed the intercooler 21. , intercooler bypass passage 2
It can be supplied to engine E through 8.

By the way, in this embodiment, a Lysholm compressor is used as the supercharger 19. As shown in FIGS. 2 and 3, a supercharger 19 using a Lysholm compressor
is arranged in a V-shaped space (between the V banks) formed between the first bank P and the second bank Q, with its axis facing the cylinder arrangement direction. And supercharger 19
Substantially, a speed-increasing gear section 19a that is rotationally driven by the crankshaft 13 via a V-belt (not shown) and a pulley 30, and a rotor section 19b that is rotationally driven by this speed-increasing gear section 19a. It is made up of. Here, the supercharger 19 is always driven to rotate during engine operation. As is well known, Lysholm type compressors have higher discharge pressure than Roots type or vane type compressors, so the supercharger 19 can provide sufficient supercharging even at low engine speeds. , therefore engine E
Low-speed torque has been significantly increased.

However, on the other hand, this type of supercharger 19
The intake device A has a high discharge pressure, a very high rotational speed, and is constantly rotated, so the noise generated from the intake device A increases due to this. Therefore, a silencing mechanism is provided to reduce the noise of the intake device A, which will be explained below. That is, the supercharger 19 and the common passage 29
The part of the collective intake passage 16 around the supercharger 19, the part of the supercharger bypass passage 25 around the supercharger 19, and the part of the intercooler bypass passage 28 around the supercharger 19 are the enclosure members. It is surrounded by 32. Therefore, the noise generated from the supercharger 19 or the intake system around it is confined within the enclosure member 32, and the noise generated from the intake device A is significantly reduced.

A communication hole 33 is provided in the common passage 29 at a portion slightly downstream of the common passage opening/closing valve 31, that is, closer to B3. ing. Here, the internal space of the enclosure member 32 is formed to function as a resonator (resonant muffler). That is, the volume of the enclosure member 32 and the diameter of the communication hole 33 are set so that the air column vibration of a predetermined frequency caused by the air in the intake system by the supercharger 19 can be reduced by resonance absorption. There is. In this way, the supercharger 19,
An enclosure member 32 surrounding the common passage 29 etc. is used as a resonator, and this enclosure member 32
Since the resonator is arranged between the V banks, the intake device A can be made much more compact than when a resonator is provided separately.

[0020] The supercharging effect or the muffling effect of the intake device A equipped with the above-mentioned muffling mechanism will be explained below with reference to FIGS. 1 to 3 as appropriate. During medium to high loads, the turbocharger bypass passage on/off valve 2 is activated to perform supercharging.
6 and the common passage opening/closing valve 31 are closed. At this time, the air discharged from the supercharger 19 flows into the intercooler 21 via the collective intake passage 16, where it is cooled and then flows into the surge tank 22, after which it flows into each cylinder #1 to #6. It is supplied to the combustion chamber 7. At this time, the temperature of the air decreases and its density increases, which in combination with the supercharging effect increases intake air filling efficiency and increases engine output. Also, since the common passage opening/closing valve 31 disposed near the branch point B1 between the collective intake passage 16 and the common passage 29 is closed, the supercharger 19
The dead volume of the downstream collective intake passage 16 is reduced, and the supercharging efficiency of the supercharger 19 is increased. As described above, since the supercharger 19, the common passage 29, etc. are surrounded by the enclosure member 32, the noise (radiated sound) generated from the supercharger 19 or its surroundings is confined within the enclosure member 32, and the intake system The noise generated from A is reduced. In addition, in this case, the intercooler 21
functions as a volume part, the vibration of the air column in the collective intake passage 16 downstream of the supercharger 19 is reduced here, and the vibration of the air column is also reduced by the surge tank 22, which is the volume part. Therefore, the noise generated from the intake device A is further reduced.

[0021] When the load is low, the supercharger bypass passage opening/closing valve 26 and the common passage opening/closing valve 31 are opened. In this case, a part of the air discharged from the supercharger 19 is transferred to the supercharger 1 via the supercharger bypass passage 25 (including the common passage 29).
9 is returned to the collective intake passage 16 (position B2) upstream of the intercooler 21, and a part of the air is returned to the collective intake passage 16 (position B4) downstream of the intercooler 21 via the intercooler bypass passage 28 (including the common passage 29). Supplied. At this time, as described above, the pressure of the air downstream of the supercharger 19
It is released into the upstream collective intake passage 16, and no supercharging is performed. Therefore, when the load is low, unnecessary increases in engine output are prevented, and fuel efficiency is improved. In this case, the intercooler 21 is connected to the intercooler bypass passage 2.
Since the ventilation resistance is greater than that of 8, air does not substantially flow through the intercooler 21.

In this case, almost all of the air discharged from the supercharger 19 passes through the common passage 29, but this common passage 29 passes through the communication hole 33 into the interior of the enclosure member 32 that functions as a resonator. Since it communicates with the space, air column vibrations generated within the common passage 29 by driving the supercharger 19 are reduced. In addition, due to the function of the enclosure member 32 itself, the discharge noise and air column vibration from the supercharger 19 are reduced, and the radiated sound emitted from the pipe surface of the common passage 29 is also reduced, and the generation of harsh noise from the intake device A is reduced. reduced. Note that, under low load conditions, the noise generated from the main body of the engine E is small, so the noise reduction effect of the intake device A is particularly effective.

As shown in FIG. 4, the intake device A' has basically the same structure as the intake device A shown in FIGS. 1 to 3, and the resonator 32' is formed separately from the enclosure member. Then, this resonator 32' may be connected to the common passage 29 on the B3 side of the common passage opening/closing valve 31 via the communication passage 33'. In this case, the resonator 32
' is preferably arranged at the rear of the supercharger 19 main body between the V banks.

[0024]

According to the first invention, during supercharging, the supercharger bypass passage opening/closing valve and the common passage opening/closing valve are closed, and the intake passage downstream of the turbocharger communicates with the large-volume resonator. This reduces the dead volume downstream of the supercharger, increases supercharging efficiency, and increases engine output. In addition, when not supercharging, the turbocharger bypass passage on-off valve and the common passage on-off valve are opened, so almost all the air downstream of the turbocharger passes through the common passage, and at this time, the resonator reduces air column vibration, and the intake air Harsh noise generated from the device is reduced. Note that during non-supercharging, that is, when the load is low, the engine noise is small, so the noise reduction effect of the intake device is even more effective.

According to the second invention, basically the same operation and effect as the first invention can be obtained. Furthermore, since the supercharger is surrounded by the enclosure member, the noise (radiated sound) generated from the supercharger is confined within the enclosure member, and the generation of noise from the intake device is reduced in the entire operating range. Further, since the enclosure member is made to function as a resonator, there is no need to separately provide a resonator. Therefore, the intake device is made more compact.

According to the third invention, basically the same operation and effect as the second invention can be obtained. Furthermore, since the common passage is also arranged inside the enclosure member, the radiated sound from the common passage on the discharge side of the supercharger, which has relatively high radiated noise, is confined within the enclosure member, further reducing noise generation. In addition, the intake device can be made even more compact.

According to the fourth invention, since the mechanical supercharger and the resonator are arranged between the V banks, the intake device can be made even more compact. In addition to this, it goes without saying that the effects of the first to third inventions can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of an intake device for a mechanical supercharged engine according to the present invention.

FIG. 2 is an explanatory partial cross-sectional plan view of a six-cylinder V-type engine equipped with an intake system according to the present invention.

FIG. 3 is a partially cross-sectional front elevational explanatory view of the engine shown in FIG. 2;

FIG. 4 is a system configuration diagram of an air intake device according to the present invention, in which a resonator is provided separately from an enclosure member.

[Explanation of symbols]

A...Intake device A’…Intake device E...Engine E’…Engine P...1st bank Q...Second bank 16...Collective intake passage 19...Supercharger 21...Intercooler 25...Supercharger bypass passage 26...Supercharger bypass passage opening/closing valve 28...Intercooler bypass passage 29...Common passageway 31...Common passage opening/closing valve 32...Enclosure member 32’…Resonator

Claims (4)

[Claims] [Claim 1] A mechanical supercharger and an intercooler are interposed in the intake passage, and a supercharger bypass passage bypasses the supercharger, and a supercharger bypass passage is interposed in the supercharger bypass passage and is opened at low load. In a mechanical supercharged engine equipped with a supercharger bypass passage opening/closing valve and an intercooler bypass passage that bypasses the intercooler, the supercharger bypass passage and the intercooler bypass passage are arranged on the upstream side in the air flow direction. An engine with a mechanical supercharger, characterized in that the common passage is unified as a single passage, a common passage opening/closing valve is provided to open and close the common passage, and a resonator is provided downstream of the common passage opening/closing valve and communicating with the common passage. intake device. 2. In the intake system for a mechanical supercharged engine according to claim 1, the resonator communicates the enclosure member surrounding the supercharger main body with the common passage downstream of the common passage opening/closing valve. An intake device for a mechanical supercharged engine, characterized in that it is formed by: 3. In the intake system for a mechanical supercharged engine according to claim 2, at least the common passage comprises:
An intake device for a mechanical supercharged engine, characterized in that the intake device is surrounded by an enclosure member together with a supercharger. 4. In the intake system for an engine with a mechanical supercharger according to claims 1 to 3, the engine is a V-type engine, and the supercharger and resonator are arranged in a V-type engine.
An intake device for an engine with a mechanical supercharger, characterized in that it is provided between banks.