JPH05156957A - Damping air bypass valve device for supercharged engine - Google Patents

Abstract

PURPOSE:To reduce the occurrence of any noise attributable to the chattering of a valve element in an air bypass valve to be generated at a medium load range. CONSTITUTION:A vibration damping means 71, damping any chattering in a valve element 65, is installed in a diaphragm type actuator 64 for opening or closing this valve element 65 of an air bypass valve 62, through which vibration in the valve element 65 at a medium load range is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration air bypass valve device for preventing the occurrence of surging during deceleration in a supercharged engine.

[0002]

2. Description of the Related Art In an engine equipped with a supercharger (turbocharger), when the throttle valve is suddenly switched from the open state to the closed state due to deceleration, the intake valve inertia and the rotational inertia of the compressor cause throttle valve The upstream pressure rises sharply. This abrupt pressure increase causes a problem that supercharging causes surging that flows back to the compressor side due to pressure reflection, and a pulsating sound (surge sound) is generated.

As an example of a technique for reducing the surge noise, Japanese Patent Laid-Open No. 60-150430 and Japanese Utility Model Laid-Open No. 64-5 are available.
The 8723 publication is known. In the devices disclosed in these publications, an air bypass valve is provided in an air bypass passage that connects the upstream side and the downstream side of the compressor of the turbocharger. During decompression, the surge tank internal pressure (negative pressure) downstream of the throttle valve and the supercharging pressure upstream of the throttle valve open the air bypass valve, and the supercharged air compressed by the compressor is returned to the upstream side of the compressor. The occurrence of is suppressed.

[0004]

However, in the case of the device as described in the above publication, there are the following problems. This will be described below. In the air bypass valve, the valve body is usually driven by a diaphragm type actuator. The diaphragm type actuator has a diaphragm chamber into which a negative pressure is introduced, and the diaphragm chamber accommodates a spring for urging the valve body in the valve closing direction. In the light load range of the engine,
The air bypass valve is opened by the negative pressure of the intake pipe introduced into the diaphragm chamber, and conversely is closed by the spring force and the supercharging pressure introduced into the diaphragm chamber in the high load range.

However, there is a region where the valve closing force and the valve opening force are balanced between the light load region and the high load region. In this region, the position of the valve element is not stable, and a phenomenon in which the valve element repeatedly opens and closes, that is, a so-called chattering phenomenon occurs. The pulsating sound of intake air due to the chattering of the valve element travels through the air bypass passage and returns to the intake port side (air cleaner side), and is heard as a strange noise in the passenger compartment. The generation of this abnormal sound gives an occupant of the vehicle an unpleasant sensation, and a solution is desired.

It is an object of the present invention to provide a deceleration air bypass valve device capable of reducing the generation of abnormal noise due to the vibration of the valve element of the air bypass valve, focusing on the above problems.

[0007]

The deceleration air bypass valve device for a supercharged engine according to the present invention, which is directed to this object, enables communication between the upstream side and the downstream side of a compressor of a turbocharger via an air bypass passage. A supercharger which is connected to the air bypass passage and is provided with an air bypass valve which is opened and closed by a diaphragm actuator so that the air bypass valve is opened by a negative pressure introduced into a diaphragm chamber of the diaphragm actuator. In a deceleration air bypass valve device for an engine, the diaphragm actuator is provided with vibration damping means for damping vibration of a valve element of the air bypass valve.

[0008]

In the deceleration air bypass valve device for a supercharged engine having such a structure, since the diaphragm actuator is provided with the vibration damping means, the damping effect of the vibration of the valve element in the intermediate load range is increased. .. Therefore, the transmission of the pulsating sound to the intake port side due to the chattering of the valve body is reduced, and the generation of abnormal noise due to the pulsating sound is reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a deceleration air bypass valve device for a supercharged engine according to the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a first embodiment of the present invention.
Especially, the case where the present invention is applied to a 6-cylinder engine mounted on a vehicle is shown. In FIG. 2, 1 is an engine, 2 is a surge tank, and 3 is an exhaust manifold. The exhaust manifold 3 includes # 1 to # 3 cylinder groups and # 4 to
Two groups of # 6 cylinders are assembled, and the assembly part is the communication passage 3a.
Is communicated by. Reference numerals 7 and 8 denote a main turbocharger and a sub turbocharger arranged in parallel with each other.
Turbine 7a, 8 of turbocharger 7, 8 respectively
The a is connected to the collecting portion of the exhaust manifold 3, and the compressors 7b and 8b are connected to the surge tank 2 via the intercooler 6 and the throttle valve 4.

The main turbocharger 7 is operated from the low intake air amount region to the high intake air amount region, and the sub turbocharger 8 is stopped in the low intake air amount region. In order to enable both the turbochargers 7 and 8 to operate and stop, the exhaust switching valve 1 is provided downstream of the turbine 8a of the auxiliary turbocharger 8.
7, an intake switching valve 18 is provided downstream of the compressor 8b. When both the intake and exhaust switching valves 18 and 17 are open, both turbochargers 7 and 8 are operated. The downstream side of the turbine 8a of the sub turbocharger 8 and the downstream side of the turbine 7a of the main turbocharger 7 can communicate with each other via an exhaust bypass passage 40. The exhaust bypass passage 40 is provided with an exhaust bypass valve 41 that opens and closes the exhaust bypass passage 40. Exhaust bypass valve 41
Are opened and closed by a diaphragm type actuator 42.

In the intake passage of the auxiliary turbocharger 8 which is stopped in the low intake air amount range, one turbocharger to two
In order to facilitate the switching to the individual turbocharger, an intake bypass passage 13 that connects the upstream side of the compressor 7b and the downstream side of the compressor 8b, and an intake bypass valve 33 disposed in the middle of the intake bypass passage 13 are provided. .. The intake bypass valve 33 is a diaphragm type actuator 1.
It is opened and closed by 0. A check valve 12 is provided in a bypass passage that connects upstream and downstream of the intake switching valve 18, and when the intake switching valve 18 is closed, the compressor outlet pressure on the side of the auxiliary turbocharger 8 is the main turbocharger 7.
When larger than the side, air is allowed to flow from the upstream side to the downstream side. In the figure, 14 indicates an intake passage on the compressor outlet side, and 15 indicates an intake passage on the compressor inlet side.

The intake passage 15 is connected to an air cleaner 23 via an air flow meter 24. The front pipe 20 forming the exhaust passage is connected to an exhaust muffler (not shown) via an exhaust gas catalyst 21. Intake switching valve 18
Is opened and closed by the actuator 11, and the exhaust switching valve 1
The diaphragm actuator 7 is opened and closed by a diaphragm actuator 16. The waste gate valve 31 is
It is adapted to be opened and closed by the actuator 9.

Actuators 9, 10, 11, 16, 4
2 is activated by the introduction of supercharging pressure or negative pressure. Each actuator 9, 10, 11, 16,
Reference numeral 42 denotes a first pressure tank 51, a supercharging pressure from the compressor outlet side 14, or a negative pressure of the surge tank 2 and a first pressure, a second pressure, in order to selectively switch the atmospheric pressure from the downstream of the air flow meter 24. Third, fourth, fifth and sixth solenoid valves 2
5, 26, 27, 28, 32, 44 are connected.
Switching of each solenoid valve 25, 26, 27, 28, 32, 44 is performed according to a command from the engine control computer 29. A check valve 45 that allows only one flow of the negative pressure is provided in the passage for introducing the negative pressure to the second solenoid valve 26.

When the first solenoid valve 25 is turned on, the intake switching valve 1
Actuating the actuator 11 so that 8 is fully opened,
When OFF, the actuator 11 is operated so that the intake switching valve 18 is fully closed. When the fourth solenoid valve 28 is turned on, the actuator 16 is operated so as to fully open the exhaust gas switching valve 17, and when it is turned off, the actuator 10 is operated so as to fully close the exhaust gas switching valve 17. O of the third solenoid valve 27
N operates the actuator 10 so as to fully close the intake bypass valve 33, and OFF operates the actuator 10 so as to fully open the intake bypass valve 33.

A fifth step of bleeding the supercharging pressure applied to the actuator 42 for operating the exhaust bypass valve 41 to the atmosphere
The solenoid valve 32 is subjected to duty control instead of ON / OFF control. Similarly, the sixth solenoid valve 44 that bleeds the boost pressure applied to the actuator 9 that operates the wastegate valve 31 to the atmosphere is not ON / OFF controlled but is duty controlled.

As is well known, the duty control is to control the energization time by the duty ratio, and the average current is variably controlled in an analog manner by digitally changing the ratio of energization and non-energization. The duty ratio is
It is the ratio of the energization time to the time of one cycle, and when the energization time in one cycle is A and the non-energization time is B, the duty ratio = A / (A + B) × 100 (%). In the present embodiment, the fifth solenoid valve 32 and the sixth solenoid valve 4
By controlling duty of No. 4, it is possible to change the opening amount of these solenoid valves.

The opening degree of the exhaust bypass valve 41 is controlled by varying the bleed amount (leak amount) of the boost pressure introduced into the diaphragm chamber 42a of the actuator 42 to the atmosphere by the duty control of the fifth solenoid valve 32. It is variable. The opening degree of the waste gate valve 31 is set so that the bleed amount (leak amount) of the supercharging pressure introduced into the diaphragm chamber 9b of the actuator 9 to the atmosphere is determined by the sixth solenoid valve 4.
It can be changed by changing the duty control of No. 4.

Engine control computer 29
Is electrically connected to various operating condition detection sensors of the engine and receives signals from the various sensors. The engine operating condition detection sensor includes an intake pipe pressure sensor 30, a throttle opening sensor 5, an air flow meter 24 as an intake air amount measuring sensor, an engine speed sensor 50, and an oxygen sensor 19. The engine control computer 29 includes a central processor unit (CPU) for calculation, a read only memory (ROM) which is a read-only memory, a random access memory (RAM) for temporary storage, and an input / output interface (I).
/ O interface) and an A / D converter for converting analog signals from various sensors into digital quantities.

The compressor 7b of the main turbocharger 7
Of the intake passage 14a located downstream of the compressor 8b of the auxiliary turbocharger 8
An air bypass passage 61 that guides the supercharged air downstream of the compressors 7b and 8b to the upstream side of the compressors 7b and 8b is connected near the confluence portion 14c where the b and the b merge. The air bypass passage 61 has the compressors 7b, 8b when the valve is opened.
An air bypass valve 62 is provided to allow the supercharged air on the downstream side to flow to the upstream side of the compressors 7b and 8b.

As shown in FIG. 1, the air bypass valve 62 comprises a valve body 63, a diaphragm type actuator 64 and a valve body 65. The diaphragm type actuator 64 includes an actuator body 64a, a diaphragm 64b, a diaphragm chamber 64c, and a compression coil spring 64d. The actuator body 64 a of the diaphragm type actuator 64 is attached to the valve body 63. The outer peripheral portion of the diaphragm 64b has an actuator body 64a and a valve body 63.
Being held by.

The diaphragm chamber 64c of the diaphragm type actuator 64 is partitioned from the valve body 63 side by the diaphragm 64b. A valve body 65 is attached to the center of the diaphragm 64b. A valve seat 63a on which the valve body 65 is seated is formed at a position of the valve body 63 facing the valve body 65. Diaphragm chamber 64c
A compression coil spring 64d for urging the diaphragm 64b in the valve closing direction is provided therein. A spring pedestal 67 that receives the compression coil spring 64d is attached to the upper surface side of the valve body 65. Diaphragm 6
The central portion of 4b is held between the valve body 65 and the spring pedestal 67.

The inside of the diaphragm chamber 64c is in communication with the downstream side of the throttle valve 4 via a sensing passage 66. In the light load region of the engine, the intake pipe negative pressure is introduced into the diaphragm chamber 64c through the sensing passage 66, and the displacement of the diaphragm 64b causes the valve body 65 to move to the valve seat 63a.
The air bypass valve 62 is opened when the air bypass valve 62 is separated from the air bypass valve 62. In the high load region of the engine, the boost pressure is introduced into the diaphragm chamber 64c through the sensing passage, and the displacement of the diaphragm 64b causes the valve body 65 to come into close contact with the valve seat 63a, thereby closing the air bypass valve 62. It is like this.

The port 64e of the diaphragm chamber 64c is provided with a throttling portion 71 as vibration damping means for throttling the flow of intake air flowing in and out of the diaphragm chamber 64c.
The flow passage cross-sectional area of the throttle portion 71 is significantly smaller than the flow passage cross-sectional area of the sensing passage 66. Note that the throttle unit 71 of the present embodiment only needs to have a function of suppressing the inflow and outflow of the intake air to and from the diaphragm chamber 64c by reducing the flow passage cross-sectional area. 1
The member is not limited to the squeezed portion 71 shown in (1), and a member such as a filter or sponge can be used.

Next, the operation of the first embodiment will be described. In the high intake air amount region, both the intake switching valve 18 and the exhaust switching valve 17 are opened and the intake bypass valve 33 is closed. As a result, the two turbochargers 7 and 8 are driven, a sufficient amount of supercharged air is obtained, and the output is improved. Both the intake switching valve 18 and the exhaust switching valve 17 are closed and the intake bypass valve 33 is opened in the low speed range and at the time of high load. As a result, only one turbocharger 7 is driven. The reason why one turbocharger is used in the low intake air amount region is that the one turbocharger supercharging characteristic is superior to the two turbocharger supercharging characteristic in the low intake air amount region. By using one turbocharger, the boost pressure and torque rise faster, and the response becomes faster.

When shifting from the low intake air amount region to the high intake air amount region, that is, when switching from one turbocharger operation to two turbocharger operation, the intake switching valve 18
When the exhaust switching valve 17 is closed, the exhaust bypass valve 41 is controlled to be small open by duty control, and the intake bypass valve 33 is closed to increase the running speed of the auxiliary turbocharger 8 to switch the turbocharger. It becomes possible to carry out more smoothly (small shock when switching).

Immediately after deceleration, the pressure upstream of the throttle valve rapidly rises due to the closing of the throttle valve 4. However, in this state, the pressure downstream of the throttle valve 4 becomes negative, so that the diaphragm chamber 64c of the air bypass valve 62 has a negative pressure. Pressure is introduced,
The air bypass valve 62 is opened. As a result, the supercharged air compressed by the compressors 7b, 8b of the turbochargers 7, 8 is returned to the upstream of the compressors 7b, 8b via the air bypass passage 61. Therefore, the occurrence of surging in which the supercharged air flows back to the compressor side due to pressure reflection is prevented.

As described above, the air bypass valve 62 is opened by the intake pipe negative pressure introduced into the diaphragm chamber 64c in the light load region, and conversely, the supercharging pressure introduced into the diaphragm chamber 64c in the high load region. However, there is a region in which the valve closing force and the valve opening force are balanced in the intermediate load region between the light load region and the high load region, and in this region, the valve body 65c opens and closes. Repeated phenomenon, so-called chattering phenomenon occurs. The chattering phenomenon generates a new pulsating sound and causes an abnormal noise in the vehicle interior. In the present embodiment, the diaphragm 71 provided in the diaphragm actuator reduces the abnormal noise.

Since the flow passage cross-sectional area of the throttle portion 71 is smaller than the flow passage cross-sectional area of the sensing passage 66, the throttling effect is enhanced, and the flow passage into the diaphragm chamber 64c when the valve body 65 vibrates. Inflow and outflow of intake air is suppressed, and vibration of the valve body 65 is damped. Therefore, the transmission of the pulsating sound due to the chattering of the valve body 65 to the air cleaner 23 side becomes small,
Abnormal noise in the passenger compartment is reduced.

Further, the diaphragm portion 71 is a diaphragm chamber 64c.
Since it has a function of suppressing a sudden change in the internal pressure, the shock when the valve body 65 is seated is alleviated. This makes it possible to enhance the durability of the seating surface of the valve body 65.

Second Embodiment FIG. 4 shows a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the configuration of the vibration damping means, and the other portions are the same as those in the first embodiment. Therefore, the description of the corresponding portions will be omitted and only the different portions will be described. The same applies to other embodiments described later.

In this embodiment, the diaphragm 64b of the diaphragm type actuator 64 is provided with a damping member 72 as vibration damping means. The damping member 72 is made of, for example, a gel-like damping member. The damping member 72 has a function of elastically deforming due to the vibration transmission of the valve body 65.

In the second embodiment thus constructed, the damping member 72 expands and contracts due to the chattering of the valve body 65, and this expansion and contraction movement is converted into heat energy. Therefore, the vibration energy of the valve body 65 is consumed by the vibration motion of the damping member 72, and the vibration of the valve body 65 is damped.

Third Embodiment FIG. 5 shows a third embodiment of the present invention. In this embodiment, the diaphragm 64b of the diaphragm type actuator 64 is provided with a damping liquid chamber portion 73 as vibration damping means. The damping liquid chamber portion 73 is composed of a film member 73a and a viscous liquid 73b. The film member 73a is joined to the diaphragm 64b in a superposed state. A viscous liquid 73b is sealed in the outer peripheral portion between the diaphragm 64b and the membrane member 73a. The viscous liquid 73b is made of a highly viscous substance such as silicon oil.

In the third embodiment thus constructed, when the valve body 65 vibrates, the expansion and contraction movement is converted into heat energy as in the second embodiment, and the vibration of the valve body 65 is damped.

Fourth Embodiment FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, the compression coil spring 64d of the diaphragm actuator 64 is provided with an elastic covering member 74 as a vibration damping means. The elastic covering member 74 is made of rubber. The elastic covering member 74 covers the outer peripheral portion and the outer peripheral portion of the compression coil spring 64d, and also fills the gap between the wire rods. That is, the elastic covering member 74 is formed in a cylindrical shape, and the cross-sectional shapes of the outer peripheral surface and the inner peripheral surface are formed in a wavy shape having valleys between the wire rods.

In the fourth embodiment thus constructed, the compression coil spring 64d is used when the valve body 65 vibrates.
Expands and contracts, and the expansion and contraction of the compression coil spring 64d is transmitted to the elastic covering member 74. As a result, the elastic covering member 74 also expands and contracts, and this expansion and contraction is converted into heat energy, whereby the vibration of the valve body 65 is attenuated.

Fifth Embodiment FIGS. 7 and 8 show a fifth embodiment of the present invention.
In this embodiment, inside the compression coil spring 64d,
A friction damping part 75 is provided as a vibration damping means. The friction damping portion 75 includes a tubular body 75a, a plate 75b,
It comprises a friction member 75c, a rod 75d, and a spring 75e.

The tubular body 75a is made of a cylindrical thin plate member, and has a slit formed on its side surface and extending in the axial direction. A plate 75b having a slit extending in the radial direction is fixed to the upper end of the tubular body 75a.
The plate 75b is a diaphragm actuator 64.
Is attached to the ceiling surface of the actuator body 64a. A friction member 75c is fixed inside the lower end of the cylindrical body 75a.

The friction member 75c is formed in a thick cylindrical shape. A slit extending in the axial direction is formed on the side surface of the friction member 75c. One of the rods 75d is connected to the central portion (spring seat 67) of the diaphragm to which the valve body 65 is attached. The other end of the rod 75d is oscillatably inserted through the center of the friction member 75c. A C-shaped spring 75 is provided on the outer peripheral portion of the cylindrical body 75a.
e is attached. The spring 75e is the friction member 7
It has a function of pressing 5c against the rod 75d.

In the fifth embodiment thus constructed, when the valve body 65 vibrates, the rod 75d and the friction member 7 are moved.
A frictional movement is carried out with 5c. That is, the valve body 6
At the time of vibration of 5, the vibration of the valve element 65 is converted into heat energy by clone friction between the rod 75d and the friction member 75c. Therefore, the vibration of the valve body 65 is attenuated, and the generation of abnormal noise is reduced.

Sixth Embodiment FIG. 9 shows a sixth embodiment of the present invention. In this embodiment, a dynamic damper 76 as a vibration damping means is arranged inside the compression coil spring 64d of the diaphragm actuator 64. The dynamic damper 76 is composed of an elastic body 76a and a mass 76b. The spring pedestal 67 has a dynamic damper 7
A base 68 for connecting 6 is connected. A mass 76b is connected to the base 68 via a ring-shaped elastic body 76a made of rubber.

In the sixth embodiment thus constructed, the mass 76b is made elastic by the vibration of the valve body 65.
Is excited via. Since the dynamic damper 76 is tuned to the resonance frequency of the valve body 65, it is possible to shift the vibration frequency that causes the abnormal noise, and the vibration of the valve body 65 is suppressed.

Seventh Embodiment FIG. 10 shows a seventh embodiment of the present invention. In this embodiment, a floating liquid chamber portion 77 as a vibration damping means is provided between the diaphragm chamber of the diaphragm type actuator 64 and the spring pedestal 67. The floating liquid chamber 77 includes a ring-shaped elastic liquid chamber portion 77a and a viscous liquid 77b. Elastic liquid chamber 77a
Is composed of a hollow rubber member. Silicon oil, for example, is filled as a viscous liquid in the hollow portion of the elastic liquid chamber 77a.

In the seventh embodiment thus constructed, the valve body 65 is connected to the diaphragm type actuator 64 via the floating liquid chamber portion 77 in a floating state. Therefore, the vibration of the valve body 65 is absorbed by the elastic deformation of the floating liquid chamber portion 77, and the vibration of the valve body 65 is converted into heat energy by the friction when the viscous liquid 77b moves in the liquid chamber. Therefore, the generation of abnormal noise due to the vibration of the valve body 65 is reduced.

In the above embodiments, the two-way twin turbo engine in which two turbochargers are provided for one engine has been described, but one turbocharger is provided for one engine. Of course, it can be applied to an engine.

[0047]

According to the present invention, since the diaphragm type actuator for opening and closing the valve body of the air bypass valve is provided with the vibration damping means for damping the vibration of the valve body, the vibration of the valve body in the medium load range is achieved. Can be suppressed, and generation of abnormal noise due to vibration of the valve body can be reduced. Further, since the vibration damping means reduces the impact when the valve body is seated, the durability of the seating surface of the valve body can be enhanced.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a deceleration air bypass valve device for a supercharged engine according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an engine with a supercharger to which the device of FIG. 1 is attached.

FIG. 3 is a partially enlarged sectional view of FIG.

FIG. 4 is an enlarged cross-sectional view of a main part of a deceleration air bypass valve device for a supercharged engine according to a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view of essential parts of a deceleration air bypass valve device for a supercharged engine according to a third embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part of a deceleration air bypass valve device for a supercharged engine according to a fourth embodiment of the present invention.

FIG. 7 is an enlarged sectional view of a main part of a deceleration air bypass valve device for an engine with a supercharger according to a fifth embodiment of the present invention.

8 is an enlarged perspective view of the vibration damping means of FIG.

FIG. 9 is an enlarged sectional view of essential parts of a deceleration air bypass valve device for a supercharged engine according to a sixth embodiment of the present invention.

FIG. 10 is an enlarged sectional view of a main part of a deceleration air bypass valve device for a supercharged engine according to a seventh embodiment of the present invention.

[Explanation of symbols]

 4 Throttle valve 7 Main turbocharger 7b Compressor 8 Sub turbocharger 8b Compressor 61 Air bypass passage 62 Air bypass valve 64 Diaphragm type actuator 65 Valve body 71 Vibration damping means (Throttle part) 72 Vibration damping means (Damping member) 73 Vibration damping means (Damping liquid chamber part) 74 vibration damping means (elastic covering member) 75 vibration damping means (friction damping part) 76 vibration damping means (dynamic damper) 77 vibration damping means (floating liquid chamber part)

Claims (1)

[Claims] 1. A turbocharger compressor upstream and downstream is communicably connected via an air bypass passage, and an air bypass valve opened and closed by a diaphragm actuator is provided in the air bypass passage. In the deceleration air bypass valve device of the engine with a supercharger, the valve is opened by a negative pressure introduced into the diaphragm chamber of the diaphragm actuator, in the diaphragm actuator,
A deceleration air bypass valve device for a supercharged engine, comprising vibration damping means for damping vibration of a valve element of the air bypass valve.