JPH0511305Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to an air intake control device for a supercharged internal combustion engine, and in particular, it also achieves speed control using a control mechanism that prevents the generation of surge noise. The present invention relates to an intake control device for a supercharged internal combustion engine.

[Conventional technology]

A supercharged internal combustion engine improves combustibility by increasing the amount of intake air supplied to the combustion chamber, thereby improving output and fuel efficiency. For example, in 1987-
As disclosed in Japanese Patent No. 133132, exhaust energy from an internal combustion engine is used to rotate a turbine provided in an exhaust passage, and this rotation is transmitted to a compressor provided in an intake passage to forcefully feed intake air. The system described in this publication includes a bypass passage that communicates the upstream and downstream sides of a compressor installed in the intake passage, a bypass valve that opens and closes this bypass passage, and closes the bypass valve during normal operation of the internal combustion engine. In addition, when the engine suddenly accelerates or decelerates, the bypass valve is kept open for a predetermined period of time to improve responsiveness and provide a good running feel.

[Problem that the invention attempts to solve]

Incidentally, conventional methods for controlling the speed of a supercharged internal combustion engine include stopping fuel supply or reducing supercharging pressure. However, in the speed control method in which the fuel supply is stopped, the fuel supply to the internal combustion engine is stopped, resulting in a problem that the combustion state deteriorates and the driving feeling deteriorates. In addition, in the speed control method that lowers the boost pressure, it is necessary to separately provide a control mechanism to control the opening and closing of the bypass passage, which increases the number of parts, complicates the configuration, and increases the cost. It was hot.

[Purpose of invention]

Therefore, the purpose of this invention is to eliminate the above-mentioned inconveniences, to prevent the generation of surge noise and to control the speed using one control mechanism, thereby reducing the number of parts and simplifying the configuration. An object of the present invention is to realize an intake control device for an internal combustion engine with a supercharger that is inexpensive and can improve running feeling during speed control.

[Means for solving problems]

In order to achieve this object, this invention provides a bypass passage that communicates the intake passage on the upstream side of the turbocharger compressor with the intake passage on the downstream side of the turbocharger compressor, and includes a control mechanism for opening and closing this bypass passage. In the intake air control device for a supercharged internal combustion engine, the control mechanism includes a first pressure chamber and a second pressure chamber defined by a diaphragm in the housing.
an on-off valve having a pressure chamber, and communicates the first pressure chamber and the second pressure chamber with a surge tank provided in the intake passage downstream of the throttle valve through a first pressure passage and a second pressure passage. The first pressure passage is configured to open the first pressure passage in a normal operating state of the internal combustion engine, and close the first pressure passage when a speed control command is received, and to control the first pressure. An electric pressure switching valve that sets the chamber to atmospheric pressure is provided, and the second pressure passage is provided with a pressure delay valve that delays the decrease in intake pipe pressure acting on the second pressure chamber. .

[Effect]

According to the configuration of this invention, when the engine enters an operating state where surging occurs during normal operating conditions, the bypass passage is opened by the control mechanism, and the pressure generated in the intake passage downstream of the turbocharger compressor is reduced. The energy of the fluctuation is reduced by the bypass passage to prevent the generation of surge noise. In the speed control operating state, the bypass passage is opened by the above-mentioned control mechanism, intake air is supplied to the internal combustion engine bypassing the supercharger compressor, and the supercharging pressure is reduced to achieve speed control. This allows speed control to be performed using the control mechanism that prevents the generation of surge noise, and there is no need to provide a separate control mechanism for speed control, reducing the number of parts and simplifying the configuration. In addition to aiming for low price. In addition, in the speed control operation state, the fuel supply is not stopped, so
The driving feeling during speed control can be improved.

〔Example〕

Embodiments of this invention will be described in detail and specifically below based on the drawings.

1 to 4 show a first embodiment of this invention. In the figure, 2 is an internal combustion engine, 4 is an intake passage, 6 is an exhaust passage, and 8 is a supercharger. Supercharger 8
is the compressor 1 installed facing the intake passage 4.
0 is rotated by a turbine 12 provided facing the exhaust passage 6, and air taken from an air cleaner (not shown) through the upstream intake passage 4-1 is sent to the internal combustion engine 2 through the downstream intake passage 4-2. to pump. A downstream intake passage 4-2 extending from the compressor 10 to a combustion chamber (not shown) of the internal combustion engine 2 is provided with a throttle valve 14 and a surge tank 16 in order from the side closer to the compressor 10. An exhaust passage 6 starting from the combustion chamber is provided with the turbine 12 facing in the middle thereof, and communicates with a muffler 18.

The downstream intake passage 4-2 on the compressor 10 side of the throttle valve 14 is connected to the other end of a bypass passage 20 whose one end communicates with the upstream intake passage 4-1 so as to bypass the compressor 10. shall be established. This bypass passage 20 is provided with a control mechanism 22 that opens the bypass passage 20 in an operating state where surging occurs during rapid deceleration operation, for example, or in a speed control operating state.

This control mechanism 22 is configured as follows.
That is, the bypass passage 20 is divided by a connecting body 28 connected to the housing 26 of the on-off valve 24, and consists of an upstream bypass passage 20-1 and a downstream bypass passage 20-2. A first pressure chamber 32 and a second pressure chamber 34 are defined in the housing 26 by a diaphragm 30 . One end of a rod 36 is fixed to the surface of the diaphragm 30 on the side of the first pressure chamber 32, and the other end of the rod 36 is connected to and separated from a valve seat 38 formed in the connecting body 28 and connected to the upstream side bypass passage 20-1. A valve body 40 is fixed to the valve body 40 for blocking and communicating the downstream side bypass passage 20-2. Furthermore, within the first pressure chamber 32,
A spring 42 is fitted into the rod 36.

The first pressure chamber 32 and the second pressure chamber 34 communicate with the surge tank 16 via a pressure passage. In other words, the first pressure chamber 32 is a first pressure chamber branched from the main pressure passage 44 communicating with the surge tank 16.
It communicates with the surge tank 16 by a pressure passage 46 . Further, the second pressure chamber 34 communicates with the surge tank 16 through a second pressure passage 48 branched from the main pressure passage 44 .

In the first pressure passage 46, the first pressure passage 46 is opened and the atmospheric opening 50 is closed in the normal operating state of the internal combustion engine 2, and the surge tank 16 of the first pressure passage 46 is provided in the first pressure passage 46 in the speed control operating state.
The first pressure chamber 3 is opened by blocking the side and opening the atmospheric opening 50.
An electric pressure switching valve 52 is provided which sets pressure 2 to atmospheric pressure. This electric pressure switching valve 52 communicates with a speed detection mechanism (not shown) such as an engine speed sensor that detects the vehicle speed, receives a signal from this speed detection mechanism, and shuts off the first pressure passage 46. atmospheric opening 5
0 is released. The second pressure passage 48 includes a check valve 54 and a throttle 56 for delaying the decrease in intake pipe pressure acting on the second pressure chamber 34 compared to the decrease in intake pipe pressure acting on the first pressure chamber 32. A valve 58 is provided.

The operation of this first embodiment will be explained below.

In the normal operating state of the internal combustion engine 2, the electric pressure switching valve 52 opens the first pressure passage 46 and closes the atmospheric opening 50, as shown in FIG. As a result, positive pressure, which is the intake pipe pressure from the surge tank 16, acts on the first pressure chamber 32 via the main pressure passage 44 and the first pressure passage 46 (indicated by the arrow in FIG. 2). At this time, the positive pressure in the main pressure passage 44 is transferred to the second pressure chamber 3 through the second pressure passage 48 and the pressure delay valve 58 in which the check valve 54 is in the open state.
4 (indicated by the arrow in Figure 2). Therefore,
Since the same positive pressure acts on the first pressure chamber 32 and the second pressure chamber 34 and there is no pressure difference, the diaphragm 30 does not displace and the valve body 40 abuts against the valve seat 38, causing the upstream side bypass passage. 20-1 and the downstream bypass passage 20-2 are cut off.

Then, for example, in a sudden deceleration operation state, the throttle valve 14
When the valve suddenly closes, that is, in an operating state where surging occurs, as shown in FIG.
The energy of the pressure fluctuation in step 2 is about to increase.
When the throttle valve 14 is closed, the surge tank 16
As the positive pressure in the main pressure passage 44 decreases, the positive pressure in the main pressure passage 44 also decreases. At this time, the check valve 54 of the pressure delay valve 58 is in the closed state, and the positive pressure acting on the second pressure chamber 34 flows only from the throttle 56. ) is the decrease in positive pressure acting on the first pressure chamber 32 (shown by 2 in Figure 3).
(indicated by the dotted chain line). That is, a pressure difference occurs between the first pressure chamber 32 and the second pressure chamber 34. Therefore, the second pressure chamber 34 has the first pressure chamber 32
A higher positive pressure acts on the diaphragm 30, and the diaphragm 30 is displaced in the direction of contraction of the first pressure chamber 32 against the biasing force of the spring 42. Due to this displacement of the diaphragm 30, the valve body 40 is moved to the valve seat 38 via the rod 36.
The upstream side bypass passage 20-1 and the downstream side bypass passage 20-2 are communicated with each other. As a result, pressure fluctuations occurring in the downstream intake passage 4-2 act on the bypass passage 20 due to the communication with the bypass passage 20, and its energy is reduced, making it possible to prevent the generation of surge noise. .

On the other hand, in the speed control operation state, as shown in FIG. 4, when a predetermined speed is reached, the electric pressure switching valve 52 closes the surge tank 16 side of the first pressure passage 46 in response to a command from the speed detection mechanism. At the same time, the atmospheric opening 50 is opened. This allows the first
Atmospheric air is introduced into the pressure chamber 32 from the atmospheric opening 50 (indicated by the black arrow in FIG. 4), and the first pressure chamber 32
becomes atmospheric pressure. Moreover, in the second pressure chamber 34,
Positive pressure from the surge tank 16 (indicated by the arrow in FIG. 4) is acting. That is, a pressure difference occurs between the first pressure chamber 32 and the second pressure chamber 34. Therefore, the positive pressure in the second pressure chamber 34 becomes higher than the atmospheric pressure in the first pressure chamber 32, so that the diaphragm 30 resists the biasing force of the spring 42 and moves toward the first pressure chamber 32.
Displaced in the direction of reduction. This displacement of the diaphragm 30 causes the valve body 40 to separate from the valve seat 38, thereby establishing communication between the upstream bypass passage 20-1 and the downstream bypass passage 20-2. Therefore, the intake air bypasses the compressor 10 and is supplied to the internal combustion engine 2 via the bypass passage 20 and the surge tank 16. Therefore, the supercharging pressure is reduced and speed control is achieved.

As a result, prevention of surge noise and speed control can be performed by one control mechanism 22, which reduces the number of parts, simplifies the configuration, and lowers the cost. Furthermore, since the fuel supply is not stopped in the speed control operating state, the driving feeling during speed control is improved.

FIG. 5 shows a second embodiment of this invention. In the following embodiments, parts having the same functions as those in the first embodiment described above are given the same reference numerals and explained.

The feature of this second embodiment is that a throttle 62 of a predetermined shape is provided at the atmospheric opening 50 of the electric switching valve 52 provided in the first pressure passage 46.

According to the configuration of the second embodiment, in the speed control operating state, positive pressure from the surge tank 16 acts on the second pressure chamber 34 of the on-off valve 24, and the first
Atmospheric pressure acts on the pressure chamber 32. If the positive pressure in the surge tank 16 approaches atmospheric pressure during speed control, the spring 4
The biasing force 2 becomes larger than the positive pressure in the surge tank 16, that is, the positive pressure acting on the second pressure chamber 34, and the valve body 40 comes into contact with the valve seat 38, closing the bypass passage 20. Therefore, when the pressure in the surge tank 16 increases and a large positive pressure acts on the second pressure chamber 48 again, the valve element 40 repeatedly separates from the valve seat 38, causing so-called hunting. However, since the aperture 62 having a predetermined aperture shape is provided at the atmospheric opening 50, the pressure difference between the first pressure chamber 32 and the second pressure chamber 34 can be balanced and hunting can be effectively prevented.

[Effect of idea]

As is clear from the above detailed description, according to this invention, the control mechanism includes an on-off valve having a first pressure chamber and a second pressure chamber defined by a diaphragm in a housing, and A second pressure chamber is provided in communication with a surge tank provided in an intake passage on the downstream side of the throttle valve through a first pressure passage and a second pressure passage, and the second pressure chamber is provided in communication with a surge tank provided in an intake passage downstream of the throttle valve. An electric pressure switching valve is provided that opens the pressure passage and closes the first pressure passage when a speed control command is received and sets the first pressure chamber to atmospheric pressure. By providing a pressure delay valve that delays the decrease in intake pipe pressure acting on the chamber, prevention of surge noise and speed control can be performed by one control mechanism, reducing the number of parts. The structure can be simplified and the cost can be reduced. Furthermore, since the fuel supply is not stopped in the speed control operating state, the driving feeling during speed control can be improved.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of this invention, FIG. 1 is a schematic diagram of the intake control device, and FIGS. 2 to 4 are explanatory diagrams showing the operation of the control mechanism. FIG. 5 shows a second embodiment of this invention, and is a schematic diagram of the control mechanism. In the figure, 2 is an internal combustion engine, 4 is an intake passage, and 6 is an internal combustion engine.
is an exhaust passage, 8 is a supercharger, 10 is a compressor,
12 is a turbine, 14 is a throttle valve, 16 is a surge tank, 20 is a bypass passage, 22 is a control mechanism, 2
4 is an on-off valve, 30 is a diaphragm, 32 is a first pressure chamber, 34 is a second pressure chamber, 46 is a first pressure passage,
48 is a second pressure passage, 50 is an atmospheric opening, 52 is an electric pressure switching valve, and 58 is a pressure delay valve.

Claims (1)

[Scope of utility model registration request] Intake control of an internal combustion engine with a supercharger, which includes a bypass passage that communicates an intake passage upstream of a supercharger compressor with the intake passage downstream of the supercharger compressor, and a control mechanism that opens and closes this bypass passage. In the apparatus, the control mechanism includes an on-off valve having a first pressure chamber and a second pressure chamber defined by a diaphragm in a housing, and connects the first pressure chamber and the second pressure chamber to a first pressure passage. and a second pressure passage that communicates with a surge tank provided in the intake passage downstream of the throttle valve, and the first pressure passage is opened in the normal operating state of the internal combustion engine. In addition, an electric pressure switching valve is provided that closes the first pressure passage and sets the first pressure chamber to atmospheric pressure when a speed control command is received, and the second pressure passage is provided with an electric pressure switching valve that closes the first pressure passage and sets the first pressure chamber to atmospheric pressure. 1. An intake air control device for an internal combustion engine with a supercharger, comprising a pressure delay valve that delays a decrease in intake pipe pressure acting on the engine.