JPS58152125A - Controller for supercharging pressure of supercharged engine - Google Patents

Abstract

PURPOSE:To enable to prevent the occurrence of knocking and the seizure of piston, by installing a pressure adjusting means which feeds a supercharging pressure signal to a bypass valve only when a super charging pressure exceeds a set value, thereby the supercharging pressure is controlled lower than the set value. CONSTITUTION:If a supercharging pressure fed to a pressure working chamber 41 is going to exceed a set pressure Pa, a diaphragm 45 moves upward against the elastic force of a spring 43 to open an opening end 39a. As a result, a supercharging pressure is fed through a path 39 into a pressure working chamber 36 of a bypass valve 31 where the set pressure Pa exceeds a set value of an opening valve, and thereby a diaphragm 34 is moved to the right against the force of a spring 37 to feed exhaust gas to a bypass path 7 through opening of a valve body 32 with the aid of a link 35. This reduces exhaust energy of rotating a turbine 3, prevents a compressor 5 from overrotating, and a supercharging pressure from increasing to higher than the set pressure Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharging pressure control device for preventing an excessive rise in supercharging pressure in a supercharged internal combustion engine, and more specifically, to an improvement of a bypass pulp control device provided in an exhaust passage.

Conventional supercharging pressure 11Ji shown in Fig. 1! The device is Japanese Patent Application Publication No. 1973.
- Disclosed in Japanese Patent No. 65712, in which a turbine 3 installed in an exhaust passage 2 of an internal combustion engine 1 is rotated by exhaust energy, and a compressor 5 connected to the turbine 3 via a shaft 4 is rotationally driven. In a supercharged internal combustion engine that supercharges intake air to the internal combustion engine 1 via the intake passage 6, a bypass pulp 10 is interposed in a bypass passage T that bypasses the turbine 3.

The bypass pulp 10ti is connected to the diaphragm 12 via the valve body 11 which opens and closes the bypass passage 70 inlet 11, and the intake passage downstream of the compressor 5 is connected to the pressure working chamber 13 which is the part of the skeleton diaphragm 12. 6 Internal pressure (
The spring 14 elastically biases the valve body 11 in the valve closing direction. In the figure, there are 15 slots.

Therefore, according to this configuration, when the supercharging pressure acting on the pressure operating chamber 13 exceeds the valve opening setting pressure determined by the spring 14, the elastic force of the spring 14 and the supercharging pressure acting on the diaphragm 12 are balanced. Okay, the one-time valve body 11 proportional to the boost pressure opens and increases the amount of exhaust gas flowing through the bypass passage T without participating in the three rotations of Tahif.
Reduce exhaust energy used for rotation. Does this compile? 5 is prevented from over-revving and the supercharging pressure exceeds the set pressure, thereby protecting the supercharger, intake system, and even the internal combustion engine itself from damage.

However, according to such a conventional structure, the bypass valve 10 is opened in proportion to the value of boost pressure that is equal to or higher than the valve opening set pressure of the bypass valve, so thermal deformation of the bypass valve 10 due to exhaust heat and exhaust gas If the sliding frictional resistance of the valve body 11 drive system (Prad, spring, etc.) increases due to the adhesion of impurities (carbon, etc.), or if there is a variation in the spring or assembly WA difference, bypass will occur due to boost pressure. Poor response, in which the valve 10 does not open to the desired degree, is likely to occur. As a result, it becomes impossible to maintain the desired optimum amount of exhaust bypass passage, and it becomes difficult to maintain the maximum value of boost pressure at the set pressure. There was a risk that this would cause inconvenience.

The present invention addresses the above-mentioned disadvantages of the conventional device and provides a pressure regulating means that guides a boost pressure signal to the bypass valve only when the boost pressure exceeds the set pressure, thereby bypassing the set pressure that activates the pressure regulating means. By setting the pulp O valve opening pressure higher than the set pressure, the bypass valve is not proportional to the boost pressure, but is controlled to open and close repeatedly in an on-off manner, thereby constantly maintaining the boost pressure below the set pressure. The present invention provides nine supercharging pressure adjustment devices.

Embodiments of the present invention will be described below based on the drawings.

The internal combustion engine 1 shown in FIGS. 2 and 3 is an electronically controlled fuel injection type, and the injection valve 21 is the primary throttle valve 15.
This is a so-called single point injection type installed directly in the intake passage 6 immediately downstream of A. This is a 15Bti secondary throttle valve. An air flow meter 22 is installed in the intake passage 6 upstream of the compressor 5, while an air flow meter 22 is installed in the exhaust passage 2 downstream of the turbine 3.
co.

An exhaust sensor 23 that detects components such as CO2 is interposed, and the intake air amount and exhaust sensor 2 are measured by the air flow meter 22.
3 and throttle sensor 24
The operating conditions of the engine such as the throttle of the primary throttle valve 15 are detected and input to a controller (not shown), and a predetermined fuel amount is calculated by ζ and the injection valve 2 is
Fuel is intermittently injected from 1 toward the intake passage 6 and mixed with intake air to form an air-fuel mixture with an appropriate air-to-air ratio.

The configuration of the supercharger, the bypass passage T, etc. are substantially the same as in the prior art example, and 25 is a spark plug.

The bypass valve 31 that opens and closes the bypass passage T has a pressure-responsive actuator 33 connected by a link 35 to a valve body 32 that opens and closes the bypass entry lower at. The actuator 33 has m diaphragms 34 linked to the valve body 32 and has pressure operating chambers 36, and has a spring 37 on the other side that biases the valve body 32 in the valve closing direction and determines the valve setting pressure. . A pressure regulating valve 4 is provided in the pressure operating chamber 36.
A supercharging pressure downstream of the compressor 5, which is controlled on and off at a set pressure of 0, is introduced through a passage 39. still,
The passage 39 opens to the atmosphere through an orifice 38.

The pressure regulating valve 40 partitions a pressure operating chamber 41 facing the open end 3sa of the passage 39 from an atmospheric type 42, and receives the elastic force of a spring 430 to bias the open end 39a in the direction in which the valve body 44 closes. A diaphragm 45 is provided. At this time, the valve opening pressure Pa (
For example, about 350-HP), that is, the set pressure is the valve body 32 opening pressure pb (by the spring 3T of the bypass valve 31).
For example, about 150 mHf), that is, the valve opening setting pressure is also set to be higher. A passage 4 is connected to the pressure working chamber 41.
7 leads to an overpressure.

Therefore, according to this configuration, when the supercharging pressure introduced into the pressure working chamber 41 of the pressure regulating valve 40 is about to exceed the set pressure Pa, the diaphragm 45 moves upward in the figure against the elastic force of the spring 430 and ends at the open end. Open 39a. Therefore, the supercharging pressure passes through the passage 39 to the pressure operating chamber 3 of the bypass valve 31.
6 will be introduced. Here, since the valve opening setting pressure is higher than the opening setting pressure as described above, the diaphragm 34 is moved to the right in the figure against the elastic force of the spring 370, and the valve body 32 is opened via the link 35 to exhaust the air. It leads to the bypass passage 7. This reduces the exhaust energy that rotates the turbine 3, prevents over-rotation of the compressor 5, and sets the boost pressure P.
Prevent the temperature from rising above a.

When the boost pressure becomes smaller than the set pressure Pa, the pressure regulating valve 4
At 0, the diaphragm 43 moves down due to the elastic force of the spring 430, and the valve body 44 opens into the opening f of the passage j139.
Block i39m. Therefore, due to the presence of orifice 38,
The pressure in the passage 39 and the pressure operating chamber 36 of the bypass valve 31 is diluted to the atmosphere, and the set load of the spring 3T, which is smaller than the valve opening set pressure pb, overcomes and moves the diaphragm 34 to the left. Along with this, the valve body 32 moves to the right via the link 35 and the bypass port 1a of the bypass passage 1 is closed. Therefore, there is no exhaust flow passing through the bypass passage 7, thereby preventing a drop in supercharging pressure.

By repeating such actions, the supercharging pressure downstream of the compressor is controlled to be constant at the set pressure Pa.

Of course, if the supercharging pressure is below the set pressure Pa, the bypass valve 31 remains closed and does not act to lower the supercharging pressure below the current value.

In the above embodiment, depending on the opening diameter of the orifice 38,
It goes without saying that the delay in closing response of the bypass valve 31 to the closing action of the opening end 39m of the pressure regulating valve 40 can be set arbitrarily. In addition, the spring 37 of the bypass valve 31 is arranged so that the valve opening setting pressure Pb of the bypass valve 31 becomes smaller and away from the valve opening setting pressure Pa of the pressure regulating valve 40.
When selecting the set load for ', when the supercharging pressure is about to rise above the set pressure Pa, the pressure rise in the bypass valve 31 and the pressure operating chamber 36 due to the opening of the pressure regulating valve 40 is prevented. The bypass valve 31 can be configured to open with good response.

Since the bypass valve is controlled to open and close in an on-off manner in this way, even if exhaust impurities (such as large particles) adhere to the valve body 32 and link 35 and are likely to cause malfunction or poor responsiveness, the bypass valve can be opened and closed in a stepwise manner. It is clear that this risk can be eliminated by opening or closing the bypass valve with a certain pressure difference.

In addition, in FIG. 4, the passage 3S in the above embodiment is largely omitted, and the pressure regulating valve 40/and the actuator 3 of the bypass valve are shown.
3 and these pressure working chambers 41゜36 mutually through a passage 39.
1' is short-circuited and both are integrally formed. In the figure, reference numerals 51 and 52 indicate stoppers fixed to the diamond 72 rim 34.

9. In the embodiment shown in FIG.
The passage 47 and the passage 39 are connected by a passage 55, which is opened to face 10 opposite passages. The open chamber at the open end 39m is an atmospheric pressure chamber.

Therefore, when the supercharging pressure is about to exceed the set pressure Pa, the diaphragm 45 moves upward in the figure and closes the opening end 39a, so that the supercharging pressure set pressure Pa passes through the passage 47, 55, 39 to the actuator. 33 to open the bypass valve. On the other hand, when the boost pressure becomes smaller than the set pressure Pa, the diaphragm 45 lowers in the figure, opens the negative end 39m, dilutes the boost pressure signal to the atmosphere, and opens the bypass valve. and close the valve. Its operation and effect are similar to those of the previous two embodiments.

As described above, according to the present invention, the pressure regulating means is provided to introduce the boost pressure signal sent to the bypass valve into the pressure operating chamber of the bypass valve only when the boost pressure exceeds the set pressure. By repeatedly controlling the valve to open and close in an on-off manner instead of using a valve proportional to the boost pressure, the boost pressure can be maintained below the set pressure. Therefore, the bypass valve is thermally deformed and the sliding resistance of the valve body dynamic system increases due to the adhesion of carbon capes], and even if there are variations in springs and assembly errors, the bypass valve can only open and close in two directions. Since only the position needs to be determined, the response accuracy is extremely high and the valve structure is simple.

Therefore, the accuracy of measuring the turbine bypass displacement amount by the bypass valve is improved, the boost pressure can be accurately suppressed to around the set pressure, and problems such as knocking phenomenon and piston burnout can be avoided.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of a conventional device, Fig. 2 is a vertical sectional view showing an embodiment of the present invention, Fig. 3 is a sectional view of the main parts of the same, and Fig. 4 is a schematic diagram of a conventional device.
FIG. 5 is a sectional view of another embodiment of the present invention, respectively. 1... Internal combustion engine 2... Exhaust passage 3... Turbine 5... Compressor T... Bypass passage 31.31'... Bypass pulp 32...
Valve body 33--Actuator 39...Passage
39 colors...Opening end 40, 40'...Pressure regulating valve 47...Passage 55...Passage patent Applicant: Nissan Motor Co., Ltd. Patent attorney Fujio Sasashima

Claims (1)

[Claims] In an internal combustion engine with a supercharger that uses exhaust gas to drive a turbine and supercharge intake air by a compressor that is rotatably connected to the turbine, a pressure-responsive bypass pulp is installed in the exhaust passage that bypasses the turbine. A pressure adjusting means is provided to introduce a boost pressure signal downstream of the compressor into the pressure operating chamber of the bypass pulp when the boost pressure becomes equal to or higher than a set pressure, and the set pressure is used to control the valve opening of the bypass pulp. A supercharging pressure control device for an inner furnace equipped with a supercharger, which is configured to control the opening and closing of bypass pulp in an on-off manner by increasing the set pressure.