JPS6367010B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a supercharged internal combustion engine equipped with a supercharger in an intake system that is driven by utilizing the energy of exhaust gas, and more particularly to an exhaust bypass passage and an exhaust relief valve that opens the exhaust bypass passage in the supercharger turbine of the exhaust system. In supercharging pressure control that prevents supercharging pressure from becoming higher than a set value by providing a control system, this is related to altitude correction when atmospheric pressure drops at high altitudes, etc.

[Conventional technology]

In such a supercharged internal combustion engine, an exhaust bypass passage is provided in the supercharger turbine of the exhaust system, and an exhaust relief valve is provided in the passage in order to prevent overspeed and overpressure of the supercharger. , the supercharging pressure of the intake system is derived and compared with the spring in the chamber of the diaphragm actuator that opens to the atmosphere, and when the supercharging pressure exceeds a set value, it operates to open the exhaust relief valve against the spring. , part of the exhaust gas escapes into the exhaust bypass passage to suppress the drive of the supercharger,
The boost pressure is controlled so that it does not rise any higher. In addition, as a prior art for controlling boost pressure,
There is a publication No. 55-114843.

[Problem to be solved by the invention]

By the way, in this type of system, the actuator operates by comparing the sum of atmospheric pressure and spring force with the supercharging pressure, so if the atmospheric pressure drops at high altitudes, etc., the actuator will operate at less than the set supercharging pressure. However, there is a problem in that the boost pressure is suppressed to a low level, making it impossible to improve the output as much as on a flat road. In view of these circumstances, the present invention provides a leak solenoid valve in the boost pressure derivation passage that derives boost pressure from the intake system and acts on the actuator of the exhaust relief valve, so that the leak solenoid valve acts on the actuator as the atmospheric pressure decreases. It is an object of the present invention to provide an internal combustion engine with a supercharger that leaks the supercharging pressure that is applied and corrects the set supercharging pressure so that the contrast relationship at the actuator is on a level ground so that the set supercharging pressure does not decrease. .

[Means to solve the problem]

In order to achieve the above object, the present invention arranges a turbine and a compressor of a supercharger in an exhaust pipe and an intake pipe, respectively, and drives the compressor of the supercharger arranged in the intake pipe by driving the turbine. The turbine is installed in the exhaust pipe so as to perform supercharging at
An exhaust bypass passage that bypasses the turbine of the exhaust pipe is connected to the exhaust pipe, and the exhaust bypass passage is provided with an exhaust relief valve that is opened and closed by a diaphragm actuator, and the diaphragm actuator is connected to the operation chamber by the diaphragm. The intake pipe on the discharge side of the compressor and the operation chamber of the diaphragm actuator are communicated through a supercharging pressure deriving passage, and the supercharging pressure from the compressor is divided into a chamber opened to the atmosphere. In a supercharged internal combustion engine that controls boost pressure by opening the exhaust relief valve when the boost pressure exceeds a set boost pressure, a leak solenoid valve is provided in the boost pressure derivation passage, and the atmospheric pressure is detected. A sensor and a control circuit for duty-controlling the leak solenoid valve based on the atmospheric pressure signal detected by the atmospheric pressure sensor are provided, and the amount of pressure leaked from the leak solenoid valve as atmospheric pressure decreases is provided. The boost pressure acting on the operation chamber of the actuator is adjusted by increasing the boost pressure.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In FIG.
is provided to communicate with the compressor 3a side, and an exhaust pipe 4 communicates with the turbine 3b side of the supercharger 3. An exhaust bypass passage 5 is configured to communicate with the exhaust pipe 4 by bypassing the turbine 3b of the supercharger 3, and an exhaust relief valve 6 is provided in this passage 5. A lead-out passage 7 is taken out and communicates with an operating chamber 9 of a diaphragm actuator 8. The actuator 8 is divided into an operation chamber 9 to which supercharging pressure acts via a diaphragm 12 and a chamber 10 open to the atmosphere.
1 is energizing the diaphragm 12. Also, the diaphragm 12 is connected to the exhaust relief valve 6 via the rod 13.
connect it to open and close it. In such a configuration, a leak solenoid valve 14 is provided in the middle of the supercharging pressure deriving passage 7, and this leak solenoid valve 14 is electrically connected to a control circuit 16. By inputting the atmospheric pressure signal detected by the atmospheric pressure sensor 15, the control circuit 16 closes the leak solenoid valve 14 without producing an output in the standard state as shown in FIG. 2a, and when the atmospheric pressure decreases. The solenoid valve 14 generates a pulse-like output as shown in FIG.
Increase the opening time. Since the present invention has such a configuration, the turbine 3 of the supercharger 3 is powered by the energy of the exhaust gas discharged into the exhaust pipe 4 when the engine is operated at a predetermined load or higher.
b is driven, which causes the compressor 3a to rotate, sucking in air or air-fuel mixture and pressurizing it to perform supercharging. At this time, a part of the supercharging pressure in the intake system is taken out through the supercharging pressure deriving passage 7 and acts on the diaphragm 12 in the operation chamber 9 of the actuator 8, and the supercharging pressure is combined with the atmospheric pressure in the chamber 10 and the spring 11. If the exhaust gas is below the set value determined by the force, the rod 13 moves back together with the diaphragm 12, the exhaust relief valve 6 closes, and all of the exhaust gas is supplied to drive the supercharger 3. On the other hand, when the supercharging pressure exceeds the set value, the supercharging pressure causes the diaphragm 12 and the rod 13 to
The exhaust gas is pushed out and the exhaust relief valve 6 is opened, so that a part of the exhaust gas escapes through the exhaust bypass passage 5, and the supercharging pressure is suppressed from increasing any further. On the other hand, when driving at high altitude, atmospheric pressure sensor 1
5 detects the atmospheric pressure in that case, and the control circuit 1
6 opens the leak solenoid valve 14, and a portion of the supercharging pressure supplied to the operation chamber 9 of the actuator 8 leaks through the supercharging pressure deriving passage 7. Therefore, in the actuator 8, the supercharging pressure in the operation chamber 9 decreases by the decrease in the pressure in the chamber 10 that opens to the atmosphere, and the same contrast relationship as in the case of flat ground is maintained. Similarly to the case on flat ground, the opening operation of No. 6 is performed only at a high set supercharging pressure, and accordingly, the supercharging pressure is set as high as on flat ground. Furthermore, as the atmospheric pressure decreases, the amount of leak increases with the opening time of the leak solenoid valve 14, and the contrast relationship in the actuator 8 is maintained constant, so that the set supercharging pressure is always kept approximately constant despite changes in atmospheric pressure. is obtained.

【Effect of the invention】

As described above, according to the present invention, when a supercharged internal combustion engine is operated at high altitudes, the supercharging pressure is corrected to atmospheric pressure, and the supercharging pressure from the supercharger 3 is adjusted to the standard state on flat ground. Since it is controlled to a similarly high set value, it is possible to prevent a decrease in output due to a decrease in supercharging pressure at high altitudes. Furthermore, a leak solenoid valve 14 is provided in the boost pressure derivation passage 7, and the leak solenoid valve 14 is driven at a duty ratio calculated by a control circuit 16 based on an atmospheric pressure signal detected by an atmospheric pressure sensor 15. Therefore, since the supercharging pressure leaks from the leak solenoid valve 14 in response to a decrease in atmospheric pressure, the set supercharging pressure in the operation chamber 9 of the actuator 8 can be changed in response to changes in atmospheric pressure. Furthermore, since the chamber 10 of the actuator 8 is open to the atmosphere and the exhaust relief valve 6 is opened and closed only by the boost pressure acting on the operation chamber 9, the actuator 8
The structure is simple and the operation is reliable. In addition, the structure is simple because it is based on a conventional structure and is provided with a leak mechanism for supercharging pressure using atmospheric pressure.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an engine according to the present invention, and FIGS. 2a and 2b are diagrams showing the output of the control circuit. 1... Engine body, 2... Intake pipe, 3... Supercharger, 3a
...Compressor, 3b...Turbine, 4...Exhaust pipe,
5... Exhaust bypass passage, 6... Exhaust relief valve, 7... Supercharging pressure derivation passage, 8... Actuator, 14... Leak solenoid valve.

Claims (1)

[Claims] 1. A turbine and a compressor of a supercharger are arranged in an exhaust pipe and an intake pipe, respectively, and an exhaust bypass passage that bypasses the turbine is connected to the exhaust pipe,
An exhaust relief valve that is opened and closed by a diaphragm actuator is provided in the exhaust bypass passage, and the diaphragm actuator is divided by the diaphragm into an operation chamber and a chamber open to the atmosphere, and the intake pipe on the discharge side of the compressor and the operation chamber of the diaphragm actuator are connected through a supercharging pressure outlet passage, and when the supercharging pressure from the compressor exceeds the set supercharging pressure, the exhaust relief valve is opened to control the supercharging pressure. In an internal combustion engine with a charger, a leak solenoid valve is provided in the boost pressure deriving passage, and an atmospheric pressure sensor detects atmospheric pressure, and the leakage solenoid valve is installed in the boost pressure derivation passage, and an atmospheric pressure sensor detects atmospheric pressure, and the leakage solenoid valve is installed in the boost pressure deriving passage. A control circuit for duty-controlling the solenoid valve is provided, and the supercharging pressure acting on the operation chamber of the actuator is adjusted by increasing the amount of pressure leaked from the leak solenoid valve as atmospheric pressure decreases. An internal combustion engine with a supercharger.