JPH0525014B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary piston engine in which intake supercharging is performed by a turbo supercharger.

(Prior Art) In order to downsize the turbocharger in an engine equipped with a turbocharger so that a supercharging effect can be obtained from a low speed rotation range, for example, an application filed by the present applicant (Japanese Patent Application No.
57-4416), two intake ports with different valve closing timings are provided in the working chamber of the engine, that is,
A primary side intake port that communicates with a primary side intake passage that has a blower of the turbocharger and a primary side throttle valve that operates in the entire operating range of the engine, and a secondary side that opens only in the high speed and high load operating range of the engine. A secondary intake port is provided that communicates with the secondary intake passage having a throttle valve and closes earlier than the primary intake port, so that only supercharging intake is taken from the primary intake port in the low to medium load range of the engine. inhale,
In addition, in a high load range, supercharged intake air is taken in from the primary side intake port, and at the same time unpressurized non-supercharged intake air is taken in from the secondary side intake port by the negative pressure suction force of the engine. This is a system designed to reduce the capacity (downsize) of a turbocharger (so-called partial supercharging system).

By the way, in general, in engines equipped with a turbocharger, if the supercharging pressure increases abnormally, the engine may be damaged. However, when the boost pressure reaches the set value or higher, the valve is opened appropriately to allow some of the exhaust gas to bypass the turbine and exhaust it, suppressing the rotation of the turbine and quickly raising the boost pressure beyond the set value. A supercharging pressure regulating valve (so-called waste gate valve) is provided that acts to reduce the boost pressure to the supply pressure.

However, in a partially supercharged engine that has a primary side intake port that takes in supercharged intake air and a secondary side intake port that takes in non-supercharged intake air, the engine operating state is low or medium load. When the operation shifts from high-load operation to high-load operation and the secondary side throttle valve opens and intake air starts to be introduced from the secondary side intake passage, the engine is operated by the intake air introduced from the secondary side intake passage. When the indoor intake pressure increases, especially when the intake pressure becomes higher than the preset supercharging pressure, the supercharging pressure regulating valve operates to lower the supercharging pressure. As a result, even if it is desired to introduce a little more supercharging intake air, no further supercharging can be performed, resulting in a problem in which the engine output decreases (high output cannot be obtained). It turns out.

(Object of the Invention) The present invention provides a rotary engine with a turbocharger that improves the above-mentioned problems in the partial supercharging system, promotes downsizing of the turbocharger, and improves the output characteristics of the engine. It was designed to provide a piston engine.

(Structure of the Invention) The present invention provides an engine casing of a rotary piston engine with a primary intake port and a secondary intake port that closes earlier than the primary intake port, and the primary intake port is provided with an intake supercharging blower. and a primary side throttle valve that operates in all operating ranges of the engine, and a secondary side intake port that has a secondary side throttle valve that opens and closes depending on the operating state of the engine. The passages are connected to each other, and depending on the operating condition of the engine, only supercharged intake air is supplied from the primary intake port side, or supercharged intake air and non-supercharged intake air is supplied from the primary intake port and the secondary intake port side, depending on the operating state of the engine. The secondary side throttle valve opens and the non-supercharged intake air is introduced from the secondary side intake port. In this case, the maximum value of the boost pressure (set boost pressure) controlled by the boost pressure regulating valve installed on the exhaust passage side is set to a predetermined pressure higher than when the secondary throttle valve is closed. The present invention is characterized in that it improves the supercharging efficiency and improves the output characteristics of the engine by increasing the supercharging efficiency.

(Embodiment) Fig. 1 shows an intake and exhaust system portion of a rotary piston engine with a turbo supercharger for an automobile according to an embodiment of the present invention, and reference numeral 1 in the figure has a trochoidal inner peripheral surface 1a. A rotor housing, 2 is a side housing that covers both sides of the rotor housing 1, 3 is a substantially triangular rotor fitted in an engine casing constituted by the rotor housing 1 and both side housings 2; The rotor 3 has an apex seal 4 provided at each top thereof.
5 is caused to rotate planetarily around a rotor shaft (not shown) while being in sliding contact with the trochoid inner circumferential surface 1a.

This rotor housing 1 and side housing 2
Inside, the rotor housing 1 has an exhaust port 6,
Further, the side housing 2 is formed with a primary side intake port 7 located on the leading side of the rotor 3 and a secondary side intake port 8 located on the trailing side. The formation positions of the primary side intake port 7 and the secondary side intake port 8 are such that when opened, the primary side intake port 7 and the secondary side intake port 8 open almost simultaneously, and when closed, the secondary side intake port 8 is the primary side intake port. It is set at a position where it closes earlier than the side intake port 7.

The intake passage 12 connected to each of the intake ports 7 and 8 is connected to the primary intake passage 13 and the secondary intake passage 14 on the intake downstream side from the mounting position of the air cleaner 9 and the air flow meter 10 for measuring the amount of intake air. The primary intake passage 13 is connected to the primary intake port 7, and the secondary intake passage 14 is connected to the secondary intake port 8.

The primary side intake passage 13 further includes a blower 47 for intake supercharging at a position on the upstream side of the intake, and a primary side throttle valve 28 that operates in conjunction with the Askel pedal in the entire operating range of the engine at a position on the downstream side of the intake. Fuel injection valves 42 are installed at positions downstream of the intake position from where the primary throttle valve 28 is installed. This blower 47 has an exhaust passage 1 communicating with the exhaust port 6.
The turbocharger 11 is connected to a turbine 48 installed in the turbine 5 via a rotating shaft 49, and together with the turbine 48 constitutes the turbocharger 11.

A secondary throttle valve 29 is attached to the secondary intake passage 14 and is controlled to open and close by a diaphragm valve 31 that operates depending on the operating state of the engine. The diaphragm valve 31 has two chambers partitioned by a diaphragm 33, that is, an atmospheric chamber 3 that is always in communication with the atmosphere and has a spring 36 fitted therein.
4 and a pressure chamber 35 which is selectively communicated with the exhaust passage 15 or the atmosphere via a pressure introduction passage 37 having a three-way solenoid valve 38,
The pressure difference between the two chambers causes the valve rod 32 to operate via the diaphragm 33. This valve stem 32 is connected to the discharging end of a rotating lever 30 attached to the secondary throttle valve 29, and is constantly biased by a spring 36 in the direction of closing the secondary throttle valve 29. It is being Furthermore, the three-way solenoid valve 38 is configured to control the engine speed detected by the engine speed sensor 40 and the primary throttle valve 2 detected by the primary throttle valve opening sensor 41.
The opening/closing is controlled by the control unit 39 according to the opening degree of the opening 8. That is, the three-way solenoid valve 38 connects the pressure chamber 35 to the exhaust passage 1 in the high-speed, high-load operation region shown in region B in FIG.
5 side and loads high exhaust pressure into the pressure chamber 35 to open the secondary throttle valve 29 against the spring force of the spring 36. - Within the medium load operating range, the pressure chamber 35 is opened to the atmosphere and the secondary throttle valve 29 is closed by the spring force of the spring 36.

On the other hand, a bypass passage 16 is formed in the exhaust passage 15 to bypass a turbine 48 installed in the exhaust passage 15. This bypass passage 16
The bypass passage 16 is opened and closed in accordance with the intake pressure (supercharging pressure) on the downstream side of the blower 47, and the supercharging pressure is adjusted by controlling the rotation of the turbine 48. A supercharging pressure regulating valve 17 is installed which functions as follows. This boost pressure regulating valve 1
7 is a diaphragm valve that responds to the supercharging pressure of the primary side intake passage 13, and is divided into two chambers by a diaphragm 21, that is, an atmospheric chamber 24 that is constantly in communication with the atmosphere and has a spring 22 attached therein. and a pressure chamber 23 that communicates with the primary side intake passage 13 at an intermediate position between the blower 47 mounting position and the primary side throttle valve 28 mounting position via the boost pressure introduction passage 25, and the atmospheric chamber 24 and the pressure The valve body 19 is driven via the valve stem 20 according to the pressure difference in the chamber 23, and the valve body 19 is driven.
The valve seat 18 is opened and closed by the following steps. That is, when the supercharging pressure is low, the supercharging pressure regulating valve 17 seats the valve body 19 on the valve seat 18 by the spring force of the spring 22 to close the bypass passage 16 and reduce the amount of exhaust gas discharged from the engine. While flowing the entire amount of gas to the turbine 48 side to promote intake supercharging,
When the boost pressure exceeds a preset boost pressure for engine protection (hereinafter referred to as set boost pressure), the spring 22 is activated by the boost pressure loaded in the pressure chamber 23. The valve body 19 is separated from the valve seat 18 against the spring force to open the bypass passage 16 appropriately, and a part of the exhaust gas is directly discharged from the bypass passage 16 without passing through the turbine 48. , thereby suppressing the supercharging effect of the intake air by the blower 47, and promptly reducing the supercharging pressure below the set supercharging pressure to prevent an abnormal increase in the supercharging pressure. It is.

Further, the supercharging pressure introduction passage 25 that communicates the pressure chamber 23 of the supercharging pressure regulating valve 17 with the blower downstream position of the primary side intake passage 13 is connected to the secondary side by a relief passage 26 that branches from this intermediate position 25a. Intake passage 1
4 and is communicated with a position upstream of the intake air from the mounting position of the secondary throttle valve 29. This relief passage 26 includes the control unit 3.
A solenoid valve 27 is installed which controls opening and closing of the relief passage 26 as appropriate in response to a control signal from the valve 9. This solenoid valve 27 functions as a supercharging pressure control means for controlling the maximum supercharging pressure downstream of the blower, which is set by the supercharging pressure regulating valve 17 according to the open/close state of the primary side throttle valve 28. It operates in response to the same control signal as the three-way solenoid valve 38, and when the engine operating state is in region A (low/medium speed, low/medium load region), it closes the relief passage 26 and operates in region B. (high speed/high load range), the relief passage 26 is controlled to be opened (see Fig. 2).

Next, to explain the operation of the illustrated rotary piston engine with a turbo supercharger, the operating state of the engine is low/medium speed shown in area A in FIG.
When the load is in the low/medium load range, the pressure chamber 3 of the diaphragm valve 31 is
5 is open to the atmosphere and the secondary side throttle valve 29 is closed, so supercharged intake air pressurized by the blower 47 from the primary side intake passage 13 side is in the working chamber 5 of the engine. only will be introduced.

On the other hand, the engine operating condition is low as shown in area A.
When moving from the medium speed, low/medium load range to the high speed/high load range shown in area B, the three-way solenoid valve 3
8, the pressure chamber 35 of the diaphragm valve 31 communicates with the exhaust passage 15, and the secondary throttle valve 29 is opened according to the exhaust pressure. Therefore, when supercharged intake air is introduced from the primary intake passage 13, At the same time, non-supercharged intake air is also introduced into the working chamber 5 from the secondary intake passage 14 side by the engine's intake negative pressure. In this case, by closing the secondary side intake port 8 earlier than the primary side intake port 7, the difference between the intake pressure in the working chamber 5 and the intake pressure in the secondary side intake passage 14 causes the working chamber 5 to This prevents intake air from flowing back into the secondary intake passage 14 side.

By the way, in the region B where intake air is introduced from both the primary side intake passage 13 and the secondary side intake passage 14, the secondary side throttle valve 29 is opened and the secondary side intake passage 14 is opened. Since a large amount of intake air is introduced into the working chamber 5 from the side, the intake pressure inside the working chamber 5 increases, and as a result, the primary side intake passage 1
The intake pressure downstream of the blower 3 also increases, and when this intake pressure reaches the preset supercharging pressure, the supercharging pressure regulating valve 17 operates to rotate the blower 47, that is, the supercharging action is activated. is suppressed and boost pressure decreases.
Therefore, if no measures are taken, even if the primary intake port 7 is still open and supercharging is possible, no further supercharging will be possible. As a result, the supercharging efficiency reaches a plateau and a problem arises in that higher output cannot be obtained.

However, in this embodiment, when the secondary side throttle valve 29 opens and the introduction of intake air from the secondary side intake passage 14 is started, the solenoid valve 27 provided in the relief passage 26 opens and the supercharging pressure is increased. Since a part of the supercharging intake air introduced into the introduction passage 25 is configured to escape from the relief passage 26 to the low pressure secondary intake passage 14 side, the supercharging pressure regulating valve 17
In order to increase the supercharging pressure loaded in the pressure chamber 23 to the opening pressure of the supercharging pressure regulating valve 17, the supercharging intake air released into the secondary intake passage 14 via the relief passage 26 is used. The boost pressure downstream of the blower must be increased by the amount of supply pressure reduction, and as a result,
The actual maximum supercharging pressure in the primary side intake passage 13 is set higher than the preset supercharging value according to the opening pressure of the supercharging pressure regulating valve 17. Therefore, even if the intake pressure in the working chamber 5 increases as intake air is introduced from the secondary intake passage 14, the boost pressure increases in accordance with the rise in intake pressure, so the intake overpressure is further increased. This results in improved supercharging efficiency in the high-speed, high-load range where supercharging is possible.

In addition, in this way, all the intake air is supercharged in the operating range other than the high speed and high load range, and a part of the intake air is introduced into the working chamber 5 without supercharging in the high speed and high load range. In a partially supercharged engine, it is possible to reduce the capacity of the turbocharger 11 by a capacity corresponding to the amount of intake air taken in from the secondary intake passage 14 side, thereby achieving miniaturization. In this way, as the turbocharger 11 becomes smaller, the moment of inertia of the turbocharger 11 becomes smaller, so the turbocharger 11 can be operated from a low speed/low load range where the displacement is small. Intake supercharging can be performed.

In this embodiment, the two intake ports 7 and 8 are formed on the same side housing 2, but in other embodiments of the present invention, the two intake ports 7 and 8 are formed on different side housings. It is also possible to separately form one piece for each. In this case, since the two intake ports 7 and 8 can be formed at positions that apparently overlap, each intake port 7 and 8 can be formed to have a larger diameter than in this embodiment to provide intake air. It is possible to reduce the inhalation resistance of

(Effects of the Invention) The rotary piston engine with a turbo supercharger of the present invention has a primary side that is connected to a primary intake passage that has a turbo supercharger blower and a primary side throttle valve that operates in the entire operating range of the engine. intake port and
A secondary intake port is provided, which is connected to a secondary intake passage having a secondary throttle valve that operates according to the operating state of the engine, and which closes earlier than the primary intake port. Since a portion of the intake air is introduced into the working chamber without supercharging, compared to the case where all intake air is supercharged throughout the entire operating range of the engine, only the amount of intake air introduced without supercharging is reduced. This has the effect of reducing the capacity of the turbocharger and making it more compact.

In addition, when non-supercharged intake air is introduced into the working chamber from the secondary side intake passage, the supercharging pressure control means sets the set pressure (i.e.,
The maximum boost pressure) is set to a predetermined pressure higher than when the secondary intake passage is closed, so even if the intake pressure in the working chamber increases due to the introduction of non-supercharged intake, Sufficient intake supercharging can be performed, and supercharging efficiency is further improved compared to a case where the maximum supercharging pressure is set to a constant pressure regardless of whether the secondary intake passage is open or closed. Another effect is that the output characteristics of the engine can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part of a rotary piston engine with a turbo supercharger according to an embodiment of the present invention, and FIG. 2 is an operating range diagram of the rotary piston engine with a turbo supercharger shown in FIG. 1. 1... Rotor housing, 2... Side housing, 3... Rotor, 5... Working chamber, 6... Exhaust port, 7... Primary side intake port, 8... Secondary side intake port, 11... Turbo Supercharger, 12...Intake passage, 13...Primary side intake passage, 14...Secondary side intake passage, 15...Exhaust passage, 16...Bypass passage, 17...Supercharging pressure adjustment valve, 26... ... Relief passage, 27 ... Solenoid valve, 28 ... Primary side throttle valve, 29 ... Secondary side throttle valve, 31 ... Diaphragm valve.

Claims (1)

[Scope of Claims] 1. A substantially triangular rotor is fitted into an engine casing formed by covering both sides of a rotor housing having a trochoidal inner peripheral surface with a pair of side housings, and the rotor is inserted into the engine casing. a turbine for driving the blower provided in an intake passage communicating with an intake port opening in the engine casing; and a turbine for driving the blower provided in an exhaust passage communicating with an exhaust port opening in the engine casing; A rotary piston engine with a turbo supercharger configured to perform intake supercharging by a turbo supercharger consisting of a turbo supercharger, wherein the intake passage is connected to the blower and a primary side throttle that operates in the entire operating range of the engine. a primary side intake passage having a valve and communicating with a primary side intake port opening in the engine casing, and a secondary side throttle valve that opens and closes depending on the operating state of the engine, and further than the primary side intake port. A secondary side intake passage communicates with a secondary side intake port that closes quickly, and a bypass passage that bypasses a turbine provided in the exhaust passage is configured so that the intake pressure downstream of the blower reaches a preset set pressure. A supercharging pressure regulating valve is provided that opens the bypass passage when the secondary throttle valve reaches the open state, and the set pressure of the supercharging pressure regulating valve is set to be lower when the secondary throttle valve is in the open state than when it is in the closed state. A rotary piston engine with a turbo supercharger, characterized in that it is equipped with supercharging pressure control means for setting a predetermined pressure on the high pressure side.