JPH045698Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotary piston engine equipped with a turbo supercharger that supercharges intake air into a working chamber using exhaust gas discharged into an exhaust passage.

(Prior Art) A rotor having a substantially triangular cross-sectional shape is disposed inside a rotor housing having a trochoidal inner circumferential surface, with its apex touching the inner circumferential surface of the rotor housing. It has a basic configuration in which a pair of side housings are arranged in the three working chambers formed between the surface of the rotor and the inner surface of each housing.
A rotary rotor in which suction, compression/explosion, and exhaust strokes are performed, and the rotor performs planetary rotational motion around an eccentric shaft while sliding its apex on the inner peripheral surface of the rotor housing. In the case of a piston engine, during the transition from the exhaust stroke to the intake stroke, exhaust gas is brought from the working chamber where the exhaust stroke takes place (exhaust working chamber) to the working chamber where the intake stroke takes place (intake working chamber). , there is a possibility that the combustion stability of the air-fuel mixture will be impaired when the engine is in a low-load operating state.

Therefore, in order to eliminate this possibility, pressurized air is supplied to the working chamber between the exhaust port connected to the exhaust passage and the intake port connected to the intake passage, as shown in Japanese Patent Application Laid-Open No. 59-18233, for example. The applicant has already proposed a rotary piston engine in which a port is opened and pressurized air is supplied to the working chamber through the pressurized air supply port.

In a rotary piston engine in which pressurized air is supplied to the working chamber between the exhaust port and the intake port, the exhaust gas is supplied with pressurized air in the working chamber between the exhaust port and the intake port. As a result, the exhaust gas is forcibly pushed out from the exhaust port into the exhaust passage, reducing the amount of exhaust gas brought into the intake working chamber, and as a result, the combustion stability of the air-fuel mixture is improved.

(Problem to be solved by the invention) By the way, the above-mentioned rotary piston engine can be modified by turbocharging, which supercharges intake air into the intake working chamber by using the energy of exhaust gas discharged from the exhaust working chamber into the exhaust passage. When equipped with a supercharger to improve the intake air filling efficiency in the intake working chamber, the turbine installed in the exhaust passage becomes a resistance to the flow of exhaust gas, especially when the engine is operated under high load. If this condition occurs, the exhaust gas is not discharged smoothly from the exhaust working chamber to the exhaust passage, and the amount of exhaust gas brought into the intake working chamber increases due to worsening of exhaust gas escape from the exhaust working chamber. A problem arises in that the engine output characteristics deteriorate. Such problems in turbocharged rotary piston engines, especially during high-load operation, cannot be sufficiently resolved by supplying pressurized air to the working chamber between the intake port and exhaust port as described above. Therefore, there is a need for a measure to effectively solve this problem with a relatively simple configuration without requiring major modification of the engine.

In view of this, the present invention is equipped with a turbo supercharger that supercharges intake air into the intake working chamber using exhaust gas discharged into the exhaust passage, and has a relatively simple configuration. During low-load operation, exhaust gas is forcibly discharged into the exhaust passage using pressurized air, ensuring combustion stability, and even during high-load operation, exhaust gas escapes from the exhaust working chamber well. An object of the present invention is to provide a rotary piston engine with a turbo supercharger which is improved in engine output performance.

(Means for Solving the Problems) In order to achieve the above-mentioned object, a rotary piston engine with a turbo supercharger according to the present invention has an exhaust port connected to an exhaust passage in which a turbine is disposed, and an exhaust port that is driven by the turbine. an intake port connected to the intake passage in which the compressor is interposed, and a bypass passage whose one end opens into the working chamber between the exhaust port and the intake port, and whose other end opens into the downstream part of the exhaust passage from the turbine. , a pressurized air supply means having a pressurized air passage opening into the bypass passage, and passage switching means provided in the bypass passage, the passage switching means being configured to switch the engine to a low load operating state. At some point, in order to communicate the working chamber between the exhaust port and the intake port with the pressurized air passage via a bypass passage, and to cut off the working chamber and the part of the exhaust passage downstream of the turbine. When the engine is operating under high load, the working chamber between the exhaust port and the intake port and the pressurized air passage are shut off, and the part of the working chamber and the exhaust passage downstream of the turbine. It is assumed that the operation is performed to establish communication between the two via the bypass passage.

(Function) In the rotary piston engine with a turbocharger according to the present invention configured as described above, the intake air filling efficiency in the intake working chamber is improved by the turbocharger formed including a turbine and a compressor. be made to improve.

Then, when the engine is in a low-load operating state, pressurized air from the pressurized air supply means is supplied to the working chamber between the exhaust port and the intake port through the bypass passage, and thereby the leading side of the exhaust working chamber is The amount of exhaust gas brought into the intake working chamber is reduced by replacing the exhaust gas in the space with pressurized air, or by forcing the exhaust gas to be discharged from the exhaust port into the exhaust passage by pressurized air. , the combustion stability of the air-fuel mixture is maintained well.

Furthermore, when the engine is in high-load operating conditions, the supply of pressurized air to the working chamber between the exhaust port and the intake port is stopped, and the turbine in the working chamber between the exhaust port and the intake port and the exhaust passage is stopped. A portion further downstream is placed in communication via a bypass passage. Therefore, in addition to exhaust gas being discharged from the exhaust port into the exhaust passage, a portion of the exhaust gas is also discharged through the bypass passage to a portion of the exhaust passage downstream of the turbine without being subjected to resistance from the turbine. Therefore, the exhaust gas can escape from the exhaust working chamber better, and as a result, the amount of exhaust gas brought into the intake working chamber is reduced, and the output performance of the engine is improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the main parts of an example of a rotary piston engine with a turbo supercharger according to the present invention.

In this example, the engine body 10 includes a rotor housing 12 and a pair of side housings 14 disposed on both sides of the rotor housing 12.
(In the figure, only one side housing 14 is shown,
The inner space of the rotor housing 12 and the side housing 14 formed by the rotor housing 12 and the side housing 14 has a substantially triangular cross-sectional shape, and an apex seal 18 attached to the apex of the rotor housing 12 It is formed with a rotor 16 that performs planetary rotational motion around an eccentric shaft 20 while slidingly contacting a trochoidal inner circumferential surface 12a. Side seals 22 are attached to both side surfaces of the rotor 16 along their peripheral edges, and the side seals 22 and the apex seal 1
A corner seal 23 is arranged between the corner seal 8 and the corner seal 23.

Between the surface of the rotor 16 and the inner circumferential surface of the rotor housing 12 and the inner surface of the side housing 14, there are three working chambers of variable volume, that is, an intake working chamber 26.
a, a compression working chamber 26b and an exhaust working chamber 26c are formed, and the compression working chamber 26 of the rotor housing 12 is
Two spark plugs 28 and 29 are arranged along the rotational direction of the rotor 16 in the part forming b, and an exhaust port 2 is provided in the exhaust working chamber 26c.
7 is open, and this exhaust port 27 is connected to the exhaust passage 25.
It is familiar to

One side of the side housing 14 is opened to an intake working chamber 26a. A primary intake port 30 in which a fuel injection valve 33 is provided is formed, and a side housing 14 (not shown) is formed.
A secondary intake port is formed on the other side of the intake working chamber 26a and faces the primary intake port 30. The primary intake port 30 communicates with the primary intake passage 34, and the secondary intake port The port communicates with the secondary intake passage 36. Primary side intake passage 34
is provided with a primary throttle valve 37 that adjusts the amount of intake air in the primary intake passage 34 in accordance with, for example, depression of an accelerator pedal (not shown), and the secondary intake passage 36 is provided with a A secondary throttle valve 38 that opens later than the primary throttle valve 37 is provided. A common intake passage 40 into which air purified by an air cleaner 39 is introduced is connected to the primary intake passage 34 and the secondary intake passage 36 .
This common intake passage 40 includes an air flow meter 4 that measures the amount of intake air supplied to the intake working chamber 26a.
1 is disposed in the downstream side of the air flow meter 41 in the common intake passage 40 and is driven by a turbine 44 of a turbocharger 43 interposed in the exhaust passage 25.
A compressor 45 is interposed to form a.

Furthermore, the intake working chamber 2 of the rotor housing 12
A direct lubrication port 48 equipped with a lubrication nozzle is formed at a predetermined position facing the intake working chamber 26a in order to directly supply lubricating oil to the intake working chamber 26a. An indirect oil supply port 49 is formed to supply lubricating oil to the intake working chamber 26a together with the air-fuel mixture supplied to the intake working chamber 26a through the primary side intake port 30.

In the above configuration, when the engine is in operation, the common intake passage 40 and the primary intake passage 34 or the secondary intake passage 3 are connected to the common intake passage 40 and the primary intake passage 34.
6, from the primary side intake port 30 and the secondary side intake port to the intake working chamber 26a.
Intake air is guided to. At this time, the fuel injected from the fuel injection valve 33 is mixed with the intake air to form an air-fuel mixture, and the air-fuel mixture led to the intake working chamber 26a is compressed in the compression working chamber 26b and ignited to cause explosive combustion. , the exhaust gas produced by combustion is
The exhaust gas is purified by the catalytic converter 47 and discharged from the exhaust working chamber 26c to the outside via the exhaust port 27 and the exhaust passage 25. The exhaust gas discharged from this exhaust working chamber 26c to the outside via the exhaust passage 25 causes the turbine 44 interposed in the exhaust passage 25 to
is rotated, and in conjunction with this, the compressor 45 provided in the common intake passage 40 is driven, and intake air is supercharged into the intake working chamber 26a.

In such an operation, as described above, there is a risk that part of the exhaust gas may be brought into the intake working chamber 26a during the transition from the exhaust stroke to the intake stroke.

Therefore, in this example, in addition to the above-described configuration, one end is connected to the exhaust port 2 in the rotor housing 12.
It opens into the working chamber formed by the rotor housing 12, the side housing 14, and the rotor 16 between the position where 7 opens and the position where the primary side intake port 30 of the side housing 14 opens, and the other end is an exhaust passage. A bypass passage 50 is provided that opens downstream of the 25 turbines 44. In this bypass passage 50,
A vane pump 52 that is driven by the eccentric shaft 20 or other driving means to suck in purified air from a portion of the common intake passage 40 between the air cleaner 39 and the air flow meter 41, pressurize the sucked air, and discharge it. The other end of the pressurized air supply passage 54 is open, and the pressurized air discharged from the vane pump 52 is connected to the flow rate control valve 5 attached to the vane pump 52.
3, and is supplied to the bypass passage 50 via a check valve 56 interposed in the middle of the pressurized air supply passage 54.

The part of the bypass passage 50 where the pressurized air supply passage 54 opens has a first operating position that communicates the part of the bypass passage 50 on the rotor housing 12 side with the pressurized air supply passage 54, and a rotor housing of the bypass passage 50. 12 side and the pressurized air supply passage 54 and the bypass passage 5
0 on the rotor housing 12 side and the exhaust passage 2
The valve body 55 assumes the second operating position communicating with the part on the 5 side, and the intake pressure in the part downstream of the primary throttle valve 37 of the primary intake passage 34 is adjusted according to the engine load. Valve body 55 according to
A switching valve 60 is provided which includes a diaphragm mechanism 57 that selectively assumes a first operating position and a second operating position. In addition, the bypass passage 50
A valve element 62 for opening and closing the bypass passage 50 is provided in a portion closer to the exhaust passage 25 than the part where the valve element 55 is disposed.
A waste gate valve 65 consisting of a diaphragm mechanism 63 is provided which opens the bypass passage 50 when the supply pressure downstream of the portion of the common intake passage 40 where the compressor 45 is disposed exceeds a set value. When the diaphragm mechanism 57 of the switching valve 60 causes the valve body 55 to assume the first operating position, the diaphragm mechanism 63 of the wastegate valve 65 operates the valve body 62 to close the bypass passage 50, and When the diaphragm mechanism 57 of the valve 60 causes the valve body 55 to take the second operating position, the diaphragm mechanism 57 and the diaphragm mechanism 63 of the wastegate valve 65 operate the valve body 62 to open the bypass passage 50. The set loads of the coil springs 57a and 63a of 63 are selected, and the switching valve 60 and waste gate valve 65 constitute passage switching means.

Further, the flow rate control valve 53 supplies pressurized air by changing its effective opening area according to the engine rotation speed and engine load, for example, the amount of intake air detected by the air flow meter 41, by a control means (not shown). While adjusting the amount of air flowing down the passage 54, when the diaphragm mechanism 57 of the switching valve 60 causes the valve body 55 to take the second operating position, the pressurized air from the vane pump 52 is released into the atmosphere without flowing downstream. It is designed to be emitted to

In the rotary piston engine with a turbo supercharger according to the present invention configured as described above, when the engine is in a low load operating state, that is, the operating state of the engine, the horizontal axis represents the engine rotation speed, The second graph represents the engine load on the vertical axis.
When in the region indicated by P in the characteristic diagram shown in the figure, the supply pressure in the downstream portion of the primary throttle valve 37 of the primary intake passage 34 is low, so the diaphragm mechanism 57 of the switching valve 60 55 to assume the first operating position, and at this time, the diaphragm mechanism 63 of the wastegate valve 65 operates the valve body 62 to close the bypass passage 50. Therefore, the pressurized air discharged from the vane pump 52 and regulated by the flow control valve 53 passes through the pressurized air supply passage 54 and the bypass passage 50 to the exhaust port 27 in the housing interior space of the engine body 10 and the primary side intake air. The working chamber between the port 30, that is, the exhaust port 27
is supplied to the leading side from the opening part. As a result, the exhaust gas in the space on the leading side of the exhaust working chamber 26c is replaced with pressurized air, or the exhaust gas is forcibly discharged from the exhaust port 27 to the exhaust passage 25 by pressurized air from the bypass passage 50. As a result, the amount of exhaust gas brought into the intake working chamber 26a is significantly reduced.

On the other hand, when the engine is operating under high load,
That is, when the operating state of the engine is in the region represented by Q in the characteristic diagram shown in FIG.
Since the supply pressure in the portion of the primary intake passage 34 downstream of the primary throttle valve 37 increases,
The diaphragm mechanism 57 of the switching valve 60 causes the valve body 55 to assume the second operating position, and at this time,
Diaphragm mechanism 63 of wastegate valve 65
operates the valve body 62 to open the bypass passage 50. Therefore, the pressurized air from the vane pump 52 is not supplied to the bypass passage 50, and the air is supplied to the working chamber between the exhaust port 27 and the primary intake port 30 in the housing interior space of the engine body 10 via the bypass passage 50. and exhaust passage 25
The downstream portion of the turbine 44 is communicated with the turbine 44 .
Therefore, in addition to exhaust gas from the exhaust working chamber 26 c being discharged from the exhaust port 27 to the exhaust passage 25 , the exhaust gas from the exhaust working chamber 26 c is discharged from the turbine 44 to the downstream side of the turbine 44 in the exhaust passage 25 through the bypass passage 50 .
is bypassed and discharged. As a result, the exhaust gas from the exhaust working chamber 26c is smoothly discharged into the exhaust passage 25, and the exhaust gas can escape smoothly.
As a result, even when the engine is in a high-load operating state, the amount of exhaust gas carried into the intake working chamber 26a is reduced, and the output performance of the engine is improved. especially,
The effect is significant when the engine is operating at low speed and high load.

In the above example, the passage switching means is configured by the switching valve 60 and the waste gate valve 65, but the rotary piston engine with a turbo supercharger according to the present invention does not necessarily have the waste gate valve 65 in this way. It is not necessary to configure the passage switching means by using the above-mentioned bypass passage 5, for example.
0 without providing a waste gate valve 65,
Separately from the bypass passage 50, as schematically indicated by the two-dot chain line in FIG. A waste gate valve 65' that opens when the supply pressure exceeds a set value is installed, and a valve element 55a' is added to the valve element 55 of the switching valve 60 in addition to the valve element 55a. When the valve body 55 assumes the first operating position, the added valve element 55a' blocks off the portion of the bypass passage 50 on the rotor housing 12 side and the portion on the exhaust passage 25 side. Good too.

(Effect of the invention) As is clear from the above explanation, in the turbocharged rotary piston engine according to the invention, the turbine installed in the exhaust passage is driven by the exhaust gas, and the intake passage operates accordingly. The compressor installed in the engine improves the filling efficiency of intake air in the intake working chamber, and when the engine is in a low load operating state,
Pressurized air is supplied to the working chamber between the exhaust port and the intake port through the bypass passage, and when the engine is under high load operation, the exhaust gas is discharged from the exhaust port into the exhaust passage. In addition, by bypassing the turbine and discharging it through the bypass passage to the downstream side of the turbine in the exhaust passage, the exhaust gas can escape in any case. , the amount of exhaust gas brought into the intake working chamber during the transition from the exhaust stroke to the intake stroke is effectively reduced. Therefore, the combustion stability of the air-fuel mixture is maintained well when the engine is in a low-load operating state, and
The output performance of the engine is improved when the engine is in a high-load operating state.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the main parts of an example of a rotary piston engine with a turbo supercharger according to the present invention, and FIG. 2 is a characteristic diagram used to explain the operation of the example shown in FIG. In the figure, 25 is an exhaust passage, 27 is an exhaust port, 3
0 is the primary side intake port, 40 is the common intake passage, 4
3 is a turbo supercharger, 50 is a bypass passage, 52 is a vane pump, 54 is a pressurized air supply passage, 60 is a switching valve, and 65 is a waste gate valve.

Claims (1)

[Scope of utility model registration request] an exhaust port connected to an exhaust passage in which a turbine is installed; an intake port connected to an intake passage in which a compressor driven by the turbine is installed; and one end in a working chamber between the exhaust port and the intake port. a bypass passage which is open and whose other end opens to a portion of the exhaust passage downstream of the turbine; a pressurized air supply means having a pressurized air passage portion which opens to the bypass passage; and a pressurized air supply means provided in the bypass passage. and when the engine is in a low-load operating state, the working chamber and the pressurized air passage are communicated via the bypass passage, and the working chamber and a portion of the exhaust passage downstream of the turbine are connected. When the engine is in a high-load operating state, the working chamber and the pressurized air passage are cut off, and the working chamber and a portion of the exhaust passage downstream of the turbine are connected to the working chamber and the pressurized air passage. A rotary piston engine with a turbo supercharger configured to include passage switching means for communication via a bypass passage.