JPS63223328A - Rotary piston engine with pumping loss reducing device - Google Patents

Abstract

PURPOSE:To prevent dilution in adjacent cylinders, by providing substituting air supply ports in the communicating passage communicating respective working chambers in a plurality of cylinders, and by providing a pump by which air is supplied to respective intermediate housings to each of which a communicating passage is provided via the substituting air supply port. CONSTITUTION:A communicating passage 23 by which respective working chambers in a compression stroke or in an intake stroke in a plurality of cylinders are communicated is provided to respective intermediate housings 21, and it is so arranged that the pumping loss due to the communication between cylinders can be controlled by a control valve 24 provided in the communicating passage 23. In this case, a substituting air supply passage 33 which communicates the position directly beneath an air-cleaner 14 in a common intake air passage 13 with respective front and rear substituting air supply ports 32f, 32r is provided. And in the substituting air supply passage 33, in order from the upstream side, a vane type air pump 34 and an open/close valve 35 are provided, and further these are controlled by a control circuit 40 in response to the operating condition of an engine RE.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotary piston engine equipped with a pump loss reduction device using a slow closing system for communication between cylinders.

[Prior Art] In a rotary piston engine, the ratio of the surface area of the working chamber to the volume of the working chamber (S /V (ratio) becomes large, which makes it easier to cool the combustion gas, and also creates a high-speed intake air flow (squish flow) from the trailing side to the leading side in the working chamber, which worsens combustibility at low rotation speeds and light loads. There is.

By the way, in a rotary piston engine, it is possible to easily provide a communication path by simply drilling a hole in the intermediate housing that communicates between the cylinders, and also to maintain a predetermined phase difference (for example, in a two-cylinder rotary piston engine, the eccentric shaft angle 1
Since each communication port is opened and closed at a predetermined timing by a rotor with an angle of 80°), there is an advantage that the intake air can be exchanged between cylinders without having to specifically control the opening and closing of the communication boat, and this advantage can be utilized. It has been proposed to improve fuel efficiency by controlling pumping loss using a delayed closing system for communication between cylinders (for example, Japanese Patent Laid-Open No. 58-17
(See Publication No. 2429).

However, in conventional rotary piston engines that perform pumping loss control using such a late-closing intercylinder communication system, the exhaust gas in the working chamber is used as a driving force to move exhaust gas through the side seals, as shown by arrow A in Figure 2. It penetrates into the space between the rotor and the intermediate housing inside the side seal (hereinafter referred to as the side seal inner envelope) through the gap with the intermediate housing, and also enters the intake port as shown by arrow B in Figure 2. When partially opened, the exhaust gas in the working chamber enters the side seal inner envelope through the intake port, and the exhaust gas that has entered the side seal inner envelope in this way flows into the positive cylinder through the communication path, and the positive cylinder The problem was that it increased the illusion. As mentioned above, rotary piston engines have the problem of poor combustibility at low speeds and light loads, so pumping loss control using a slow-closing inter-cylinder communication system is recommended at low speeds and light loads. This illusion further worsens flammability, so
There was a problem in that the operating range of the pumping loss reduction system could only be extended to low rotation speeds and light load ranges.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to solve the dilution that occurs when the exhaust gas in the inner seal of the side seal flows into the positive cylinder through the communication path during communication between the cylinders. We have expanded the operating range of the pumping loss reduction system to lower rotation speeds and lighter load ranges.
The purpose is to improve fuel efficiency.

"Structure of the Invention" In order to achieve the above object, the present invention provides a communication path in the intermediate housing that communicates the working chamber during the compression stroke of one cylinder with the working chamber during the intake stroke of the other cylinder. In a rotary piston engine that is equipped with a control valve that controls the amount of airflow in the communication passage and controls popping loss through communication between cylinders, the communication passage is connected to the communication passage through the side seal inner part of the intermediate housing. A rotary piston engine with a pump loss reduction device is provided, characterized in that a displacement air supply hole is provided in communication with the displacement air supply hole, and an air supply means is provided for supplying air to a side seal inner envelope of an intermediate housing through the displacement air supply hole.

[Effects of the Invention] According to the present invention, air is supplied to the side seal inner envelope through the displacement air supply hole by the air supply means, and this displacement air flows into the communication passage, so that the exhaust gas within the side seal inner envelope is communicated. It can prevent it from flowing into the passage. Also,
The displacement air reduces the negative pressure inside the side seal, so exhaust gas from the working chamber enters the side seal inside through the gap between the side seal and the intermediate housing due to combustion pressure, and when the intake port opens, the exhaust gas enters the side seal through the intake port. It is possible to reduce the amount of exhaust gas that enters the seal inner envelope. As a result, the amount of exhaust gas flowing into the positive cylinder through the communication passage is significantly reduced, preventing an increase in illusion in the positive cylinder, improving combustibility, and thereby lowering the operating range of the pumping loss reduction sensor 13. It can be expanded to the rotation/light load side, and fuel efficiency can be improved.

[Example] Examples of the present invention will be specifically described below.

As shown in Fig. 1, the two-cylinder rotary piston engine RE consists of front and rear mountain cylinders F and R, which are made of almost the same material, respectively, and form the side walls of the front and rear casings Ir and Ir, respectively. Front and rear intake boats 3f open on the inner surfaces of the front and rear side housings 2f and 2r.

When 3r is opened, the front and rear branch intake passages 4
Intake air is drawn from f and 4r into the front and rear working chambers 5f and 5r, and this intake air (air mixture) is sent to the front.

It is compressed by the rear rotors 6f and 6r, ignited and combusted by the front and rear spark plugs 7f and 7r, and the resulting combustion gas is sent to the front and rear rotor housings 8f.
, a front opening on the inner peripheral surface of 8r.

A series of steps for discharging from the rear exhaust ports 1-9f and 9r to the front and rear branch exhaust passages 1ff and Ilr are continuously repeated, and as a result, Freon h is exhausted.

The basic configuration is such that the rear rotors 6f and 6r perform planetary rotational motion around the eccentric shaft 12, and the rotational force thereof is extracted as the output of the Ennon RE.

A common intake passage 13 is provided to supply intake air to the freon l- and rear working chambers 5f and 5r, and in this common intake passage 13, an air cleaner 14 for removing floating dust in the intake air is installed in this common intake passage 13 in order from upstream. , an air flow meter 15 that detects the amount of intake air from moment to moment, and a throttle valve 16 that opens and closes in response to depression of an accelerator pedal (not shown).
is interposed. In addition, in order to correct the intake air amount according to the operating state of the engine, the throat valve I6 is bypassed and the position upstream of the throttle valve 16 and the position downstream of the throttle valve 16 in the common intake passage 13 are adjusted. A communicating bypass intake passage 17 is provided, and a bypass valve 18 for controlling the amount of bypass intake air is interposed in the bypass intake passage 17.

As will be explained in detail later, the bypass valve 18 is normally opened according to a first base duty, and is opened according to a second base duty when the bypass intake air amount should be increased. The common intake passage 13 is branched into a front side branch intake passage 4f and a rear side branch intake passage 4r at a volume portion 19 downstream of the throttle valve 16, and these front and rear branch intake passages 4f, 4
Front and rear manifold fuel injection valves 2Of and 2Or, respectively, which inject fuel during intake are interposed in r with injection ports slightly inclined in the downstream direction. The volume portion 19 is
Front or rear intake boat 3f.

When the negative pressure wave generated in the vicinity of 3r is opened and propagates upstream through the front or rear branch intake passages 4f and 4r, this is reversed into a positive pressure wave, Again front or rear branch intake passage 4
Sufficient volume is secured to effectively perform pressure wave supercharging due to the so-called inertial effect, which propagates the waves f and 4r downstream and reaches the front or rear working chambers 5r and 5r at the end of the intake stroke. ing. Further, the lengths of the front and rear branch intake passages 4r, 4r are set so that pressure wave supercharging due to the inertial effect is effectively performed as described in -.

On the other hand, in order to perform pumping loss control using the inter-cylinder communication slow closing system, front and rear communication ports are provided on the front and rear sides of the intermediate housing 21, which forms the partition walls of the front and rear mountain cylinders F and R, respectively. Boat 22f, 22r
are provided with openings on the leading side in the rotational direction of the front and rear rotors 6f, 6r from the front and rear intake bows 1-3r, 3r. A communication passage 23 that communicates both the front and rear communication boats 22f and 22r is provided to penetrate the intermediate housing 2I in the thickness direction. A communication path 2 is located at an intermediate position of this communication path 23.
A rotary control valve 24 that opens and closes the communication passage 23 is interposed to control the amount of intake air flowing through the intake air passage 3 . In order to drive this control valve 24, an actuator 25 consisting of a negative pressure responsive diaphragm device is provided, and in order to introduce negative pressure into the pressure chamber of this actuator 25, this pressure chamber and the volume portion 19 are communicated. A negative pressure introduction passage 26 is provided. A first solenoid valve 27 is interposed in the negative pressure introduction passage 26, and the negative pressure introduction passage 26 is connected to the atmosphere introduction passage 28 on the actuator 25 side from the first solenoid valve 27. A second solenoid valve 29 is provided in the atmosphere introduction passage 28 . Then, when the first solenoid valve 27 is opened and the second solenoid valve 29 is closed in response to a signal from the control circuit 40, which will be explained in detail later, and negative pressure is introduced into the pressure chamber of the actuator 25, control is performed. The valve 24 was opened by the actuator 25, and on the other hand, upon receiving a signal from the control circuit 40, the first solenoid valve 27 was closed and the second solenoid valve 29 was opened, so that atmospheric pressure was introduced into the pressure chamber of the actuator 25. At times, control valve 24 is closed. Further, when the control valve 24 is opened and pumping loss control is performed by communication between cylinders, the communication passage 23
Intake air flows through the intake air at high speed, and injecting fuel into this intake air promotes atomization of the fuel. A communication passage injector 30 is provided for this purpose.

By the way, as mentioned above, for example, in the front cylinder F, a space defined between the rotor 6r and the intermediate housing 21 inside the side seal 31f of the rotor 6r (hereinafter, this is referred to as a side seal inner part). ) to side seal 31f using combustion pressure as driving force.
Exhaust gas that enters from the sliding contact part with the intermediate housing 2I (see Figure 2), or exhaust gas that enters the side seal inner part from the working chamber 5r through the intake port 3f when the intake boat 3f is partially opened. Regardless of the position of the rotor 6f, in order to prevent air from flowing into the rear working chamber 5r through the communication passage 23 and deteriorating the combustibility of the rear cylinder R by causing air to flow into the inner envelope of the side seal. A front side displacement air supply boat 32f is opened on the front side surface of the intermediate housing 22 at a position always inside the side seal 31f. Similarly, a rear displacement air supply boat 32r opens on the rear surface of the intermediate housing 21 at a position inside the side seal 31r of the rear rotor 6r.

An air cleaner 14 in the common intake passage 13 is used to supply air to the inner seals of the front and rear side seals.
A displacement air supply passage 33 is provided that communicates the position immediately downstream with the front and rear displacement air supply bows 32f and 32r. A vane type air pump 34 that discharges air and an on-off valve 35 that opens and closes the displacement air supply passage 33 are interposed in this displacement air supply passage 33 in order from upstream.

Additionally, part of the exhaust gas may be recirculated to the intake system (EG
R) to lower the combustion temperature slightly and reduce nitrogen oxides (NOx) in the exhaust gas. Common exhaust passage 3 where r are collected
6 and the volume portion 19 of the intake system.
is provided. An EGR valve 38 is provided in the EGR passage 37 to control the amount of EGR gas.

The control circuit 40 detects the intake air temperature detected by the intake air temperature sensor 41, the intake air amount detected by the air flow meter 15, the throttle opening detected by the throttle valve opening sensor 42, and the control valve opening sensor 43. Various predetermined controls are performed using control information such as the control valve opening degree, the engine speed detected by a rotation speed sensor (not shown), and the coolant temperature detected by a coolant temperature sensor (not shown). However, the control method by the control circuit 40 will be explained below.

First, pumping loss control by the control circuit 40 will be explained.

If the operating state of the engine RE is in the high rotation range or high load range as shown in region I in Figure 3, it is necessary to increase charging efficiency and perform high output operation, so communication between cylinders is not performed. . Further, when the operating state of the engine RE is in the idle range, communication between the cylinders is not performed because combustibility deteriorates as described in 12-1 Prior Art of the present application. At this time, in response to a signal from the control circuit 40, the first solenoid valve 27 is closed, the second solenoid valve 29 is opened, and the actuator 2
Atmospheric pressure is introduced into the pressure chamber 5, the control valve 24 is closed, and fuel injection from the communication passage injector 30 is stopped.

On the other hand, when the operating state of the engine RE is in the low rotation/light load range as shown in area ■ in Figure 3, the intake negative pressure is large, so the pumping loss is also large, and reducing this will greatly improve fuel efficiency. This allows communication between the cylinders. At this time, upon receiving a signal from the control circuit 40, the first solenoid valve 27 is opened and the second solenoid valve 29 is closed, so that negative pressure is introduced into the pressure chamber of the actuator 25 and the control valve 24 is closed. When opened, fuel injection is performed from the communicating path injector 30. When the control valve 24 is opened in this way, the front working chamber 5f is in the intake stroke, and the rear working chamber 5r is in the compression stroke at a predetermined time (for example, the eccentric shaft rotation angle is 85°). Since the front and rear communication ports 22f and 22r are both opened at an angle of 225°), intake air flows at high speed from the rear working chamber 5r to the front working chamber 5r through the communication passage 23. This intake suppresses the negative pressure in the front working chamber 5f, thereby reducing pumping loss caused by the intake negative pressure.

Similarly, when the front working chamber 5f is in the compression stroke and the rear working chamber 5r is in the intake stroke, the front working chamber 5f is activated at a predetermined time (for example, at an eccentric shaft rotation angle of 265° to 405°). Communication path 2 from to the rear working chamber 5r
3, the intake air flows in, and the pumping loss of the rear cylinder R is reduced.

However, when the cylinders are communicating with each other, the exhaust gas that enters the side seal inner envelope as described above flows into the other cylinder, so air is introduced into the side seal inner envelope to prevent this. At this time, in response to a signal from the control circuit 40, the air pump 34 is driven and the on-off valve 35 is opened. Air flows into the side seal inner envelope of F. As a result, as shown in FIG. 2, an air flow as shown by arrow C occurs in the inner envelope of the side seal, and the air flows through the communication path 23.
and flows into the rear side working chamber 5F. by this,
Exhaust gas in the side seal inner part of the front cylinder F is prevented from flowing into the rear working chamber 5r. In addition, since the negative pressure in the side seal inner part is suppressed by the air flowing in from the displacement air supply boat 32f, the combustion pressure is used as a drying force to enter the side seal inner part from the sliding contact part between the Zide seal 31f and the intermediate housing 21. The exhaust gas that enters the side seal inner envelope through the intake boat 3f when the intake port 3f is partially opened is reduced.

As a result, the combustion in the rear working chamber 5r is reduced, so that the combustibility of the rear cylinder R is improved. In exactly the same process, air flowing from the rear individual displacement air supply 15 = supply boat 32r into the side seal inner part of the rear cylinder R reduces the risk of collision in the front working chamber 5r, and Flammability is improved. Note that when the control valve 24 is closed and there is no communication between the cylinders, the exhaust gas in the side seal inner part does not flow into the other cylinder, so the air pump 34 is stopped and the on-off valve 35 is closed to remove the replacement air. supply will be stopped.

By the way, in this embodiment, as described above, when the cylinders are communicating with each other, fuel is injected from the communication passage injector 30 into the intake air flowing at high speed in the communication passage 23 to promote atomization of the fuel. However, when the intake air flowing through the communication passage 23 passes through the control valve 24, it expands adiabatically and its temperature decreases due to the Joule-Thomson effect. Intake air temperature becomes very low. Therefore, a problem arises in that a portion of the fuel injected from the communication passage injector 30 into the intake air flowing through the communication passage 23 solidifies due to the low temperature, and the solidified fuel sticks around the control valve 24. As a result, the operability of the control valve 24 deteriorates, and for example, the control valve 24 does not close completely when it should be fully closed during high load, resulting in a decrease in output due to a decrease in filling efficiency. A problem arises in that the valve does not open completely when it should be fully opened, resulting in insufficient reduction of pumping loss and reduced fuel efficiency. Therefore, in this embodiment, when the intake air temperature is low and when the cooling water temperature of the engine RE is low, fuel injection from the communicating path injector 30 is stopped. At this time, as shown in FIG. 4, when the intake air temperature is lower than tl, fuel injection from the communication passage injector 30 is stopped regardless of the opening degree of the control valve 24,
When the intake air temperature is higher than t2, fuel is injected from the communication passage injector 30 regardless of the opening degree of the control valve 24, and when the intake air temperature is 8 or more and t2 or less, the opening degree is small according to the control valve opening degree. The fuel injection is stopped at higher temperatures (because the temperature drop becomes larger).

As a result, fuel injection is performed in region (2) in FIG. 4, while fuel injection is stopped in region (2). Further, as shown in FIG. 5, when the cooling water temperature is lower than t3, fuel injection from the communicating path injector 30 is stopped (region (3)). On the other hand, if the cooling water temperature is 13 or higher, fuel injection is performed (region ■).

Furthermore, in this embodiment, when the control valve 24 fails, various countermeasures are taken by the control circuit 40, which will be explained below.

When the operating state of the engine RE corresponds to region H in FIG. 3 and the control valve 24 is to be opened to establish communication between the cylinders,
When the control valve 24 fails and enters the closed state, the intake negative pressure becomes higher than a predetermined value. However, in this operating range, the EGR valve 38 is controlled assuming that the intake negative pressure is at the predetermined value, so the EGR amount increases as the intake negative pressure increases, and the driving performance deteriorates. To prevent this, if the control valve 24 fails and becomes closed when the operating state of the engine RE corresponds to region H in FIG. 3, the control circuit 40 reduces the EGR amount or Alternatively, EGR is stopped. Control circuit 40
As shown functionally in FIG. 6, the part that performs the above-mentioned control is a data reading circuit 51 that reads engine speed, throttle opening, cooling water temperature, etc., and a data reading circuit 51 that reads the data read by the data reading circuit 51. a control valve target opening setting circuit 53 that sets a control valve target opening corresponding to the operating state of the engine RE while referring to a control valve target opening map; , the control valve opening detection circuit 54 that detects the actual control valve opening, and the control valve target opening set by the control valve target opening setting circuit 53 and the control detected by the control valve opening detection circuit 54. a comparison calculation circuit 55 that calculates a control deviation by comparing the valve opening degree; a composite negative pressure setting circuit 56 that sets the opening degrees of the first solenoid valve 27 and the second solenoid valve 29 according to the control deviation; The control valve failure determination circuit 57 includes a control valve failure determination circuit 57 that determines whether or not the control valve 24 has a failure, and an EGR control circuit 58 that receives a signal from the control valve failure determination circuit 57 and controls the EGR valve 38.

Hereinafter, with reference to the control flowchart shown in FIG.
A method of controlling the EGR valve 38 when the control valve 24 is out of order will be explained.

When the control is started, first in step S1, the engine speed, throttle opening, cooling water temperature, and control valve opening are read as control information.

Next, in step S2, it is compared whether the operating state of the engine RE is in the open region of the control valve 24 or not.

If the operating state of the engine RE corresponds to region H in FIG. 3, the control valve 24 is in the open region. As a result of the comparison, if the operating state of the engine RE does not fall within the control valve open region (No), control is skipped to step S7.

In step S7, the EGR valve 38 is closed.

This is because at this time, the engine RE is in the high load range or in the idle range, so if it is in the high load range, it is necessary to stop EGR in order to increase the output.
When in the idle range, to prevent deterioration of flammability,
This is because it is necessary to stop EGR. Thereafter, the control proceeds to step S8, and depending on whether the ignition switch is turned on or off, the control returns to step S1 and continues or is terminated.

As a result of the comparison in step S2, if the operating state of the engine RE is in the control valve open region (YES), the control is performed in step S.
You can proceed to 3.

In step S3, it is compared whether the cooling water temperature is 70° C. or higher. As a result of the comparison, if the cooling water temperature is less than 70℃ (NO), the engine RE is in a cold state, and the E
If GR is performed, combustibility will deteriorate, so EGR valve 3
8, control skips to step S7. Note that the flow of control after step S7 is the same as that in the case where the determination is NO in step S2, so the explanation will be omitted.

On the other hand, as a result of the comparison in step S3, the cooling water temperature is 70.
If the temperature is higher than 0.degree. C. (YES), the engine RE is in a warm-up state, and the control proceeds to the next step S4.

In step S4, it is compared whether the control valve 24 is open. Here, since it has already been determined in step S2 that the control valve 24 is in the open region, if there is no failure in the control valve 24, another control valve control routine is performed to open the control valve 24.
4 should of course be open. Therefore, if the control valve 24 is closed, it means that the control valve 24 is out of order.

As a result of the comparison, if the control valve 24 is open (YES),
Since the control valve 24 is normal, control proceeds to step S5.

In step S5, the EGR valve 38 is opened, EGR is introduced into the intake system according to the intake negative pressure, and the combustion temperature is slightly lowered to reduce NOx in the exhaust gas.

Thereafter, the control proceeds to step S8, and depending on whether the ignition switch is turned on or off, the control returns to step S1 and continues, or is terminated.

As a result of the comparison in step S4, if the control valve 24 is closed (NO), the control valve 24 is out of order, so the EG
If the Ii valve 38 is opened in the same way as in normal conditions, the intake negative pressure will be greater than the expected value, so E G Rffl will be excessive and combustion performance will deteriorate. Therefore, control proceeds to step 86 to reduce EGRi.

In step S6, the EGR amount is throttled by a predetermined amount, and the control valve 24
The increase in EGR amount due to the increase in intake negative pressure due to the failure is canceled out. To throttle EGRfi, a second three-way solenoid valve is installed in parallel with a three-way solenoid valve (not shown) that operates the EGR valve 38 fully open or fully closed. TeEG
The atmosphere may be introduced through the R valve 38 through a throttle to reduce the EGR amount appropriately. Furthermore, the EGR valve 38 may be fully closed when the control valve 24 fails. In this way, an increase in EGRffi is prevented and deterioration of combustibility is prevented. Thereafter, the control proceeds to step S8, and depending on whether the ignition switch is turned on or off, the control returns to step S1 and continues, or is terminated.

In addition, in this embodiment, as shown in FIG. 3, in the deceleration region corresponding to region IV, in order to prevent unburned fuel due to misfire from deteriorating the three-way catalyst in the exhaust purification device, Fuel supply is stopped, and in the area corresponding to area ■, the fuel supply to one cylinder on the specified side is stopped in order to prevent the occurrence of torque shock by transitioning from fuel injection to the fuel injection stop area in stages. I try to do that. and,
When the operating state of the engine RE is in the one-cylinder fuel cut region corresponding to the region (■), if the control valve 24 is opened due to a failure (under normal conditions, the control valve 24 is closed outside the region (2)). Since the air-fuel mixture flows from the fuel injection side cylinder to the fuel injection stop side cylinder, the air mixture in the fuel injection side cylinder becomes lean and misfires occur repeatedly. Note that the cylinder on the side where fuel injection is stopped is also extremely lean with only the fuel contained in the air-fuel mixture that has flowed in, so of course it will not ignite. Therefore, when such a failure occurs, drivability deteriorates due to misfire, and unburned fuel causes excessive temperature rise and deterioration of the three-way catalyst.

Therefore, in order to prevent this, when the control valve 24 is opened while the operating state of the engine RE is in the one-cylinder fuel cut region corresponding to region (3) in FIG. This control method will be explained with reference to the control flowchart shown in FIG. 8.

When the control is started, first in step Sll, the engine speed, throttle opening, cooling water temperature, and control valve opening are read as control information.

Next, in step SI2, the operating state of the engine RE is changed to the third state.
A comparison is made to determine whether or not the fuel falls within the one-side cylinder fuel cut region as shown by region (■) in the figure. As a result of the comparison, if the operating state of the engine RE does not fall under the one-side cylinder fuel cut region (No.
), the control skips to step S16 and returns to step Sll to continue or end depending on whether the ignition switch is turned on or off.

On the other hand, as a result of the comparison in step SI2, if the operating state of the engine RE falls within the one-cylinder fuel cut region, the control proceeds to step SI3 in order to determine whether the control valve 24 is out of order.

In step S13, it is compared whether the control valve 24 is open. Here, the opening/closing of the control valve 24 is directly determined based on the control valve opening detected by the control valve opening sensor 43, but the control valve 24 is determined based on the difference in intake pressure between when the control valve 24 is opened and when the control valve 24 is closed. 24 may be opened or closed. As a result of the comparison, if the control valve 24 is closed (
NO), the control valve 24 is normal and there is no risk that the air-fuel mixture in the fuel injection side cylinder will flow into the fuel injection stop side cylinder, so the control proceeds to step SI4 and normal one-side cylinder fuel cut operation is performed. . After this, the control goes to step S
] 6, and returns to step Sll to continue or end depending on whether the ignition switch is turned on or off.

As a result of the comparison in step S13, if the control valve 24 is open (YES), the control valve 24 is out of order, and the control proceeds to step S15 to deal with this problem.

In step S15, the single cylinder fuel cut operation is stopped and both cylinder fuel cut operation is performed, or both cylinder fuel injection operation is performed. This prevents the air-fuel mixture in one cylinder from flowing out unilaterally to the other cylinder, thereby making it possible to prevent misfires as described above.

Thereafter, the control proceeds to step SI6, and returns to step S11 to continue or end depending on whether the ignition switch is turned on or off.

Furthermore, if the operating state of the engine RE falls under a very light load range such as the idle range shown in Fig. 3, or if the inter-cylinder communication range is defined as shown in Fig. 10, When it falls under the area shown in area A,
If the control valve 24 is opened due to a failure, problems may occur, such as the engine RE becoming unable to start due to a decrease in the amount of filling, or combustibility worsening due to a decrease in filling teeth and an increase in internal EGR, resulting in engine stalling. . Therefore, for example, when the control valve 24 is opened when the operating state of the engine RE corresponds to region A in FIG. 1O, the bypass valve 1
8 is corrected and controlled to increase the amount of intake air flowing through the bypass intake passage 17 to prevent the above problem from occurring. Hereinafter, the control method will be explained with reference to a control flowchart not shown in FIG. 9. .

When the control is started, first in step S21, the engine speed, throttle opening, and control valve opening are read as control information.

Next, in step S22, a comparison is made to see if the operating state of the engine RE corresponds to a control valve closed region, for example, as shown by region A in FIG. 1O. As a result of the comparison, if the control valve is not in the closed region (No), the control is skipped to step S27, and depending on whether the ignition switch is turned on or off, the control returns to step S2+ and is continued or terminated.

As a result of the comparison in step S22, if the operating state of the engine RE corresponds to the control valve closed region (region A in Figure 1O), then (
YES), in order to determine whether there is a failure in the control valve 24,
Control proceeds to step S23.

In step S23, it is compared whether the control valve 24 is open. As a result of the comparison, if the control valve 24 is closed (NO), the control valve 24 is operating normally.
Control proceeds to step S24, where normal bypass intake control is performed. Thereafter, the control proceeds to step S27, and returns to step S2I to continue or end depending on whether the ignition switch is turned on or off.

On the other hand, if the comparison result in step S23 is that the control valve 24 is open (YES), the control valve 24 is out of order.
If left as is, the engine will become unable to start or the engine will stall as described above, so the control proceeds to step S25 to perform bypass intake correction control.

In step S25, the second base duty at which the bypass valve I8 is opened wide is set.

Subsequently, in step 826, the bypass valve 18 is adjusted based on the second base duty set in step S25.
is controlled, and an increase correction of bypass intake air is performed. This provides the necessary intake air and effectively prevents the engine from stalling or being unable to start as described above. After this, the control proceeds to step S27, and depending on whether the ignition switch is turned on or off, the control proceeds to step S2+.
Either return to and continue, or be terminated.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a two-cylinder rotary piston engine showing an embodiment of the present invention. FIG. 2 is an explanatory front view of the front cylinder showing an intrusion path of exhaust gas into the Zydosole inner envelope and a distribution path of replacement air. FIG. 3 is a diagram showing the operating range in which the control valve is opened, etc., using engine speed and throttle opening as parameters. FIG. 4 is a diagram showing the operating range in which fuel injection from the communication passage injector is stopped when the intake air temperature is low, using the intake air temperature and the control valve opening degree as parameters. FIG. 5 is a diagram showing the operating range in which fuel injection from the communication passage injector is stopped when the cooling water temperature is low, using the cooling water temperature and the control valve opening degree as parameters. FIG. 6 is a block diagram functionalizing a portion of the control circuit related to EGR control when a control valve fails. FIG. 7 is a control flowchart showing a control method for EGR control when a control valve fails. FIG. 8 is a control flowchart showing a fuel control method when a control valve fails in a one-sided fuel cut region. FIG. 9 is a control flowchart showing a control method for bypass intake control when a control valve fails. FIG. 10 is a diagram similar to FIG. 3 showing another example of the control valve opening area. RE・Rotary piston engine, F...Front side cylinder, R・Rear side cylinder, 3f, 3r...Front rear intake boat. 5f, 5r...Front, rear working chamber, 21 Intermediate housing, 23...Communication passage, 24...Control valve, 32f, 32r Front, rear displacement air supply port, 33...Displacement air supply passage, 34...・Air pump, 35... Open/close valve. Patent applicant Mazda Motor Corporation representative Patent attorney Aoyama Ao and two others No. 70 Figure 8 9t-1 Start/Start/Jin times a few dollars PJiI search control annual search experience, MiN. ES ES Opening force - O ,, S24 , -'i25 10th exit 11

Claims (1)

[Claims] (1) A communication passage that communicates the working chamber of one cylinder during the compression stroke with the working chamber of the other cylinder during the intake stroke is provided in the intermediate housing, and a control valve is provided to control the amount of ventilation in the communication passage. In a rotary piston engine that controls pumping loss through communication between cylinders, a displacement air supply hole is provided that communicates with the communication passage through the side seal inner part of the intermediate housing, and an intermediate A rotary piston engine equipped with a pump loss reduction device, characterized in that an air supply means is provided for supplying air to the side seal inner part of the housing.