JP2004116492A - Fuel injection apparatus for rotary engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve combustibility of a mixture by optimizing fuel distribution in working chambers 5 to efficiently lead fuel into the working chambers 5 without sticking the fuel to a side face or the like of a rotor 6 in a rotary engine 1 wherein the working chambers 5, 5, 5 on the outer peripheral side carry out each stroke of intake, compression, expansion and exhaust in sequence while moving circumferentially following the rotation of rotors 6 accommodated in housings 2, 3. <P>SOLUTION: First and second intake ports 11, 13 opened to side housings 3, 3 on both sides of the rotor 6 are provided for every cylinder 4. When the total injection quantity Q corresponding to the operating state of the engine 1 is larger than the first set quantity Q1, fuel is distributed to three injectors 25, 26, 32 to basically lead approximately the same quantity of fuel into the working chambers 5 through the first and second intake ports 11, 13, and the injection operation of fuel by each injector is performed in a prescribed suitable injection period. When fuel distribution to the secondary injector 32 reaches the quantity which cannot be injected within the suitable injection period, the fuel is injected beyond the suitable injection period. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel injection device for supplying fuel to a rotary engine, and more particularly to a fuel injection device provided with a plurality of fuel injection valves for each cylinder.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a fuel injection device for a rotary engine, for example, as disclosed in Patent Literature 1, two first and second fuel injection valves are provided in an intake passage for each cylinder, and the fuel is injected at low load and low rotation. In a state where the supply amount is small, the fuel is injected only by the first fuel injection valve having a relatively small capacity, thereby improving the controllability of the fuel. The fuel is injected by both of the fuel injection valves to ensure a sufficient fuel supply amount.
[0003]
Further, in the above-described apparatus, a small-capacity first fuel injection valve is disposed at the intake port to reduce the delay in transporting the fuel to the working chamber, thereby improving the responsiveness of the fuel control. (2) The fuel injection valve is disposed in the intake manifold on the upstream side so as to increase the time required for the injected fuel to be transported to the working chamber in the cylinder to some extent, thereby promoting vaporization and atomization of the fuel. Like that.
[0004]
[Patent Document 1]
JP-A-7-158478 (pages 2 to 3, FIG. 2)
[0005]
[Problems to be solved by the invention]
By the way, in the rotary engine as in the conventional example, the intake port to the working chamber is opened and closed by the side surface of the rotor rotating in the housing, and the fuel is efficiently removed by avoiding the attachment to the side surface of the rotor. In order to supply the fuel to the working chamber, when at least a part of the intake port communicates with the working chamber and the flow rate of the intake air sucked into the working chamber is higher than a certain level and high, that is, during a predetermined crank angle period, (Hereinafter, a predetermined crank angle period is also referred to as a suitable injection period).
[0006]
In this regard, in the conventional rotary engine, the intake port is opened only on the wall on one side of the rotor in the working chamber, and there is a geometric restriction on the size of the opening, so that the preferred injection period In particular, in a high load state where the fuel injection amount is large or a high rotation state where the time interval with respect to the crank angle period is relatively short, the fuel is injected beyond the preferable injection period. I have to do it.
[0007]
In addition, when the intake air is introduced only from one side of the working chamber, the fuel distribution in the working chamber tends to be uneven, which may significantly reduce the combustibility. That is, when the speed of the intake air flowing into the working chamber is low, the fuel introduced into the working chamber on this intake diffuses as the working chamber moves and its volume increases, so that the fuel distribution is largely biased. Never. On the other hand, when the flow rate of the intake air is sufficiently high, a strong intake flow is generated in the working chamber, and the fuel is widely dispersed. Therefore, the bias of the fuel distribution is relatively small also at this time.
[0008]
However, when the flow rate of intake air to the working chamber is in the intermediate state described above, the fuel introduced on the intake air flowing into the working chamber from one side is unevenly distributed to the opposite side, and the air-fuel mixture The air-fuel ratio is greatly biased, and the flammability deteriorates. When the combustibility deteriorates in this way, the amount of unburned fuel in the air-fuel mixture increases, leading to deterioration in fuel efficiency and output. In addition, the so-called afterburning increases the temperature of the exhaust gas, which adversely affects reliability.
[0009]
The present invention has been made in view of the above-described points, and the object thereof is to pay attention to the characteristics of the rotary engine as described above, and to devise a configuration for supplying fuel to the working chamber in each cylinder. It is an object of the present invention to efficiently introduce fuel into the working chamber without adhering the fuel to the side surface of the rotor as much as possible and to optimize the fuel distribution in the working chamber to realize good combustion of the air-fuel mixture.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, first and second intake passages are provided so as to supply intake air from both sides to a working chamber in a cylinder of a rotary engine, and each of the intake passages has a capacity. By disposing different fuel injection means and changing the distribution of fuel to each intake passage in various ways according to the operating state of the engine, the efficiency of introducing fuel into the working chamber is increased, This is to optimize the fuel distribution.
[0011]
Specifically, according to the first aspect of the present invention, a plurality of working chambers are defined on the outer peripheral side of the housing by accommodating the rotor in the housing, and each working chamber moves in the circumferential direction as the rotor rotates. It is intended for a fuel injection device of a rotary engine that sequentially performs the intake, compression, expansion, and exhaust strokes. The housing inner wall surfaces that are in sliding contact with both side surfaces of the rotor respectively communicate with the working chamber in the intake stroke. The first and second intake passages are respectively opened so as to perform the above. The first and second fuel injection means having different capacities and arranged to inject fuel into the first and second intake passages, respectively, and the fuel injection amounts of the first and second fuel injection means are different. Basic distribution determining means for determining the distribution of fuel to each of the fuel injection means so as to have substantially the same amount, and at least so that fuel injection by each of the fuel injection means can be performed within a predetermined crank angle period. Limiting means for limiting the distribution of fuel to each fuel injection means in accordance with the engine rotation speed; and under predetermined conditions, the distribution of the fuel injection amount determined by the basic distribution determining means is smaller than the restriction by the limiting means. An injection amount control means for controlling a fuel injection amount by each fuel injection means is preferentially provided.
[0012]
With the above configuration, during the operation of the rotary engine, basically, the distribution of the fuel injection amount to the first and second fuel injection units is determined by the basic distribution determining unit so as to be substantially equal to each other. A substantially equal amount of fuel is injected into both the first and second intake passages and introduced into the working chamber from both sides thereof. As a result, the deviation of the fuel distribution in the working chamber becomes extremely small, and the combustibility of the air-fuel mixture is greatly improved, so that the output of the engine can be improved, the fuel efficiency can be improved, and even when the fuel injection amount is large. The reliability can be improved by relatively lowering the exhaust gas temperature.
[0013]
The amount of fuel injected by each of the fuel injection means is limited by the limiting means at least according to the engine speed so that the fuel injection amount is performed within a predetermined crank angle period (preferable injection period) in principle. This allows the fuel injected into the intake passage to be efficiently introduced into the working chamber without adhering to the side surfaces of the rotor and the like, thereby improving fuel efficiency and output.
[0014]
Here, since the first and second fuel injection means have different capacities, when trying to inject the same amount of fuel, the injection period of one fuel injection means having a relatively small capacity is relatively short. When the fuel injection amount increases and the fuel injection amount increases, the injection period of one of the fuel injection means first exceeds the suitable injection period. At this time, under a predetermined condition, that is, for example, when the speed of the intake air flowing into the working chamber is high to some extent and the bias of the fuel distribution in the working chamber tends to be large, The injection amount control is performed so that the fuel injection amount to the two intake passages becomes substantially the same even when the fuel injection period by the one fuel injection unit exceeds the preferred injection period, giving priority to the fuel allocation by the allocation determination unit. The means controls the fuel injection means. In other words, in a situation where the uneven fuel distribution tends to be large, priority is given to the fuel allocation by the basic allocation determining means in order to prevent this, thereby maintaining good combustion performance of the engine and improving output and fuel efficiency. realizable.
[0015]
According to the second aspect of the present invention, the first fuel injection valve is disposed downstream of the first intake passage, and the second fuel injection valve having a larger capacity than the first fuel injection valve is disposed in the second intake passage. Further, a third fuel injection valve having substantially the same capacity as the second fuel injection valve is disposed in the first intake passage upstream of the first fuel injection valve. And a fuel supply amount determining unit for determining a target fuel supply amount based on an operation state of the engine, wherein the basic distribution determining unit determines that the target fuel supply amount determined by the fuel supply amount determining unit is larger than a set amount. In some cases, the fuel is distributed such that the sum of the injection amounts of the first and third fuel injection valves is substantially the same as the injection amount of the second fuel injection valve. It is assumed that the distribution of fuel to the first, second and third fuel injection means is limited to an amount which can be performed within a predetermined crank angle period. Further, when the fuel amount distributed to the second fuel injection valve by the basic distribution determining means exceeds the amount that can be injected in a predetermined crank angle period, the injection amount controlling means controls the fuel distribution by the basic distribution determining means. Prioritizing distribution, the second fuel injection valve injects fuel beyond the predetermined crank angle period.
[0016]
Thus, the capacity of the first fuel injection means including the first and third fuel injection valves is larger than that of the second fuel injection means including the second fuel injection valve. Even if the first and third fuel injection valves can respectively inject fuel during the preferred injection period, the second fuel injection valve cannot completely inject the fuel during the preferred injection period. At this time, by prioritizing the distribution by the basic distribution determining means and injecting the fuel by the second fuel injection valve beyond the suitable injection period, the deviation of the fuel distribution in the working chamber becomes large. Even in a situation where it is easy to become difficult, the same amount of fuel can be introduced into the working chamber from both sides thereof, and the effect of the invention of the first aspect can be sufficiently obtained.
[0017]
According to a third aspect of the present invention, the injection amount control means according to the second aspect of the present invention is configured such that the amount of fuel distributed to the first and third fuel injection valves exceeds the amount that can be injected during a predetermined crank angle period. In this case, the first fuel injection valve injects fuel beyond the predetermined crank angle period.
[0018]
As a result, when the target fuel supply amount becomes considerably large and the amount of fuel distributed to the first and third fuel injection valves by the basic distribution determining means becomes an amount that cannot be injected in the preferred injection period, (2) Instead of increasing the fuel distribution to the fuel injection valves, that is, giving priority to the fuel distribution by the basic distribution determining means, the first fuel injection valve injects the fuel beyond the preferred injection period. That is, the first fuel injection valve, which has a relatively small capacity and is located on the downstream side of the first intake passage and has excellent control responsiveness, causes the fuel to be injected beyond the suitable injection period. With this configuration, when the target fuel supply amount subsequently decreases, the fuel injection amount of the first fuel injection valve having excellent responsiveness can be reduced relatively quickly, so that the fuel injection beyond the suitable injection period is performed. The adverse effects of doing so can be relatively small.
[0019]
According to a fourth aspect of the present invention, in the second aspect of the present invention, a shutter valve is provided in the second intake passage, and when the target fuel supply amount determined by the fuel supply amount determining means is equal to or less than the set amount, the fuel is supplied. And a shutter valve control unit for closing the shutter valve when the target fuel supply amount is equal to or less than a set amount.
[0020]
Thus, when the target fuel supply amount is relatively small and equal to or less than the set amount, the fuel is distributed only to the first fuel injection valve by the small amount distribution determining means, and the second intake passage is closed by the shutter valve. Thus, the intake air flows only through the first intake passage. That is, even when the flow rate of the intake air is relatively small, the flow velocity of the intake air flowing only through the first intake passage can be made sufficiently high, and the fuel injected there can be efficiently introduced into the working chamber. . In addition, the adhesion of the fuel to the port wall surface can be reduced, and the vaporization and atomization can be promoted.
[0021]
In addition, since the first fuel injection valve having a relatively small capacity has a high minimum resolution, highly accurate fuel control can be performed even when the fuel injection amount is small, so that the efficiency of introducing fuel into the working chamber is high as described above. Together with this, high fuel controllability is obtained.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
(Overall configuration of engine)
FIG. 2 shows a configuration of a main part of the rotary engine 1 according to the embodiment of the present invention, in which a rotor housing chamber 4 (cylinder) surrounded by a cocoon-shaped rotor housing 2 having a trochoid inner peripheral surface 2 a and a side housing 3. 3) accommodates a generally triangular rotor 6, and three working chambers 5, 5, 5 are defined on the outer peripheral side thereof. As shown in FIG. 3, the rotary engine 1 is integrated by sandwiching two rotor housings 2, 2 between three side housings 3, 3, 3, and two cylinders 4, formed therebetween. 4 is a two-rotor type in which rotors 6 and 6 are accommodated respectively. Hereinafter, in this embodiment, the side housing 3 (shown in FIG. 2) located between the two rotor housings 2 and 2 will be referred to as an intermediate housing 3 to be distinguished from those at both ends.
[0024]
An internal gear (not shown) is formed inside the rotor 6, and the internal gear meshes with an external gear on the side housing 3 side, and the rotor 6 passes through the intermediate housing 3 and the side housing 3. It is supported so as to make a planetary rotation with respect to the crankshaft 7. That is, the rotational movement of the rotor 6 is defined by the engagement between the internal gear and the external gear, and the rotor 6 is provided with three seals disposed on the three tops on the outer circumference, each on the trochoid inner peripheral surface 2a of the rotor housing 2. While rotating around the eccentric wheel 7a of the crankshaft 7 in the abutted state, it revolves around the axis X of the crankshaft 7. While the rotor 6 makes one rotation, the working chambers 5, 5,... Formed between the respective tops of the rotor 6 move in the circumferential direction, and each of the intake, compression, expansion (combustion), and exhaust A stroke is performed, and the generated rotational force is output from the crankshaft 7 via the rotor 6.
[0025]
More specifically, as viewed in the direction of the axis X of the crankshaft 7 as shown in FIG. 2, one side (the left side in the example) of each cylinder 4 in the left-right direction is substantially an intake and exhaust stroke region, The opposite side (the right side in the example in the figure) is generally a compression and expansion stroke area. As shown, the working chamber 5 (the upper left working chamber) communicating with the first intake port 11 (described later) and the like is in the latter half of the intake stroke, and the working chamber 5 is rotated as the rotor 6 rotates. When the air-fuel mixture moves clockwise to the compression stroke, the air-fuel mixture sucked therein is compressed, and then at a predetermined timing from the end of the compression stroke to the expansion stroke as in the working chamber 5 shown on the right side of the drawing. The mixture is ignited by the ignition plugs 9 and 10 to perform combustion.
[0026]
The intermediate housing 3 has a pair of first intake ports 11, 11 (only one is shown in FIG. 2) so as to communicate with the working chamber 5 in the intake stroke in each of the two cylinders 4, 4 on both sides. Similarly, a pair of first exhaust ports 12 and 12 (only one is shown in FIG. 2) are formed to communicate with the working chambers 5 and 5 in the exhaust stroke, respectively. On the other hand, the side housing 3 is formed with second and third two intake ports 13 and 14 so as to communicate with the working chamber 5 in the intake stroke, respectively, and communicates with the working chamber 5 in the exhaust stroke. The second exhaust port 15 is formed so that
[0027]
The first, second and third intake ports 11, 13, 14 constitute downstream ends of an intake passage 16 for supplying intake air to the working chamber 5 in the intake stroke of each cylinder 4, respectively. . That is, as shown in FIG. 1, the intake passage 16 branches into three for each cylinder 4 and communicates with the three intake ports 11, 13, and 14, respectively. By changing the state according to the operation state of the engine 1, the cylinder 4 can be efficiently charged with intake air over the entire operation range from low load low rotation to high load high rotation. FIG. 1 schematically shows one of the two cylinders 4 and 4 (the one on the near side in FIG. 3) which is schematically divided into two to show the overall configuration of the intake / exhaust system and the configuration of the control system. 2, the intermediate housing 3 side is shown on the left side of FIG. 2, and the side housing 3 side is shown on the right side of FIG.
[0028]
As shown in FIG. 1, an air cleaner 17 is disposed at an upstream end of the intake passage 16, and the air cleaner 17 is driven by a hot wire type air flow sensor 18 and a stepping motor in order from the downstream to cut the passage. A first electric throttle valve 23 for adjusting the area is provided. The intake passage 16 branches into two passages 19 and 20 downstream of the throttle valve 23, and one of the passages 19 is further divided into two independent intake passages 21 and 22 downstream. The downstream end of the first independent intake passage 21 is connected to the first intake port 11, and the downstream end of the second independent intake passage 22 is connected to the second intake port 13.
[0029]
The downstream end of the other passage 20 is connected to the third intake port 14, and an electromagnetic rotary valve (not shown) driven by an actuator is disposed there. The rotary valve is opened to supply the intake air only in a predetermined high rotation state in which the intake air amount is insufficient only by the supply of the intake air through the second independent intake passages 21 and 22. Hereinafter, this passage 20 is referred to as an additional intake passage 20.
[0030]
The first independent intake passage 21 is provided with a relatively large-capacity first injector 25 (fuel injection valve) for injecting fuel into a passage in the intake manifold 24, and is provided with a relatively large capacity. A relatively small-capacity port injector 26 (fuel injection valve) is provided to inject fuel into the downstream first intake port 11. The port injector 26 is arranged so as to inject fuel toward the vicinity of the downstream end of the first intake port 11 that opens into the working chamber 5. An air blowing passage 27 is provided so as to blow out a high-speed air flow taken out of the intake passage 16 upstream of the throttle valve 23 toward the port wall surface.
[0031]
On the other hand, the second independent intake passage 22 is provided with a shutter valve 28 for opening and closing the passage 22. The shutter valve 28 is composed of a butterfly valve, and is driven by an electromagnetic pneumatic actuator 29 that utilizes the negative pressure of the intake passage 16 to either fully close or fully open the second independent intake passage 22. State. The shutter valve 28 is provided so that a predetermined amount of gap is formed between the shutter valve 28 and the peripheral wall of the passage 22 even in the fully closed state in order to prevent the valve body from sticking. In the second independent intake passage 22 downstream of the shutter valve 28, the same injector (the second injector 32 for manifold injection) as the first injector 25 for manifold injection of the first independent intake passage 21 is provided. Have been.
[0032]
Reference numeral 30 shown in FIGS. 1 and 2 is a catch tank for collecting a part of the blow-by gas blown from the side surface of the rotor 6 or the like. The blow-by gas collected here is a blow-by gas passage shown only in FIG. The air is introduced into the intake passage 16 by 31.
[0033]
In contrast to the intake system having the above-described configuration, the exhaust system of the engine 1 is configured such that the first and second exhaust ports 12 and 15 are respectively connected to an exhaust manifold 33, and from the two cylinders 4 and 4 in the exhaust manifold 33. Exhaust gas is gathered and flows to the exhaust pipe 34 on the downstream side. The exhaust manifold 33 is provided with a linear O2 sensor 35 for detecting the oxygen concentration in the exhaust gas. The exhaust pipe 34 is provided with two catalytic converters 36 and 37 for purifying the exhaust gas in series. Is established. The linear O2 sensor 35 outputs a signal that is linear with respect to the oxygen concentration in a predetermined air-fuel ratio range including the stoichiometric air-fuel ratio, and is used for feedback control of the fuel injection amount by the injectors 25, 26, and 32. Can be
[0034]
Reference numeral 38 shown in FIG. 1 is an electromagnetic crank angle sensor that is disposed at one end of the crankshaft 7 of the rotary engine 1 and detects the rotation angle thereof. Reference numeral 39 denotes a water temperature sensor that detects a temperature state of the cooling water (engine water temperature) facing a water jacket (not shown) formed inside the rotor housing 2.
[0035]
The ignition circuits of the ignition plugs 9 and 10, the motors of the throttle valve 23, the injectors 25, 26 and 32, and the actuator 29 of the shutter valve 28 are controlled by a control unit 40 (hereinafter abbreviated as ECU). Has become. The ECU 40 receives at least the output signal of the air flow sensor 18, the output signal of the linear O2 sensor 35, the output signal of the crank angle sensor 38, and the output signal of the water temperature sensor 39. From the computer. The ECU 40 determines the operating state of the engine 1 (eg, engine load and engine rotational speed), and controls the ignition timing and the fuel injection amount and the injection timing of each cylinder 4 according to the operating state. Further, switching of a route through which intake air flows is performed.
[0036]
That is, as shown in an example of the control map in FIG. 4, the ratio of the air and fuel (air-fuel ratio) supplied to the working chambers 5, 5,. Control is performed so as to be substantially the stoichiometric air-fuel ratio (shown in the figure as a λ = 1 region), while in the high load region, control is performed so as to be richer than the stoichiometric air-fuel ratio (shown as an enriched region in the diagram). Specifically, the flow rate of the intake air adjusted by the throttle valve 23 is detected by the air flow sensor 18, and the fuel injection amount by the injectors 25, 26, and 32 is adjusted to the target air-fuel ratio in accordance with the detected value. Is controlled.
[0037]
In the enriched region shown in the figure, the region of the high-rotation side is indicated by diagonal lines, and it is necessary to intentionally lower the temperature of the exhaust gas in order to suppress an excessive rise in temperature of the engine 1 and the catalytic converters 36 and 37. For this purpose, the air-fuel ratio is controlled so as to be particularly rich (for example, A / F = 11 to 12) even in the enriched region.
[0038]
The open / close state of the shutter valve 28 is switched mainly in accordance with the engine speed. That is, the shutter valve 28 is fully closed in a low rotation range (for example, 3000 rpm or less), is fully closed on a relatively low load side in a low and middle rotation range (for example, 3000 to 4000 rpm), and is relatively closed on a relatively high load side. It is fully opened. In the middle and high rotation regions and the high rotation region (for example, a rotation region higher than 4000 rpm), it is fully opened. Further, in the high rotation range (for example, higher than 6500 rpm), the rotary valve between the additional intake passage 20 and the third intake port 14 is opened, and the additional intake passage 20 and the third intake port The intake air is also supplied from 14.
[0039]
(Fuel injection control)
Next, as a main feature of the present invention, a procedure of fuel injection control in which the three injectors 25, 26, and 32 are properly used will be described in detail.
[0040]
First, as shown in the functional block diagram of FIG. 5, the ECU 40 includes a rotation speed calculation unit 40a that calculates the engine rotation speed based on a signal from the crank angle sensor 38, and the engine rotation speed and the airflow obtained by the calculation. An engine load calculating section 40b for calculating an intake air charging efficiency (engine load) into the working chamber 5 based on the intake air amount obtained from a signal of the sensor 18, an engine water temperature and an atmospheric pressure, and an operating state of the air conditioner, etc. And an environmental condition calculating unit 40c for calculating a correction coefficient for air-fuel ratio enrichment correction or the like in accordance with the environmental conditions and the operating state of the engine 1, and the calculation results of the respective calculating units. That is, the total injection amount calculation for calculating the total injection amount (target fuel supply amount) by the three injectors 25, 26, and 32 based mainly on the operating state of the engine 1. And a 40d (fuel supply amount determination means).
[0041]
Furthermore, the ECU 40 controls the first and second independent intake passages 21 and 22 so that the fuel injection amounts are substantially equal based on the total injection amount calculated by the total injection amount calculation unit 40d. In other words, the fuel injection to each injector is basically performed such that the fuel injection amount by the manifold injector first injector 25 and the port injection injector 26 is substantially the same as the fuel injection amount by the manifold injection second injector 32. And a fuel distribution calculation unit 40e that determines a proper distribution, and injects fuel to each injector according to at least the engine speed so that fuel injection by each of the injectors 25, 26, and 32 is performed within a predetermined crank angle period. Basic fuel distribution by fuel distribution restricting unit 40f (restriction means) for restricting fuel distribution and fuel distribution calculating unit 40e The fuel distribution in consideration of the restriction by the restricting portion 40f, and a fuel injection amount control unit 40g that controls the amount of fuel injection by each of the three injectors 25,26,32.
[0042]
Further, the ECU 40 is provided with a shutter valve opening / closing determining unit 40h that determines whether the shutter valve 28 is to be opened or closed according to the distribution of fuel to the manifold injector second injector 32.
[0043]
The functions of each of the units 40a to 40h are realized by executing a program electronically stored in the memory of the ECU 40 by the CPU.
[0044]
More specifically, the order of fuel injection by the three injectors 25, 26, and 32 is as follows: first, the port injector 26 is operated, then the second manifold injector 32 is operated, and then the manifold injector 32 is operated. The first injector 25 is operated. Accordingly, hereinafter, the port injector 26 will be referred to as a primary injector 26, the manifold injector second injector 32 will be referred to as a secondary injector 32, and the manifold injector first injector 25 will be referred to as a third injector 25. I do.
[0045]
The predetermined crank angle period means that the fuel injected by each of the injectors 25, 26, and 32 is favorably transported along the flow of the intake air, and the wall surfaces of the intake passages 21 and 22 and the side surfaces of the rotor 6 and the like. This is a period during which the fuel is introduced into the working chamber 5 without adhering much, and this period is hereinafter referred to as a suitable injection period.
[0046]
The diagram shown in FIG. 6 shows a specific method of selectively using the three injectors 25, 26, and 32 mainly according to the total injection amount Q as described above. First, when the total injection amount Q shown on the horizontal axis of the figure is small and equal to or less than the first set amount Q1 that can be injected only within the preferred injection period by the primary injector 26 (Q ≦ Q1), as shown by a solid line in the figure. Then, only the primary injector 26 performs the fuel injection operation. Although the fuel injection start timing by the injector 26 is changed to some extent depending on the operating state of the engine 1, whether or not the injection period falls within the preferable injection period is substantially determined by the length of the valve opening period of the injector 26. (Crank angle), that is, whether the pulse width T1 is equal to or less than the set value T0.
[0047]
As described above, if the fuel is injected only by the primary injector 26 within the preferred injection period, the fuel is injected only by the small-capacity injector 26 having a high minimum resolution, thereby naturally controlling the injection amount. The accuracy is increased, and the fuel is injected into the first intake port 11 near the opening to the working chamber 5, so that the transport delay is reduced and the control response is increased.
[0048]
At this time, the shutter valve 28 is fully closed so that the intake air is mainly circulated only to the first independent intake passage 21. As a result, even when the flow rate of the intake air is small, the flow velocity of the intake air in the first independent intake passage 21 is sufficiently high, and the intake of the intake air and the fuel into the working chamber 5 is performed extremely efficiently, and the transport delay is reduced. Is reduced as much as possible, the adhesion of the fuel to the port wall is reduced, and the vaporization and atomization are also improved.
[0049]
Next, when the total injection amount Q is larger than the first set amount Q1 and is equal to or less than the second set amount Q2 which is approximately twice as large, the fuel is injected not only by the primary injector 26 but also by the secondary injector 32. (Indicated by a broken line in the drawing), and the fuel injection amounts of both injectors 26 and 32 are controlled to be substantially the same. Here, the fuel pulse width shown on the vertical axis of the figure reflects that the capacity of the primary injector 26 is smaller than that of the secondary injector 32, and the pulse width T1 of the primary injector 26 becomes longer than the pulse width T2 of the secondary injector. However, the amount of fuel injected into the first and second independent intake passages 21 and 22 by the two injectors 26 and 32 is substantially the same.
[0050]
At this time, the shutter valve 28 is opened at least when the secondary injector 32 operates (even when Q ≦ Q1, the shutter valve 28 is opened when the engine speed is high). As a result, substantially the same amount of intake air flows through the first and second independent intake passages 21 and 22, and a mixture of intake air and fuel is supplied to the working chamber 5 by the first and second intake ports 11 and 13 on both sides thereof. Will be introduced from. That is, the first and second intake ports 11, 13 are respectively opened on the inner wall surfaces of the intermediate housing 3 and the side housing 3 slidably in contact with both side surfaces of the rotor 6. When the working chamber 5 communicates with the first and second intake ports 11 and 13 and the volume of the working chamber 5 further increases, the first and second independent intake passages 21 and 22 and the first and second Approximately the same amount of air-fuel mixture is introduced into the working chamber 5 from the two intake ports 11 and 13 so as to face each other. As described above, since substantially the same amount of air-fuel mixture (suction and fuel) is introduced from the left and right sides with respect to the direction in which the rotor 6 and the working chamber 5 move, the distribution of fuel in the working chamber 5 is extremely small. This greatly improves the combustibility of the air-fuel mixture.
[0051]
Next, when the total injection amount Q becomes larger than the second set amount Q2, fuel is injected by all of the three injectors 25, 26, and 32. At this time, the fuel injection amount by the primary injector 26 is fixed to the first set amount Q1 (T1 = T0), the fuel injection amount by the secondary injector 32 is set to approximately half of the total injection amount Q, and the injection amounts are further reduced. The remaining fuel, which is insufficient for the total injection amount Q even when combined, is injected by the third injector 25 as shown by the dashed line in FIG. In other words, the primary injector 26 and the third injector 25 cause substantially half of the total injection amount of fuel to be injected into the first independent intake passage 21, and the secondary injector 32 allows substantially half of the total injection amount Q of fuel to be injected into the second independent intake passage 21. The fuel is injected into the intake passage 22.
[0052]
Thus, even if the total fuel injection amount Q increases, the fuel injection period by the primary injector 26 can be kept within the suitable injection period, and the injected fuel can be favorably introduced into the working chamber 5. The amount of fuel injected into each of the first and second independent intake passages 21 and 22 is made substantially the same, so that substantially the same amount of fuel can be introduced into the working chamber 5 from both sides.
[0053]
Further, even when the total injection amount Q subsequently increases and the fuel injection amount by the secondary injector 32 exceeds the amount that can be injected within the preferred injection period (Q> Q3), the fuel injection amount by the secondary injector 32 is The amount is increased substantially similarly to the third injector 25 (T2> T0). This takes into account the fact that the total injection amount Q has increased and the speed of the intake air flowing into the working chamber 5 has increased to some extent, which has led to a situation in which the bias in the fuel distribution in the working chamber 5 tends to increase. Thus, rather than increasing the efficiency of introducing fuel injected into the second independent intake passage 22 into the working chamber 5, the working chamber 5 is supplied with substantially the same amount of fuel from both the first and second independent intake passages 21 and 22. Therefore, it is possible to improve the output and the fuel efficiency while maintaining the good combustibility of the air-fuel mixture.
[0054]
Further, if the total injection amount Q further increases and the fuel injection amount by the third injector 25 exceeds the amount that can be injected within the preferred injection period (Q> Q4), the fuel injection amount by the third injector 25 becomes the first setting. The amount is fixed at Q1 (T3 = T0), and the fuel injection amount by the primary injector 26 is increased beyond the first set amount Q1 (T1> T0). That is, instead of increasing the fuel distribution to the secondary injector 32, the primary injector 26 causes the fuel to be injected beyond the preferred injection period. At this time, the reason why the injection amount of the third injector 25 is kept unchanged and only the injection amount of the primary injector 26 is increased is that when the total injection amount Q subsequently decreases, the injection amount of the primary injector 26 having high control responsiveness rapidly increases. This is because it can be returned to the first set amount Q1 or less.
[0055]
When the total injection amount Q further increases and the fuel injection amount by the secondary injector 32 reaches an upper limit value for controlling fuel injection by the injector 32 (Q = Q5), the secondary injector 32 Since the fuel injection amount must be fixed to the upper limit (T2 = Tmax), thereafter, only the fuel injection amount of the primary injector 26 is increased. Then, if the fuel injection amount by the primary injector 26 also reaches the upper limit of control (Q = Q6), the fuel injection amount by the injector 26 is fixed to the upper limit (T1 = Tmax) and thereafter. Is to increase the fuel injection amount by the third injector 25 beyond the first set amount Q1 (T3> T0).
[0056]
Hereinafter, a control procedure for selectively using the injectors 25, 26, and 32 as described above will be described with reference to flowcharts shown in FIGS. This control is executed for each of the working chambers 5, 5,... Of each cylinder 4 at a predetermined timing synchronized with the ignition timing.
[0057]
First, in step SA1 after the start of the flow shown in FIG. 7, the engine speed is calculated based on the signal from the crank angle sensor 38. In the following step SA2, the engine speed is calculated based on the engine speed and the signal from the air flow sensor 18. To calculate the efficiency of charging air into the working chamber 5 (engine load). Subsequently, in step SA3, a correction coefficient is calculated based on environmental conditions such as the engine water temperature and the like, and in the following step SA4, the target air-fuel ratio for the calculated intake air charging efficiency (see the control map in FIG. 4). The total injector injection amount Q is calculated such that The engine rotation speed, intake charging efficiency, total injection amount Q, and the like calculated as described above are sequentially stored and updated in the memory of the ECU 40. This is the same for the injection pulse widths T1, T2, and T3 in the following steps.
[0058]
Subsequently, in step SA5, the pulse width T1 of the fuel injection pulse output to the primary injector 26 is calculated. What is determined here is the pulse width required when all of the injector total injection amount Q determined in step SA4 is injected by the primary injector 26, and is a known value based on the total injection amount Q and the flow coefficient of the injector 26. It may be obtained by calculation. Then, in step SA6, it is determined whether or not the pulse width T1 thus obtained is within a set range corresponding to a suitable injection period (T1 ≦ T0?). If this determination is YES, the step of the flow in FIG. Proceeding to SA17, a fuel injection pulse is output to the primary injector 26 to inject fuel (execution of injection), and thereafter, the process returns.
[0059]
On the other hand, if the determination is NO, the process proceeds to step SA7, where the pulse width T2 of the fuel injection pulse to be output to the secondary injector 32 is calculated, and subsequently, in step SA8, the fuel injection pulse width T1 to the primary injector 26 is calculated. Is calculated again, and the flow advances to step SA9 shown in the flow of FIG. That is, the fuel injection pulse widths T1 and T2 are determined so that the total injection amount Q is divided into two equal parts and injected by the primary and secondary injectors 26 and 32, respectively. At this time, since the injector capacities are different, the magnitude relationship between the fuel injection pulse widths T1 and T2 is T1> T2. The fuel injection pulse width T1 of the primary injector 26 may be calculated again as described later, but the fuel injection pulse width T2 of the secondary injector 32 is not calculated again. Therefore, the pulse width T2 is limited to the control upper limit value Tmax or less.
[0060]
That is, when the fuel of the total injection amount Q can be injected within the predetermined crank angle period only by the primary injector 26, the fuel is injected and supplied only from the primary injector 26, otherwise, at least the primary and secondary injectors 26 and 32 supply the fuel. And controls such that their injection amounts are substantially the same.
[0061]
Following step SA8, in step SA9 of the flow shown in FIG. 8, as in step SA6, it is determined whether the fuel injection pulse width T1 of the primary injector 26 is within a set range corresponding to the preferred injection period ( T1 ≦ T0?). If the determination is YES, the process proceeds to Step SA17, in which fuel injection pulses are output to the primary and secondary injectors 26 and 32, respectively, and approximately the same amount of fuel is injected from both the injectors 26 and 32 (execution of injection). Will return later.
[0062]
On the other hand, if the determination is NO, the process proceeds to step SA10, where the fuel injection pulse width T1 of the primary injector 26 is once fixed to the set pulse width T0 which is the upper limit of the set range (T1 ← T0), and the following step In SA11, the pulse width T3 of the fuel injection pulse output to the third injector 25 is calculated. That is, first, the total injection amount Q is halved, the amount of fuel injected by the primary injector 26 is subtracted from the set pulse width, and the amount of fuel thus obtained is injected by the third injector 25. Find the pulse width. Then, in step SA12, it is determined whether the fuel injection pulse width T3 of the third injector 25 is within a set range corresponding to a suitable injection period (T3 ≦ T0?). If this determination is YES, the flow proceeds to step SA17. Then, a fuel injection pulse is output to each of the primary, secondary and third injectors 26, 32, and 25, and fuel is injected by the three injectors 25, 26, and 32 (injection is performed), and thereafter, the process returns.
[0063]
That is, when the fuel that is substantially half of the total injection amount Q can be injected by the primary injector 26 within the predetermined crank angle period, the primary injector 26 and the secondary injector 32 inject substantially the same amount of fuel. Even when it is not the case, the fuel injection amount of the primary injector 26 is limited to an amount that can be injected within the predetermined crank angle period, and the shortage is injected by the third injector 25, and the fuel is injected by the primary and third injectors 26, 25. The fuel injection amount and the fuel injection amount by the secondary injector 32 are made substantially the same.
[0064]
If the determination in step SA12 is NO and the fuel cannot be injected by the third injector 25 within the suitable injection period, the process proceeds to step SA13, where the fuel injection pulse width T3 of the third injector 25 is fixed to the set pulse width T0 ( T3 ← T0) In the subsequent step SA14, the fuel injection pulse width T1 to the primary injector 26 is calculated again. That is, the fuel injection amount by the secondary injector 32 is subtracted from the total injection amount Q, and the fuel injection amount by the third injector 25 (the amount of fuel injected by the third injector 25 at the set pulse width T0) is further subtracted therefrom. The pulse width for injecting the obtained amount of fuel by the primary injector 26 is determined.
[0065]
Subsequently, in step SA15, it is determined whether or not the fuel injection pulse width T1 of the primary injector 26 is equal to or smaller than an upper limit value Tmax for control (T1 ≦ Tmax?). If this determination is YES, the process proceeds to step SA17. Then, a fuel injection pulse is output to each of the primary, secondary and third injectors 26, 32, and 25, and fuel is injected by the three injectors 25, 26, and 32 (injection is performed), and thereafter, the process returns.
[0066]
That is, if the total injection amount Q becomes large and half of the fuel cannot be injected within the preferred injection period by both the primary and the third injectors 32, thereafter, the primary injectors having relatively high responsiveness thereafter The fuel injection amount 26 is increased until the fuel injection amount reaches the control upper limit.
[0067]
On the other hand, if the fuel injection pulse width T1 of the primary injector 26 exceeds the control upper limit value Tmax (determination is NO), the process proceeds to Step SA16, where the fuel injection pulse width T3 to the third injector 25 is calculated again. I do. That is, the fuel injection amount by the secondary injector 32 and the amount of fuel injected by the primary injector 26 with the pulse width Tmax of the upper limit are subtracted from the total injection amount Q, and the fuel amount obtained by this is subtracted from the total injection amount Q. The pulse width for injection by the injector 25 is determined. Then, the process proceeds to Step SA17 to output fuel injection pulses to the primary, secondary, and third injectors 26, 32, and 25, respectively, so that the three injectors 25, 26, and 32 inject fuel (execution of injection). Will return later.
[0068]
That is, when the fuel injection amount of the primary injector 26 reaches the control upper limit value, thereafter, only the fuel injection amount of the third injector 25 is increased until it reaches the control upper limit value.
[0069]
Step SA1 of the flow shown in FIG. 7 corresponds to the rotational speed calculator 40a of the ECU 40, and step SA2 corresponds to the engine load calculator 40b. Further, step SA3 corresponds to the environmental condition calculation unit 40c, and step SA4 corresponds to the total injection amount calculation unit 40d.
[0070]
In step SA5 of the flow, when the total injection amount Q calculated by the total injection amount calculation unit 40d is equal to or less than the first set amount Q1, the small amount distribution determining means for allocating the fuel to only the primary injector 26 is performed. Constitute.
[0071]
Further, steps SA7, SA8, SA11, SA14, and SA16 of the flow correspond to the fuel distribution calculation unit 40e, steps SA6, SA9, SA10, SA12, and SA13 correspond to the fuel distribution restriction unit 40f, and step SA17 corresponds to the fuel injection. Each corresponds to the amount control unit 40g.
[0072]
Next, a control procedure of the shutter valve 28 by the shutter valve opening / closing determination unit 40h of the ECU 40 will be specifically described based on a flowchart shown in FIG. This control is also executed at the same timing as the injector control described above.
[0073]
First, in steps SB1 and SB2 after the start, the engine rotational speed and intake charging efficiency calculated in steps SA1 and SA2 of the flow of FIG. 7 and updated in the memory of the ECU 40 are read, respectively. Subsequently, at step SB3, the fuel injection pulse width T2 of the secondary injector 32, which is similarly calculated at step SA7 of the flow and stored and updated in the memory of the ECU 40, is read.
[0074]
Subsequently, in step SB4, based on the fuel injection pulse width T2, it is determined whether or not to inject fuel by the secondary injector 32, and it is also determined whether or not the engine speed is equal to or higher than a predetermined value (for example, 4000 rotations). . Then, as a result of these determinations, if at least one is YES, the process proceeds to step SB5 to open the shutter valve 28. If all the determination results are NO, the process proceeds to step SB6 to close the shutter valve 28, and thereafter returns. .
[0075]
That is, in this embodiment, the shutter valve 28 is opened and closed mainly in accordance with the presence or absence of the injection operation by the secondary injector 32. As a result, when the total injection amount Q is larger than the first set amount Q1, the shutter valve 28 is opened. 28 will be opened.
[0076]
Note that, even if the total injection amount Q is equal to or less than the first set amount Q1, the shutter valve 28 is opened when the engine rotation speed is equal to or more than the predetermined value. That is, when the engine speed is equal to or higher than a predetermined value (shown by a broken line in the figure) in the control map of FIG. 4, the shutter valve 28 is opened regardless of the magnitude of the engine load. If it is low and the total injection amount Q is equal to or less than the first set amount Q1, so-called fuel cut control is actually performed, and the fuel supply is temporarily stopped, and then the accelerator pedal is depressed. Thus, the shutter valve 28 is opened in advance in order to restart the supply of fuel.
[0077]
Therefore, according to the fuel injection device A of the rotary engine 1 according to this embodiment, for example, when the engine load is low and the injector total injection amount Q is equal to or less than the first set amount Q1, the shutter valve 28 is closed to mainly intake air. And the fuel is injected into the first intake port 11 only by the primary injector 26. That is, even when the intake flow rate is small, the flow rate of the intake air flowing through the first intake port 11 is sufficiently increased to suppress the adhesion of the fuel to the intake port wall surface, and to promote the vaporization and atomization. Can be introduced into the working chamber 5 extremely efficiently.
[0078]
Moreover, at this time, the fuel injection by the primary injector 26 is performed during a predetermined suitable injection period so that the fuel can be satisfactorily introduced into the working chamber 5 without adhering to the intake port wall surface or the rotor 6 side surface. The above-mentioned effects are further enhanced.
[0079]
On the other hand, if the total injection amount Q is larger than the first set amount Q1, the shutter valve 28 is opened to allow the intake air to flow through the second independent intake passage 22, and at the same time, at least the primary and secondary injectors Fuel is injected from the first and second independent intake passages 21 and 22 so that substantially the same amount of intake air and fuel is introduced into the working chamber 5 from both the first and second independent intake passages 21 and 22. That is, in each cylinder 4, substantially the same amount of air-fuel mixture (suction and fuel) is introduced from both the left and right sides in the direction in which the working chamber 5 moves with the rotation of the rotor 6. The deviation of the fuel distribution in the above becomes very small, the combustibility of the air-fuel mixture is greatly improved, and the output and the fuel efficiency are improved.
[0080]
When the total injection amount Q further increases and the amount of fuel distributed to the secondary injector 32 exceeds the amount that can be injected within the preferred injection period, the secondary injector 32 injects fuel beyond the preferred injection period. Also, when the amount of fuel distributed to the primary and third injectors 26 and 25 cannot be injected during the preferred injection period, the primary injector 26 injects fuel beyond the preferred injection period. I do. This makes it possible to prevent the fuel distribution from being biased as described above even in a situation where the fuel distribution in the working chamber 5 tends to be biased, thereby maintaining a good combustion property of the air-fuel mixture. Can be.
[0081]
In particular, in a high-load and high-speed state, the fuel distribution in the working chamber 5 is optimized as described above to improve the combustibility, so that the unburned mixture remains less. Decreases. For this reason, for example, the degree of enrichment of the air-fuel ratio can be reduced in the enrichment region shown in the control map of FIG. 4, thereby further improving the output and the fuel efficiency.
[0082]
Note that the configuration of the present invention is not limited to the above-described embodiment, but includes other various configurations. That is, in the above-described embodiment, the additional intake passage 20 is provided, and especially in the high rotation region where the intake air amount is large, the working chamber 5 is also provided from the additional intake passage 20 in addition to the first and second independent intake passages 21 and 22. Although the intake air is introduced into the intake passage, the additional intake passage 20 may not be provided.
[0083]
Further, in the above-described embodiment, the three injectors 26, 32, and 25 of the primary, secondary, and third are arranged. However, two injectors having different capacities are provided in the first and second independent intake passages 21 and 22, respectively. It may be arranged. In that case, it is preferable to arrange the one having a relatively small capacity in or near the first intake port 11. Further, the shutter valve 28 does not necessarily have to be provided.
[0084]
【The invention's effect】
As described above, according to the fuel injection device for a rotary engine according to the first aspect of the present invention, the first and second intake passages are provided so as to supply the intake air to the working chamber in the cylinder from both sides thereof. First and second fuel injection means having different capacities are respectively disposed in the intake passage, and the fuel is basically injected so that the fuel injection amounts by the first and second fuel injection means are substantially the same. The distribution is determined, and the fuel injection by each fuel injection unit is limited so that it can be performed within a predetermined crank angle period. Under a predetermined condition, that is, in a situation where the deviation of the fuel distribution in the working chamber tends to be large, the distribution of the basic fuel injection amount is prioritized over the restriction of the predetermined crank angle period, and each fuel injection means is controlled. By controlling the fuel injection amount by the above, it is possible to suppress the bias of the fuel distribution in the working chamber, maintain good combustion characteristics of the engine, and improve the output and fuel efficiency.
[0085]
According to the invention of claim 2, when the amount of fuel distributed to the second fuel injection valve becomes incapable of being injected in the predetermined crank angle period, the fuel is injected beyond the predetermined crank angle period, Even in a situation in which the deviation of the fuel distribution in the working chamber tends to be large, the deviation can be suppressed and the effect of the invention of claim 1 can be sufficiently obtained.
[0086]
According to the third aspect of the invention, when the amount of fuel distributed to the first and third fuel injection valves cannot be injected during the preferred injection period, the fuel distribution to the second fuel injection valve is increased. Rather, the first fuel injection valve injects the fuel beyond the preferred injection period, thereby suppressing the uneven distribution of the fuel in the working chamber. After that, when the target fuel supply amount decreases, the responsiveness is reduced. The fuel injection amount of the first fuel injection valve, which is excellent in the above, can be reduced relatively quickly, so that the adverse effect of injecting fuel beyond the suitable injection period can be reduced.
[0087]
According to the present invention, when the target fuel supply amount is relatively small, the fuel is distributed only to the first fuel injection valve, and the second intake passage is closed to sufficiently increase the flow velocity of the intake air in the first intake passage. By increasing the height, the fuel can be efficiently introduced into the working chamber, the adhesion of the fuel to the port wall surface can be reduced, and the vaporization and atomization can be promoted. In addition, high fuel controllability is obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a fuel injection device for a rotary engine according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a main part of an engine.
FIG. 3 is a partially cutaway perspective view showing a configuration of a main part of the engine.
FIG. 4 is a diagram illustrating an example of an engine operation control map.
FIG. 5 is a functional block diagram showing a configuration of fuel injection control.
FIG. 6 is a diagram showing a correspondence relationship between a change in the total injection amount and a change in the fuel injection pulse width of each injector corresponding thereto.
FIG. 7 is a flowchart illustrating a first half procedure of fuel injection control;
FIG. 8 is a flowchart showing the latter half of the procedure of fuel injection control.
FIG. 9 is a flowchart illustrating a control procedure of a shutter valve.
[Explanation of symbols]
A fuel injection device
1 Rotary engine
2 Rotor housing
3 Side housing, intermediate housing
5 Working chamber
6 rotor
11 First intake port (first intake passage)
13 Second intake port (second intake passage)
21 1st independent intake passage (first intake passage)
22 Second independent intake passage (second intake passage)
25 Third injector (third fuel injection valve: first fuel injection means)
26 primary injector (first fuel injection valve: first fuel injection means)
28 Shutter valve
32 secondary injector (second fuel injection valve: second fuel injection means)
40 Control Unit (ECU)
40d total injection amount calculation unit (fuel supply amount determination means)
40e Fuel distribution calculation unit (basic distribution determining means)
40f Fuel distribution restriction unit (restriction means)
40g fuel injection amount control unit (fuel injection amount control means)
40h Shutter valve open / close determination unit (shutter valve control means)

Claims (4)

The rotor is accommodated in the housing, and a plurality of working chambers are defined on an outer peripheral side of the housing. Each of the working chambers moves in the circumferential direction as the rotor rotates, and each stroke of intake, compression, expansion, and exhaust is sequentially performed. A rotary engine fuel injection device,
First and second intake passages are respectively opened on an inner wall surface of the housing that is in sliding contact with both side surfaces of the rotor so as to communicate with a working chamber in the intake stroke.
First and second fuel injection means having different capacities and arranged to inject fuel into the first and second intake passages, respectively;
Basic distribution determining means for determining the distribution of fuel to each of the fuel injection means such that the amount of fuel injected by the first and second fuel injection means is substantially equal;
Limiting means for limiting the distribution of fuel to each fuel injection means according to at least the engine speed so that fuel injection by each of the fuel injection means can be performed within a predetermined crank angle period,
An injection amount control unit that controls the fuel injection amount of each fuel injection unit under a predetermined condition, with the distribution of the fuel injection amount determined by the basic allocation determination unit being given priority over the restriction by the restriction unit. A fuel injection device for a rotary engine, comprising: In claim 1,
A first fuel injection valve disposed downstream of the first intake passage;
A second fuel injection valve having a larger capacity than the first fuel injection valve is disposed in the second intake passage.
A third fuel injection valve having substantially the same capacity as the second fuel injection valve is disposed in the first intake passage upstream of the first fuel injection valve,
Fuel supply amount determining means for determining a target fuel supply amount based on an operation state of the engine,
When the target fuel supply amount determined by the fuel supply amount determining unit is larger than the set amount, the basic distribution determining unit determines that the fuel is equal to the sum of the injection amounts of the first and third fuel injection valves in the second fuel injection amount. It is distributed so as to be approximately the same as the injection amount by the fuel injection valve,
The limiting means limits the distribution of fuel to the first, second, and third fuel injection means to an amount which can be performed within a predetermined crank angle period, respectively.
The injection amount control means, when the fuel amount distributed to the second fuel injection valve by the basic distribution determining means exceeds the amount that can be injected in a predetermined crank angle period, the fuel distribution by the basic distribution determining means. A fuel injection device for a rotary engine, wherein fuel is injected by priority over the predetermined crank angle period by the second fuel injection valve. In claim 2,
Injection amount control means, when the amount of fuel distributed to the first and third fuel injection valves both exceeds the amount that can be injected during a predetermined crank angle period, the first fuel injection valve controls the predetermined crank angle. A fuel injection device for a rotary engine, wherein the fuel injection device is configured to inject fuel over a period. In claim 2,
A shutter valve is provided in the second intake passage,
When the target fuel supply amount determined by the fuel supply amount determination unit is equal to or less than the set amount, the small amount distribution determination unit that distributes the fuel to only the first fuel injection valve;
A fuel injection device for a rotary engine, comprising: shutter valve control means for closing the shutter valve when the target fuel supply amount is equal to or less than a set amount.

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