JPS6390627A - Pumping loss reducer for rotary piston engine - Google Patents

Abstract

PURPOSE:To improve combustibility, by installing an on-off valve and a fuel injection valve both in an interconnecting port which interconnects an interval between operating chambers of two cylinders in each of both suction and compression strokes, opening this on-off valve at a driving area other than inclusive of a high load area, and operating the fuel injection valve. CONSTITUTION:In case of a 2-cylinder engine having both cylinders A and B with rotor chambers (operating chambers) 8 and 9 where each of rotors 10 and 11 are housed freely rotatably, an interconnecting port 41, interconnecting the operating chamber of the cylinder on one side in a suction stroke to that of the cylinder on the other in a compression stroke, is formed in an intermedi ate housing which partitions off these rotor chambers 8 and 9. In this interconnecting port 41, there are provided with an on-off valve 42 opening or closing this port 41 and a fuel injection valve 43. And, this on-off valve 42 is closed at a first area inclusive of at least a high load area, and fuel supply is carried out from fuel injection valves 29A, 29B, 30A and 30B in a suction system, while the on-off valve 42 is opened at the area other than that and simultaneously it is controlled so as to do the fuel supply from the fuel injection valve 43.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application +n) The present invention relates to a pump loss reduction device for a rotary piston engine.

(Prior art) The intake air 11 (
In an engine that performs load control by adjusting the throttle valve, when the opening degree of the throttle valve is small, the throttling loss, that is, the pumping loss, becomes large.

Therefore, in rotary piston engines, in order to reduce pumping loss due to the throttle valve, the intermediate housing that separates the first cylinder and the second cylinder is provided with a working chamber for one cylinder in the intake stroke and the other cylinder in the compression stroke. There is a device in which a communication boat is formed that communicates with the working chamber of the cylinder, and an on-off valve that opens when a predetermined operating range is reached is provided on this communication boat (Japanese Patent Laid-Open No. 58-1724).
(See Publication No. 29). In other words, by utilizing the exchange of intake air between the first and second cylinders through the communication boat, it is possible to open the throttle valve to a larger degree, thereby reducing ribbon loss. It will be reduced.

(Problems to be Solved by the Invention) As mentioned above, in systems that utilize a communication boat to reduce pump loss, the engine temperature increases due to the reduction in compression pressure and the large movement of the mixture through the communication boat. This caused new problems such as a decrease in combustion rate and an increase in HC.

Incidentally, in a rotary piston engine, fuel is supplied to the intake passage in the same way as in a normal reciprocating engine, but this fuel supply position has a large effect on combustibility, etc. Various efforts have been made to optimize this, such as changing the fuel supply position depending on the load.

Therefore, an object of the present invention is to solve the problem in reducing pump loss by optimizing the fuel supply mode, assuming that a communication boat is used to reduce pump loss. First, it is an object of the present invention to provide a pump loss reduction device for a rotary piston engine that is capable of supplying fuel in a preferable manner depending on the engine load.

(Means and operations for solving the problems) In order to achieve the above-mentioned object, the present invention has the following configuration. In other words, a communication boat is formed in the intermediate housing that defines the first cylinder and the second cylinder, and communicates the working chamber of one cylinder in the intake stroke with the working chamber of the other cylinder in the compression stroke. an on-off valve that opens and closes the communication boat; a first fuel injection valve that injects fuel into the intake passage; and a second fuel injection valve that injects fuel into the communication boat; In a region 1, the on-off valve is closed and fuel is supplied from the first fuel injection valve, and in a region other than the first region, the on-off valve is opened and fuel is supplied from the second fuel injection valve. This is the configuration that is set up like this.

In this way, by injecting fuel into the communication boat in the area where the communication boat is open, the area in which the mixture moves is reduced compared to when the mixture is supplied from the intake passage.
The amount of fuel adhering to the housing wall and rotor surface is reduced (reduction in flame extinction), and HC is reduced. In addition, almost all of the injected fuel can be carried on the fast movement of air through the communication boat, promoting atomization of the fuel, and the air-fuel mixture supplied through the communication boat becomes rich, i.e., only partially It is possible to form a rich mixture layer (stratification) and improve the combustion rate. Of course, it becomes possible to shorten the travel distance of the fuel, which is preferable in terms of ensuring responsiveness, and furthermore, the oil washing effect by the fuel becomes smaller, making it possible to reduce oil consumption.

It is also possible to control the on-off valve to close in the light load range, including idle, and in this case, it is possible to prevent the effective compression ratio from becoming low while ensuring combustion stability, which is the most important problem in this light load range. can.

In addition, in a high load region, the on-off valve is closed to prevent a drop in the effective compression ratio, etc., and the output is secured (Example) Examples of the present invention will be described below based on the attached drawings. .

In FIG. 1, the housings of the engine body 1 are sequentially arranged from one end of the output shaft 2 (eccentric shaft) to the other end: side housing 3, rotor housing 4, intermediate housing 5.
, a rotor housing 6, and a side housing 7. A rotor 10 or 11 is housed in two rotor chambers 8.9 defined by the intermediate housing 5. In this way, the engine main body 1 is designed for two cylinders having two cylinders, the first cylinder A having the rotor 10 and the second cylinder B having the rotor 11.

As shown in FIG.
(12B), 13A (13B), and 14A (14B)
It is defined as In this Figure 2, 15A (
15B) is the secondary g! defined in the side housing 3 or 7. (The primary intake port formed in the intermediate housing 5 is shown in the figure), 16A (16B
) is an exhaust port, and l 7A (17B) is a spark plug. Therefore, in the state shown in FIG. 2, the working chamber of the first cylinder A is in the intake stroke for 12A and 13A.
As for A, it is in the explosion stroke (initial stage), and as for 14A, it is in the #air stroke. Moreover, the working chamber of the second cylinder B is 12
B is in the exhaust stroke (final 1 tA), 13B is in the compression stroke, and 14B is in the explosion (final) stroke.

The intake passage 21 including the intake port is provided with a surge tank 22 in the middle, and the upstream side of the surge tank 22 is made into one common intake passage 23. , air cleaner 24, air flow meter 25. A throttle valve 26 is provided. In addition, the intake passage downstream of the surge tank 22 includes primary and secondary independent intake passages 27A and 28A for the first cylinder A, and a second intake passage.
Primary and secondary independent intake passages 27B and 28B for cylinder B
It is configured as a total of four independent intake passages. This primary independent intake passage 27A (27B) is a primary intake bow formed in the intermediate housing 5 as is known.
(15B), and also a secondary independent intake passage 28A
(28B) is the 2 formed on the side housing 3 (7).
It is connected to the next intake boat.

A fuel injection valve 29A (29B) is provided in the 7m21st independent intake passage 27A (27B), and a fuel injection valve 30A (30B) is provided in the secondary independent intake passage 28A (28E).
0B) is provided. This primary fuel injection valve 29
A (29B) is the primary independent intake passage 27A (27B)
It is located sufficiently downstream of the Further, the secondary fuel injection valve 30A (30B) has a secondary independent intake passage 28A (
28B). Of course, this one
Both the next and secondary fuel injection valves 29A, 29B, 30A, 3
OB constitutes a first fuel injection valve that injects fuel into the intake passage 21. And the secondary independent intake passage 28
A (28B) has a secondary fuel injection valve 30A (30B).
A control valve 31 that is opened only in a high load region is provided on the upstream side of the control valve 31 .

The intermediate housing 5 includes, as shown in FIGS. 1 to 3,
A communication port 41 is formed to communicate between the two cylinders A and B. This communication port 41 is connected to the working chamber of one cylinder in the intake stroke (the working chamber 12 of the first cylinder A in FIG. 2).
A) and the working chamber of the other cylinder in the compression stroke (in FIG. 2, the working chamber 13B of the second cylinder B) are communicated with each other, and its opening position is determined. That is, communication port 4
1 is connected to the intake boat 1 by the rotor 10 or 11.
It is designed to close after a delay after 5A or 15B is closed (the same applies to the secondary intake port).

Note that this communication port 41 has an extremely short length (approximately 5 cm) corresponding to the thickness of the intermediate housing 5, and is formed linearly.

The intermediate housing 5 is provided with an on-off valve 42 for opening and closing the communication port 41 and a fuel injection valve 43 for injecting fuel into the communication port 41. This fuel injection valve 43 constitutes a second fuel injection valve, and in the embodiment, it is used commonly for the ff11 cylinder A and the second fuel injection valve 0B.

As shown in FIGS. 3 to 5, the on-off valve 42 includes a bottomed cylindrical housing 44 that forms a part of the communication bow 41, and
It has a rotor 45 as a valve body which is rotatably fitted into this housing 44, and this rotor 45 is formed with a communication port 46 that penetrates in the radial direction. As a result, the communication port 41 is opened (see FIG. 4) or closed (see FIG. 5) depending on the rotational position of the rotor 45. The rotor 45 is driven to open and close via the rotor 47 by an actuator 48 such as a steering wheel motor or a DC motor.

The fuel injection valve 43 is configured to inject fuel toward a communication port 46 of the rotor 45.

Therefore, as shown in FIG. 3, on an extended line passing through the axis of the rotor 45 and orthogonal to the axis of the communication boat 41, A mouth 51 (rotor 45) is formed,
A fuel injection valve 43 is inserted into this mounting hole 49 . The extension line, that is, the axial center of the fuel injection valve 43 is made to rise as it moves away from the rotor 45,
Further, the introduction port 51 is formed to be perpendicular to the communication port 46 so as to coincide with the opening 50 when the rotor 45 is in the open position, as shown in FIG. With this configuration, the fuel injected by the fuel injection valve 43 is supplied to the communication port 46, that is, the communication boat 41, through the opening 50 and the introduction port 51 only when the communication boat 41 is open. A collision plate 52 is provided in the communication hole 46 for colliding the injected fuel from the fuel injection valve 43 to promote vaporization and atomization. The rotor 45 is supported by the rotor 45 via a stay 53. Note that the inlet 51 has an open end to the opening 50 set to be long in the circumferential direction of the rotor 45, so that even when the opening degree of the on-off valve 42 is small, the fuel from the fuel injection valve 43 can be communicated with the boat 41. It is designed to be able to be supplied to

In FIG. 2, U is a control unit composed of a microcomputer, and this control unit U receives an intake air amount signal from an air flow meter 25 and a rotation speed sensor 61.
The engine speed signal is input. Further, the control unit U controls the opening and closing of the on-off valve 42 and the fuel injection from each fuel injection valve 29A, 29B, 30A, 30B, and 43.

Note that the control unit U basically includes a CPU and a ROM.
, RAM, and CLOCK, as well as a human output interface and a drive circuit, but since the method of using this microcomputer itself has been known for a long time, further explanation will be omitted.

Next, an overview of the control of the control unit U mentioned above will be explained. First, the opening/closing region of the opening/closing valve 42 is, for example, the sixth
As shown in the figure, engine speed Ne and engine load (
The intake air sparrow Q a ) is set as a parameter. That is, in this embodiment, the on-off valve 42 is closed both near the idle region (area work) and during high rotation or high load (area ■), and in the region II, the on-off valve 42 is closed.
2 will be opened. In addition, the fuel injection valves where fuel injection is performed are primary fuel injection valves 29A and 29B in area engineering.
In region II, only from the common fuel injection valve 43 that injects fuel to the communication boat 41,
In region (3), both the primary and secondary fuel injection valves 29.
It is said to be from 29B, 30A, and 30B.

FIG. 7 also shows the operation area I where the communication boat 41 is open.
1 shows a combustion cycle when the fuel injection valve 41 is in a position I, the direction of exchange of intake air through the communication boat 41, and an example of the timing of fuel injection from the fuel injection valve 43. That is, in FIG. 7, ■0 indicates the intake boat opening timing, IC indicates the intake boat closing timing, L○ indicates the communication port 41 opening timing, and LC indicates the communication boat closing timing. The shaded area is when the intake air flows back and forth between the inner cylinders A and B, and the white arrow indicates the flow direction of the intake air. Four strokes of intake, compression, explosion, and exhaust are performed per rotation of the rotor 10 or 11.Since the output shaft 2 rotates three times per rotation of the rotor, the number of strokes of the rotor 10 or 11 per stroke is The rotation angle is 270°, and rotor 1
The rotational phase difference between 0 and 11 is 180'' because there are two cylinders.

Based on the above-mentioned premise, the timing of fuel injection from the common fuel injection valve 43 is such that, in the embodiment, the communication port 41 is open, as shown by injection pulses (■) and (■) in FIG. It is set to end at some point. In the example shown by this injection pulse (■), the injection start and end are both when the communication boat 41 is open, and the injection pulse (
? ), the injection starts at the communication boat 41.
This is done when the port is closed, and the communication port 41 is
This is what you want to do when it's open.

As mentioned above, in the operating region (3), the communication bolt 41 remains closed (fuel is supplied to the primary fuel injection valves 29A, 29).
B), thus ensuring compression pressure and stable combustion near idle.

Further, the on-off valve 42 is closed even in the operating region m, and fuel injection is performed by both the primary and secondary fuel injection valves 29A, 29B, 30.
From A and 30B, the fuel injection ratio for primary and secondary purposes is set to a predetermined value to promote vaporization and atomization (
(fuel supply from secondary fuel injection valves 30A, 30B);
Sufficient output is ensured by ensuring compression pressure. Of course, the fuel injection in these two operating ranges (1) is performed at a cycle of 360° corresponding to one rotation of the output shaft 2, as in the conventional case.

On the other hand, in operating region II, as shown in FIG. 7, the communication boat 41 is opened at a predetermined timing, and intake air flows from one cylinder in the compression stroke to the other cylinder in the intake stroke. At this time, all of the fuel injected into the communication boat 41 from the common fuel injection valve 43 rides on the fast intake air flowing through the communication boat 41 and is stratified into the working chamber in the intake stroke while becoming rich. will be supplied. Since the fuel supplied from the communication boat 41 has a short distance to travel until it is combusted, the fuel supplied from the communication boat 41 is stored in the housing 3.4.
5.6.7 The amount of fuel adhering to the walls and the surface of the rotor 10.11 is reduced. As a result, an improvement in the combustion rate and a reduction in HC can be obtained. Of course, in this operating region II, since the distance traveled by the fuel is shortened, the effect of washing away the lubricating oil by the fuel is also weakened, making it possible to reduce the amount of oil consumed. In particular, since this medium-load operating range is generally considerably longer than the high-load operating time, the effect of reducing oil consumption is considerable.

The control contents of the control unit U mentioned above will be explained with reference to the flowchart shown in FIG. Note that in the following explanation, P indicates a step.

First, the engine rotation speed Ne and the intake air amount Qa are detected at Pl, and then, at P2, the fuel injection amount T to be injected per cylinder is determined based on both Ne and Qa.
P is calculated.

At PS, it is determined whether the current engine operating state is in operating region II shown in FIG. This PS
If YES, the on-off valve 42 is opened at P4, and then at PS the fuel injection amount TP at P2 is set as the fuel injection amount TPL from the common fuel injection valve 43.

Thereafter, the CPU waits for a predetermined fuel injection timing at P6, and when the predetermined fuel injection timing arrives, TPL is output at P7. Of course, the period of fuel injection in this route passing through P4 to P7 is 180°.

On the other hand, when the determination in P3 is No, the on-off valve 42 is closed in PS, and then it is determined in P9 whether or not the current engine detour is in the operating range I.

When the determination in P9 is YES, the process moves to PIO and the fuel injection amount T from the primary fuel injection valves 29A and 29B is
PP is set to TP calculated at P2, and fuel injection TPS from the secondary fuel injection valves 30A and 30B is set to 0. In addition, when it is determined No in P9, it is in the operating region ■, so shift to pH,
Fuel injection from the primary fuel injection valve 29A (29B) (+
+,: T PP as TPXCI and fuel injection from the secondary fuel injection valve 30A (30B) 7it T
PS is set as TPXC2 (TP to C1:
Distribute to C2 - However, both C1 and c2 are not 0).

After this PIO or Fil, the system waits for a predetermined fuel injection timing at Pl2, and when the predetermined fuel injection timing arrives, TPP and TPS are output at Pl3. Of course, the fuel injection period in the case of the route passing through P8 to P13 is 360' as in the conventional case.

Although the following two embodiments have been described, the present invention is not limited thereto, and includes, for example, the following cases.

The opening/closing valve 42 is not limited to a rotary type having a rotor 45, but may be of any suitable type, such as a butterfly valve, for example.

(2) When the control unit U is configured by a computer, it may be of either a digital type or an analog type.

■The primary fuel injection valve 29A is located near the boundary between area engineering and II.
, 29B and the common fuel injection valve 43, and near the boundary between the region H and the mouth, the primary fuel injection valves 29A, 29B or the secondary fuel injection valves 30A, 30B may inject fuel. , and the common fuel injection valve 43. By doing this, the connection of fuel supply accompanying the region transition can be smoothly established.

(4) In region II, in addition to fuel injection from the common fuel injection valve 43, fuel injection may also be performed from the primary fuel injection valves 29A and 29B. In this case, the dynamic range of the common fuel injection valve 43 itself is reduced to 1
This can be reduced by the amount of fuel injected from the next fuel injection valves 29A, 29B, which is preferable for promoting atomization of the fuel injected from the common fuel injection valve 43. Of course, as has been conventionally done, not only the primary and secondary fuel injection valves 29A, 29B, 30A, and 30B, but also the
Assist air for promoting atomization may also be supplied to the common fuel injection valve 43.

(5) The second fuel injection valves for injecting fuel into the communication boat 41 may be provided separately for the first cylinder A and the second cylinder B.

(The 6-throttle valve may be divided into a primary use and a secondary use (the opening degree of the primary throttle valve increases and begins to open at the contact parts that are in a predetermined high load area). In this case, when providing a surge tank, surge tanks may be configured separately for primary use and secondary use.

■Without dividing the intake passage into primary and secondary use, the intake passage is designed to constantly supply intake air throughout the entire load range, and fuel injection valves are installed on the downstream and upstream sides of the intake passage. You can do it like this.

(8) Only one first fuel injection valve for injecting fuel into the intake passage 21 may be provided for each cylinder without distinguishing between primary and secondary fuel injection valves.

(Effects of the Invention) As is clear from the above description, the present invention is capable of reducing the pump loss by using the communication boat, and at the same time preventing the combustion rate from decreasing and the HC from increasing when the pump loss is reduced. can.

In addition, during light loads and high loads, including idle, when the communication port is closed, it is possible to ensure combustion stability and output that meet the demands of the load, resulting in an optimal operating state according to the engine load as a whole. It becomes possible to secure the following. Furthermore, it is possible to reduce the number of oil consumption meters, which is particularly likely to be a problem in rotary piston engines.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the engine main body portion of a vertical piston engine to which the present invention is applied. Figure 7fSz is an overall system diagram showing an embodiment of the present invention. FIG. 3 is a main part #fr side view showing the detail M11 of the Kutsu boat part. Figures 4 and 5 show the open and close states of the on-off valve.
FIG. FIG. 6 is a graph showing an example of the setting of the operating range in which the on-off valve is opened and closed. FIG. 7 is a graph showing the relationship between opening and closing of the intake port, opening and closing of the communication port, and fuel injection timing. FIG. 8 is a flowchart showing a control example of the present invention. A2 1st cylinder B: 2nd cylinder 1: Engine body 2: Output shaft 5: Intermediate housing 8.9: Rotor chamber 10.11: Rotor 12A, 12B: Working chamber 13A, 13B: Working chamber 14A, 14B = Operation Chambers 15A, 15B: Intake port (secondary) 16A, 16B: #Air port 17A, 17B: Spark plug 21: Intake passage 23: Common intake passage 26: Throttle valve 27A, 27B: Independent intake passage (primary - 1) 28A,
28B: Independent intake passage (secondary-first) 29A, 29B:
Fuel injection valve (primary) 30A, 30B: Fuel injection valve (secondary) 41: Communication port 42: Open/close valve 43: Fuel injection valve (common - second) 45: Rotor 46: Communication port 49: Mounting hole 51 :Introduction A B

Claims (1)

[Claims] (1) A communication boat formed in an intermediate housing that defines a first cylinder and a second cylinder and communicates the working chamber of one cylinder in the intake stroke with the working chamber of the other cylinder in the compression stroke; a first fuel injection valve that injects fuel into the intake passage; and a second fuel injection valve that injects fuel into the communication port; the first fuel injection valve includes at least a high load region. In a region, the on-off valve is closed and fuel is supplied from the first fuel injection valve, and in a region other than the first region, the on-off valve is opened and fuel is supplied from the second fuel injection valve. A pump loss reduction device for a rotary piston engine, characterized in that: