JPS6390628A - Pumping loss reducer for rotary piston engine - Google Patents

Abstract

PURPOSE:To aim at reduction in a pumping loss, by installing an on-off valve in an interconnecting port which interconnects an interval between operating chambers of two cylinders in each of both suction and compression strokes, and at the time of light load, controlling it so as to delay timing for opening the on-off valve as compared with at the time of medium load. 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. And in this intermediate housing, there are provided with an on-off valve 42 for opening or closing this interconnecting port 41, and a fuel injection valve 43 for spraying fuel to the inside the interconnecting port 41. And, the on-off valve 42 is opened at times of light and medium load, but at the time of light load, the valve opening timing is controlled by a timing adjusting mechanism V so as to be delayed as compared with at the time of medium load.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary piston engine ribbon loss reduction device.

(Prior art) In an engine that controls the load by adjusting the intake air J with a throttle valve disposed in the intake passage, when the opening degree of the throttle valve is small, the throttling loss, that is, the pumping loss is large. Become.

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 system in which a communication port is formed that is opened and closed by a rotor at the timing of communicating with the working chamber of the cylinder, and this communication port is provided with an on-off valve that opens when a predetermined operating range is reached. (Refer to Japanese Patent Application Laid-Open No. 172429/1983)
. In other words, by utilizing the flow of intake air between the first cylinder and the second cylinder through the communication port, it becomes possible to open the throttle valve to a larger degree.
This will reduce pumping losses.

(Problems to be Solved by the Invention) Incidentally, it has been thought that the communication port must be opened by the on-off valve only during medium load. To explain this point in detail, when the communication port is used to reduce pump loss, the compression pressure decreases. For this reason,
As for the operating range in which the communication port is opened by opening and closing the valve, it is desirable to exclude high-load situations where output is required and the throttle valve is wide open so that pumping loss is not much of a problem.

On the other hand, during light loads including idling, particularly at light loads and low rotations, in addition to the above-mentioned reduction in compression pressure, the mixing ratio of dilution gas increases, resulting in poor combustion stability. In other words, for rotary piston carrots, 1
Because the two working chambers have timings that overlap the intake and exhaust ports, and because dilution gas tends to stay in the spark plug mounting hole, the ratio of dilution gas to intake air tends to be relatively large. be.

In this way, due to the influence of dilution gas, the pumping loss is not reduced at all using the communication port at light loads when the opening of the throttle valve is small and the pumping loss is the most problematic. This poses a problem in making full use of the effects of this device.

Therefore, an object of the present invention is to provide a pump loss reduction device for a rotary piston engine that can reduce pumping loss by using a communication port even under light loads while avoiding the influence of dilution gas as much as possible. There is a particular thing.

(Means and operations for solving the problem) In order to achieve the above-mentioned object, in the present invention, when the load is light, the most problematic timing of mixing the dilution gas, i.e. The communication ports are opened at times when one working chamber overlaps the intake and exhaust ports. Specifically, it is formed in an intermediate housing that defines a first cylinder and a second cylinder, and is formed at a timing when the working chamber of one cylinder in the intake stroke communicates with the working chamber of the other cylinder in the compression stroke. a communication port that is opened and closed by a rotor; an on-off valve that is provided in the communication port and is opened during light and medium loads; and a delay means that delays the opening timing of the communication port during light loads compared to medium loads. The configuration includes the following.

With this configuration, during medium loads where the drop in dilution gas and compression pressure is not a big problem, the communication port can be used to ensure a sufficient reduction in bonding loss, while at light loads, The communication port opens slightly later than during medium load to prevent an increase in the proportion of illusion gas mixed in (while ensuring combustion stability).
It becomes possible to reduce the bonding loss by using the communication port.

Of course, even if there is a slight delay in opening the communication port, it will be possible to open the throttle valve wide since the throttle valve is originally largely throttled, so the effect of reducing pumping loss during light loads will be sufficient. It becomes a big thing.

(Example) Examples of the present invention will be described below based on the attached drawings.

In the if diagram, the housing of the engine body 1 is sequentially arranged from one end of the output @h2 (eccentric shaft) to the other end: a side housing 3, a rotor housing 4, an intermediate housing 5,
It is composed of 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, the first cylinder A having the rotor 10 and the second cylinder B having the rotor 11.

As shown in FIG. 2, each rotor chamber 8 (9) has three working chambers 12A (
12B), 13A (13B), and 14A (14B)
It is defined as In this Figure 2, 15A (1
5B) is a primary intake port formed in the intermediate housing 5, 16A (16B) is an exhaust port, and 17
A (17B) is a spark plug. Therefore, in the state shown in FIG. 2, in the working chamber of the first cylinder A, 12A is in the intake stroke, 13A is in the explosion stroke (initial stage), and 14A is in the exhaust stroke. Further, in the working chamber of the second cylinder B, cylinder 12B is in the exhaust stroke (final stage), cylinder 13B is in the compression stroke, and cylinder 14B is in the explosion (final stage) 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 used as a part of the common intake passage 23. , an air cleaner 24, an air flow meter 25, and a throttle valve 26 are provided. In addition, the intake passages downstream of the surge tank 22 include primary and secondary independent intake passages 27A and 28A for the first cylinder A, and i2
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 port 15A (27B) formed in the intermediate housing 5 as is known.
15B), and a secondary independent intake passage 28A (
28B) is connected to a secondary intake port formed in the side housing 3 (7).

A fuel injection valve 29A (29B) is disposed in the primary independent intake passage 27A (27B), and a fuel injection valve 30A (30B) is disposed in the secondary independent intake passage 28A (28B).
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 In addition, the secondary fuel injection valve 3OA (30B) has a secondary independent intake passage 28A (
28B). Furthermore, this 1
Both the next and secondary fuel injection valves 29A, 29B, 30A, 3
0B 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 downstream side.

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 port 1 by the rotor 10 or ti.
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, is used commonly for the first cylinder A and the second cylinder B.

As shown in FIGS. 3 to 5, the on-off valve 42 includes a bottomed cylindrical housing 44 that forms part of the communication port 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. Thereby, depending on the rotational position of the rotor 45, the communication port 41 can be fully opened (see No. 41N) or fully closed (see FIG. 5), or can have a desired opening degree.

The fuel injection valve 43 is connected to the communication port 46 of the rotor 45 with σi
It is designed to inject fuel by pressing l+.

Therefore, as shown in FIG. 3, a mounting hole 49 and an inlet 51 (rotor 45) are formed on an extension line that passes through the axis of the rotor 45 and is perpendicular to the axis of the communication port 41. A fuel injection valve 43 is inserted into this mounting hole 49 .

The extension line, that is, the axis of the fuel injection valve 43 is
The introduction port 51 is configured to rise as it moves away from the rotor 45, and the inlet 51 is connected to the communication port 46 so as to coincide with the mounting hole 49 when the rotor 45 is in the open position, as shown in FIG. They are formed orthogonally. With this configuration, fuel injected by the fuel injection valve 43 is supplied to the communication port 46, that is, the communication port 41, through the inlet 51 only when the communication port 41 is open.

In addition, in the communication hole 46, there is a collision plate 5 for colliding the injected fuel from the fuel injection valve 43 to promote vaporization and atomization.
2, and this collision plate 52 is supported by the rotor 45 via a stay 53 fitted into the introduction port 51.

Further, the inlet 51 connects the open end to the mounting hole 49 to the rotor 4.
It is set to be long in the direction of 50 rotations so that fuel from the fuel injection valve 43 can be supplied to the communication port 41 even when the opening degree of the on-off valve 42 is small.

Now, referring to FIG. 8, the JJ adjustment mechanism V that adjusts the opening degree and opening timing of the on-off valve 42 will be described. The adjustment mechanism (2) has a pair of rotating shafts 71, 72 that are rotatably supported by the housing 3.4 or 5 so as to be colinear with each other. Rotating shaft 71
is linked to the output shaft 2 via a toothed pulley 73, a timing belt 74, and a toothed pulley 75, and is rotated in synchronization with the output shaft 2. Further, the rotating shaft 72 is linked to the rod 47 of the rotor 45 via a pair of bevel gears 76 and 77, and by changing the rotational position of the rotating shaft 72, the rotor 45 is brought to a desired rotational position. (The opening/closing valve 42 is set to the desired opening degree).

Both rotating shafts 71 and 72 are connected and connected via a clutch 78. This clutch 78 has a 51 clutch piece 78A fixed to the rotating shaft 71 and a second clutch piece 78B spline-fitted to the 1 rotating shaft 72. As shown in FIGS. 9 and 10, engagement grooves 7 are provided on opposing surfaces of both clutch pieces 78A and 78B.
8a, and an engaging protrusion 78b is formed on the other side. This engagement groove 78a extends in the circumferential direction and has a tapered groove bottom. And the engagement protrusion 78b
has a shape corresponding to the engagement groove 78a. As a result, when the first clutch piece 78A is rotated as indicated by the solid line arrow in FIG. It is rotated synchronously with the rotation 1671 (output shaft 2) with a predetermined phase relationship. And this clutch 7
The opening timing of the on-off valve 42 when the rotor 8 is connected is set to be slightly later than the timing when the communication port 41 is opened by the rotor 10 or 11.

A southern portion 78C is formed at the outer portion of the second clutch piece 78B, and a gear 80 driven by a rotary electromagnetic actuator 79 such as a step motor or a DC motor is constantly meshed with this crest 78c. As a result, when the clutch 78 is disengaged (the engagement protrusion 78b is removed from the engagement groove 78a), by adjusting the rotational position of the motor 79, the on-off valve 42 is adjusted to the desired opening degree. is set to

The engagement and disengagement of the clutch 78 is controlled by a negative pressure actuator 8.
This is done using 1. This actuator 81 has a diaphragm 81b that defines a pressure chamber 81a, and a rod 81c attached to the diaphragm 81b is connected to the second clutch via a swinging lever 82 that swings about a fulcrum 82a. It is linked to piece 78B. As a result, when negative pressure is supplied to the pressure chamber 81a, the second clutch piece 78B moves to the left in the figure to connect the clutch 78, and conversely, the negative pressure in the pressure chamber 81a is released (atmospheric pressure is introduced), the clutch 78 is disengaged.

The pressure chamber 81a is connected to a negative pressure tank 84 via a negative pressure introduction passage 83, and an electromagnetic on-off valve 85 is engaged with this negative pressure introduction passage 83. Further, the pressure chamber 81a can be opened to the atmosphere through an atmosphere introduction passage 86, and an electromagnetic on-off valve 87 is connected to the atmosphere introduction passage 86. As a result, when the on-off valve 85 is opened and the on-off valve 86 is closed, the pressure chamber 81a
Negative pressure is introduced into (clutch 78 connected), and conversely the on-off valve 8
5 is closed and 86 is opened, the negative pressure in the pressure chamber 81a is released (clutch 78 is disengaged). Note that the negative pressure tank 84
is connected to the intake passage immediately downstream of the throttle valve 26 via a check valve 88, and stores the negative pressure generated in this intake passage.

U in FIGS. 2 and 8 is a control unit composed of a microcomputer, and this control unit U receives an intake air amount signal from the air flow meter 25, an engine rotation speed signal from the rotation speed sensor 61, and an opening degree signal. An opening degree (rotational position) signal of the on-off valve 42 from the sensor 89 is input.

Further, the control unit U controls the opening degree and opening timing of the on-off valve 42 (on/off control of the clutch 78, rotation control of the motor 79), and controls the opening degree and opening timing of the on-off valve 42, and controls the respective fuel injection valves 29A, 29.
Fuel injection control is performed from B, 30A, 30B, and 43.

Note that the control unit U basically includes a CPU, a ROM,
The microcomputer is equipped with a RAM, a CLOCK, and 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 area of the opening/closing valve 42 is, for example, MS
As shown in FIG. 6, the engine speed Ne and the engine load (intake air fQa) are set as parameters. In other words, at high rotation or high load (area m)
When the on-off valve 42 is closed (fully open), light load including idle, low rotation (area B), and medium load, medium rotation (area ■)
The on-off valve 42 is opened. Further, the fuel injection valves in which fuel is injected are, for example, only the primary fuel injection valves 29A and 29B in area engineering, and in area II, the common fuel injection valve 43 injects fuel to the communication port 41. In region m, the fuel injection valves 29, 29B, 30A, and 30B are the primary and secondary fuel injection valves.

FIG. 7 also shows an operating region I in which the communication port 41 is open.
3 shows a combustion cycle when the fuel injection valve 1 is in the position I, the direction of exchange of intake air through the communication port 41, and an example of the timing of fuel injection from the fuel injection valve 43. That is, in FIG. 7, IO indicates the intake port opening timing, IC indicates the intake port closing timing, LO indicates the communication port 41 opening timing, and LC indicates the communication port closing timing. The shaded area is when the intake air flows back and forth between the two cylinders A and B, and the white arrow indicates the flow direction of the intake air.

Then, air is taken in per revolution of the rotor 10 or 11,
Four strokes of compression, explosion, and exhaust are performed, and the output shaft 2 rotates three times for one rotor rotation, so the rotor 1 per stroke
The rotation angle of 0.11 is 270', and the rotors 10 and 1
The rotational phase difference with respect to 1 is 180° because it is a 2-cylinder engine. Therefore, the fuel injection period from the fuel injection valve 43 common to each cylinder A and B is 180 degrees, and the fuel injection period of the remaining fuel injection valves 29A, 29B, 3OA, and 30B is 36 degrees.
0".

Based on the above premise, in the embodiment, the timing of fuel injection from the common fuel injection valve 43 is set when the communication port 41 is open, as shown by injection pulses ■ and ■ in FIG. It is set to end at . In the example shown with this injection pulse ■, the injection start and end are both when the communication port 41 is open, and the injection pulse ■
In another example, injection is started when the communication port 41 is closed, and injection is ended when the communication port 41 is open.

Here, in regions (2) and (II) where the on-off valve 42 is open, the opening degree and opening timing thereof are set as follows. That is, in FIG. 12, when the opening degree of the on-off valve 42 is set from O (fully closed) to 100 (fully open),
The opening degree is set to 50 (%) near the boundary between area work and ■ to improve the connection between opening and closing. Also, the 12th
The meaning of the value shown in Figure r-10J is that the opening timing of the on-off valve 42 is delayed (
Clutch 78 is connected, on-off valve 42 is fully open).

As described above, in the operating region 1■, the communication port 41 is opened as shown in FIG. 7, and intake air flows from one cylinder in the compression stroke to the other cylinder in the intake stroke. At this time, the common fuel injection valve 43 is inserted into the communication port 41.
All of the fuel injected from the inlet is stratified and supplied to the working chamber in the intake stroke while remaining rich on the fast intake air flowing through the communication port 41. Since the fuel supplied from this communication port 41 has a short travel distance until it is combusted,
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, this medium load operation area is
Since the time is generally much longer than the time of high-load operation, the effect of reducing oil consumption is considerable.

Furthermore, when the load is high, the communication port 41 is closed, thereby preventing the rE compression pressure from decreasing and ensuring sufficient output.

Furthermore, in area work, although the communication port 41 is opened, the timing is delayed compared to area II (
The position of FIG. 7 LO is changed to the right). This reduces the inflow rate of dilution gas, satisfies the requirement for combustion stability, and sufficiently reduces pumping loss.

Among the control contents of the control unit U described above, the on-off valve 42
The control portion will be explained in detail with reference to the flowchart shown in FIG. In addition, in the following theory II, P indicates a step.

First, the engine speed Ne and the intake air amount Qa are detected at PI, and then at P2, the 12th
The target opening degree Lo of the on-off valve 42 is read from the map shown in the figure.

After this, at P3, the target opening LO at P2 is changed to "
It is determined whether or not the value is smaller than 0.

When the determination in P3 is YES, it is the time of area work, so the clutch 78 is connected in P4.

Conversely, if the determination in P3 is No, the clutch 78 is disengaged in P5, and then in P6 the motor 79 is used to control the opening of the on-off valve 42 to the target opening Lo (fully open). , fully closed or partially open).

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

(2) The on-off valve 42 is not limited to a single type having a rotor 45, but may be of any suitable type, such as a butterfly valve.

(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 regions , and the common fuel injection valve 43. By doing this, the connection of fuel supply accompanying the region transition can be smoothly established.

(2) In region H, 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 can be reduced by the amount of fuel injected from the primary fuel injection valves 29A and 29B, and the fuel injected from the common fuel injection valve 43 can be atomized. Seven is preferred. Of course, as is conventional practice, assist air for promoting atomization is supplied not only to the primary and secondary fuel injection valves 29A, 29B, 30A, and 30B, but also to the common fuel injection valve 43. You may also do so.

(2) The second fuel injection valve that injects fuel into the communication port 41 may be provided separately for the first cylinder A and the second cylinder B.

(2) The throttle valve may be divided into a primary throttle valve and a secondary throttle valve (the opening of the primary throttle valve increases and begins to open at the connections that are in a predetermined high load area). In this case, when providing a surge tank, it is sufficient to configure separate surge tanks 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.

(The first fuel injection valve injects fuel into the Φ intake passage 21,
Only one cylinder may be provided for each cylinder without distinguishing between primary and secondary cylinders.

(2) Fuel may be supplied from the common fuel injection valve 43 in area engineering. In this case, further combustion stability can be ensured by stratified combustion, and it is also possible to eliminate the primary fuel injection valves 29A and 29B.

(Effect of Emission 1) As is clear from the above description, the present invention extends the range of reducing pump loss by using the communication port to the light load range while preventing the effects of illusion gas. be able to.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the engine main body portion of a rotary piston engine to which the present invention is applied. FIG. 2 is an overall system diagram showing one embodiment of the present invention. FIG. 3 is a sectional view of main parts showing the communication port portion in detail. Figures 4 and 5 show the open and close states of the on-off valve.
FIG. 3 is a cross-sectional view taken along line XX in the figure. 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 detailed diagram of the part that adjusts the opening degree and opening timing of the on-off valve. FIG. 9 is a thin-biline sectional view of FIG. 8. FIG. 10 is a sectional view taken along line XX in FIG. 9, showing how both clutch pieces are engaged and engaged in a predetermined phase relationship. FIG. 11 is a flowchart showing a control example of the present invention. FIG. 12 is a graph showing an example of setting the opening degree of the on-off valve and the opening timing of the communication port. A: 1st cylinder B: 2nd cylinder 1: Engine body 2: Output shaft 5: Intermediate housing 8.9: Rotor chamber 10.11: l: 7-ta 12A, 12B 2 Working chambers 13A, 13B: Working chamber 14A , 14B: Working chambers 15A, 15B: Intake port (secondary) 16A, 16B: Exhaust port 17A, 17B: Spark plug 21: Intake passage 23: Common intake passage 26: Throttle valve 27A, 27B: Independent intake passage (primary -1st) 28A,
28B: Independent intake passage (secondary - first) 41: Communication port 42: Open/close valve 45: Rotor 46 Two communication lower 8: Clutch (for opening timing adjustment) 79: Motor (for opening degree adjustment)

Claims (1)

[Claims] (1) It is formed in an intermediate housing that defines the first cylinder and the second cylinder, and is actuated by a rotor at the timing when the working chamber of one cylinder in the intake stroke communicates with the working chamber of the other cylinder in the compression stroke. a communication port that opens and closes; an on-off valve that is provided in the communication port and opens during light and medium loads; and a delay means that delays the opening timing of the communication port during light loads compared to medium loads; A pump loss reduction device for a rotary piston engine, characterized by comprising: