JPS5851377Y2 - Rotary piston engine intake system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an intake device for a rotary piston engine.

Conventionally, a polygonal rotor moves inside a casing consisting of a rotor housing having a trochoidal inner circumferential surface and side housings disposed on both sides of the rotor housing, and rotates a planet while sliding its top edge against the trochoidal inner circumferential surface. rotational movement,
In a rotary piston engine that performs the intake, compression, explosion, expansion button, and exhaust strokes, the exhaust and intake stroke working chambers overlap, meaning that the intake port and exhaust port open simultaneously for one working chamber. Due to the pressure difference between the two ports, the exhaust gas remaining in the exhaust port is sucked into the intake passage from the intake port, and during the intake stroke in which this working chamber expands, the exhaust gas in the intake passage enters the intake stroke working chamber together with the fresh air mixture. In order to bring it to the old place,
The fresh air mixture is diluted with inert exhaust gas, causing the spark plug to ignite the mixture incorrectly, a so-called misfire phenomenon.
It has been recognized that this causes problems such as deterioration in running performance and an increase in harmful components in exhaust gas due to poor combustion.

Particularly in light load operating ranges, including idling, where the filling efficiency of the fresh air mixture is low, the negative effects of the above overlap are noticeable. The ignitability was maintained in the operating range.

However, the method described above supplies unnecessary extra fuel, and deterioration of fuel efficiency is unavoidable.
This is a major obstacle in reducing fuel consumption in rotary piston engines and responding to requests for resource conservation.

Therefore, in order to improve the ignition performance in the light load operating range including idling without setting the air-fuel mixture to be rich as described above, the present invention provides an intake port so as not to have the above-mentioned overlap. This suppresses the introduction of exhaust gas into the intake stroke working chamber, maintains good ignitability with a lean air-fuel mixture, and improves fuel efficiency.

That is, in the present invention, when one working chamber transitions from the exhaust stroke to the intake stroke, the exhaust port is set to substantially close and then the intake port opens, thereby eliminating overlap.

In this case, there are generally two types of intake ports: a peripheral port type in which the intake port is opened on the inner peripheral surface of the rotor housing, and a side port type in which the intake port is opened on the inner surface of the side housing. In the peripheral port type, it is difficult to set the port so that there is no overlap with the exhaust port due to its structural limitations.

Therefore, in the present invention, a side port type intake port provided in the latter side housing is adopted.

However, the opening shape of the above-mentioned side port-type intake port is restricted by various requirements, and if it is set so that there is no overlap with the exhaust port as described above, the opening area becomes narrow and is not sufficient under high loads. This causes a problem in which a suitable air-fuel mixture cannot be supplied, resulting in a decrease in output performance.

In other words, the contour shape of the intake port opened in the side housing is regulated so that the inner edge on the center side is outward from the sliding trajectory of the oil seal, and the outer edge on the outer periphery side regulates when the intake port begins to open. On the other hand, the upper edge regulates the closing timing of the intake port, and as described above, in order to delay the opening timing so as to eliminate overlap with the exhaust port, the outer edge must be set inward.

This narrows the opening area of the intake port, but the only way to increase this without causing the overlap is to widen the upper edge and delay the closing timing.

However, delaying the closing timing causes a phenomenon in which the intake air-fuel mixture is blown back into the intake passage under high load and low rotation, leading to a decrease in filling efficiency and compression pressure, and deteriorating the operating performance at low rotation. .

In view of this, the present invention provides a light load intake port including an idle port and a high load intake port in the side housing, and the light load intake port is set to open after the exhaust port is substantially closed. This eliminates overlap, suppresses the carry-in of exhaust gas, and improves the intake flow rate to promote fuel atomization, making it possible to ignite with a lean mixture even during idling, improving fuel efficiency. A cylindrical valve body is fitted to the high-load intake port, which closes a set value later than the normal intake port, and the valve body is rotated by a predetermined angle at high loads to connect the communication hole of the valve body with the high-load intake port. During high loads due to the reduction in the opening area of the intake port by communicating with the opening on the working chamber side and supplying fresh air from this high load intake port to eliminate the above overlap and advance the closing timing. This eliminates the decrease in output performance of the engine, and also eliminates the introduction of exhaust gas into the high-load intake port and high-load intake passage during light loads, thereby improving fuel efficiency and improving fuel efficiency in the light load range. In addition to satisfying output performance in a high load range with a simple structure, we also installed an inclined wall inside the cylindrical valve body that directs the air-fuel mixture toward the communication hole to reduce intake resistance and improve output performance. The present invention provides an intake device for a rotary piston engine.

Embodiments of the present invention will be described below with reference to the drawings.

This example shows a three-point intake system in which a light load intake port including an idle port, a medium load intake port, and a high load intake port are opened in the side housing of a rotary piston engine. be.

In FIGS. 1 to 6, reference numeral 1 denotes a rotor housing 2a having a trochoidal inner peripheral surface 1a.

Reference numeral 2b denotes side housings arranged on both sides of the rotor housing 1, and the polygonal rotor 3 runs inside the casing constituted by the rotor housing 1 and the side housings 2a and 2blC, with its top side being a trochoid-shaped inner housing. The working chamber 4 is formed by planetary rotation while being brought into sliding contact with the circumferential surface 1a.

The rotor 3 is supported by an eccentric shaft 5 (see Figures 5 and 6), and an apex seal 6, a corner seal 7, and a side seal 8 are attached to the rotor 3 in order to maintain a no-cush seal between each working chamber 4. An oil seal 9 is attached to the center side.

Further, numeral 10 is a light load intake port including an idle having an opening 10a opened on the inner surface of one side housing 28, and reference numeral 11 is an intake port for light load including an idle having an opening 10a opened on the inner surface of the other side housing 2b. The load intake port 12 is a high load intake port which has a working chamber side opening 12a opened on the inner surface of the other side housing 2b together with the medium load intake port 11;
This is a dual carburetor that supplies air-fuel mixture to each of the ports NO, 12 through the intake manifold 14.

Working chamber side openings 10a, 11a of each of the ports.

12a is opened and closed by the rotation of the rotor 3, and as shown in FIG. 5, the light load intake port 10 opens after the exhaust port 15 opened in the rotor housing 1 is substantially closed, and closes at an early stage. It is set as follows.

Further, the medium-load intake port 11 has the same shape as the light-load intake port 10, and opens and closes after the exhaust port 15 is substantially closed, and is substantially the same as the light-load intake port 10. They are set to close at the same time.

On the other hand, the intake port 12 for high load is the intake port 1 for light load.
It is set to close after a delay of a set value after 0 closes.

In addition, 16 in FIG. 5 is a spark plug.

Next, reference numeral 17 denotes a control valve that is interposed in the high-load intake port 12 and opens when the load is high, and is composed of a cylindrical valve body 18 and an actuator 19.

The high load intake port 12 has a side
b The working chamber opening 12a opened on the inner surface, and the opening 1
The valve element 18 is rotatably fitted into the cylindrical hole 12b of the high-load intake port 12.

The valve body 18 is formed in a cylindrical shape with an open end in the axial direction,
The opening 12 of the high load intake port 12 is located on the side of the tip.
A communication hole 18a that communicates with a at a predetermined angular position is provided.

Further, inside the valve body 18, the air-fuel mixture flowing from the opening at one end in the axial direction is passed through the communication hole 18 in the vicinity of the communication hole 18a.
A slanted wall 40 is provided to guide the device in the direction a (see FIG. 3).

The valve body 18 is rotated by an actuator 19,
Opening and closing of communication between the opening 12a and the communication hole 18a is performed.

In the above actuator 19, 19a is the case 19
19e is a diaphragm connected to the diaphragm 19a), 19f is a spring compressed in the atmospheric chamber 19d, 19g is an adjustment screw, and 19h is a pressure chamber 19c. The exhaust pressure introduction pipe 19i is a solid bellows with slits formed alternately on the inner and outer peripheries.

Further, the tip of the shaft 19e of the actuator 19 is connected to a rod 22 via a link 20 and a lever 21, and the rod 22 is inserted into the high-load intake port 12 through the intake manifold 14. It is connected to the opening base of the cylindrical valve body 18 via a pin 23.

Furthermore, 24 is a rubber seal interposed between the rod 22 and the intake manifold 14, which prevents external dust from being sucked in by the intake negative pressure generated in the secondary intake passage 26.

The exhaust pressure introduced into the pressure chamber 19c of the actuator 19 changes in accordance with the intake amount of the air-fuel mixture into the engine, and the pressure introduced into the pressure chamber 19c rises beyond a set value. At high loads, the diaphragm 19
a is biased downward against the biasing force of the spring 19f,
The valve body 18 is rotated via the rod 22 by the retracting operation of the cylinder 19e, and the communication hole 18a and the opening 12a are communicated to open the high-load intake port 12, and the exhaust pressure is lower than the set value. When the load is low, the shunt 19e protrudes due to the biasing force of the spring 19f, and the valve body 18 is rotated closed via the rod 22.

Furthermore, 25 is a 1 having a carburetor 130 primary throttle valve 27.
A primary intake passage 26 is constituted by a secondary carburetor 13A and a passage formed independently in the intake manifold 14, and a secondary carburetor 13B having a secondary throttle valve 28 of the carburetor 13 and an independent passage in the intake manifold 14. The primary intake passage 25 is connected to the light load intake port 10, and the secondary intake passage 25 is connected to the light load intake port 10.
The downstream side of 6 is branched into two to form the medium load intake port 1.
1 trigram and the high load intake port 12, respectively.

In addition, in the carburetor 13, 29 is a primary side venturi part,
30 is a secondary side venturi part, 31 is a primary side main nozzle (secondary side is not shown), 32 is a float chamber, 33 is a main jet, 34 is an air bleed, and the secondary throttle valve 28 is a primary vaporizer. It is linked to a diaphragm type actuator so as to open when the venturi negative pressure of the container 13A exceeds a set value.

In addition to the intake manifold 14, 35 is an intake air heating passage provided on the outer periphery of the primary intake passage 25.
Engine cooling water circulates from the inlet 35a to the outlet 35b (communicated with the rotor housing 1) to heat the air-fuel mixture in the primary intake passage 25.

Note that the control valve 17 is assembled to the intake manifold 14.
The valve body 1 is inserted into the tip of the rod 22 through the bottle 23.
8 is connected, the intake manifold 14 is tightened to the casing while the valve body 18 is fitted into the high-load intake port 12.

The operation of the above embodiment will be explained below.

First, in a light load range including idle, the carburetor 13
The secondary throttle valve 28 is closed, the exhaust pressure acting on the actuator 19 is also small, and the valve body 18 closes the high-load intake port 12.

Therefore, the air-fuel mixture from the primary intake passage 25 is supplied to the working chamber 4 only through the light-load intake port 10.

The light-load intake port 10 is set to open after the exhaust port 15 is substantially closed, and since there is no overlap with the exhaust port 15, the intake of exhaust gas due to this overlap is reduced, and at the same time,
The opening area of the light-load intake port 10 is small, and the air-fuel mixture is supplied from the independently formed primary intake passage 25, so that the flow rate of the air-fuel mixture is high and the vaporization and atomization of the fuel are good. Therefore, in conjunction with the reduction in the carry-in of exhaust gas, good ignition performance can be obtained even with a lean air-fuel mixture, resulting in a significant improvement in fuel efficiency under light loads, including idle.

At this time, since the medium-load intake port 11 is configured to open after the exhaust port 15 is closed, similar to the light-load intake port 10, the amount of exhaust gas carried in does not increase.

In addition, when the load is light, the high-load intake port 12 is closed near the opening 12a by the valve body 18, and the dead volume inside the boat is extremely small. Idle and light load operation is obtained.

Next, in the medium load range, the secondary throttle valve 2 of the carburetor 13
8 is opened, but the exhaust pressure acting on the actuator 19 is lower than the set value, and the valve body 18 still closes the high-load intake port 12.

Therefore, the secondary intake passage 2 is also connected to the medium load intake port 11.
6 is supplied at a high flow rate, and a sufficient mixture according to the increase in load ensures good output performance in the medium load range.

On the other hand, in the high load range, the secondary throttle valve 2 of the carburetor 13
8 further opens, the exhaust pressure acting on the pressure chamber 19c of the actuator 19 increases, and when the set load state is exceeded, the actuator 19 operates and the control valve 17
By rotating the cylindrical valve body 18, the communication hole 18a of the valve body 18 and the opening 12a of the high-load intake port 12 are connected.
The air-fuel mixture in the secondary intake passage 26 is also supplied from this high-load intake port 12.

At this time, the opening 12a of the high-load intake port 12 is opened from the upper part (leading side) by the valve body 18 as shown in FIG. The air-fuel mixture supplied from the opening 12a is
It is configured to eject in the leading direction, that is, toward the vicinity of the spark plug 16, and better combustion performance can be obtained.

The inside of the valve body 18 is provided with an inclined wall 40 that directs the air-fuel mixture flowing in from the opening at one end in the axial direction toward the communication hole 18a, so that a air-fuel mixture flow with low intake resistance and high flow velocity is provided. It is supplied into the working chamber 4 through the opening 12a.

At the above-mentioned high load, a large amount of fresh air mixture is supplied from all of the light load, medium load, and high load intake ports N0, 11, and 12, resulting in high output performance and good high load, High speed operation can be obtained.

In particular, the high-load intake port 12 closes later than the light-load intake port 10 button and the medium-load intake port 11, that is, the end of the intake stroke is delayed, so more air-fuel mixture is supplied. This improves filling efficiency.

Note that the closing timing of the high-load intake port 12 is limited due to the relationship with the blowback of intake air that occurs when the button is pressed at high load and low rotation speeds, but in this embodiment, the control valve 17 is adjusted according to the load and rotation speed. Opening/closing is controlled by exhaust pressure, so it is set to the optimum value in terms of improving output performance under high loads and high rotations.

In the above embodiment, the cylindrical valve body 18 of the control valve 17
The outer peripheral surface of the valve body 18 is preferably coated with a resin film made of fluororesin or the like in order to further ensure the rotational operation of the valve body 18 even in poor lubrication conditions.

Further, the communication hole 18a of the control valve 17 is formed larger than the opening 12a of the high-load intake port 12 and is pressed.

Furthermore, the design of the actuator 19 can be modified in various ways, and in addition to the exhaust pressure, the intake negative pressure that changes depending on the engine load state, the throttle valve opening, etc. can be used as a signal for opening the actuator at high loads. Alternatively, this may be used in combination with the rotation speed, etc.

However, if the control valve 11 is opened and closed using the exhaust pressure, the high-load intake boat 12 will be opened only during high load and high rotation, and the light-load intake boat 1
This is preferable because it has the effect of improving the phenomenon of intake air blowback, which becomes a problem at high load and low rotation speeds where a sufficient amount of air-fuel mixture can be secured in the zero or medium load intake boat 11.

Furthermore, in the above embodiment, the opening timing of the high load intake port 12 is set to open after the exhaust port 15 is closed as shown in FIG. In the light load range where this is a problem, the control valve 17 closes the area near the opening, and the dead volume near the opening is extremely small, and the amount of exhaust gas brought in from this dead volume is small. It may be set so that there is some overlap with the exhaust boat 15.

Furthermore, in the above embodiment, the intake port 10 for light load, medium load, and high load is provided in the side housing 2.
, 11 and 12 are opened, and these three ports constitute an intake boat, but the medium-load intake boat 1
1 may be omitted and the intake boat may be configured with two ports, the light-load intake port 10 and the high-load intake port 12. In that case, the light-load intake port 10 will be larger than the 3-port type. It is also necessary to increase the opening area to ensure sufficient fresh air mixture even in the medium load range.

On the other hand, as the fuel supply method, in addition to the method using the carburetor 13 as in the above embodiment, a fuel injection method may be adopted.

Therefore, according to the intake device of the present invention as described above, a light load intake port including an idle port and a high load intake port are provided in the side housing of a rotary piston engine.
The light load intake port is set to open after the exhaust port is substantially closed, and the high load intake port is set to close a set value later than the light load intake port, and
By installing a cylindrical valve body in the high-load intake port that opens at high loads, during light loads including idling, it reduces the introduction of exhaust gas due to overlap with the exhaust port, improves ignition performance, and improves ignition performance. In addition to enabling good operation and significantly improving fuel efficiency, it also opens the high-load intake port to supply a large amount of air-fuel mixture when the load is high, improving output performance, making it practical in all driving ranges. Also, favorable fuel efficiency and output performance can be obtained.

In addition, in the present invention, as a structure for opening and closing the high-load intake port, a cylindrical valve body having an opening at one end in the axial direction and a communication hole laterally communicating with the working chamber side opening at a predetermined angular position. is inserted into the high-load intake port, and the valve body is rotated by a predetermined angle under high loads.The processability of the high-load intake port and the valve body is good, and the valve body can be formed with high precision. It has the advantage of good sealing between the two, excellent operability, and reliable operation with a simple structure.

Furthermore, in the present invention, the flow from the opening near the communication hole into the cylindrical valve body having an opening at one end in the axial direction and a communication hole laterally communicating with the working chamber side opening at a predetermined angular position. By providing an inclined wall that directs the air-fuel mixture toward the orthogonal communication hole, the air-fuel mixture changes its flow direction smoothly, reducing intake resistance at this changing direction, improving intake flow velocity and filling efficiency. This makes it possible to further improve output performance in high-load operating ranges.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional side view of a main part of a rotary piston engine showing an embodiment of the present invention, Fig. 2 is a perspective view of a main part of a side housing, and Fig. 3 is a main part taken along line A-A in Fig. 1. 4 is a front view of the intake manifold section, FIG. 5 is an explanatory diagram showing the timing of opening and closing of the intake boat and exhaust port, and FIG. 6 is a longitudinal sectional view of the main part. 1...Rotor housing, 1a...Inner peripheral surface, 2a, 2b...Side housing, 3
...Rotor, 4...Working chamber, 5...
...Eccentric shaft, 10...Intake port for light load,
11...Medium load intake boat, 12...
・High load intake ports, 10a, 11a, 12a...
...opening, 13...carburizer, 13A...
...Primary vaporizer, 13B...Secondary vaporizer, 1
4...Intake manifold, 15...Exhaust port, 17...Control valve, 18...
Valve body, 18a... Communication hole, 19... Actuator, 20... Link, 21...
...Lever 22...Rod, 23...
Pin, 24...Rubber seal, 25...
・Primary intake passage, 26...Secondary intake passage, 27
...Primary throttle valve, 28...Secondary throttle valve, 35...Intake air heating passage, 40...
sloping wall.

Claims (1)

[Scope of utility model registration request] The side housing is provided with a light-load intake port that opens after the exhaust port is substantially closed, and a high-load intake port that closes a set value later than the light-load intake port. The intake port is provided with a cylindrical valve body that has an opening at one end in the axial direction and a communication hole that communicates with the working chamber side opening at a predetermined angular position on the side. A slanted wall is provided near the hole to direct the air-fuel mixture flowing from the opening toward the communication hole, and the valve body is rotated by a predetermined angle under high load to connect the communication hole of the valve body and the working chamber of the high-load intake port. An intake device for a rotary piston engine, characterized in that an air-fuel mixture is supplied from a high-load intake port that communicates with a side opening.