JPS5970835A - Intake device of rotary piston engine - Google Patents

Abstract

PURPOSE:To improve the output of an engine throughout from its medium speed range to high speed range, by obtaining a supercharge effect due to the exhaust interference mutually between cylinders at high speed operation of the engine while a supercharge effect due to the inertia pulsation of each cylinder itself at medium speed operation of the engine, in the case of a two-cylinder engine of side intake port type. CONSTITUTION:At high speed operation of an engine, a compression wave, generated in, for instance, a passage 16b when an intake port 3 in a cylinder 1B is opened, is propagated to an intake port 3 immediately before full closing with a 180 deg. phase difference in a cylinder 1A by setting a passage in an adequate length between the intake ports 3, 3, and a supercharge is operated. Similarly thereafter, an output of the engine is increased by an exhaust interference effect mutually between the cylinders 1A, 1B. While a compression wave, generated in passages 16a, 16b at closing, causes inversion and reflection with expansion and compression by setting the length of a passage between each intake port 3 and an expansion chamber 21 with the reference at medium speed time, and is propagated as a secondary pulsating compression wave to the next intake port 3 immediately after opening, thus an output at the medium speed time can be improved by a supercharging effect due to the inertia pulsation of each cylinder itself.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake system for a rotary piston engine, and more specifically, to an intake system for a rotary piston engine.
In engine engines, this technology utilizes the intake pressure waves generated in the intake passage, especially the overlapping compression waves generated when the intake boat is opened and closed, to increase the supercharging effect by 1q from medium to high engine speeds. It relates to something that is made to look like this.

In general, side intake boat type two-cylinder rotary vis 1-
The casing engine has a rotor housing with a two-section trochoidal inner circumferential surface, and a side housing with an intake boat with an intake passage opening on both sides. is supported by an eccentric shaft and rotates in an M star,
In addition, one coater in each cylinder has a phase difference of 180° with respect to the rotation angle of the eccentric shaft, and while maintaining the above 180° phase difference between both cylinders, intake, compression, and explosion are performed in each cylinder as the rotor rotates. , expansion and exhaust strokes are performed sequentially.

By the way, it is well known that conventionally, in such a rotary piston engine, a supercharger is installed in the intake passage in order to improve the power, but the structure becomes complicated due to the supercharger, and the loss is increased. I had a dislike for it that made me angry.

In addition, conventionally, as a technology to increase the supercharging effect by 4Q using intake pressure waves, in a single cylinder rotary rev engine, the intake pipe is It is divided into two passages with different methods, each with a separate intake boat, and when the engine is running at high speeds, the two intake passages are used, and when the engine is running at low rotations, the intake passage that is at the later closing position is closed, and the intake air is blocked. By occluding the air early, optimal charging is achieved over a wide range of engine speeds by utilizing the supercharging effect caused by the occlusion of the intake air at the point of maximum intake pressure, which is a function of the intake pipe dimensions and cone engine speed. A method has been proposed that achieves the highest efficiency. However, this is for a middle-cylinder rotary piston engine,
It was not clear how to utilize the intake pressure waves generated in the intake passage, and the effect of the first structure was not clear, so it could not be put to practical use immediately. Moreover, since a peri-boat is used as the intake boat, the intake boat communicates with the exhaust working chamber before the intake working chamber closes, making it difficult to obtain a supercharging effect due to exhaust gas blowing back from the exhaust working chamber. It was frequent. In particular, in recent years commercially available cars, the engine exhaust pressure has increased to reduce noise and purify exhaust gas, and at high speeds and loads, normal engines have a pressure of 400 to 600 mmH (1 (gauge pressure)), and engines with turbochargers Then 1000 rm
n l-1g or more, and no improvement in filling efficiency can be expected by the VeriBot method.

Therefore, when examining the intake characteristics of the side intake boat in a rotary piston engine, the inventors found that (+) When the intake boat is open, the intake air is compressed by the pressure of the residual exhaust gas in the working chamber, and the intake boat in the intake passage is compressed by the pressure of the residual exhaust gas in the working chamber. (i) When the intake boat is closed, the intake air is compressed due to the inertia of the intake air, and compression waves are generated in the intake boat section in the intake passage. Above (+
), the supercharging effect can be obtained by applying the aperture compression wave of the other cylinder, especially to the intake boat just before full opening, where intake air blowback occurs. If the opening compression wave of 11) is reversed twice to create a secondary pulsating compression wave and applied to each cylinder, especially to the intake bow 1 immediately after the next opening where exhaust gas blowback occurs, "supercharging effect" can be achieved. (hereinafter referred to as the inertial pulsation effect).In particular, the above-mentioned exhaust interference effect has been developed in recent years due to the introduction of catalyst devices for exhaust purification in engine exhaust systems, which have increased exhaust pressure. The effect is remarkable and is effective when the engine is under high load and at high rotation speeds with strong output requirements.In addition, unlike the side intake bows 1~, the intake passage is located on the rotor housing. In this case, the intake bow 1~ always opens into the working chamber, so the above-mentioned exhaust interference effect does not occur.

That is, an object of the present invention is to provide a side intake boat type two-cylinder rotary piston engine as described above, to connect the intake passages of each cylinder during the intake boat frontage period, and to convert the compression wave to the expansion wave when the engine is closed. By appropriately setting the position of the expansion chamber of the reservoir which then reverses into a secondary pulsating compression wave, the passage length between the intake boats of the rain cylinder, and the passage length from the expansion chamber to the intake boat of each cylinder, the 5000 ~7000 rpni
When the engine speed is high, the exhaust interference effect occurs.
By performing supercharging using the inertial pulsation effect during engine rotations of 0 to 5000 rIlm, the existing intake system can be easily configured without using a supercharger or the like.
This is an extremely simple configuration with one change, and aims to increase the charging efficiency and improve the output from medium to high engine speeds.

In order to achieve this object, the configuration of the present invention is to provide a rotor housing having a two-node rotor housing and an intake boat having an intake passage located on both sides of the rotor housing. A substantially triangular rotor is supported by an eccentric shaft and performs planetary rotation within the casing formed by the housing, so that each 1" and 1" angle has a phase difference of 180° with respect to the rotation angle of the eccentric shaft. 2
In a cylinder rotary piston engine, a. The frontage period θ to the intake bow 1 is set in the range of 270 to 320 degrees at the rotation angle of the eccentric 1 to the cylinder 1 fufu [-. b. The intake passage of each cylinder is set. downstream of the throttle valve (connection J8 An enlarged chamber extending to the right of the communication passage is provided; C6 the passage length between the intake boats of both cylinders formed in the intake passage downstream of the communication passage) Sashio 0.57~1
．． Under the conditions that d is set to be 37 m, the length 91 of the intake passage from the expansion chamber to the intake boat of each cylinder is set to 0.17, and Q is set to 15 m. When the engine is running at a high speed of 5,000 to 7,000 ppm, the compression wave generated in the intake passage when the intake port of one cylinder is opened is propagated through the communication passage to the intake boat of the other cylinder just before it is fully opened, thereby generating supercharging. while doing 30
During medium rotation of the engine at 00 to 5000 ppm, the compression wave generated in the intake passage when the intake port of each cylinder is closed is reversed twice in the expansion chamber, and a secondary pulsating compression wave is generated at the intake bow 1 immediately after the frontage of each cylinder. Therefore, the exhaust interference effect between cylinders at high engine speeds and the inertial pulsation effect of each cylinder itself at medium engine speeds cause supercharging to be carried out from the mid-speed range of the engine. This is designed to increase charging efficiency over a wide range of high rotational speeds.

Here, the limitation of 5,000 to 7,000 ppm at high engine speed to obtain the above-mentioned exhaust interference effect does not apply to the engine's high-load, high-speed operation range, since the maximum output and maximum speed are generally set within this range. hand,
This is because it is an effective area for improving charging efficiency and output by exerting a significant supercharging effect. In addition, 3,500 to 3,500 at engine medium rotation to obtain the above-mentioned inertial pulsation effect.
The limitation of 5°O, Orpm is that if it is set so that the inertial pulsation effect is exerted in the engine's medium rotation range, a trough of the pulsation wave (first-order pulsation expansion wave) will occur in the high rotation range, impairing the above exhaust interference effect. Therefore, in order to set the valley so that it occurs at 700 Orpm or more, which is the time when the engine is at high speed, the lower limit must be 350 Orpm or more.

In addition, the upper limit of the intake bow 1-frontage period θ in the above setting item a, 320°, is to prevent the preceding working chamber from communicating with the succeeding working chamber via the nide intake bow 1. The opening period due to the side seal is approximately 40° longer than the actual opening period due to the side seal opening period, and it is necessary to provide an interval of 40° or more between the side seal opening periods to avoid overlap. In order to suppress the opening period to less than this, the intake working chamber is connected to the intake working chamber through a minute gap (usually about 200μ) between the inner sliding surface of the side housing on the outside of the nide seal and the rotor side. This prevents communication with the intake chamber and prevents exhaust gas from being carried into the intake working chamber during low rotation and low load conditions such as idling, thereby ensuring stable combustion. On the other hand, the lower limit of 270° is from top dead center (TDC) to bottom dead center (BDC).
This is the minimum period of the geometrical intake stroke up to ), and in order to effectively perform intake, it is necessary to set at least one period longer than this.

Incidentally, the opening period of the intake boat of the present invention is the substantial opening/closing period of the intake boat on the side surface of the rotor, and is not due to the intake seal. This means that regarding the effective generation and propagation of pressure waves in the high rotation range that is the problem of the present invention,
This is because the minute gap outside the side seal has no substantial effect.

In addition, the downstream position of the throttle valve in the expansion chamber that has the communication path as described above is important because the presence of the throttle valve acts as a resistance to the propagation of pressure waves (compression waves and expansion waves), so it is necessary to avoid it. This is to reduce the attenuation of pressure waves and propagate them effectively.

Furthermore, the length of the passage between the intake boats of the inner cylinder in the above setting C is set to obtain the exhaust interference effect, L = (θ-゛180-00) X (60/36ON) Xc...There is a value C obtained from the formula (I). That is, in the above formula, θ
is the intake bow 1-opening period, θ-270 to 32o, 180° is the phase difference between internal air stations, and θ0 is the invalid period, during which compression waves are substantially generated from the intake boat opening. This is approximately 20°, which is the sum of the period from the time immediately before the intake boat is fully closed to the time when the intake boat is fully opened, during which the frontage compression wave is propagated in order to effectively perform supercharging. Therefore,
θ-180-〇〇) represents the rotation angle of the eccentric shaft required from generation of compression waves in one intake boat to propagation to the other intake boat. In addition, N is the engine rotation speed, N = 5000 to 7000 rpm,
60 / 360 N is the time required to rotate 1 degree (
seconds). Also, C is the propagation speed of compression waves! 1 m (sound speed) and 20°Crc = 343m/S°C. From these values, L=0°57~1.37m.

Furthermore, the passage length ρ1 between the expansion chamber and the intake boat of each cylinder in the setting item d above is set to obtain an inertial pulsation effect, and is 1+, = (360-θ+61
) X60/36ONXc X 1/22- (II) That is, in the above formula 83, 36° is the interval of the intake stroke, and the intake boat opening period θ-270 to 320', ! : 7jθ1 is an invalid period that is defined by the period when the intake boat is fully closed while the compression wave is generated at the time of closing, and the period until the secondary pulsating compression wave is propagated from the intake boat opening, and the side intake θ+ Therefore, (360-θ+θ1) represents the rotation angle of the eccentric shaft required from the generation of the compression wave at the time of closing the mouth to the propagation of the secondary pulsating compression wave. In addition, the engine rotation speed N = 3500 to 5000 ram te, similar to the above formula (I), represents the time (seconds) required to rotate 1 degree. Also, the propagation speed of the pressure wave c = 343 m /s (20'C).Furthermore, since 2 is a positive order of the pulsating wave and uses the second-order pulsation, Z=
2, and 1/2z represents the reciprocal of the stroke in which the secondary pulsation makes two reciprocations. Therefore, from these values, U+=0.17~
It becomes 0.45m.

Note that <I), Equation (I) ignores the influence of the flow of intake air on the propagation of pressure waves. This is because the flow velocity is smaller than the speed of sound and causes almost no change in the length of the intake passage.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

In FIGS. 1 and 2, 1△ and J: and 1B are the first and second cylinders of a side-intake boat type two-cylinder low-repetition piston engine, and each cylinder IA, I
B includes a rotor housing 2 having a two-bar trochoidal inner circumferential surface 2a, and an intake boat 3 located on both sides of the rotor housing 2, in which intake passages 16a and 16b, which will be described later, are opened. The inside of the casing 5 formed by
A substantially triangular rotor 6 connects the eccentric 1 to lift shaft 7.
Each cylinder IA is supported by a planetary rotary motion.

1B rotor 6.6 is eccentric 1-Ricci A771~
Each rotor 6 has a phase difference of 180° at a rotation angle of 7.
As the casing 5 rotates, three working chambers 8, 8 .
18 in each cylinder 1Δ, 1B.
The intake, compression, explosion, expansion J3, and exhaust strokes are performed in sequence with a phase difference of 0°. In addition, 9 is each cylinder 1
Exhaust ports opened in the rotor housing 2 at Δ and IB, 10 a3 and 11 are leading side and trailing side spark plugs, 12 is a side seal attached to the side of the rotor 6, 13 is attached to each top of the rotor 6 The IC apex seals 14 are corner seals attached to both sides of the top of the rotor 6.

The intake ports 1 to 3 are opened and closed by the side surface of the rotor 6,
The opening period θ of the intake port 1-3 is set in the range of 270 to 320 degrees based on the rotation angle of the eccentrics 1 to 71 to 7.

On the other hand, 15 is an air cleaner, and 16 is an inner cylinder 1A.

1B, and the main intake passage 16 is provided with an aflow meter 17 for detecting the amount of intake air and a throttle valve 18 downstream thereof for controlling the amount of intake air. It is set up.

The main intake passage 16 has first and second intake passages 1 of equal length.
6a and 16b are the above-mentioned intake bow I-3,
3 to the working chambers 88 of each cylinder 1A, 1B. In addition, the first J5 and the second intake passages 16a, 1
6b are respectively provided with electromagnetic valve type fuel injection nozzles 19 and 19 that control the fuel injection depending on the output of the air flow meter 17.

The branch portion 4J of the main intake passage 16 is located downstream of the throttle valve 18, and the branch portion is located in the first intake passage 16.
It is constituted by an enlarged chamber 21 having a communication passage 20 that communicates the intake passage a with the second intake passage 16b. The above communication path 20
The passage area is the first to effectively transmit pressure waves (compression waves due to exhaust interference effects) by reducing their attenuation. Second
It is set to be equal to or larger than the minimum passage area of the intake passages 16a and 16b. In addition, the volume of the expansion chamber 21 is 0.5 to 2 times the engine displacement (for low load use).
: If two systems of intake boats for high loads are installed, the total value is set to 0. This is because the pressure horn waves are diffused and the inertial pulsation effect is significantly reduced. The enlarged chamber 21 functions as a surge tank for intake air during transient operations such as acceleration or deceleration of the engine, ensuring good fuel response.

Further, the passage length between the intake ports 1 to 3°3 of the inner cylinders 1△ and 1B is the passage length 92 of the communication passage 20 and the passage length 92 of the communication passage 20.
0 downstream first and second intake passages 1 (3a, 16b
-(7) Each passage length9. +, 9+ (L-U2+2Q+), and the passage length L is 500
0 to 7000 ppm at high engine speed tlF-
From the above formula (I>, L-((270-320)
-180-20)x60/360x (5000~70
00)×343 to 0.57 to 1.3.7 (m). In this case, the passage lengths 91 and 9.2 respectively correspond to the center length of each passage.

Furthermore, the above 1. The passage length of the second intake passage 168.16b is 1, that is, each intake passage 16a.

The passage length pl from the opening end face to the expansion chamber 21 of 16b to the frontage (intake boat 3) to the working chamber 8 is 3500 to 5
000rl), m from the equation (I) based on the engine's medium rotation: 9+ = (360-(270~320)
-1-20)X60/360X (3500~5000
)X343X1/2X2 ~0.17~0.45 (m).

In Fig. 2, 22 is an exhaust passage connected to the exhaust port 9, and 23 is an enlarged manifold for exhaust purification that auxiliary feeds a catalyst device (not shown) interposed in the middle of the exhaust passage 22. be.

Next, to explain its operation with reference to FIG. 3, when the engine is running at a high speed of 5,000 to 700 rpm, which requires high output, a phenomenon occurs in the second intake passage 16b when one cylinder, for example, the intake boat 3 of the second cylinder 1B, is opened. The compression wave at the time of opening is
Based on the above equation (1), the intake boat 3 of the inner cylinders 1A and 1B is
By setting the passage length L between 3 to 0.57 to 1.37 m, the communication passage 2 from the second intake passage 16b to the enlarged chamber 21
0 → via the first intake passage 16a, and is propagated to the intake boat 3 of the first cylinder 1Δ, which enters the intake stroke first with a phase difference of 18o and is in a state immediately before full opening.

As a result, due to this compression wave, the first cylinder 1Δ just before full opening is
The blowback of the intake air from the intake boat 3 is suppressed, and the intake air is forced into the working chamber 8, which results in supercharging. Next, the intake port 3 of the first cylinder 1A opens 18 o' after the opening of the intake port 3 of the second cylinder 1B.
Similarly, the compression wave generated at the time of opening is propagated through the intake boat 3 of the second cylinder 1B just before full opening, and supercharging is performed. Thereafter, in the same way, due to the remarkable supercharging effect due to the exhaust interference effect between the cylinders 1Δ and 1B, the temperature was increased to 5060~7000.
The charging efficiency increases at high engine speeds of rl'1m, and the output can be greatly improved.

On the other hand, at medium engine speeds of 3500 to 5000 ppm, when the intake port 3 is closed in each cylinder 1A and IB, the first. The compression waves generated in the second intake passages 16a, 16a at the time of closing are determined by the above (( H) In the formula, J: 0.17~0
．． By setting it to 45tn, the first. Second intake passages 16a, 16b → expansion chamber 21 (inverted and reflected by expansion waves)
=) 1st゜Second intake passage 16a, 16b-'Intake port 1
-3 (foul as an expansion wave due to intake boat 3 opening) → 1st degree, second intake passages 16a, 16b → expansion chamber 21 (reversed to a compression wave and becomes anti-IJJ) → 1st degree. Second intake passage 16a.

16b, each cylinder IA as a secondary pulsating compression wave.

It is propagated to the intake bow 1-3 immediately after the next opening of 1A.

As a result, this secondary pulsating compression wave suppresses the blowback of exhaust gas from the intake ports 3 of each cylinder IA and 1B when the cylinders are opened, and the intake air is forced into the working chamber 8 to perform supercharging. . Therefore, for each cylinder 1△, the supercharging effect due to the inertial pulsation effect in IB itself is J: 3500~5000p.
It is possible to increase the filling efficiency during one rotation of pm and improve the output. The above inertial pulsation effect is
It acts as a primary pulsating expansion wave in the high rotation range of the engine, but the acting range of the secondary pulsating compression wave has been reduced from 3500 to 5000 rpm.
By setting m as a reference, the primary pulsating expansion wave acts only at 7000 ppm or more, which impairs the supercharging effect due to exhaust interference effect at high engine speeds (5000 to 7000 rpm). There isn't.

Therefore, in this way, in each cylinder 1Δ, 1B,
Exhaust interference effect on the intake boat 3 just before full opening at high engine speeds (5000-7000ppm) and at medium engine speeds (ζ3500-5000rl)
Due to the inertial pulsation effect on the intake boat 3 immediately after opening 1'', the output of the engine can be improved from the middle rotation range to the high rotation range of the engine, as shown in FIG. In addition, in Fig. 4, compared to the conventional example (shown by the broken line) which does not have the communication passage 20 and the expansion chamber 21 and has no exhaust interference effect or inertial pulsation effect, the engine speed is 6000pp at high engine speed.
Set to obtain the exhaust interference effect as m@14 standard (
〉 indicated by a solid line, and when rotating during 1-resin, 1'C.
The output torque characteristics of the engine are shown when the setting is set to obtain the 1η pulsation effect with reference to 4000 rpm (as shown by the dashed line).

Furthermore, since the enlarged chamber 21 extending to the right in the communication path 20 is located downstream of the throttle valve 18, the pressure waves are not attenuated by the throttle valve 18, and the exhaust interference effect a'3J and the inertial pulsation effect are prevented. can be effectively exerted, and the supercharging effect can be ensured.

Further, the supercharging effect due to the exhaust interference effect and the inertial pulsation effect is caused by the opening period of the intake boat 3 of each cylinder IA, 1B,
The first intake passage 16a and the second intake passage 16b are communicated with each other.
The position of the enlarged nitrogen 21 having the communication passage 20, the passage length L between the intake ports 3 and 3 of the inner cylinders IA and 1B, and the passage length 91 between the enlarged chamber 21 and the intake port 3 are determined as described above. Since it does not require a supercharger or the like, only a slight change in the existing intake system is required, and the structure is extremely simple, so it can be implemented easily and inexpensively. simplification and cost reduction can be achieved to a large extent.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. For example, in the above embodiment, an example was shown in which the present invention was applied to a single fuel injection type rotary piston engine, but it goes without saying that the present invention can also be applied to a carburetor type engine. However, in the case of fuel injection type,
As in the above embodiment, by providing the fuel nozzle 19 in the intake passages 15a, 161 downstream of the communication passage 20 (enlarged chamber 21), the passage length 91 of the intake passages 16a, 16b is
This is preferable because it is possible to prevent deterioration in fuel responsiveness due to improvement in .

Further, in the above embodiment, one system is provided in which each cylinder 1Δ, 1B is provided with one intake passage 16a, 161), but the present invention provides an independent system with a different intake port for each cylinder. It can also be applied when two intake passages are provided, one for low load and one for high load. In this case, both or one of the two intake systems may be set to obtain the exhaust interference effect and the inertial pulsation effect. However, if the closing timings of the two systems have different intake bows, it is preferable to set the closing timing later so as to obtain the above effect.

In addition, in order to improve the charging efficiency, it is preferable to set the timing between the intake bows 1 and 1 of each cylinder to a range of 30 to 60 degrees in rotation angle of the eccentric shaft after top dead center. In addition, setting the intake/exhaust overlap period to a range of 0 to 20° in terms of the rotation angle of the eccentric shaft improves charging efficiency and reduces the amount of 1-dilution gas brought in during low engine loads. This is preferable because misfires can be prevented.

As explained above, according to the present invention, in a 1-noid intake point type 2-cylinder rotary vis 1-hen engine,
At high engine speeds of 5,000 to 7,000 ppm, the supercharging effect is reduced by 1q due to the exhaust interference effect between cylinders, and at medium engine speeds of 3,500 to 5,000 ppm, the supercharging effect is obtained by the inertial pulsation effect of each cylinder itself. Therefore, with an extremely simple configuration that requires only a slight design change to the existing intake system without the need for a supercharger, the charging efficiency can be increased from the mid- to high-speed range of the engine, and it can be used under high loads. This greatly contributes to the ease of implementation of measures to improve engine output and to cost reduction.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall explanatory diagram, FIG. 2 is an overall schematic configuration diagram, FIG. 3 is an explanatory diagram showing the intake stroke of the first and second cylinders, and FIG. 4 is an illustration of the main body. 3 is a graph showing output torque characteristics according to the invention. 1△...First cylinder, 1B...Second cylinder, 2...Rotor housing, 2a...2-node 1 herocoid-shaped inner peripheral surface, 3...Intake port, 4...Side housing , 5
...Casing, 6...Rotor, 7...Eccentric shaft, 16...Main intake passage, 16a...
・First intake passage, 16b...Second intake passage, 18...
- Throttle valve, 20... Communication passage, 21... Expansion chamber. ←201

Claims (1)

[Claims] (1) A substantially triangular rotor runs inside a casing formed by a rotor housing with a two-bar trochoidal inner circumferential surface and a side housing with intake boats located on both sides of the rotor housing with intake passages opening. In a two-cylinder rotary piston engine that is supported by an eccentric shaft and performs planetary rotation, and each rotor has a phase difference of 180° at the rotation angle of the eccentric shaft, a. Set the rotation angle of the foot in the range of 270 to 320 degrees. b. Set the intake passage of each cylinder from the thrower 1 to the downstream side of the valve. , C6 The length of the passage between the intake boats of both cylinders formed by the communication passage and the intake passage downstream thereof is 0.57 to 1.
The length of the intake passage from the enlarged chamber to the intake bow 1 of each cylinder is set to be 0.17 to 0.45 m. and 5000 to 7000 ppm (D
When the engine is running at high speed, a compression wave generated in the intake passage when the intake bow of one cylinder is opened is propagated through the communication passage to the intake boat of the cylinder in use just before it is fully opened, and supercharging is performed. When the engine rotates at 3500 to 500 Q rpm, the compression wave generated in the intake passage when the intake port of each cylinder is opened is reversed twice in the expansion chamber, and the secondary pulsating compression wave is transferred to the intake port 1 immediately after the opening of each cylinder. - An intake system for a U-crivis 1-engine, characterized by supercharging by propagation to the engine.