JPS63268925A - Intake controller for engine equipped with supercharger - Google Patents

Abstract

PURPOSE:To obtain a proper air fuel ratio by installing an opening/closing valve into a communication part between a supercharge port and a natural intake passage and supplying fuel after the lapse of a prescribed time after the opening of the opening/closing valve. CONSTITUTION:A communication part 27 is formed between a supercharge port 15 and a natural intake passage 11b, and an opening/closing valve 28 is installed in the communication part 27. Fuel is supplied from a fuel injection valve 17 after the lapse of a prescribed time after the generation of communication state in the communication part 17 by opening the opening/closing valve 28. Fuel is not supplied for a prescribed time until the reverse flow of the intake is ceased after the generation of communication state in the communication part. Therefore, the reverse flow of fuel is prevented, and a proper air fuel ratio can be obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an air intake control device for a so-called partial supercharging supercharged engine that connects a natural intake passage and a supercharging passage equipped with a supercharger. It is related to.

(Prior Art) Conventionally, as shown in Japanese Patent Application Laid-Open No. 61-43526, for example, a supercharging passage (auxiliary intake aisle)
The natural intake port (main intake port) leading to the natural intake passage and the supercharging port (auxiliary intake port) leading to the supercharging passage are opened into the combustion chamber of the first engine, and the turbocharging port downstream of the turbocharger A partial supercharging one-engine intake system is known in which a timing valve is provided in a passage so that supercharged air is supplied to a combustion chamber in addition to naturally aspirated air. In this type of intake device, the above natural intake port,
In a reciprocating engine, the intake valves for naturally aspirating and for supercharging open and close the intake valves, and in rotary piston engines, the rotor opens and closes the supercharging port, and the supercharging port closes later than the naturally aspirating port. On the other hand, the timing valve operates in synchronization with the engine and opens the supercharging passage for a predetermined period from near the end of the natural intake stroke (open period of the natural intake port). . Therefore, until the timing valve is opened, supercharging air is not supplied even if the supercharging port is open.

By the way, in this type of intake device, if the supercharging S is increased so as to sufficiently increase the charging efficiency through the supercharging effect, the load on the supercharger increases. Also, to some extent when starting supercharging 71
11 (opening timing of the supercharging passage by the timing valve) and extending the supercharging period, the intake air tends to blow back into the natural intake passage in the low speed range where the intake flow velocity is low, so the charging efficiency can be effectively increased. I can't. Therefore, in order to lighten the load on the supercharger and effectively increase charging efficiency, it is desirable to increase the amount of naturally aspirated air up to the time when supercharging is started. However, since there is a limit to the size of the natural intake port, there is a limit to the increase in the intake air amount from the natural intake port, and there is room for improvement in this respect.

(Objective of the Invention) The present invention addresses the above-mentioned circumstances, and aims to reduce the burden on the supercharging tank while sufficiently increasing the charging efficiency by increasing the natural intake suspension by using the supercharging port. The basic purpose is to enable

Furthermore, the present invention prevents the air-fuel ratio from fluctuating due to the backflow of intake air immediately after the supercharging port and the natural intake passage are brought into communication. A backflow of the intake air occurs, and if fuel is being supplied, this flows back together with the intake air, causing fluctuations in the air-fuel ratio, so attempts are made to solve this problem.

(Structure of the Invention) The present invention provides an intake passage of an engine with a natural intake passage and a supercharging passage equipped with a supercharger, and a natural intake port communicating with the natural intake passage and a supercharging passage communicating with the supercharging passage. The charging port is opened into the combustion chamber of the engine, and the supercharging passage downstream of the supercharger is opened for a certain period of time from near the end of the natural intake stroke to allow supercharging air to flow from the supercharging port into the combustion chamber. In a supercharged engine provided with a timing valve that supplies air to the natural intake passage, the communication portion communicates the supercharging port with the natural intake passage, and the communication portion is kept open for a specific period of time before the timing valve opens the supercharging passage. and a fuel supply timing setting means for setting the fuel supply timing so that fuel is supplied to the combustion chamber after a predetermined period of time has elapsed since the supercharging port communicated with the natural intake passage. We have established this.

With this configuration, before supercharging air is supplied, naturally aspirated air is supplied to the combustion chamber from the supercharging port in addition to the naturally aspirating port P, increasing the amount of naturally aspirated air. Depending on the structure, fuel is supplied while avoiding times when intake air backflow occurs.

(Example) FIG. 1 shows an example of the present invention. The engine shown in this figure is a rotary piston engine, and a casing 1 of the engine body is composed of a rotor housing 2 having a trochoidal inner peripheral surface and side housings 3 located on both sides of the rotor housing 2. A substantially triangular rotor 5 is provided which is attached to the eccentric shaft 4 and rotates freely. The rotor 5 and the inner surface of the casing 1 define three working chambers 6 corresponding to combustion chambers. The casing 1 also includes a natural intake port 14 and a supercharging port 15, which will be described later, and an exhaust passage 7.
An exhaust port 8 leading to the exhaust port 8 is provided, and a spark plug (not shown) is provided. As the rotor 5 rotates, each stroke of intake, 1) compression, explosion, expansion, and exhaust are sequentially performed.

The intake passage 10 of the engine is provided with a natural intake passage 11 and a supercharging passage 12 equipped with a supercharger 13.
A natural intake port 14 communicating with the natural intake passage 11 and a supercharging port 15 communicating with the supercharging passage 12 are formed in the side housing 3 of the engine body so as to open into the created chamber 6 at predetermined positions, respectively. ing. In the figure, the natural intake passage 11 is roughly divided into the following passages and the primary passages 1.
It is divided into 18 degrees 11b, and these passages 11a.

11b communicates with a pair of natural intake ports 14 (one not shown) provided at corresponding locations on both side housings 3. The above naturally aspirated port 14 and supercharging port 1
The frontage position of 5 is set so that it is opened and closed at the opening and closing timing shown in FIG. 3, which will be described later.

The natural intake passage 11 is provided with throttle valves 16a, 16b on the negative side and the secondary side, and is also equipped with a fuel injection valve 17. In addition, natural intake passage 1
1 and the supercharging passage 12 are gathered on the upstream side, and an air cleaner 18 and an air flow meter 19 are provided in the intake passage 10 upstream of the gathering part.

The supercharger 13 in the supercharging passage 12 is composed of a mechanical one-engine pump, and is driven by a one-engine output shaft via a transmission mechanism (not shown). The supercharging passage 12 also includes an intercooler 21 that cools the supercharging air, a relief passage 22 and a relief valve 23 that relieve excess supercharging air, and a supercharging control valve 24 that adjusts the supercharging air according to the engine load. , a surge tank 25, etc. are provided, and a timing valve 26 is provided downstream from these. This timing valve 26 is composed of a low-return valve, and by rotating in conjunction with the engine output shaft, it rotates in synchronization with the engine rotation.
The supercharging passage 12 is opened for a predetermined period from near the end of the natural intake stroke.

Furthermore, the intake system has a structure that is a feature of the present invention, including a communication section 27 that communicates the supercharging port 15 with the natural intake passage 11, and a communication section 27 that communicates the supercharging port 15 with the natural intake passage 11, and the communication part 27 that communicates the supercharging port 15 with the natural intake passage 11 for a predetermined period before the timing valve 26 opens the supercharging passage. In this embodiment, the timing valve 26 has the communication section opening/closing means built into the timing valve 26, and the communication section 27 communicating with the natural intake passage 11 is connected to the timing valve 2.
6. 28 is the communication part 2 depending on the operating condition.
This is a valve that adjusts the opening of No.7.

Reference numeral 29 denotes a control unit (ECU) constituting fuel supply timing setting means. A detection signal from the sensor 30 is input, and a signal for controlling the fuel injection amount and injection timing according to these signals is sent to the control O-.
The fuel is output from the fuel units 1 to 29 to the fuel injection valve 17.

FIG. 2 shows a specific example of the structure of the timing valve 26, the communication section 27, etc. incorporating the above communication section opening/closing means. In this figure, the timing valve 26 includes a cylindrical valve body 31 that is driven and rotated by the engine output shaft, and
It is provided with a valve case 32 that accommodates this. The valve case 32 has, on its population side, a pair of left and right openings 33.34 communicating with the supercharging passage 12 upstream of the timing valve 26, and a communication section 27 located between these openings 33.34. On the outlet side, two openings 36, 37 are provided which communicate with each of the supercharging ports 15 of the two cylinders. In addition, the valve body 31 has a population (Ql(7) V'd
, 3413 Yo (1' 35 (7) connection, 'I!Xr
! Two sets of passage parts 38.39 for performing fI are provided, and each passage part 38.39 has two rows of through holes 3Ba, 38b and 39a, which are inclined at a certain angle with respect to the diametrical direction.
39b.

For example, at the location where the passage portion 34 on the left in this figure is formed, in the state shown by the solid line in this figure, the opening 33 of the upstream supercharging passage 12 is closed and the space between the communication portion 27 n When the portion 35 communicates with the outlet side opening 36 via the n-hole 38a and the valve body 31 is in the reversed state shown by the two-dot chain line, the opening 33 of the upstream supercharging passage 12 communicates with the outlet side opening 36 through the It communicates with the opening 36 on the outlet side through the holes 38a and 38b, and the opening 35 of the communication section 27 is closed.

Further, when the passage section 38 is circumferentially displaced from the opening 33, 35, 36, both the opening 33, 35 on the inlet side and the opening 36 on the outlet side are closed.

Even at the location where the right passage portion 39 is formed, the frontage portion 37 on the exit side
On the other hand, the openings 34 and 35 on the person's side are communicated with and shut off with a phase difference of 180° from the left side. In this way, as the valve body 31 rotates, the upstream weekly pay passage 12 and the communication section 2
The timing valve 26 also serves as a communication section opening/closing means. In this case, the respective opening/closing timings are set as required depending on the size and arrangement 1tW of each through hole of the passage section 38, 39.

Figure 3 shows the area between ports and valves as well as the fuel injection area, with the horizontal axis representing the rotation angle of the eccentric shaft. A is the area between the naturally aspirated ports 14, line B is the opening 1 to 7 of the supercharging port 15, and line C is the area between the timing valves 2 above.
The area between the supercharging passages 25 indicated by 6 and the line is the opening 1 rear of the communication portion 27, and the shaded portion E is the fuel injection area.

In addition, two-point chain I! 1lc- indicates the area between supercharging passages in the case of a conventional supercharged engine of this type.

As shown in this figure, the natural intake port 14 is opened for an appropriate period of time to perform natural intake, and the supercharging ports 1 to 15 are opened almost at the same time as the natural intake port 14.
It is set to close later. Further, the opening period of the supercharging passage 12 by the timing valve 26 ranges from near the end of the opening period of the natural intake port 14 to the opening period of the supercharging port 15.
It is said to be a fixed period of time until around the closing time. On the other hand, the opening period of the communication portion 27 is longer than the opening period of the supercharging passage, and the opening period of the natural intake port 14 is longer than the opening period of the natural intake port and the supercharging port. It is set to last until a predetermined time during the period. Further, at the fuel injection timing, the supercharging port 15 is connected to the communication portion 2.
7 or the working chamber 6 to communicate with the natural intake passage 11, that is, after a predetermined period of time has elapsed from the time when the natural intake port 14 and the supercharging port 15 are opened.

According to the intake control m device as described above, the natural intake port 1
During the natural intake stroke when port 4 is open, naturally intake port 14
Naturally aspirated air is supplied from the supercharging port 15 to the rotation chamber 6, and during the period when the supercharging port 15 and the communication portion 27 are open, naturally aspirated air is also supplied from the supercharging port 15. In other words, the supercharging port 15 During the opening period, supercharging air is not supplied until the supercharging passage 12 is closed by the timing pulse 126, but if the communication section 27 is in contact during this period,
Natural intake air is also sent from the natural intake passage 11 to the supercharging port 15. In this way, the supercharging port 15 is also used for supplying naturally aspirated air, and naturally aspirated air is supplied from both the naturally aspirated port 14 and the supercharged port 15, increasing the naturally aspirated air M.

Then, after the communication portion 27 is closed, when the supercharging passage 12 is opened by the timing valve 26, supercharging air is supplied from the supercharging port 15 to the moving chamber 6, and the supercharging port 15
is used for the original supercharging air + 3' supply.

In this case, the charging efficiency is increased by increasing the natural intake amount as described above, so when a predetermined charging efficiency is provided, the amount of supercharging is smaller than before, and the negative 1j' of the supercharger is i is reduced. In addition, the open period of the supercharging passage 12 (line C in FIG. 3) is shorter than the period in the case of the conventional device (line C' in FIG. 3), and the open period of the natural intake port 14 and the supercharging passage 12 can be made smaller than before, which is advantageous in preventing air from blowing back into the natural intake passage 11. .

Also, the supercharging port 15 is in communication with the natural intake passage 11 via the communication passage 27 or the working chamber 6 (in spring, the supercharging port 15, the working chamber 6 and the natural intake passage 11
Due to the pressure difference between With this setting, backflow of fuel will not occur. Therefore, fluctuations in the air-fuel ratio are suppressed.

In the above embodiment, the timing valve 26 also serves as a means for opening and closing the communication portion, but as shown in FIG. A communication section 27' is provided between the supercharging passage 12 and the natural intake passage 11 downstream of the timing valve 26-, and a separate communication section opening/closing means is provided in the communication section 27'. A timing valve 37 may be provided.

Furthermore, although the above embodiment shows a case in which the present invention is applied to a rotary piston engine, when applied to a reciprocating engine, the natural intake port and the supercharging port opening into the combustion chamber are each operated by a valve mechanism. The intake valves for the natural intake port and the supercharging port may be opened and closed, and the rest may be the same as in the above embodiment.

Further, the installation location of the fuel injection valve 17 is not limited to the above embodiment, but the present invention is also applicable to cases where the fuel injection valve 17 is installed at a position facing the working chamber (combustion chamber) 6 or near the supercharging port. be able to.

(Effects of the Invention) As described above, the present invention provides a natural intake passage and a naturally intake port leading thereto, a supercharging passage provided with a supercharger, a supercharging port 1 to leading thereto, and a natural intake passage in the supercharging passage. In a partially supercharged engine equipped with a timing valve, by communicating the supercharging port and the natural intake passage for a predetermined period of time before the timing valve opens the supercharging passage, the naturally aspirated air is Since naturally aspirated air is supplied from the supercharging port in addition to the supercharging port, the amount of natural intake air can be increased using the supercharging port, increasing charging efficiency and reducing the negative impact of the supercharger. 1f3 can be reduced. Furthermore, in the present invention, taking into consideration that some intake air backflow occurs immediately after the supercharging port and the natural intake passage are brought into communication, the time required for the intake air backflow to subside after the above-mentioned communication state is established is taken into account. Since fuel is supplied after a predetermined period of time has elapsed, backflow of fuel can be prevented and the air-fuel ratio can be maintained at an appropriate level.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing one embodiment of the present invention, Fig. 2 is a sectional view showing the structure of the timing valve and the communication part in the supercharging passage, and Fig. 3 is a schematic sectional view showing the structure of the timing valve and the communication part in the supercharging passage. FIG. 4 is an explanatory view showing each open area of the supply passage and the communication portion and one rear of the fuel injection, and FIG. 4 is an explanatory view of the structure of the main part showing another embodiment. 10...Intake passage, 11...Natural intake passage, 12.
...Supercharging passage, 13...Supercharger, 14...Natural intake port, 15...Supercharging port, 17...Fuel injection valve, 26...Timing valve, 27...i11 ! 29 Control unit (fuel supply timing setting means). Patent applicant Mazda Co., Ltd. Agent
People Patent Attorney Etsushi Kosho
Patent Attorney Chief 1) Masamukai Patent Attorney
Board Yasuo No. 2 Figure 4

Claims (1)

[Claims] 1. A natural intake passage and a supercharging passage equipped with a supercharger are provided in the intake passage of the engine, and a natural intake port communicating with the natural intake passage and a supercharging port communicating with the supercharging passage are connected to the combustion engine of the engine. At the same time, a timing valve is provided in the supercharging passage downstream of the supercharger to open the supercharging passage for a certain period of time from near the end of the natural intake stroke to supply supercharging air from the supercharging port to the combustion chamber. In the supercharged engine, the communication part communicates the supercharging port with the natural intake passage, and the communication part opening/closing means keeps the communication part open for a specific period before the timing of opening the supercharging passage by the timing valve. , further comprising fuel supply timing setting means for setting the fuel supply timing so that fuel is supplied to the combustion chamber after a predetermined period of time has elapsed since the supercharging port communicated with the natural intake passage. Engine intake control device.