JPS63179134A - Suction device for engine - Google Patents

Abstract

PURPOSE:To perform high-efficient air intake and to produce a slow opening inertia effect, by a method wherein a main suction port and an auxiliary suction port, closed at a timing slower than that of the main suction port, are formed, and a timing valve situated in an auxiliary suction passage is opened at the middle stage of a suction stroke. CONSTITUTION:Main and auxiliary suction ports 6 and 7, opened to an actuating chamber 5 under a suction stroke formed to the outer periphery of a rotor 4 contained in a casing, are formed in a side housing 3 with which the casing is formed in association with a rotor housing 2. Meanwhile, an intake air passage 8 communicated to the actuating chamber 5 is branched into main and auxiliary intake air passage 8a and 8b. A timing valve 15 is situated in the middle of the auxiliary intake air passage 8b, and the end on the downstream side of the auxiliary intake air passage is communicated to the auxiliary intake air port 7. The timing valve 15 is driven through the auxiliary intake air passage 7 through an output shaft 16 of an engine 1. In this case,, the timing valve 15 is opened at the middle stage of a suction stroke, and is closed togetherwith the auxiliary suction port 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine that includes a main intake port and an auxiliary intake port.

(Prior art) Conventionally, an engine intake device has been equipped with a main intake port and an auxiliary intake port that opens later than the main intake port, and in addition to natural intake from the main intake port, supercharging is performed from the auxiliary intake port. Partial supercharging technology that aims to improve charging efficiency by supplying air is disclosed, for example, in Japanese Patent Application Laid-Open No. 58-20921.
It is publicly known as seen in the publication No.

In addition, a timing valve is provided in the natural intake passage, and this timing valve is opened later than the intake valve opening timing, thereby increasing the negative pressure at the beginning of intake when the timing valve opens, and correspondingly increasing the negative pressure at the end of the intake stroke. An inertia effect technology has been proposed for so-called continuous connections that increase the pressure and increase the filling efficiency of intake air.

(Means for Solving the Problems) However, the partial supercharging intake system as described above requires a supercharger, which complicates the structure for controlling its operation timing, etc., and is disadvantageous in terms of cost.

On the other hand, in an intake system that uses the inertia effect, the timing valve creates intake resistance when filling a large amount of intake air such as in high-speed, high-load areas, so a large timing valve is required. Large timing valves have the problem of increased mechanical resistance and driving resistance.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an engine air intake device that has a simple structure and is capable of improving charging efficiency.

(Means for Solving the Problems) The intake device of the present invention has a main intake port for an engine,
An auxiliary intake port whose closing timing is later than that of the main intake port is provided, a timing valve is provided in the auxiliary intake passage communicating with the auxiliary intake port, and the timing valve is opened in the middle of the intake stroke. That is.

(Function) In the above-mentioned intake system, natural intake is performed through the main intake port, and a timing valve is provided in the auxiliary intake passage for the auxiliary intake port without a supercharger. ! The opening is designed to improve filling efficiency due to inertia effect. In addition, the passage area of the main intake port is narrowed by the installation of the auxiliary intake port, resulting in a larger pressure change, and the filling efficiency is improved by the pushing effect of intake air, resulting in a large overall filling efficiency improvement effect. It is.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the overall configuration of an intake system for a rotary piston engine.

The engine 1 includes a rotor 4 housed in a casing made up of a rotor housing 2 and a side housing 3 so as to be capable of planetary rotation, and a working chamber 5 is formed around the outer periphery of the rotor 4 . The side housing 3 is provided with a main intake port 6 and an auxiliary intake port 7, each of which opens into the working chamber 5 for the intake stroke.

Intake passage 8 that supplies intake air to the working chamber 5 of the engine 1
is equipped with an air cleaner 9 and an intake air amount sensor 10 on the upstream side, and branches midway into a main intake passage 8a and an auxiliary intake passage 8b. The main intake passage 8a includes a surge tank 12 on the downstream side of the first throttle valve 11, and its downstream end is connected to the main intake port 6. On the other hand, the auxiliary intake passage 8b includes a surge tank 14 on the downstream side of the second throttle valve 13, has a timing valve 15 interposed therein, and has its downstream end connected to the auxiliary intake port 7.

The rotation of the output shaft 16 of the engine 1 is transmitted to the timing valve 15 via the belt 17, and the timing valve 15 is driven to rotate in synchronization with the rotation of the engine 1 at a predetermined timing (see FIG. 2).
It opens and closes the auxiliary intake passage 8b. Also,
Both throttle valves 11 and 13 are linked so that they open and close synchronously with the same opening degree.

The opening and closing timings of the main intake port 6, the auxiliary intake port 7, and the timing valve 15 are set as shown in FIG. With respect to the opening/closing timing (dashed line) of the main intake port 6, the opening/closing timing (dashed line) of the auxiliary intake port 7 opens at approximately the same timing and closes later. Furthermore, the timing valve 15 opens late in the middle of the intake stroke and closes together with the auxiliary intake port 7.

The pressure change in the port corresponding to the above opening/closing timing is such that in the main intake port 6 (solid line), the negative pressure increases when the main intake port 6 is open, and the pressure increases when it closes. . In addition, auxiliary intake port 7
As shown by the chain line, a large negative pressure similar to that of the main intake port 6 occurs between the opening of the auxiliary intake port 7 and the opening of the timing valve 15.
5 opens, intake air flows in and the pressure rises, reaching the highest pressure near the auxiliary intake port 7 closing. In this auxiliary intake port 7, the negative pressure increases when the timing valve 15 opens, increasing the inflow speed, and the pressure at the time when the auxiliary intake port 7 closes increases, causing an inertial effect on the passage that pushes intake air. This improves the overall filling efficiency.

On the other hand, in the main intake port 6, if there is no auxiliary intake port 7, the passage area must be made large, and the pressure change at a single intake port due to such a large passage area is as shown by the broken line. In addition, the pressure changes during the opening and closing periods are small, and the pressure during the opening period is particularly low, resulting in little effect of pushing intake air, resulting in a low intake air filling efficiency.

In contrast, in the main intake port 6, where the passage area is set to be narrower due to the provision of the auxiliary intake port 7, the pressure changes are large, as shown by the solid line, and the pressure is particularly high at the closing time, so that the filling efficiency can be improved. be. As a whole, the connection of the auxiliary intake ports 7 improves the charging efficiency by utilizing the inertia effect, thereby obtaining a large increase in the charging efficiency and improving the output without using a supercharger. It is something that can be done.

(Effects of the Invention) According to the present invention as described above, a main intake port and an auxiliary intake port whose closing time is later than the main intake port are provided, and a timing valve provided in the auxiliary intake passage is opened in the middle of the intake stroke. As a result, the main intake port performs efficient natural intake, and the auxiliary intake port provides an inertia effect, increasing charging efficiency and engine output with a simple overall configuration. It is possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an engine intake system according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing opening/closing timing and pressure change characteristics. 1...Engine 6...Main intake port 7...Auxiliary intake port 8...
...Intake passage 8a... Main intake passage 8b.
...Auxiliary intake passage 15... Timing valve Fig. 1 Fig. 2

Claims (1)

[Claims] (1) Provide the engine with a main intake port and an auxiliary intake port that closes later than the main intake port, and
An intake system for an engine, characterized in that a timing valve is provided in an auxiliary intake passage communicating with the auxiliary intake port, and the timing valve is opened in the middle of the intake stroke.