JPH02221670A - Engine intake quantity control device - Google Patents

Abstract

PURPOSE:To prevent the adhesion of oil to an intake passage and the generation of a turbulent flow by communicating a bypass passage for bypassing a throttle valve to pass idle air to an intake passage with specified direction and position. CONSTITUTION:In a device body 102, one end of an intake passage 104 formed by an outer wall 106 is communicated to an engine through a surge tank 122. A throttle valve 132 is combined into the intake passage 104 with a shaft 130 as the center in such a manner as to be capable of freely opening and closing. Further, a bypass passage 126 for idle air suction bypassing the throttle valve 132 is formed on the outer wall 106. In the above constitution, the lower stream side opening (idle port) 124 of the bypass passage 126 is communicated with the intake passage 104 from the nearly tangential direction of the nearly vertical section to the air flow direction of the intake passage 104 and just close to the contact point between the tangential line and the section.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is designed to reduce the amount of oil, carbon, etc. that accumulate in blow-by gas, exhaust gas, etc. adhering to the inner wall of the intake passage of an engine intake air amount control device used in the intake system of an engine. It relates to a structure that prevents

[Prior Art] Oil, carbon, etc. tend to adhere to the inner wall of the intake passage of the intake ff1i, lJ control device due to a phenomenon that will be explained in detail later. Conventional technology to counter this problem
The structure described in Publication No. 4 is known.

This structure is schematically shown in FIG. 3, and the prior art will be explained with reference to this. Note that detailed explanations of parts that will be explained in conjunction with the embodiments of the present invention will be omitted.

In FIG. 3, 112 is a PCv vibe, and one end (not shown) communicates with the engine head. The blow-by gas guided from the PCv vibe 112 contains engine oil vapor and is further mixed with liquid engine oil particles.

Zaranimata exhaust gas reburning system (EGR) is often used, but in this case the exhaust gas is usually stored in the surge tank 12.
Returned to 2. Furthermore, in order to minimize variations between cylinders, it is returned to the most upstream part of the surge tank.

When the throttle valve 132 is opened wide, blow-by gas, exhaust gas, etc. ride on the flow of intake air and are smoothly sucked into the surge tank 122, causing no problems. However, when the throttle valve 132 opens small, blow-by gas and exhaust gas Gas and the like are drawn directly downstream of the throttle valve shaft 130 and further begin to flow along the inner wall of the intake passage 104. For this reason, particulate engine oil may adhere to the inner wall of the intake passage 104, or oil vapor may liquefy on the inner wall of the intake passage 104 and mix with carbon in the exhaust gas and adhere to it, causing dirt. generate.

In order to solve the above problem, the following measures are provided in the conventional technology.

Reference numeral 126 in FIG. 3 is a bypass passage for idle intake. When the engine is at idle, the throttle valve 132 is nearly fully open and intake air flows through the bypass passage 126. Air in the bypass passage 126 is guided to the vibrator 125.

The vibrator 125 is located behind the throttle valve 132 and parallel to the throttle valve shaft 130. Further, a plurality of outlet holes 127 are provided on the circumferential surface of the vibrator 125 in the direction of the throttle valve 132. The idle air is guided from the bypass passage 126 to the vibe 125 via the idle boat 124, blown toward the throttle valve 132 from the outlet hole 127, and then guided to the engine side.

This structure greatly prevents blow-by gas, exhaust gas, etc. from flowing back to the position of the throttle valve 132 due to the back pressure of the idle air even when the throttle valve 132 is almost fully closed. Therefore, the adhesion of dirt to the inner wall of the intake passage is reduced.

[Problems to be Solved by the Invention] However, according to this method, since the vibrator 125 crosses the inside of the intake passage 104, intake resistance increases, and this particularly affects people when the opening degree of the throttle valve 132 is large. In addition, in order to prevent the transverse position of the vibrator 125 from interfering with the opening/closing operation of the throttle valve 132, the vibrator 125 must be provided in the immediate vicinity of the throttle valve 132, so it must be located either upward or downward from the center of the intake passage 104. becomes. For this reason, the flow of intake air becomes asymmetric between the upper and lower portions of the vibrator, causing turbulence, which is one of the causes of variations in intake characteristics for each cylinder.

Based on the above knowledge q5, the present invention prevents oil or a mixture of oil and carbon from adhering to the inner wall of the intake passage 104, especially the part that interferes with the opening and closing of the throttle valve 132, and eliminates harmful resistance within the intake passage. In addition, the problem to be solved is to avoid turbulence of intake air.

[Means for solving the problem] The above problem is an engine intake volume υ with the structure of each part below.
III device.

The engine intake air amount control device has an intake passage, a throttle valve, and a bypass passage.

The intake passage communicates with the combustion chamber of the engine via an intake valve.

The throttle valve opens and closes within the intake passage to control the amount of air intake into the engine.

The bypass passage is for passing idle air by bypassing the throttle valve.

The bypass passage communicates with the intake passage in a substantially tangential direction of a cross section perpendicular to the airflow direction of the intake passage, and in close proximity to a point of contact between the tangent and the cross section.

[Function] In the engine intake air amount control device having the above means,
When the engine is at idle, the throttle valve is almost fully open, and idle air flows through the bypass passage. This idle air is blown into the intake passage from a substantially tangential direction of a cross section that is nearly perpendicular to the airflow direction of the intake passage. Therefore, the idle air is guided toward the engine while flowing in a circular manner along the inner wall surface of the intake passage.

[Effect of the Invention 1] As a result, blow-by gas, exhaust gas, etc. that are sucked into the intake passage on the downstream side of the throttle valve are guided to the engine side while being caught up in the flow of idle air. Therefore, there is no backflow to the throttle valve side, and the inner wall of the intake passage,
Particularly, oil or a mixture of oil and carbon is prevented from adhering to parts that interfere with opening and closing of the throttle valve. Therefore, the opening/closing operation of the throttle valve is maintained well. Further, since a cross pipe for blowing out idle air is not required in the intake passage, there is no harmful resistance and the flow of intake air is not disturbed.

Therefore, smooth opening and closing operations of the throttle valve are ensured over a long period of time, and accurate engine control is maintained.

[Example] Hereinafter, embodiments will be specifically described with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. The engine intake air amount control device 102 has a substantially cylindrical outer wall 1
06, and an intake passage 104 is formed by this outer wall 106. One end of the intake passage 104 communicates with an air cleaner, and the other end communicates with the engine, usually via a surge tank 122. A disk-shaped throttle valve 132 is built into the intake passage 104 so as to be openable and closable around a valve shaft 130 . By having this configuration,
Air intake is air cleaner, intake path 104, surge tank 1
22 and is taken into the combustion chamber of the engine when the intake valve opens. The intake air amount at this time is throttle valve 1
32.

In the figure, 126 is a bypass passage for idle intake. When the engine is at idle, throttle valve 1
32 is in a nearly fully closed state, and the intake air is through the bypass passage 126.
flows through. At this time, the flow rate of the bypass passage 126 is controlled by moving the plunger 128 back and forth.
Stable idle rotation of the engine can be obtained.

In the figure, reference numeral 124 denotes the downstream opening (idle boat) among the intake passage side openings of the bypass passage. Air intake path 1 in the vicinity of the point of contact with the cross section
It communicates with 04.

When the engine is at idle, bypass passage 1
After the idle air passing through 26 is blown from the idle boat 124, it is guided to the engine side while flowing in a circle along the inner wall surface of the intake passage having a substantially circular cross section.

On the other hand, numeral 112 in the figure is a PCV vibe, and one end (not shown) communicates with the engine head. The other end of the PCv vibe 112 (this other end is shown) is
It is attached to the plug 110 of the intake air amount control device 102. The base of plug 110 communicates with intake passage 104 by port 108. A jet 114 is provided on the side of the plug 110, and a PC1 passage 116 is formed downstream of the jet 114. The PCv passage 116 communicates with the intake passage 104 through an intake passage side Un port 118.

Blow-by gas sucked into the intake passage 104 from the PC ■ passage 116 on the downstream side of the throttle valve 132 is drawn into the flow of idle air flowing in a circle along the inner wall surface of the intake passage, and is guided toward the engine.

As a result, according to this embodiment, oil or a mixture of oil and carbon is prevented from adhering to the intake passage 104 and the portion that interferes with the opening and closing of the throttle valve 132. Also,
No harmful intake resistance is generated in the intake passage 104, and no disturbance is caused to the flow of intake air.

Therefore, smooth opening and closing operation of the throttle valve 132 is ensured over a long period of time, and accurate engine control is maintained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an engine intake air amount control device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the engine intake air amount control device according to an embodiment of the present invention, and FIG. 1 is a diagram schematically showing a conventional engine intake air amount control device. 104... Intake path 116... PCV path 124... Opening on the downstream side of the intake path side openings of the bypass passage (idle boat) 126... Bypass path 128... Plunger 130... Pulp Shaft 132...throttle valve

Claims (1)

[Scope of Claims] An intake passage communicating with a combustion chamber of an engine via an intake valve; a throttle valve that opens and closes within the intake passage to control the amount of intake air into the engine; and a throttle valve that bypasses the throttle valve. A bypass passage for passing idle air is provided, and the bypass passage is arranged to pass the intake air from a substantially tangential direction of a cross section perpendicular to the air flow direction of the intake passage, and in the vicinity of a point of contact between the tangent and the cross section. An engine intake air amount control device characterized by communicating with a road.