JPH02223663A - Engine suction amount control device - Google Patents

Abstract

PURPOSE:To hold proper engine control by providing a throttle valve to control an amount of intake air to an engine and a bypass passage through which idle air passes after bypass of it through the throttle valve. CONSTITUTION:A throttle valve 132 is incorporated in a suction passage 104 in a manner to be openable around a valve shaft 130 to control an amount of intake air to an engine. A bypass passage 126 for idle intake air bypasses the throttle valve 132 and idle intake air is caused to pass therethrough. An opening 124 on the suction passage side of the bypass passage 126 is positioned on the downstream side of the throttle valve 132 in a state in which the throttle valve 132 is approximately in a fully closed state, and is opened along the surface of the shaft 130 of the throttle valve 132. This constitution ensures smooth opening and closing operation of the throttle valve 132 for a long period, and hold proper engine control.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is aimed at preventing oil, carbon, etc. derived from blow-by gas, exhaust gas, etc. from 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. This relates to a structure that prevents this from occurring.

[Prior Art 1] Oil, carbon, etc. tend to adhere to the inner wall of the intake passage of an intake air amount control device due to a phenomenon that will be explained in detail later. A structure described in Japanese Utility Model Application Laid-Open No. 57-171144 is known as a conventional technique for dealing with this problem.

This structure is schematically shown in FIG. 3, and the prior art will be explained with reference to this. It should be noted that detailed explanations of parts explained in connection with the embodiments of the present invention are 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 PC vibrator 112 is mixed with engine oil vapor and also contains coarse particles of liquid engine oil.

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. In addition, in order to minimize variations among cylinders, it is returned to the upper 5i portion of the surge tank.

When the throttle valve 132 is wide open, blow-by gas and exhaust gas are smoothly sucked into the surge tank 122 by the flow of intake air and do not cause any problems. However, when the throttle valve 132 is opened small, blow-by gas and exhaust gas Gas, etc. is connected to the valve shaft 13
The air is attracted directly downstream of the air and begins to flow along the inner wall of the air intake path 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 at full throttle and intake air flows through the bypass passage 126. Air in bypass passage 126 is guided to pipe 125.

The pipe 125 is located behind the throttle valve 132 and parallel to the pulp shaft 130. Also, pipe 1
A plurality of outlet holes 127 are provided in the direction of the throttle valve 132 on the side 25 . The idle air is guided from the bypass passage 126 to the pipe 125 via the idle boat 124, blown from the outlet hole 127 toward the throttle valve 132, and then guided to the engine side.

According to this structure, even when the throttle valve 132 is almost fully closed, blow-by gas, exhaust gas, etc. are prevented from flowing back to the position of the throttle valve 132 due to the back pressure of the idle air. 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 pipe 125 crosses within the intake passage 104, intake resistance increases, and the influence is particularly large when the opening degree of the throttle valve 132 is large. Furthermore, in order to prevent the cross-sectional position of the pipe 125 from interfering with the opening/closing operation of the throttle valve 132, the pipe 125 must be provided in the immediate vicinity of the throttle valve 132, so that it is biased either upward or downward from the center of the intake passage 104. . For this reason, the flow of intake air becomes asymmetric between the top and bottom of the pipe, causing turbulence, which is one of the causes of variations in intake characteristics for each cylinder.

Based on the above findings, the present invention prevents oil or a mixture of oil and carbon from adhering to the inner wall of the intake passage 104, especially near the throttle valve shaft 130, which is a part that interferes with the opening and closing of the throttle valve 132, and The problem to be solved is to eliminate harmful resistance in the airway and to prevent disturbance of intake air.

[Means for solving the problem] The above problem is an engine intake air amount control i! having the structure of each part below. 1 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 rotates around a shaft within the intake passage to open and open the intake passage to control the amount of air taken into the engine.

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

The opening of the bypass passage on the intake path side is located downstream of the throttle valve when the throttle valve is substantially fully open, and opens along the shaft surface of the throttle valve.

[Function] In the engine intake air amount control system 15A having the above means, when the engine is in an idling state, the throttle valve is almost fully open, and most of the idling air flows through the bypass passage. This idle air is blown out from an opening along the shaft surface of the throttle valve on the downstream side of the throttle valve, and is guided toward the engine while flowing along the throttle valve shaft and the throttle valve surface.

[Effects of the Invention] 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 toward the engine while being caught up in the flow of idle air flowing along the throttle valve shaft and throttle valve surface. Ru.

Therefore, there is no backflow to the throttle valve side.
This prevents oil or a mixture of oil and carbon from adhering to the inner wall of the intake passage, especially near the throttle valve shaft, which is the part that interferes with opening and closing of the throttle valve.

In addition, since there is no need for a cross-vibrator in the intake passage to blow out idle air, there is no harmful resistance and the flow of intake air is not disturbed, ensuring smooth opening and closing of the throttle valve 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 m tii m ff 102 has a substantially cylindrical outer wall 1106, and an air 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 4J tank 122. A disk-shaped throttle valve 132 is disposed within the intake passage 104 and is connected to the valve shaft 13.
It is built in so that it can be opened and closed around 0. With this configuration, the intake air is supplied to the air cleaner, the intake passage 104,
The air passes through the surge tank 122 and is taken into the combustion chamber of the engine when the intake valve opens. The amount of intake air at this time is controlled by the throttle valve 132.

In the figure, 126 is a bypass passage for idle intake. When the engine is at idle, throttle valve 1
32 is almost fully closed, and about 80% of the intake air flows through the bypass passage 126.

At this time, by moving the plunger 128 back and forth, the flow rate of the bypass passage 126 is controlled, and stable idle rotation of the engine is obtained.

In the figure, 124 is the downstream opening (idle boat) among the openings on the intake path side of the bypass passage.

The idle boat] 24 is located downstream of the throttle valve 132 when the throttle valve 132 is in a fully closed state, and is open along the surface of the throttle valve shut 130. When the engine is in an idle state, idle air passing through the bypass passage 126 is blown out from the idle boat 124 and guided toward the engine while flowing along the throttle valve shaft 130 and the throttle valve surface 132.

On the other hand, numeral 112 in the figure is a PC vibrator, 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 ff102. The base of plug 110 communicates with intake passage 104 by boat 108 . A jet 114 is provided on the side of the plug 110, and a PC is connected to the FWt of the jet 114.
A V passage 116 is formed. The PC passage 116 communicates with the intake passage 104 through an opening 118 on the intake passage side. The blow-by gas sucked into the intake passage 1.04 on the downstream side of the throttle valve 132 from the PC passage 116 is guided to the engine side while being drawn into the flow of idle air flowing along the throttle valve shaft 130 and the throttle valve surface 132. .

As a result, according to this embodiment, a mixture of oil and carbon is prevented from adhering to the intake passage 104 and the vicinity of the throttle valve shaft 134, which is a portion that interferes with the opening and closing of the throttle valve 132. In addition, the intake path 10
No harmful intake resistance is generated within the air intake system 4, and no disturbance is caused to the intake air flow.

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 sectional view of the engine intake air amount control device according to an embodiment of the present invention, and FIG. FIG. 1 is a diagram schematically showing a conventional engine intake air amount control device. 104... Intake path 116... PC ■ passage 118... Intake path side opening of PCV passage 124... Opening on the downstream side of the intake path side openings of the bypass passage (idle boat) 126... Bypass path 128... Plunger 130... Throttle valve shaft 132... Throttle valve

Claims (1)

[Scope of Claims] An intake passage that communicates with the combustion chamber of the engine via an intake valve, and an intake passage that rotates around a shaft within the intake passage to open and close the intake passage to control the amount of air taken into the engine. and a bypass passage for passing idle air by bypassing the throttle valve, and an opening of the bypass passage on the intake passage side is located on the downstream side of the throttle valve when the throttle valve is substantially fully closed. 1. An engine intake air amount control device, characterized in that the engine intake air amount control device is located at the throttle valve and has an opening along the surface of the shaft of the throttle valve.