JPH02207116A - Engine intake air volume controlling device - Google Patents

Abstract

PURPOSE:To feed blowby gas smoothly to an engine without back surge by arranging an intake passage side opening in a PCV passage on guiding the blowby gas into the intake passage on an engine side from a throttle valve. CONSTITUTION:A throttle valve 132 for controlling intake air volume of an engine is arranged inside of an intake passage 104 communicated to the combustion chamber of the engine. And a PCV passage 116 for guiding blowby gas is attached to the intake passage 104. On the above mentioned device, the intake passage 104 side opening 2 in the PCV passage 116 is arranged to the engine side from the throttle valve 132. And blowby gas supplied from the PCV passage 116 is guided to the engine side. Moreover, the opening 2 is tilted to the downstream side of the intake passage 104. Thereby, the blowby gas taken in from the PCV passage 116 is smoothly ejected out from an idle port 124, and fed to a surge tank 122.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an engine intake air amount control device that is used in an engine intake system and has a PCV passage that controls the intake air amount and guides blow-by gas to the intake passage. Regarding improvements.

[Prior art and its problems] (First prior art) Figure 8 shows an engine intake mυ with a conventional PCV passage.
An example of a +m device is shown.

The engine intake air amount control device N102 has a substantially cylindrical outer wall 106.
The outer wall 106 forms an air intake passage 104. 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 the pulp shaft 130 . With this configuration, the intake air flows through the air cleaner, the intake passage 104, and the surge tank 122.
When the intake valve opens, the air is drawn into the engine's combustion chamber.

At this time, the intake air amount is adjusted to 1 by the throttle valve 132.
Ii11111 is done.

In the figure, 126 is a bypass for idle intake.

When the engine is at idle, the throttle valve 132 is approximately fully closed and approximately 475 of the intake air ω flows through the bypass 126. At this time, the plunger 128
By moving forward and backward, the flow of the bypass 126 is controlled, and stable idle rotation of the engine is obtained.

In the figure, 112 is a PCV vibe, and one end (not shown) communicates with the engine head. PCV vibe 1
The other end of 12 (the other end is shown) is attached to a plug 110 of the intake air amount control device 102. The base of the plug 110 is connected to the intake passage 104 by the boat 108.
It communicates with A jet 11 is provided on the side of the plug 110.
4 is provided, and a PCV passage 11 is provided downstream of the jet 114.
6 is formed. The PCV passage 116 communicates with the intake passage 104 through an intake passage side opening 118.

As is well known, there is a negative pressure downstream of the throttle valve 132, and the blow-by gas generated in the engine crankcase due to this negative pressure is transferred to the engine head and PC.
The air is guided to the intake M control device 102 via the V-vibrator 112 . The blow-by gas from the PCV pipe 112 is mixed with fresh air from the boat 108 and sent to the jet 111.
4, the air is drawn into the intake passage 104 from the intake passage side opening 118 via the PCV passage 116.

For normal manufacturing reasons, the end face of the intake air amount control device 102 on the surge tank 122 side is partially cut out,
When the device 102 and the surge tank 122 are connected via the gasket 120, this notch and the surge tank 12
An idle boat 124 and an intake path side opening 118 are formed by the end surfaces of 2 and 2.

Next, the operation and problems of this conventional structure will be explained.

The blow-by gas guided from the PCV vibe 112 is mixed with engine oil vapor and further mixed with liquid engine oil particles.

When the throttle valve 132 is wide open, blow-by gas is smoothly sucked into the surge tank along with the intake air flow and does not cause any problems. The air is drawn to the side and further begins to flow along the inner wall of the air intake passage 104. For this reason, particulate engine oil may adhere to the inner wall of the intake passage 104,
Alternatively, oil vapor liquefies and adheres to the inner wall of the intake passage 104. In particular, when the throttle valve 132 is fully opened and only the idle air from the idle boat 124 is taken in, the area immediately downstream of the throttle valve 132 becomes a dead end, and oil tends to adhere to the valve and the inner wall. Oil adhering to the valve moves along the valve to the inner wall.

If oil adheres to the inner wall of the intake passage 104, especially the portion 134 where the throttle valve 132 opens and closes, the viscosity of the oil will impair the smooth movement of the throttle valve 132.

Further, combustion gas may flow backward due to engine backfire, and in this case, carbon in the combustion gas mixes with oil and adheres to the inner wall of the intake passage 104. Additionally, exhaust gas reburning systems (EGR) are often used, in which case exhaust gases are typically returned to a surge tank.

Moreover, in order to minimize variations among cylinders, it is returned to the most upstream part of the surge tank. In this case, if the opening degree of the throttle valve 132 is small, the exhaust gas flows backward to the position immediately downstream of the throttle valve 132, and carbon in the exhaust gas mixes with oil and adheres to the inner wall of the intake passage 104.

In this way, if carbon and oil are mixed and adhere to the part 134 where the throttle valve 132 opens and closes, the smooth movement of the throttle valve 132 will be impaired, and the force required to open and close the throttle valve 132 will decrease over time. It gets bigger.

The inventor has made earnest efforts to solve the problem of increasing the operating force of the throttle valve over time, and as a result of repeated experiments, discovered the existence of the above-mentioned problem.

(Second Prior Art) The "tm structure" shown in FIG.
It communicates with a vibrator 125 disposed directly downstream of and parallel to the 0. A suitable number of small holes 127 are provided on the side of the vibrator 125 facing the shaft 130 so that idle intake air can be blown onto the shaft 130.

With this structure, blow-by gas and exhaust gas are significantly prevented from flowing back to the position immediately downstream of the throttle valve 132, and consideration is given to preventing dirt from adhering to the inner wall of the intake passage 104.

(Problems Remaining in the Second Prior Art) It is clear from a3ti shown in FIG. disrupt the flow of Therefore, in order to secure the necessary amount of intake air, it is necessary to
In order to compensate for the resistance valve caused by the presence of 25, the diameter of the intake passage 104 must be increased.

In addition, the pipe 125 must be placed at a position offset from the shaft 130 so that the valve 132 can rotate to the fully open state, which may disrupt the flow of intake air.
The intake characteristics of each cylinder are not uniform. Furthermore, the amount of idle intake air is generally not sufficient, and the structure shown in FIG.
Since the structure does not take into account the rotating portion 134 where the inner wall of the intake passage 104 approaches each other, there still remains a problem in maintaining stable and smooth rotation of the valve 132 over a long period of time.

Based on the above findings, the present invention aims to prevent oil or a mixture of oil and carbon from adhering to the inner wall of the intake passage, particularly the portion 134 that interferes with the opening and closing of the throttle valve 132. be.

[Means for Solving the Problem] The above problem is solved by: an intake passage communicating with a combustion chamber of an engine via an intake valve; and a throttle valve that opens and closes in the intake passage to control the intake air amount of the engine. , one end communicates with the crankcase of the engine and guides blow-by gas to the other end; one end communicates with the other end of the PCV pipe;
a PCV passage that communicates the PCV vibe with the intake passage; an opening of the PCV passage on the intake passage side is located closer to the engine than the throttle valve;
An engine intake m characterized in that it guides blow-by gas supplied from a V passage to the engine side.
Solved by control device.

[Function] According to the intake m control device having the above means, blow-by gas is sucked into the intake passage downstream of the throttle valve by the opening on the intake passage side of the PCV passage, and the sucked blow-by gas is smoothly transferred to the engine side. will be guided to. Therefore, the blow-by gas does not flow back to the throttle valve side, and the inner wall of the intake passage, especially the throttle valve 13,
This prevents oil or a mixture of oil and carbon from adhering to the portion 134 that interferes with the opening/closing of 2.

Further, according to this structure, since no extra structure is added to the intake passage 104, the flow of intake air is disturbed and the
It's never done.

[Effects of the Invention] As a result, smooth opening and closing operations of the throttle valve are ensured over a long period of time, and accurate engine control is maintained over a long period of time.

[Example 1] Hereinafter, an example will be specifically described with reference to the drawings. Note that detailed explanations of parts that are equivalent to the conventional ones will be omitted.

FIG. 1 shows a first embodiment of the present invention, in which a PC
The opening 2 on the suction path side of the V passage 116 is inclined toward the downstream direction of the suction path.

When tilted in this manner, blow-by gas taken in from the PCV passage is smoothly drawn into the idle intake from the idle boat 124 even when the throttle valve 132 is almost fully open, and is quickly sucked into the surge tank 122 side. It will be done. Is this an experimental result? It was confirmed that sufficient effects could be obtained by J2 observation. As a result, according to this embodiment, the portion 134 that interferes with the throttle valve 132
No oil will stick to the surface, and no carbon will mix with the oil and stick to it.

FIG. 2 shows a second embodiment, in which the suction passage side opening 4 is directed toward the inner wall of the enlarged portion of the surge tongue 122. In this case as well, the blow-by gas is sucked into the surge tank as smoothly as or more smoothly than in the first embodiment, and does not flow back to the throttle valve side.

FIG. 3 shows a third embodiment, in which a guide nozzle 8 is further provided at the suction passage opening 6 facing downstream. The blow-by gas is guided by the guide nozzle 8 and quickly sucked into the surge tank 122 side. In this case, the intake air is disturbed by the nozzle 8, or the
The degree of ramming is much smaller than in conventional pipe-traversed structures.

FIGS. 4 and 5 show a fourth embodiment.

In this embodiment, a guide 12 is rotatably attached to the suction passage side opening 14 by a pin 10.

In this case, when the engine is operating at low speed, where backflow of blow-by gas is a problem, the re-guide 12 is rotated to the position shown by the dashed line due to the negative pressure in the intake passage, and the blow-by gas is smoothly guided to the surge tank 122 side. Ru. On the other hand, when the throttle valve opens, the flow velocity in the intake passage 104 is high and the negative pressure becomes close to atmospheric pressure, so the guide 12 is affected by its own weight and moves to the solid line position shown in the figure, and the resistance in the intake passage 104 disappears. , full intake is achieved.

FIG. 6 shows a fifth embodiment, and in this embodiment, the distance between the intake passage 104 and the PCV passage 116 is set to be significantly smaller than that of the prior art. When the distance A is made small in this way, the suction force in the direction perpendicular to the suction passage 104 received by the blow-by gas flowing through the PCV passage 116 when it is sucked into the suction passage 104 is only a short distance 11! As a result, the velocity of the blow-by gas in the direction perpendicular to the suction passage 104 when it enters the suction passage 104 becomes small.

Therefore, the blow-by gas is immediately removed from the surge tank 12.
It is attracted to 2. In experiments, the distance was 0.5 to 1.5 aw.
Good coleoptiles were obtained.

In this embodiment, the idle boat 20 is located slightly upstream of the intake passage opening 18 of the PCM, and the blow-by gas is quickly guided to the surge tank along with the idle intake air.

FIG. 7 shows a sixth embodiment. In this embodiment, a part of the end face of the gas tank 122 is cut out diagonally as shown in FIG. 22, so that the blow-by gas is sucked out downstream. It is.

In any of the above embodiments, the suction side opening of the PCV passage is located immediately downstream and on the same side of the portion 134 where the throttle valve rotates very close to the inner wall, while the idle boat is located on the opposite side. It is open to

For this reason, the inner wall 134 is filled with idle intake air, and care is taken to prevent blow-by gas from flowing backward.

Incidentally, it is clearly confirmed from the record of the inventor's experiment conducted using VTRM that the desired effect can be obtained by this embodiment.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of an intake air amount control device according to a first embodiment, FIG. 2 is a longitudinal sectional view of the second embodiment, FIG. 3 is a third embodiment, and FIG. 4 is a first diagram of a fourth embodiment. It is a similar figure. FIG. 5 is a partial cross-sectional view of the fourth embodiment. FIG. 6 is a diagram similar to FIG. 1 for a fifth embodiment, FIG. 7 is a diagram for a sixth embodiment, and FIG. 8 is a longitudinal sectional view of a conventional intake air amount control device. FIG. 9 is a longitudinal sectional view of another conventional intake air amount control device. 104...Intake path 130...Valve shaft 132...Throttle valve 124.20...Idle boat

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 intake air amount of the engine; and one end connected to the crankcase of the engine. connected to the other end of the PCV pipe that leads the blow-by gas to the other end,
a PCV passage that communicates the PCV pipe with the intake passage; an opening of the PCV passage on the intake passage side is located closer to the engine than the throttle valve;
An engine intake air amount control device, characterized in that it guides blow-by gas supplied from a V passage to the engine side.