JPS58126411A - Compulsory ventilating apparatus for crankcase - Google Patents

Abstract

PURPOSE:To permit compulsory ventilation by reducing transmission of pressure pulsation of the blow-by gas to the upstream side of a throttle valve, in the light-loading and low-revolution range, e.g., in idling. CONSTITUTION:A flow control mechanism 22 is arranged midway in a blow-by gas passage 20. Said flow control mechanism 22 has a small bypass hole 24 formed on a partitioning wall 23 and is equipped with a unidirectional valve 25 installed in parallel to said small bypass hole 24. As a negative pressure is formed on the crankcase side in the light-loading and low-revolution range of an engine, the valve body 26 of the unidirectional valve 25 is closely attached onto the seat surface. Therefore, the blow-by gas passage 20 is allowed to communicate only through the small bypass hole 24, so the pressure pulsation generated in a crankcase 8 is damped through said small bypass hole 24.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a device for forced ventilation of blow pie gas in a crankcase of an internal combustion engine.

Conventionally, there has been a crankcase ventilator for an internal combustion engine equipped with a fuel injection device, as shown in FIG. That is, in FIG. 1, P is an intake pipe, b is a throttle valve, C is a fuel injection nozzle, and d is a 1WIJ 1 wholesale circuit. There is also a blow pipe gas line f connecting the head 4-e that communicates with the crankcase with the upstream side of the throttle valve, and a blow pipe connecting the downstream side of the throttle valve with the head cover 〇. A single thread dg is provided.

In the conventional device configured as described above, the air sucked in via the air cleaner h during ennon @load operation is as shown by the arrow F1 above! In addition to introducing it into the crankcase through Ropai Goss iM f,
The blow pie gas is returned to the intake pipe a via the mountain passage g. Therefore, in the ennon's continuous load operating state, the air exits the opening g1 and is introduced into the intake aa on the downstream side of the 7-torre valve! Low pie gas 1 body is returned to proper clothing to control itt! The diameter of the opening of the outlet g is 1 to 27 mm, and the diameter of the opening f of the upstream of the throttle valve 0411 is 2 mm or more to prevent the internal pressure of the crankcase from becoming higher than a predetermined negative pressure. diameter is required.

On the other hand, under high-load operating conditions, the generation and deposition of glow gas increases, and as the pressure in the intake pipe a increases, the pressure difference at the opening gl downstream of the throttle valve decreases, so air is taken in from this opening gt.・Blow pie gas stitches flowing into aa will be reduced. Therefore, the processing cannot be completed by the opening g1! The low pipe gas flows backward through the blow pipe gas passage f in the direction of arrow F2, and is returned to the upstream side of the throttle valve through the opening f1, but if the diameter of this opening f1 is too small, the internal pressure of the crankcase will increase. It rises abnormally and causes problems such as oil leaking from the gaskets of various parts of the engine. Therefore, in order to keep the crankcase internal pressure below a predetermined pressure, it is necessary to set the inner diameter of the opening f1 to 4 to 8 mm, but this value is smaller than the inner diameter of 2 an, which is required during light load operation. is also quite big i
Become direct.

By the way, in the conventional device K=-, the pressure pulsations of the blow pie gas generated in the crankcase are caused by the opening fl.
Since the upstream of the throttle valve +1llIK is used for the engine, if this rM mouth part type 1 is large as shown in the above example, large lateral pulsations will occur, especially in the engine's light load and low rotation range. is transmitted to the first rule upstream of the throttle valve.

Therefore, as shown in Fig. 1, in the air a it a j using the rotating dam plate i, the dam plate i vibrates within a certain angular range due to the pressure pulsations propagated upstream of the throttle valve. By doing this, the support of the dam plate i is I−￥ilI! Harmful relative movement gjlH occurs between the acid A1g point linked to ItI and the Type 7 tension meter m which converts the opening degree of the dam plate i into an hypochondriacal signal. This force movement is large in the no-load, low-speed range, such as when idling, and when idling, the force signal from the potentiometer fluctuates, making it impossible to accurately measure the intake air. .

The misfire 1 son was created based on the above article by Sui, and its purpose is to reduce the pressure 1 vibration that propagates to the upstream side of the throttle valve, especially in the light load and low rotation range such as when idling, and to reduce the pressure 1 vibration that propagates to the upstream side of the throttle valve. Is the crankcase strong enough to stably extract electrical output from the i4? The purpose of the present invention is to provide a lI ventilator.

That is, the present invention includes a blow pie gas passage whose one end communicates with the crankcase and the other end communicates with the upstream side of the throttle valve, and a flow control mechanism disposed in the middle of the blow pie gas passage. The mechanism has a small hole that communicates with the blow-by gas passage at all times, and the valve opens automatically when the pressure on the crankcase side increases relatively when the ennon is under high load, and when the load is light, the above pressure increases. It is a crankcase forced regret device equipped with a 10,000-cycle valve that closes due to a relative decrease.

・ Therefore, in the light load and low rotation range such as during idling, only the above-mentioned pi-cess small hole communicates with the blower gas curve, so the pressure pulsations in the crankcase are caused by the pressure pulsation above the throttle valve. can be prevented from spreading to l. Therefore, it is possible to prevent fluctuations in the electrical output from the potentiometer due to periodic relative motion occurring between the electrical contact interlocked with the dam plate of the airflow meter and the potentiometer on which this sliding point slides.

On the other hand, during high-negative operation, the pressure on the crankcase side increases relatively, causing the one-way valve to open and increasing the amount of blow-pipe gas flowing into the distribution area, which prevents the crankcase internal pressure from increasing abnormally. This prevents oil from leaking from the gaskets of various parts of the engine and other problems.

An embodiment of the present invention will be described below with reference to FIG. In the figure, 1 is the engine body, 2 is the piston, 3 is the destriver, 4 is the fuel injection nozzle, 5 is the control circuit, and 6 is the head cover.
It communicates with the crankcase 8 via. Also, 10
is a 6-intake U, in which a throttle valve I is provided in the middle of this intake U10, and a dam plate 13 constituting an air flow meter 12 is provided rotatably around a pivot 14. There is. This dam plate 13VC is the d air contact 15
The air mixture contact 15 operates a potentiometer 16.

17 is an air cleaner.

In addition, there is a blow pie gas passage 2 in the front head cover 6.
0 is connected to this blow pie gas passage 2.
In addition to 0, the Sr height is opened on the upstream side of the throttle valve 11. 20a is its opening. Furthermore, the head cover 6 is connected to the Prono Gui gas return) Yamaji 21.
The north end opening 21a of this first return path 21 is connected to the F flow side of the throttle valve 11.

And the distribution 11 is located in the middle of the supply pipe gas passage 20.
flJ Miiso J 22 is located here. This distribution control/
1 and 22 are composed of a small hole 24 formed in the partition wall 23VC, and a one-way valve 25 provided in parallel with this small hole 24.

This one-way valve 25 opens and closes a valve hole 27 by means of a valve body 26 made of an elastic member such as a dem. When the valve body 26 is in a free state where no external force is applied, its elasticity closes the valve hole 27. 27, and when the opening 20a side becomes negative pressure, the valve automatically moves away from the seat surface and opens as shown by the lines in the drawing. ing. The diameter of the valve hole 27 is set to be large enough so that the flow of blow-by gas is not obstructed. - The i+ of the 10,000-hole small hole 24 is optimally set to have a diameter of 2 to 31 degrees so that it can dampen the troublesome pressure pulsations that occur on the crankcase 8 side and also sufficiently eliminate blowing and gas treatment. This has been confirmed by experiment.

Next, the operation of the above configuration will be explained. In the light load and low rotation range of Ennon, the air sucked in via the air cleaner 17 is as shown by the solid arrow F1! The blow-by gas is introduced into the crankcase 8 through the low-by gas passage p20, and is returned to the intake pipe 10 via the blow-by gas return passage 21 as shown by arrow F3.

This ibis! Since the crankcase sub-pressure is under negative pressure in the low piston passage 20, the valve body 26 of the one-way valve 25 is in close contact with the seat surface. Therefore, since the blow pie gas passage 20 communicates only through the bypass small hole 24, the child pulsation generated in the crankcase 8 is attenuated by the bypass small hole 24, and hardly propagates to the opening 20a on the upstream side of the throttle valve.

Therefore, when idling, etc., the dam plate 13
is prevented from generating harmful vibrations, and the potentiometer 16 can be protected.

On the other hand, at times other than light load operation, the amount of blow gas generated increases and the pressure inside the intake pipe 10 increases, and the pressure difference at the opening 21h downstream of the throttle valve decreases. The amount of propy gas flowing into the intake pipe 10 from this opening 21a is reduced. Therefore, the blow pie gas that cannot be processed by the part 21a of the opening 9 is
The water flows backward through the path 20 in the direction of arrow F2, and the opening 20
It is returned to the upstream side of the throttle valve after 1rh of a. At this time, since the pressure on the opening 20a side is low, the valve element 26 of the one-way valve 25 automatically moves away from the seat surface and opens due to this pressure difference. That is, both the valve hole 27 and the bypass small hole 24 are in an open state, and the blow/air gas passage 20 is fully open.

Therefore, it is possible to increase the amount of Zoropi gas recirculated into the intake air ffzo from the opening 20h, and it is possible to prevent the internal pressure of the crankcase 8 from increasing abnormally.

In the above embodiment, an elastic member is used as the material for the valve body 26, but instead of using this material, a valve body made of synthetic resin or gold 4, for example, can be pressed against the seat surface using an elastic member such as a suge ring. It may be configured as follows. Moreover, the present invention
The same application can be applied to the intake/d where a detection element is installed when the dam plate is removed.
- Since it can prevent pressure pulsations from propagating,
Electrical output fluctuations caused by pressure pulsations can be prevented, and a stable intake air amount measuring device e can be obtained.

As described above, the present invention can prevent pressure pulsations on the crankcase side from being transmitted to the upstream side of the throttle valve in a light load and low rotation range such as during idling.
This is highly effective in eliminating measurement errors caused by electrical output fluctuations caused by pressure pulsations in equipment installed on the throttle valve flow side.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional crankcase forced ventilation system, and FIG. 2 is a sectional view of a crankcase forced ventilation system showing an embodiment of the present invention. 8... Crank case, 10... Intake pipe, 11...
・Throttle valve, 20...Blow pie gas passage, 20
h...opening, 22...flow control mechanism, 24...
Pinos j small hole, 25... one-way valve. 11-

Claims (1)

[Claims] The blow pipe, which communicates one end with the crankcase and the other end with the upstream side of the throttle valve in the intake pipe, is connected to the air passage, and this glow pie is placed in the middle of the air passage.
Equipped with 1e11 mechanism, this distribution Jl-Iso 1 can is the above! The pi-gusu small hole that is always connected to the low pipe passage and the high load operation of the engine: The valve opens due to the relative increase in pressure in the crankcase, and during light load operation, the above pressure increases A crankcase forced ventilation system ff characterized by comprising a one-way valve that closes when the amount of air decreases.