JPS62150021A - Gas flow control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable a flow of gas, allowed to flow in an intake system, to be controlled to a proper value, by controlling a flow of gas, passing through an opening and closing valve provided interposing in a blow-bye gas flow path or the like, by a pneumatic control unit actuated corresponding to an intake negative pressure. CONSTITUTION:This blow-bye gas processing unit, interposing in a pipe line for recirculating gas in a crankcase 22 to an intake manifold 29, provides an opening and closing valve 20 having a valve main unit 12 opening and closing a gas flow path 23 by balancing pressing force of a spring 11 with a negative pressure in an intake manifold 29. While the unit has a bypass passage 24 detouring the gas flow path 23, and said passage 24 is opened and closed by a plunger 30 of a pneumatic control unit 25. And the pneumatic control unit 25 is constituted so as to control a flow of the bypass passage 24 through the plunger 30 corresponding to a negative pressure value of the intake manifold 29 introduced to a negative pressure chamber 26a partitioned by a diaphragm 27, in this way, a recirculating amount of gas is properly maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a gas flow rate control device for an internal combustion engine, particularly to a control device for a PCV valve that controls the flow rate of gas flowing from a crankcase to an intake hole of an internal combustion engine. .

BACKGROUND OF THE INVENTION Blowby gases are known to degrade engine performance and cause air pollution.

In order to prevent air pollution, many automobiles currently use a blowby gas reduction method in which blowby gas is sucked into the intake manifold and reburned within the cylinder. In the blow-by gas reduction method, in order to maintain a balance between the amount of blow-by gas sucked into the intake hole and the amount of fresh air-fuel mixture, a metering valve is installed in the manifold suction tube that connects the crankcase and intake manifold. or pc
A V-valve is provided to automatically control the flow rate of reducing gas to the engine to prevent the mixture from rising excessively.

In addition, the blow-by gas treatment device is a PCv device (Po5it
iveCrankcase Ventilation
system) or crankcase forced ventilation system.

The PCV valve, as shown in FIGS. 10 and 11,
The valve body 12 has a valve body 12 which is slidably pressed by a valve spring 11 in a valve closing direction within a case 10, and an inclined slot 14 is formed in a shaft portion 13 of the valve body 12. When the engine is stopped, the crank portion 15 of the valve body 12 contacts the valve seat 16 formed in the case 10 by the spring 11, and the valve body 12 is in the closed position.

The PCV valve opens and closes the gas passage by balancing the pressing force of the spring 11 and the negative pressure of the manifold. That is, if the negative pressure in the intake manifold is greater than the spring force, the PCV valve will be in an open state, but if the negative pressure increases further, the gas passage will be narrowed down. Therefore, the amount of gas passing through the PCV valve is.

Automatically and dynamically controlled by the intake manifold vacuum level. In other words, as shown in Fig. 10, during eye lift, the negative pressure level of the intake manifold is high and the suction force is strong, so the gas passage of the PCV valve is narrowed to a small extent, but the amount of blow-by gas generated also corresponds to this. It becomes less. However, during acceleration and high loads, the amount of blow-by gas generated increases as shown in Figure 11.
The above negative pressure level decreases in proportion to this, so PC
The gas passage of the V-valve opens wide.

FIG. 12 shows changes in fresh air iA and blow-by gas amount B during operation of the PCv valve. In this figure, the horizontal axis shows the manifold negative pressure P (-mmHg), and the vertical axis shows the flow i1Q (43/min) t-.

The above PCv valve is used in nine different blow-by gas reduction systems. For example, a PCV valve is used in an open system where fresh outside air is taken into the crankcase through the air hole in the oil filler cap, and gas mixed with blow-by gas is sucked from the crankcase into the intake manifold via the manifold suction tube and re-burned. Ru. In an open system, the PCV valve is
Provided at the outlet of the manifold suction tube.

The open system described above has the simplest structure and is less likely to malfunction, but during high-load operation, the negative pressure in the intake manifold weakens even though the amount of blow-by gas increases, making it impossible to take in all the blow-by gas. Therefore, a large amount of H is released from the air holes in the oil filler cap.
There is a drawback that harmful gases containing Ctl must be released into the outside air.

Next, as another method, there is a closed system in which the crankcase and the intake manifold are connected by a manifold suction tube having a PC't/valve, and the top cover and the air cleaner are further connected by a pipe. In a closed system, fresh air is taken into the crankcase from the air cleaner and sucked into the intake manifold along with blow-by gas for re-combustion. In a closed system, the intake amount of blow-by gas is measured by the PCV valve, and when the negative pressure is strong at light loads, it is sucked in by the intake manifold, and when the manifold load is weak, such as during full-load low-speed operation, the blow-by gas is sucked into the top cover. The air is sucked into the carburetor via an air cleaner.

Reburning takes place. However, in a closed system,
If oil and impurities contained in the blow-by gas adhere to the cleaner element, it has the disadvantage of accelerating clogging.

Problems to be Solved by the Invention As mentioned above, the PCV valve is installed between the crankcase and the intake manifold, and the valve body moves in response to manifold negative pressure to change the opening area of the gas passage. It has the function of controlling the flow rate of gas sucked into the

However, in recent years, improvements in the functions of the PC'v valve have been required from the viewpoints of strengthening air pollution prevention, facilitating fuel consumption control, and improving the stability of idling operation. It is desired to adapt the gas flow rate of the PCV valve to a corresponding flow value.

That is, in the conventional PCV valve, as shown in FIG. 12, the amount of fresh air flowing into the crankcase is significantly larger than the amount of normal blow-by gas.

This state of supplying an excess amount of fresh air into the crankcase is desirable from the perspective of preventing air pollution, but
In the open system or closed system described above, if the PCv valve is installed so that blow-by gas is supplied between the throttle valve and the engine intake hole, fuel control becomes difficult. In other words, the amount of air taken into the engine is the amount of fresh air passing through the air cleaner and PC
It is expressed as the sum of the valve flow rate, and when the engine speed is increased under light load, the PCV valve flow chamber becomes large relative to the amount of fresh air that contributes to fuel control. Therefore, the relative ratio of the fresh air amount compared to the PCv valve flow rate decreases, and a small amount of fresh air passes through the throttle valve, Kameko fuel control system (EFR), or electronically controlled fuel injection system (PE).
Since fuel control must be performed through I), it is obvious that fuel control becomes difficult. For the same reason, it is difficult to obtain operational stability during idle link operation.

Also, with the conventional PCV valve, the amount of excess fresh air flowing into the crankcase is completely reduced.

The flow rate of gas flowing through the PCV valve is determined by the balance between the manifold negative pressure and the elastic force of the spring that presses the valve body, so the amount of fresh air can be accurately controlled.
was difficult. With this kind of gas flow meter control of the PCV valve, it is not possible to accurately control the gas current, and the amount of blow-by gas generates more fVC than the amount of fresh air, making it impossible to ventilate the crankcase sufficiently. There are many things.

In short, the blow-by gas reduction device using the PCV valve allows the entire flow of blow-by gas generated in the crankcase to flow into the intake manifold, completely eliminating defects that cause blow-by gas to be released into the atmosphere, and at the same time While maintaining the amount of fresh air to the case at the minimum necessary level.

The air flow f used for fuel control must be increased as much as possible. Conventional gas flow control device ηf for internal combustion engine
However, it was not possible to meet such a request.

An object of the present invention is to provide a complete gas flow rate control device for an internal combustion engine that can meet the above requirements.

Means for Solving the Problems In this invention, in a gas flow control device for an internal combustion engine provided in a gas passage that supplies unburned gas flowing out from the internal combustion engine to the combustion chamber again, the device is operated by the intake action of the internal combustion engine. A passive control device (IT) is provided to control the flow rate of gas passing through the on-off valve, and the intermediate control device (IT) is activated in response to the negative pressure value generated by the intake action of the internal combustion engine. It is characterized by causing

Function: The pneumatic control device, which is activated in response to the negative pressure generated by the intake action of the internal combustion engine, controls the flow of gas (ffk) passing through the on-off valve, so the gas flow kt flowing into the intake hole is adjusted to an appropriate value. can be controlled.

Embodiments All embodiments of the present invention shown in FIGS. 1 to 9 will be explained below. Among the parts shown in these drawings, the parts that are the same as those shown in Figs. 10 to 12 are as follows:
The same reference numerals are given and explanations are omitted.

The gas flow rate control device of the present invention shown in FIG.
It has the same on-off valve 20 as the PCV valve shown in FIGS. 0 and 11. However, in the embodiment shown in FIG. 1, a tapered part 21 is formed at the upper part of the shaft part 13. Gas within crankcase 22 flows through valve passage 23 to intake manifold 29 . The side of the valve passage 23 is connected to the case 1.
The bypass passage 24 communicates with an intake manifold 29 .

A pneumatic control device 25 is provided above the bypass passage 24 . The intermediate motion control device 25 includes a diaphragm 27 whose outer periphery is airtightly fixed within the pressure chamber 26 .

and a diaphragm compression spring 28 that presses the diaphragm 27 toward the bypass passage 24K.

The plunger 30 is fixed to the diaphragm 27. Since the diaphragm 27 is constantly pressed by the spring 28, the tip 31 of the plunger 30 closes the bypass passage 24 when the pressure chamber 26 has a pressure equal to or higher than a predetermined level. The pressure chamber 26 has a diaphragm 27
It consists of a negative chamber 26a and a normal pressure chamber 26b, which are separated by
Negative pressure chamber 26a V'i+the spring 28 is arranged and connected to intake manifold 29 through a boat 32 and a known pressure control valve 33.

In the configuration shown in FIG.
By introducing the negative pressure of the intake manifold 29 into a, the plunger 30 resists the elasticity of the spring 28.
is moved to the open position, the flow rate of the bypass passage 24 is controlled in accordance with the negative pressure value of the intake manifold 29, and the gas flow rate of the on-off valve 20 can be controlled. To explain this situation with reference to Figure @7, whereas in the conventional device, the airflow SiL flowing into the crankcase is indicated by D.

In this invention, it is indicated by C, and it can be understood that the gas flow rate through the on-off valve 20 is not increased unnecessarily.

In the graph of FIG. 7, at low load and high speed, the blow-by gas t increases as shown by E, but in this case, the pressure control valve 33 is all connected to the negative pressure 26a corresponding to the blow-by gas needle that applies the puff. can be reduced to a predetermined level of negative pressure and the plunger 30 can be moved to the open position.

FIG. 2 shows another embodiment of the invention. In this example, the negative pressure chamber 26a is depressurized to a predetermined level through all of the pressure control valves 33, and the 7-lunger 30 is moved downward against the external force of the spring 28.
The gas flow rate of the on-off valve 20 can be controlled by pressing G to a predetermined value.

The diaphragm 27 is set at a predetermined position by the adjustment screw 35, and the shield member 36 maintains the airtightness of the negative royal chamber 26a.

FIG. 3 shows yet another embodiment of the invention. In this example, the spring 39 connects the diaphragm 27 and the plunger 3.
0 is pressed to move the valve body 12 to the closed position, and the plunger 30 is fully opened by manifold negative pressure. The normal pressure chamber 26b is kept airtight by the shield member 37. In this embodiment, the valve body 12 is provided with a groove-shaped slot 38. In one example, +3i! 4
As shown in the figure, an orifice 38a is formed. or.

As shown in FIG. 5C', a spiral shaped slot 38b is formed. Further, as shown in FIG. 6, the detail 13 has a Vi difference portion 40, and a slot 38c extending to this stepped portion 4° is formed.

The equipment shown in Figures 2 and 3; the blow-by gas flowing within the chamber and flowing into the crankcase? 1 [Air flow rate characteristics are shown in FIG. Similarly to FIG. 7, FIG. 8 also shows the air flow rate C in the device of this invention.

You can understand that it can be adjusted to the minimum necessary.

Therefore, in the manufacturing process of the present invention, as shown in FIG. 9, the air flow rate CK is reduced overall compared to the conventional air flow MD.
It is also possible to set

The above-described embodiments of the present invention can be modified in various ways within the same technical scope. For example, the above example is a prove-by gas reduction system! ! ':1, but the exhaust gas recirculation system (Exhaust Gas Recirculati
A similar configuration can be applied to an EGR valve (on System). Furthermore, the pressure control valve 33 can also be used as part of a mechanical or electrical control system that controls the pressure value in response to the maniographic vacuum.

In addition, in the embodiment shown in FIG. 1 or 2, the valve body 1
2 and the plunger 30 and presses the valve body 12 or the diaphragm 27, one of the springs may be omitted.

Effects of the Invention As mentioned above, in this invention, the air 45 i'J: control rack f? is suddenly moved in response to the negative pressure generated by the intake action of the internal combustion engine. Since the configuration is such that the flow rate of the gas that opens 12,1 valve □I (1; 7FJ) is controlled by A, it is possible to control the gas flow jI''C flowing into the intake hole to the appropriate value. For.

For blow-by gas that uses a PCV valve, the total flow rate of the blow-by gas generated in the crankcase is increased by inserting the intake manifold (intake manifold) so that the blow-by gas is released into the atmosphere. (In order to reach the crankcase, it is possible to ensure the maximum amount of air flow to be used, while waiting for the air flow to the crankcase with a minimum of 1 degree and 5 degrees.) In the invention of the lever,
Since the entire intake action of an internal combustion engine can be used, the system can be manufactured in a small size, and at the same time, blow-by gas can be absorbed by the gas flow 4 passing through the on-off valve, preventing contamination of air cleaners or air blowers, etc., and preventing high-speed unloading. All blow-by gas emissions can be completely prevented when 0

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a sectional view showing one embodiment of the gas flow ii) control device for an internal combustion engine according to the present invention, i29 is a sectional view of another embodiment, and Fig. 3 is a sectional view of another embodiment. A cross-sectional view of the embodiment, FIG.
FIGS. 5 and 6 are partial sectional views showing still further embodiments of the valve body. FIGS. 7, 8, and 9 are graphs showing the amount of fresh air inflow and the amount of blow-by gas generated relative to the manifold negative pressure in the gas flow rate control device for an internal combustion engine according to each embodiment of the present invention, and FIG. A cross-sectional view of a conventional PCv valve under light load, and Fig. 11 is a cross-sectional view of a conventional PCv valve under high load.
A cross-sectional view of a V-valve. Figure 12 shows the fresh air inflow amount and blow-by gas generation ft with respect to manifold negative pressure in a conventional PCV valve.
It is a graph showing k. 20... Opening/closing valve, 25... Pneumatic control device r't,
27...Diaphragm, 28...Spring,
30...Plunger. 33...Pressure control valve

Claims (10)

[Claims] (1) In a gas flow rate control device for an internal combustion engine provided in a gas passage that supplies unburned gas flowing out of the internal combustion engine to the combustion chamber again. The pneumatic control device includes an on-off valve operated by the intake action of the internal combustion engine, and a pneumatic control device that controls the flow rate of gas passing through the on-off valve. A gas flow control device for an internal combustion engine, characterized in that it is operated in accordance with a value. (2) The unburned gas is blow-by gas flowing from the combustion chamber to the crankcase.
1) The gas flow rate control device for an internal combustion engine as described in item 1). (3) Claim (2) wherein the on-off valve is a PCV valve that includes a valve body and a valve spring that presses the valve body in the valve closing direction, and that controls the flow of the blow-by gas. The gas flow rate control device for an internal combustion engine as described. (4) The pneumatic control device includes a diaphragm that is actuated by negative pressure generated by the intake action of the internal combustion engine, a plunger having one end fixed to the diaphragm, and a direction in which the pneumatic control device is actuated by the negative pressure. a diaphragm spring that presses the diaphragm in the opposite direction, and the other end of the plunger controls the flow rate of gas passing through the on-off valve to a predetermined value when the diaphragm is moved by the negative pressure or the diaphragm spring. Claim No. 1 (1)
) The gas flow rate control device for an internal combustion engine as described in item 2. (5) The other end of the plunger controls a bypass passage for gas passing through the on-off valve.
The gas flow rate control device for an internal combustion engine as described in 2. (6) The gas flow control device for an internal combustion engine according to claim (3), wherein the pneumatic control device controls the position of the valve body. (7) The opening/closing valve includes a valve body and a valve spring that presses the valve body in the valve closing direction, and the plunger controls the position of the valve body by the negative pressure. The gas flow rate control device for an internal combustion engine according to item (4). (8) The opening/closing valve includes a valve body and a valve spring that presses the valve body in the valve closing direction, and the plunger controls the position of the valve body by the diaphragm spring. The gas flow rate control device for an internal combustion engine according to item (4). (9) The pneumatic control device is connected to an intake hole of an internal combustion engine through a control valve, and the control valve is opened and closed in response to the negative pressure value. Gas flow control device for internal combustion engines. (10) The gas flow rate control device for an internal combustion engine according to claim (4), wherein the rest position of the diaphragm is adjusted by an adjustment screw.