JPS6011667A - Oxygen rich air feeder - Google Patents

Abstract

PURPOSE:To feed oxygen rich air only under low load through simple structure, by connecting an oxygen-rich film unit through a branch to the downstream of a throttle valve of a suction tube then sucking the oxygen-rich air into a suction tube by means of the suction negative pressure. CONSTITUTION:An annular partition 5 is provided in the center of casing 4 of an air filter unit 3 provided at the tip of a suction tube 2 then a suction filter 6 is contained above said partition 5 while an oxygen-rich film unit 7 is contained below said partition 5. An air take-in port 14 and a vent duct 15 are communicated with the outercircumferential chambers 10, 11 to be formed above and below the casing 4 while a ventilation blower 16 is provided to said duct 15. A branch 19 communicating with the downstream of a throttle valve 20 of suction tube 2 is coupled to the bottom face of the casing 4. The negative pressure produced at the downstream of said valve 20 is applied onto the unit 7 to suck the air through a separation film. In such a manner, the oxygen-rich air is fed into the suction tube 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an apparatus for oxygen-enriching air taken into an engine using an oxygen-selective separation membrane.

Back-Technology In gasoline engines, supplying oxygen-enriched air to the engine in the low-load operating range improves ignition performance and combustion speed, thereby improving fuel efficiency and reducing HC and CO in exhaust gas. can be reduced. Particularly in the idling operating range, combustion is stabilized, so the rotational speed and air-fuel ratio can be lowered, making it possible to significantly improve fuel efficiency.

On the other hand, it is already known that in a diesel engine, by throttling the intake valve in a low-load operating range, the maximum pressure inside the cylinder is reduced, and rotational fluctuations and vibrations are reduced. Attempts have also been made to reduce combustion noise by slowing combustion, but although this method maintains the vibration reduction effect of throttling the intake valve, it causes ignition delay and increases the premixed combustion ratio. However, there are problems in that the noise is not reduced and the combustion is worsened, resulting in a significant increase in HC.

Purpose of the Invention The object of the present invention is to provide a device that can supply oxygen-enriched air to an engine with a simple configuration, and that can supply oxygen-enriched air only at low loads, especially in diesel engines, which eliminates the need for a special force mechanism. It has been done.

Structure of the Invention The present invention includes an intake pipe, a throttle valve provided on this pipe, and a branch pipe connected downstream of the throttle valve of the intake pipe and communicating with an oxygen enrichment membrane unit having a separation membrane. As a result, the air enriched with oxygen by the separation membrane is permeated using the negative pressure generated on the downstream side of the throttle valve, and the oxygen-enriched air is introduced into the intake pipe.

In particular, in gasoline engines, supplying oxygen-enriched air to the engine in high load ranges is difficult to improve fuel efficiency, and also increases NOx, so it is undesirable to adjust the opening in the middle of the branch pipe. A valve is provided to provide oxygen-enriched air only at low loads.

Example The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 shows a first embodiment, in which the present invention is applied to a gasoline engine. An air filter unit 3 is provided at the tip of an intake pipe 2 that introduces the atmosphere into the Ennon main body 1. An annular partition plate 5 is provided at the center of the casing 4 of this unit 3, and an intake filter 6 is housed above the partition plate 5, and an oxygen enrichment membrane unit z is housed below the partition plate 5. The two-way opening portion of the casing 4 is closed by an upper cover 8, thereby fixing the intake filter 6. On the other hand, the oxygen enrichment membrane unit 7 is connected to the casing 4
It is fixed by the lower blade ri-9 attached to the lower opening. Both the intake filter 6 and the oxygen enrichment membrane unit 7 have an annular shape, and their respective outer peripheral surfaces are spaced apart from the inner surface of the casing 4, forming peripheral chambers 12 and 11, respectively, and central chambers 12 and 13. It communicates with the intake pipe 2.

An air intake port 14 communicating with the outer peripheral chamber 10 is provided in the upper part of the casing 4, and a ventilation duct 15 communicating with the outer peripheral chamber 11 is added in the lower part of the casing 4. A ventilation blower 16 provided in the ventilation duct 15 blows air sucked in from the air intake port 14 into the peripheral chamber 10. Intake filter 6
, central chamber 12゜13, oxygen enrichment membrane unit 7, peripheral chamber 1
1. Exhaust air through the ventilation duct 15 to constantly supply fresh air to the oxygen enrichment membrane unit 7.

A connecting pipe 17 is formed in the center of the bottom surface of the casing 4, that is, the bottom surface of the lower cover 9, and a hole is formed on the side thereof, through which a pipe portion 18 protruding from the bottom surface of the oxygen enrichment membrane unit 7 passes. is drilled. The connecting pipe 17 is fitted into the opening of the intake pipe 2. On the other hand, the pipe portion 18 is connected to a branch pipe 19, and this branch pipe 19 communicates with a protruding pipe 21 that opens immediately downstream of the portion of the intake pipe 2 where the throttle valve 20 is provided. Therefore, the negative pressure generated downstream of the throttle valve 20 is guided to the oxygen enrichment membrane unit 7 via the branch pipe 19.

A negative pressure sensor 23 is installed downstream of the force throttle valve 20 via a twisted joint pipe 22, and the negative pressure signal detected by this sensor 23 is a water temperature signal S0 and an engine rotational speed signal 82.
etc. are input into the computer 24.

Figures 2 (1 to 4) show in detail the structure of the oxygen-enriched membrane cell 30 that constitutes the oxygen-enriched membrane unit 7. The oxygen-enriched membrane cell 30 is formed by forming a porous support membrane 31 into a thin box shape, with a thin tube 32 connected to the lower end, and a separation membrane 33 made of a polymer membrane such as silicone rubber or butyl rubber on the outer surface. It is a very thin coating.

Thus, through the thin tube 32, the inside 3 of the oxygen-rich cell 30 is
When negative pressure is introduced into the membrane 4, a pressure difference is generated between both sides of the separation membrane 33 through the porous support 31. Ordinary air is led to the outside 35 of the oxygen-rich membrane cell 30, and on the outer surface of the separation membrane 33, oxygen and nitrogen are dissolved within the separation membrane 33. Oxygen and nitrogen are separated by the separation membrane 33 based on the pressure difference.
Oxygen (%hL) is released from the separation membrane 33 on the inner surface, but since the proportion of oxygen dissolved in the separation membrane 33 is 2 to 3 times larger than that of oxygen, the inside of the oxygen-rich membrane cell 30 34, oxygen-enriched air is obtained.

The thin tube 32 of each oxygen-rich membrane cell 30 communicates with the pipe section 18, thereby introducing the negative pressure downstream of the throttle valve 20 in the intake pipe 2 into the interior 34 of each oxygen-rich membrane cell 30. The larger the value, the greater the amount of oxygen-enriched air, which means that air with a high oxygen concentration is supplied to the engine body 1.

Since the device of this embodiment has the above configuration, it operates as follows.

A part of the air that has looked into the air filter unit 3 from the air intake port 14 and passed through the intake filter 6 is directly guided into the intake pipe 2 via the connecting pipe 17 without passing through the oxygen enrichment membrane unit 7. It passes through the throttle valve 20 and enters the engine body 1.
supplied to However, the lever air is normal air with an oxygen concentration of 21%.

On the other hand, the remaining air that has passed through the intake filter 6 is supplied to the outer surface of each oxygen-rich membrane cell 30. These y It is introduced downstream of the valve 20 and supplied to the engine body 1.

In this way, normal air and oxygen-enriched air are mixed, and air containing a predetermined amount of oxygen is supplied to the engine body 1. On the other hand, the computer 24 calculates the amount of fuel to be supplied to the engine based on signals such as the negative pressure, water temperature, and engine speed detected by the negative pressure sensor 23.

As described above, the device t+ of this embodiment has a simple configuration in which the negative pressure generated on the downstream side of the throttle valve 20 is guided to the oxygen enrichment unit 1j', 4F unit 7, and the oxygen-enriched air is converted to fR.
') It is designed to be introduced downstream of the valve 20. Therefore, the partial pressure of oxygen in the air supplied to the engine increases, and the combustion rate becomes very low.

This concentration makes it possible to significantly improve combustion, especially in areas where combustion tends to deteriorate, such as low-speed, low-load operating ranges, improving fuel efficiency and reducing T-T in exhaust gas.
C, Co f: Can be decreased. Since the oxygen enrichment membrane unit 7 and the intake filter 6 are housed in the casing 4, and the upstream side of the oxygen enrichment membrane unit 7 is connected to the downstream side of the intake filter 6, the oxygen enrichment membrane unit 7 can be separately filtered. It is not necessary to have a device, and the entire device can be made as small as possible, which is advantageous for mounting on a vehicle.

FIG. 5 shows a second embodiment, in which the present invention is applied to a diesel engine. The basic structure and operation/system are substantially the same as those of the first embodiment, and only the different points will be explained.

The throttle valve 20 is driven by an actuator (not shown), and this actuator is controlled by a computer 24. The output signal of the opening degree detection switch 42 that is linked to the accelerator pedal 41 is input to the computer 24 along with the water temperature signal SI%, the engine rotation speed signal S7, and the like. The computer 24 controls the throttle valve 20 by driving the actuator 7b during idling operation and low speed and low load operation ranges.
Close the intake pressure and keep the intake negative pressure at a constant value, for example 100~200wn.
I lose 1 to H.

Therefore, in the above operating range, negative pressure is generated downstream of the throttle valve 20, and this negative pressure acts on the oxygen-enriching membrane unit 7 through the branch pipe 19 to direct the oxygen-enriched air downstream of the throttle valve 20. lead to the side. However, this oxygen-enriched air is mixed with normal air that is directly led to the intake pipe 2 without passing through the oxygen-enriched membrane unit 7, and is supplied to the engine with a predetermined oxygen concentration. This reduces the maximum pressure inside the engine's cylinders, reduces rotational fluctuations and vibrations, and at the same time
Despite the reduction in compression pressure, the ignition delay of the fuel is alleviated and the premix combustion ratio is reduced, resulting in a reduction in noise. Furthermore, since the combustion state is improved and HC is significantly reduced, the fuel injection timing can be delayed, making it possible to further reduce noise and vibration.

Note that outside the manual operation range, the throttle valve 20 is opened and the negative pressure on the downstream side reaches approximately 0, so that no negative pressure acts on the oxygen-enriched JI type unit 7, and the oxygen-enriched air is Figure 6 shows the third implementation [5 (1). The basic configuration is the same as that of the first embodiment "[1]. To explain the difference from FIG. The signal of the opening degree of the valve 43 is sent to the converter 24 along with the signals of water temperature, outside temperature, intake temperature, engine speed, engine load (accelerator opening, throttle opening, intake negative pressure), etc.
is input. The conbeater 24 controls the opening degree of the opening adjustment valve 43 according to signals such as the water temperature, outside temperature, and engine load.

Now, depending on the magnitude of the intake negative pressure value, the oxygen concentration of the oxygen-enriched air introduced via the oxygen-enriching membrane unit 7 tends to change, but the amount of oxygen-enriched air and oxygen-enriched air also changes. This embodiment takes advantage of this fact.

That is, the opening degree of the regulating valve 43 is adjusted by the converter 24 according to the operating state of the engine, and the negative pressure in the branch pipe 19 is controlled to bring the amount of oxygen-enriched air to a predetermined value.

When the opening degree of the regulating valve 43 is relatively small, the pressure in the upstream part of the branch pipe 19 from the regulating valve 43 approaches atmospheric pressure due to the introduced oxygen-enriched air. The amount of oxygen-enriched air decreases.On the contrary, when the opening degree of the regulating valve 43 is relatively large, the intake negative pressure always acts directly on the oxygen-enriched membrane unit 7, and the amount of oxygen-enriched air increases. .

Third embodiment jd1 oxygen enrichment membrane unit 7 as shown below
A regulating valve 43 is provided in the branch pipe 19 that leads intake negative pressure to the engine, and by adjusting the opening degree of this valve 43, the amount of oxygen-enriched air is adjusted. The oxygen concentration of the inhaled air can be controlled. For example, when the engine load is small and combustion is in an unstable region or when the engine is in a state of high momentum, the oxygen concentration is increased, but when the engine load is a little large and powerful, the oxygen concentration is decreased to prevent an increase in NOx. The engine speed will change if the oxygen adhesion is changed by 1 degree, but it is also possible to increase the idle speed during warm-up operation by changing this.Also, it is possible to increase the idle speed during warm-up operation. It is also possible to control the idle speed by controlling the opening degree of the engine according to the engine speed.

In both FIGS. 5 and 6, the same parts as those in FIG. 1 are designated by the same reference numerals.

Effects of the Invention As described above, according to the present invention, the effect that oxygen-enriched air can be supplied to the engine with a simple configuration can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the first embodiment of the present invention, FIG. 2 is a side view showing an oxygen-rich membrane cell, FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. 2, and FIG. FIG. 5 is a cross-sectional view showing a second embodiment, and FIG. 6 is a cross-sectional view showing a third embodiment. 2... Intake pipe, 6... Intake filter, 19... Branch pipe, 20... Throttle valve, 33... Separation membrane. Figure 1 Figure 2 Figure 3 Figure 4 1 3 1) Normal Figure 5 Elbow opening

Claims (1)

[Claims] 1. An intake pipe that introduces the atmosphere to the cylinders of the engine, a throttle valve that is provided in the middle of this intake pipe and changes the flow path area, and an opening on the downstream side of the throttle valve of the intake pipe. At the same time, a branch pipe communicating with an oxygen enrichment membrane unit having an oxygen-selective separation membrane is provided, and the air enriched in oxygen in the oxygen-selective separation membrane is transferred to a negative pressure generated downstream of the throttle valve. An oxygen-enriched air supply device characterized in that the oxygen-enriched air is permeated through the oxygen-enriched air and introduced into the intake pipe. 2. The oxygen-enriched air supply device according to claim 1, wherein the upstream side of the separation membrane is connected to the downstream side of an intake filter provided at the entrance of the intake pipe. 3. The oxygen-enriched air supply device according to claim 1, wherein an opening adjustment valve is provided in the middle of the branch pipe.