JPH08296422A - Oil mist recovery device - Google Patents

Abstract

PURPOSE: To prevent oil granules stuck to the internal wall of an oil mist recovery device from splashing into a gas exhaust pipe. CONSTITUTION: A main body 10 is provided with a cylindrical part 11, an inverse conical part 12, and an oil pan part 13. A gas supply pipe 21 is installed in an opening part 11b in the vicinity of the upper end of the cylindrical part and a support plate 22 is fixed to the upper end of the cylindrical part. A gas exhaust pipe 23 is penetratingly fixed to the support plate. A top bypass pipe 24 is connected to the opening part 23a in the vicinity of the support plate of the gas exhaust pipe. The bottom bypass pipe 14 is installed in the opening part 13a in the vicinity of the upper end of the oil pan part and the top bypass pipe and the bottom bypass pipe are connected to each other by a connecting pipe 25. The oil pan side is set into a negative pressure state by a venturi effect according to the negative pressure state of the gas exhaust pipe side and oil granules splashed by a circulation flow are effectively recovered by being attracted to the oil pan part side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil mist collecting device, and more particularly to a small oil mist suitable for collecting oil mist contained in blow-by gas accumulated in a crank chamber of an engine for vehicles such as automobiles. Regarding the recovery device.

[0002]

2. Description of the Related Art Heretofore, as an oil mist collecting device of this type, as shown in, for example, Japanese Utility Model Publication No. 51-7540, an oil mist collecting device is installed in a part of a blow-by gas recirculation pipe of an automobile engine. A device (blow-by gas reduction device) is known. As shown in FIG. 4, this oil mist recovery device includes a cylindrical portion 2 having an upper end sealed,
A main body 1 having an inverted conical cylindrical portion 3 connected to the lower end thereof and an oil receiving portion 4 provided on the lower side thereof, a gas supply pipe 5 connected to an opening near the upper end of the cylindrical portion 2, and a cylinder. The gas discharge pipe 7 is provided so as to penetrate the center of the sealing plate 6 that covers the upper end of the portion 2. Then, the gas containing the oil mist sent from the gas supply pipe 5 swirls in the cylindrical space in the main body 1 to collect the oil mist by the cyclone effect in which the oil mist hits the pipe wall and is condensed. It is like this.

[0003]

By the way, in the above-mentioned oil mist recovery device, since the gas is discharged from the gas discharge pipe 7 at a high speed, the inside of the gas discharge pipe 7 is in a high negative pressure state. On the other hand, the gas flowing into the cylindrical portion 2 becomes a swirling flow and reaches the reverse conical cylindrical portion 3, but at this time, a part of the oil particles attached to the inner wall of the reverse conical cylindrical portion 3 is blown off by the gas swirling flow. Be done. There is a problem that the blown oil particles are pulled by the negative pressure in the gas discharge pipe 7 and carried to the outlet side.

In order to cope with this, for example, as shown in FIG. 5, an opening is provided near the upper end of the oil receiving portion 4, and a gas suction device (not shown) is used from a suction pipe 8 connected to the opening. A method is known in which the inside of the oil receiving portion 4 is brought into a negative pressure state by sucking gas at a predetermined ratio to prevent the oil particles from scattering toward the gas discharge pipe 7. However, the amount of gas supplied varies depending on the operating conditions of the system to which the oil mist recovery device is connected,
If the amount of gas suctioned from the suction pipe 8 is controlled in accordance with this, there is a problem that the gas suction device becomes very expensive. In particular, for applications in which the gas supply amount varies depending on running conditions such as the engine of an automobile, an oil mist recovery device with a simple configuration and at a low cost is required. Therefore, the gas suction device is used as an oil mist recovery device. Attaching it is difficult in terms of structure and price. The present invention is intended to solve the above-mentioned problems, and provides an oil mist recovery device capable of preventing the oil particles attached to the inner wall due to the swirling flow of gas from scattering into the gas discharge pipe with a simple configuration. The purpose is.

[0005]

In order to achieve the above-mentioned object, the structural feature of the invention according to claim 1 is that the upper end surface is a tubular portion sealed with a lid, and the lower end of the tubular portion. A cylindrical body having an inverted conical cylinder part connected to the cylindrical body, a cylindrical oil receiving part connected to the lower end of the inverted conical cylinder part, and a gas connected to an opening provided near the upper end of the cylindrical part. In an oil mist recovery device having a supply pipe and a gas discharge pipe provided at the center of the cover body so as to penetrate the cover body, a discharge pipe opening is provided on the wall of the gas discharge pipe and the vicinity of the upper end of the oil receiving portion The receiving part opening is provided at the position, and the discharge pipe opening and the receiving part opening are connected by the connecting pipe to communicate the inside of the gas discharge pipe with the inside of the oil receiving part.

Further, the structural feature of the invention according to claim 2 is that in the oil mist recovery device according to claim 1, the discharge pipe opening is a cylindrical portion with the lid of the gas discharge pipe as a boundary. It is located in the outer part of the.

[0007]

In the invention according to claim 1 configured as described above, the discharge pipe opening provided in the gas discharge pipe and the receiving portion opening provided near the upper end of the oil receiving portion are provided. By connecting with the connecting pipe, the negative pressure generated in the gas exhaust pipe pulls the gas in the oil receiving portion through the connecting pipe into the gas exhaust pipe by the Venturi effect. As a result, the inside of the oil receiving part is in a negative pressure state, so that the oil particles scattered by the gas swirling flow from the wall surface of the inverted conical cylinder part above the oil receiving part are pulled toward the oil receiving part side, Is efficiently collected.

Further, in the invention according to claim 1, the degree of the negative pressure in the gas exhaust pipe changes according to the change in the gas supply amount from the gas supply pipe, but the gas exhaust pipe and the oil receiving portion are connected pipes. Since it is communicated via the, the negative pressure on the oil receiving side automatically changes. The change in the differential pressure between the pressure inside the gas discharge pipe and the pressure on the oil receiving portion side with respect to the change in the negative pressure can be suppressed to a very small level. Therefore, the amount of gas sucked from the oil receiving part through the connecting pipe to the gas exhaust pipe does not change regardless of the amount of gas supply, and the oil mist recovery efficiency of the oil mist recovery device is almost unchanged due to fluctuations in the gas supply. Not affected. Further, in the present invention, the oil mist recovery device is provided at a low cost because it has a simple structure in which the discharge pipe opening and the receiving portion opening provided near the upper end of the oil receiving portion are connected by the connecting pipe. be able to.

Further, in the invention according to claim 2 configured as described above, since the exhaust pipe opening is provided on the gas exhaust pipe wall outside the tubular portion with the lid as a boundary, the exhaust pipe is provided. The connection configuration of the opening portion and the receiving portion opening portion by the connecting pipe can be further simplified. As a result, in addition to the effect of the invention described in claim 1, the oil mist recovery device can be provided at a lower cost.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. FIGS. 1 and 2 are an exploded perspective view and a longitudinal section of a cyclone type oil mist collecting apparatus for an automobile engine according to the embodiment. Is schematically illustrated by. This oil mist recovery device has a main body 10 made of plastic. The main body 10 is provided with a cylindrical portion 11, an inverted conical cylindrical portion 12 is integrally attached to the lower end of the cylindrical portion 11, and an oil receiving portion 13 is integrally attached to the lower side thereof. .

The cylindrical portion 11 is provided with a ring-shaped flange portion 11a at the upper end and an opening portion 11b near the upper end. One end of the gas supply pipe 21 is attached to the opening 11b. The other end of the gas supply pipe 21 is connected to the crank chamber (not shown) of the engine. Cylindrical part 1
A support plate 22 is fixed to the flange portion 11 a at the upper end of 1. A gas discharge pipe 23 is provided at the central opening of the support plate 22.
However, it is fixed by penetrating the support plate 22. The lower end of the gas discharge pipe 23 extends to a substantially lower end position of the cylindrical portion 11. The upper end of the gas exhaust pipe 23 is connected to the intake pipe (not shown) side of the engine. An opening 23a is provided near the support plate 22 of the gas exhaust pipe 23. An upper bypass pipe 24 is connected to the opening 23 a, and the upper bypass pipe 24 is integrally fixed on the support plate 22.

An opening 13a is provided near the upper end of the oil receiving portion 13, and one end of a lower bypass pipe 14 is attached to the opening 13a. The upper bypass pipe 24 and the lower bypass pipe 14 are connected by a flexible connecting pipe 25 made of resin.

Next, the operation of the above embodiment will be described. In the oil mist recovery device, the exhaust gas containing the oil component supplied from the gas supply pipe 21 becomes a swirling flow in the cylindrical portion 11 and is struck on the inner wall surface to be condensed by the cyclone effect in which the oil component is condensed. To be removed. Then, the swirling flow of the exhaust gas is discharged at a high speed while swirling through the gas discharge pipe 23 arranged in the center of the cylindrical portion 11, so that the inside of the gas discharge pipe 23 is in a high negative pressure state. On the other hand, the gas flowing into the cylindrical portion 11 becomes a swirling flow and reaches the inverted conical cylindrical portion 12 and blows off a part of the oil particles adhering to the inner wall of the inverted conical cylindrical portion 12 from the inner wall. However, the upper bypass pipe 2 provided in the gas discharge pipe 23
4 and the lower bypass pipe 14 provided in the oil receiving portion 13 are connected by the connecting pipe 25, the gas exhaust pipe 23
Depending on the negative pressure state on the side, the inside of the oil receiving portion 13 is brought to a negative pressure state due to the Venturi effect in which the gas on the oil receiving portion 13 side is pulled toward the gas discharge pipe 23 side. Therefore, the oil particles blown off by the swirling flow are attracted to the oil receiving portion 13 side, so that the oil particles are efficiently collected in the oil receiving portion 13.

In this oil mist recovery device, the amount of gas supplied from the crank chamber of the engine changes due to changes in the running state of the vehicle, and the degree of negative pressure in the gas exhaust pipe 23 changes accordingly. However, since the gas discharge pipe 23 and the oil receiving portion 13 communicate with each other through the connecting pipe 25, the negative pressure on the oil receiving portion 13 side also automatically changes. The change in the differential pressure PS between the pressure in the gas discharge pipe 23 and the pressure in the oil receiving portion 13 due to the change in the negative pressure in the gas discharge pipe has the result shown in FIG. That is, the flow rate of gas supplied from the engine is set to 4
The change of the differential pressure PS in the range of 5 to 100 l / min is suppressed to a very small range of 10 to 15 mmAQ. Therefore, the amount of gas sucked from the oil receiving portion 13 to the gas discharge pipe 23 through the connecting pipe 25 is reduced regardless of the amount of gas supply, and the oil mist collecting efficiency of the oil mist collecting device is also improved. Is hardly affected by the fluctuation of the gas supply amount accompanying the change of. Further, since this oil mist recovery device has a simple structure in which the upper bypass pipe 24 and the lower bypass pipe 14 are simply connected by the connecting pipe 25, it can be provided at a low cost, and is therefore suitable for low-cost applications such as automobiles. is there.

Next, the result of the oil mist recovery experiment by the oil mist recovery device according to the above embodiment will be shown. The test product of the oil mist recovery device has an inner diameter of 40
mmφ, and the inner diameter of the connecting pipe 25 is 4 mmφ. In addition, for comparison, a conventional product having the same size without upper and lower bypass pipes was prepared. The flow rate of gas supplied to the oil mist recovery device is 45 l / min. The oil mist collection efficiency of the test product and the comparative product is 9 for the test product.
It was 3.5% and the conventional product was 87.4%. That is, the test product has an oil mist recovery rate of 6.1% compared to the conventional product.
It is higher, and the effect of the present invention is clarified.

Although the upper bypass pipe 24 is fixed on the support plate 22 in the above embodiment, the support plate 2
It may be separated from 2. Further, instead of providing the upper bypass pipe 24 outside the cylindrical portion 11, a part thereof is
It may be provided inside. Further, in the above-mentioned embodiment, the oil mist collecting device is used for an automobile engine, but it may be used for collecting oil mist of other engines or gas turbines.

[Brief description of drawings]

FIG. 1 is an exploded perspective view schematically showing a cyclone type oil mist recovery device according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the oil mist recovery device.

FIG. 3 is a graph showing a relationship between a supply gas flow rate of the oil mist recovery device and a pressure difference between a gas exhaust pipe side and an oil receiving portion side.

FIG. 4 is a vertical sectional view schematically showing an oil mist recovery device according to Conventional Example 1.

FIG. 5 is a vertical sectional view schematically showing an oil mist recovery device according to Conventional Example 2.

[Explanation of symbols]

10 ... Main body, 11 ... Cylindrical part, 12 ... Reverse conical cylindrical part, 13 ...
Oil receiving portion, 13a ... Opening portion, 14 ... Lower bypass pipe, 21 ... Gas supply pipe, 22 ... Support plate, 23 ... Gas discharge pipe, 23a ... Opening portion, 24 ... Upper bypass pipe, 25 ...
Connection pipe.

Claims (2)

[Claims] 1. A cylindrical portion having an upper end surface sealed by a lid,
A tubular body having an inverted conical tubular portion connected to the lower end of the tubular portion, a tubular oil receiving portion connected to the lower end of the inverted conical tubular portion, and an opening provided near the upper end of the tubular portion. An oil mist recovery device comprising a gas supply pipe connected to the gas discharge pipe and a gas discharge pipe provided at the center of the lid body so as to penetrate the lid body, wherein a discharge pipe opening portion is formed on a wall of the gas discharge pipe. And a receiving portion opening is provided near the upper end of the oil receiving portion.
An oil mist recovery device, characterized in that the discharge pipe opening and the receiving portion opening are connected by a connecting pipe so that the inside of the gas discharging pipe and the inside of the oil receiving portion communicate with each other. 2. The oil mist recovery device according to claim 1, wherein the exhaust pipe opening is provided at an outer portion of the tubular portion with the lid of the gas exhaust pipe as a boundary. Oil mist recovery device.