JP2012087684A - Closed breather system - Google Patents

Abstract

To provide a closed breather system capable of preventing inflow of oil droplets liquefied in a gas return pipe for guiding blow-by gas from a breather chamber to an intake pipe into the intake pipe.
A closed breather system in which blow-by gas extracted from an engine side is separated and recovered through a breather chamber and oil mist is returned to an intake pipe, and a gas return pipe that guides the blow-by gas from the breather chamber. And a pipe 16 extending upstream of the gas return pipe 6 at a required distance from the inner wall of the gas return pipe 6 at the connecting portion between the gas return pipe 6 and the gas return pipe 6 at the distal end side. An oil droplet return member 18 having a flange 17 that fits closely with the inner wall of the tube 6 is provided.
[Selection] Figure 1

Description

  The present invention relates to a closed breather system.

  The blow-by gas that leaks into the crankcase through the gap between the piston rings during the compression stroke and explosion stroke of the engine fills the crankcase and the cylinder head cover that communicates with the crankcase. The crankshaft and connecting rod are moving at high speed in the crankcase, and the rocker arm and valve are operating in the cylinder head cover communicating with the crankcase. The inside is filled with oil mist.

  For this reason, if the blow-by gas is released into the atmosphere as it is, the oil mist mixed with the blow-by gas may be discharged to the outside. Therefore, as shown in FIG. 2, the oil mist in the blow-by gas 1 A breather chamber 2 equipped with a filter net or labyrinth structure for separating and recovering the oil is provided, and the blow-by gas 1 extracted from the cylinder head cover 4 of the engine 3 through the gas extraction pipe 5 is passed through the breather chamber 2 to provide oil. The mist is separated and recovered and then returned to the intake pipe 7 via the gas return pipe 6, and the oil 8 recovered in the breather chamber 2 is returned to the oil pan (not shown) via the oil recovery pipe 9.

  In FIG. 2, 10 is an air cleaner, 11 is a turbocharger, 11a is a turbine, 11b is a compressor, 12 is an intercooler, 13 is intake air, and 14 is exhaust gas.

  A system for processing the blow-by gas 1 in a closed circuit in this way is called a closed breather system. As prior art document information related to this type of closed breather system, there is the following Patent Document 1 or the like.

JP 2003-278523 A

  However, in such a conventional closed breather system, although the oil mist contained in the blow-by gas 1 is separated and recovered, it is difficult to completely remove the oil mist. As shown in FIG. A small amount of oil mist that has not been liquefied in the gas return pipe 6 becomes oil droplets 15, and these oil drops 15 are guided along the inner wall of the gas return pipe 6 to the intake pipe 7 by the flow of blow-by gas 1. 7, especially when light load operation and stop are repeated, the negative pressure of the intake system by the turbocharger 11 (see FIG. 2) is weakened, and the oil droplets 15 become air cleaners. 10 (see FIG. 2) can easily go back, and the air cleaner 10 (see FIG. 2) can easily become clogged with oil droplets 15 to increase the intake resistance. Was Tsu.

  The present invention has been made in view of the above circumstances, and provides a closed breather system that can prevent the inflow of oil droplets liquefied in a gas return pipe that guides blow-by gas from a breather chamber into the intake pipe into the intake pipe. It is aimed.

  The present invention relates to a closed breather system in which blow-by gas extracted from the engine side is separated and collected through a breather chamber and returned to an intake pipe, and a gas return pipe for introducing blow-by gas from the breather chamber and an intake pipe are provided. The connecting portion is provided with a cylindrical portion extending to the upstream side of the gas return pipe at a predetermined interval with respect to the inner wall of the gas return pipe, and is closely fitted to the inner wall of the gas return pipe at the proximal end side. An oil droplet return member provided with a collar portion is provided.

  Thus, in this way, a small amount of oil mist that could not be removed in the breather chamber liquefies in the gas return pipe and becomes oil droplets, and the oil droplets are sucked by the flow of blow-by gas along the inner wall of the gas return pipe. Even if it is guided to the vicinity of the pipe, the oil drop return member is provided at the connection part between the gas return pipe and the intake pipe, so that the oil drop is folded back from the inner wall of the gas return pipe through the flange. Only the blow-by gas that is prevented from flowing into the intake pipe by the extending cylindrical portion and can circulate around the cylindrical portion of the oil droplet return member flows into the intake pipe.

  Further, in the present invention, it is preferable to form a bent portion in the gas return pipe that is bent at a required angle with respect to the axial center direction of the oil droplet return member immediately before the oil droplet return member. The flow of the blow-by gas is bent just before the drip return member, and the oil mist accompanying the flow is easily detached from the flow due to inertia and easily collides with the inner wall of the gas return pipe or the cylinder portion of the oil drop return member. It is also possible to prevent the oil mist accompanying the flow of blow-by gas from flowing into the intake pipe.

  According to the above-described closed breather system of the present invention, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, the oil droplet return member effectively prevents the inflow of oil droplets liquefied in the gas return pipe for guiding the blow-by gas from the breather chamber into the intake pipe. As a result, it is possible to prevent the situation where the air cleaner is contaminated with oil droplets and the intake resistance increases, and the connection between the gas return pipe and the intake pipe is avoided without causing major design changes such as changing the structure of the breather chamber. It can be carried out at a low cost and in a space-saving manner simply by providing an oil droplet return member in the part.

  (II) According to the invention described in claim 2 of the present invention, the flow of the blow-by gas is bent immediately before the oil droplet return member, and the oil mist accompanying the flow is desorbed from the flow due to inertia and gas Since it can be made easy to collide with the inner wall of a return pipe and the cylinder part of an oil drop return member, the inflow to the intake pipe of the oil mist accompanying the flow of blowby gas can also be prevented.

It is sectional drawing which shows an example of the form which implements this invention. It is the whole schematic figure which shows a prior art example. It is sectional drawing which expands and shows the principal part of the closed breather system of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an example of an embodiment for carrying out the present invention, and the portions denoted by the same reference numerals as those in FIGS. 2 and 3 represent the same items.

  As shown in FIG. 1, in this embodiment, a closed breather system configured in the same manner as in FIGS. 2 and 3, a gas return pipe 6 and an intake pipe 7 for introducing blow-by gas 1 from a breather chamber 2 (see FIG. 2) The connecting portion is provided with a cylindrical portion 16 extending on the upstream side of the gas return pipe 6 at a required interval with respect to the inner wall of the gas return pipe 6 and on the proximal end side with the inner wall of the gas return pipe 6. An oil droplet return member 18 having a flange 17 that fits tightly is provided, and an axial direction of the oil droplet return member 18 is provided immediately before the oil droplet return member 18 in the gas return pipe 6. On the other hand, a bent portion 6a that is bent at a substantially right angle is formed.

  Thus, when the closed breather system is configured in this way, a small amount of oil mist that cannot be removed in the breather chamber 2 (see FIG. 2) is liquefied in the gas return pipe 6 to become oil droplets 15. Even if 15 is guided to the vicinity of the intake pipe 7 by the flow of blow-by gas 1 along the inner wall of the gas return pipe 6, an oil droplet return member 18 is provided at the connection between the gas return pipe 6 and the intake pipe 7. Therefore, the oil droplet 15 is prevented from flowing into the intake pipe 7 by the cylindrical portion 16 extending so as to be folded in the reverse direction from the inner wall of the gas return pipe 6 via the flange portion 17. Only the blow-by gas 1 that can wrap around flows into the intake pipe 7.

  Also, the flow of the blow-by gas 1 is bent at a substantially right angle just before the oil droplet return member 18 by the bent portion 6a of the gas return pipe 6, and the oil mist accompanying the flow is detached from the flow by inertia. As a result, the oil mist easily collides with the inner wall of the gas return pipe 6 and the cylindrical portion 16 of the oil drop return member 18, so that the oil mist accompanying the flow of the blow-by gas 1 can be prevented from flowing into the intake pipe 7.

  Therefore, according to the above-described embodiment, the oil droplet return member 18 can effectively prevent the oil droplet 15 liquefied in the gas return pipe 6 that guides the blow-by gas 1 from the breather chamber 2 (see FIG. 2) from flowing into the intake pipe 7. Therefore, it is possible to prevent the air cleaner 10 (see FIG. 2) from becoming dirty with the oil droplets 15 and increasing the intake resistance, and to change the structure of the breather chamber 2 (see FIG. 2). Without incurring a major design change, the oil drop return member 18 can be provided at the connection portion between the gas return pipe 6 and the intake pipe 7 at low cost and in a small space.

  Also, the flow of the blow-by gas 1 is bent immediately before the oil drop return member 18, and the oil mist accompanying the flow is detached from the flow due to inertia, and the inner wall of the gas return pipe 6 and the cylinder of the oil drop return member 18 are removed. Since it can be made to collide easily with the part 16, the inflow to the intake pipe 7 of the oil mist accompanying the flow of the blow-by gas 1 can also be prevented.

  The closed breather system of the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Blow-by gas 2 Breather chamber 3 Engine 6 Gas return pipe 6a Bending part 7 Intake pipe 15 Oil drop 16 Cylinder part 17 Gutter part 18 Oil drop return member

Claims (2)

  In the closed breather system in which the blow-by gas extracted from the engine side is separated and recovered through the breather chamber and the oil mist is returned to the intake pipe, the connection between the gas return pipe that leads the blow-by gas from the breather chamber and the intake pipe A cylindrical portion extending upstream of the gas return pipe with a predetermined interval with respect to the inner wall of the gas return pipe is provided on the distal end side, and a flange portion is fitted on the proximal end side so as to closely fit the inner wall of the gas return pipe. A closed breather system characterized by providing an oil drop return member.   2. The closed breather system according to claim 1, wherein a bent portion that is bent at a required angle with respect to the axial center direction of the oil droplet return member is formed in the gas return pipe immediately before the oil droplet return member.

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