JP5950592B2 - Closed breather system - Google Patents

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 ventilator 2 (CCV: Closed Crankcase Ventilator) with a built-in filter net or labyrinth structure for separating and recovering gas is provided, and the blow-by gas 1 extracted from the cylinder head cover 4 of the engine 3 via the gas extraction pipe 5 is provided in the ventilator 2. The oil mist is separated and recovered by passing it through and then returned to the intake pipe 7 via the gas return pipe 6, and the oil 8 recovered by the ventilator 2 is returned to the oil pan (not shown) via the oil recovery pipe 9. Yes.

  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.

  Generally, a system for processing the blow-by gas 1 as described above in a closed circuit is called a closed breather system. As prior art document information related to this type of closed breather system, the following patent document 1 and the like are disclosed. is there.

JP 2003-278523 A

  However, in such a conventional closed breather system, the return port 6a of the gas return pipe 6 with respect to the intake pipe 7 is directly cooled by the intake air 13 as shown in an enlarged view in FIG. When the engine is idle for a long time or when the engine room is running at a low speed where the temperature in the engine room does not increase, moisture contained in the blow-by gas 1 is condensed at the return port 6a, and the condensed water is frozen as it is. The return port 6a may be blocked, and in such a case, the pressure in the crankcase may increase to induce oil leakage.

  In addition, it has been proposed to heat by installing an electric heater in the return port 6a of the gas return pipe 6 with respect to the intake pipe 7, but such installation of the electric heater causes a significant increase in cost. There's a problem.

  The present invention has been made in view of the above circumstances, and it is possible to reliably prevent the blockage caused by the condensation of moisture in the blow-by gas at the return port of the gas return pipe with respect to the intake pipe without causing a significant increase in cost. It aims to be able to prevent.

The present invention provides a closed breather system in which blow-by gas extracted from an engine is separated and recovered through an air ventilator and returned to an intake pipe so as to surround the intermediate part in the middle of the intake pipe. An annular chamber for covering is provided, and a gas return pipe for guiding blow-by gas from the ventilator is connected to the chamber, and the internal space of the chamber and the internal flow of the intake pipe are divided so as to divide the intake pipe in the middle of the intake pipe. A communication portion that communicates with the road in an annular shape is formed.

  Thus, in this way, the return port of the gas return pipe is indirectly connected to the intake pipe via the chamber, and the return port of the gas return pipe is directly exposed to the flow of intake air. As a result, the moisture in the blow-by gas condenses and freezes at the return port of the gas return pipe even during idling for a long time at extremely low temperatures or during low-speed driving where the temperature in the engine room does not rise. Such a situation will not occur.

  Further, in order to avoid freezing at the return port of the gas return pipe in this way, there is no need for an expensive equipment such as an electric heater, and the return port of the gas return pipe is indirectly sucked through the chamber. Since only a structural idea of connecting to the pipe is required, the present invention can be implemented at a low cost without causing a significant increase in cost.

  Although moisture in the blow-by gas may condense at the communication part, the opening area of the communication part can be expanded as much as possible within the range covered by the chamber. It is easy to avoid the situation of being blocked by freezing.

  Also, even if condensation water freezes at a part of the communication section, if the chamber is warmed by heat transfer from the engine side after shifting from idle operation or low-speed driving operation to the high-speed driving operation, it will thaw and evaporate immediately. However, it is excluded together with the blow-by gas to the intake pipe.

  According to the above-described closed breather system of the present invention, the return port of the gas return pipe is indirectly connected to the intake pipe through the chamber without requiring an expensive equipment such as an electric heater. Only by devising it, it is possible to prevent the return port of the gas return pipe from being directly exposed to the flow of the intake air, and it is caused by condensation of moisture in the blow-by gas at the return port of the gas return pipe and freezing. It is possible to achieve an excellent effect that the blockage can be surely prevented without causing a significant increase in cost.

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 FIG. 2 and FIG.

  As shown in FIG. 1, in the present embodiment, a closed breather system configured in the same manner as in FIG. 2 is provided, and a chamber 15 is annularly provided in the middle of the intake pipe 7 so as to surround the whole of the middle. In addition, a gas return pipe 6 that guides the blow-by gas 1 from the ventilator 2 (see FIG. 2) is connected to the chamber 15, and the internal space of the chamber 15 and the intake pipe 7 are arranged in the middle of the intake pipe 7. A communication portion 16 that communicates with the internal flow path is formed in an annular shape so as to divide the intake pipe 7.

  Thus, if the closed breather system is configured in this way, the return port 6a of the gas return pipe 6 is indirectly connected to the intake pipe 7 via the chamber 15, and the return port of the gas return pipe 6 Since 6a is not directly exposed to the flow of the intake air 13, the return port 6a of the gas return pipe 6 can be used during idling for a long time at a very low temperature or during low-speed driving where the temperature in the engine room does not rise. Thus, the situation where the moisture in the blow-by gas 1 is condensed and frozen does not occur.

  Further, in order to avoid freezing at the return port 6a of the gas return pipe 6 as described above, the return port 6a of the gas return pipe 6 is connected to the chamber 15 without requiring a costly auxiliary facility such as an electric heater. Therefore, it can be implemented at low cost without incurring a significant increase in cost.

  Although moisture in the blow-by gas 1 may be condensed in the communication portion 16, the opening area of the communication portion 16 can be greatly expanded within the range covered by the chamber 15, and the communication portion It is easy to avoid the situation where 16 is blocked by freezing of condensed water.

  In particular, in the case of the present embodiment, the communication portion 16 is formed in an annular shape so as to divide the intake pipe 7, so that the opening area is sufficiently large compared to the return port 6a of the gas return pipe 6 and all of them. It becomes the communicating part 16 which is extremely unlikely to freeze to the extent that it is blocked.

  Further, even if the condensed water freezes in a part of the communication section 16, the chamber 15 is heated by heat transfer from the engine 3 (see FIG. 2) after shifting from idle operation or low-speed traveling operation to high-speed traveling operation. If so, it will immediately thaw and evaporate, and it will be removed together with the blow-by gas 1 to the intake pipe 7.

  Therefore, according to the above-described embodiment, the return port 6a of the gas return pipe 6 is indirectly connected to the intake pipe 7 via the chamber 15 without requiring high-cost incidental equipment such as an electric heater. The return port 6a of the gas return pipe 6 can be prevented from being directly exposed to the flow of the intake air 13 only by applying a special device, and moisture in the blow-by gas 1 is condensed at the return port 6a of the gas return pipe 6. Thus, the blockage caused by freezing can be surely prevented without causing a significant increase in cost.

  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 Ventilator 3 Engine 6 Gas return pipe 6a Return port 7 Intake pipe 13 Intake 15 Chamber 16 Communication part

Claims (1)

In a closed breather system in which blow-by gas extracted from the engine is separated and collected via an air ventilator and returned to the intake pipe , an annular chamber that covers the middle of the intake pipe so as to surround the entire circumference And connecting a gas return pipe for introducing blow-by gas from the ventilator to the chamber, and annularly connecting the internal space of the chamber and the internal flow path of the intake pipe so as to divide the intake pipe in the middle of the intake pipe closed breather system characterized in that the formed communicating portion communicating to.

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