JP2019090386A - Blow-by gas treatment device - Google Patents

Abstract

To inhibit freezing of moisture in a PCV valve and inhibit oil mist from being suctioned into the PCV valve.SOLUTION: A blow-by gas treatment device 1 includes: a first gas passage 20 in a cylinder head 10; a second gas passage 40 in an intake manifold 30; and a PCV valve 60 provided at a joint part 3 between the cylinder head 10 and the intake manifold 30. The first gas passage 20 includes: a gas introduction passage 21; an expansion part 51 in which a passage cross section area is expanded compared to the gas introduction passage 21; and an expansion chamber 50 having a recessed part 54 provided above the expansion part 51. The PCV valve 60 is disposed inclining so that a gas inflow port 61 is located below a gas outflow port 62. The expansion chamber 50 includes an inclined wall part 53 which connects an inner wall of the expansion part 51 to an inner wall of the recessed part 54 and inclines so as to separate from the gas inflow port 61 further toward the lower side of the expansion chamber 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blowby gas processing apparatus.

  The internal combustion engine includes a blowby gas processing device that causes blowby gas generated in the combustion chamber and leaking into the crankcase to be returned to the intake passage and burned (see, for example, Patent Document 1). The blowby gas processing apparatus includes a crankcase and a blowby gas passage connecting the intake passage downstream of the throttle valve. The blowby gas passage is provided with a positive crankcase ventilation (PCV) valve for adjusting the flow rate of the blowby gas.

JP, 2013-151905, A

  In the blowby gas processing device described in Patent Document 1, the PCV valve is exposed to the outside of the internal combustion engine. For this reason, at the time of low temperature, the moisture contained in blowby gas freezes in a PCV valve, and the problem that a PCV valve does not operate normally arises.

In addition, if blow-by gas containing oil mist is recirculated to the intake passage via the PCV valve, oil may be accumulated in the PCV valve or the intake passage.
An object of the present invention is to provide a blowby gas processing apparatus capable of suppressing freezing of water in a PCV valve and suppressing suction of oil mist in the PCV valve.

  In order to achieve the above object, in the blowby gas processing apparatus, a first gas passage provided in a cylinder head, a second gas passage provided in an intake manifold, and the intake manifold of the cylinder head are joined. A blow-by gas processing apparatus including a PCV valve provided at a portion where the first gas passage communicates with the second gas passage, the first gas passage extending upward; A channel, an extension connected to the downstream end of the gas introduction channel, and a channel cross-sectional area being expanded from the gas introduction channel, and an extension chamber having a recess provided above the extension, The PCV valve has a gas inlet located below the recess in the expansion chamber, and a gas outlet located in the second gas passage, and the gas flow The port is inclined to be positioned below the gas outlet, and the expansion chamber connects the inner wall of the expansion portion and the inner wall of the recess, and extends downward in the expansion chamber. And an inclined wall portion which is inclined to be away from the gas inlet.

  According to the same configuration, the PCV valve is provided at the site where the intake manifold of the cylinder head is joined. Therefore, the PCV valve is not directly exposed to the outside air. Furthermore, the heat transfer from the cylinder head to the PCV valve heats the inside of the PCV valve. Therefore, it is possible to suppress the water contained in the blowby gas from freezing in the PCV valve.

  Further, the expansion chamber has an expansion portion in which the passage cross-sectional area is expanded than the gas introduction path, and a recess is provided on the upper side. For this reason, when the blowby gas flows from the gas introduction path into the expansion portion, the flow velocity decreases, and the blowby gas containing the oil mist is dispersed in the expansion chamber. At this time, most of the oil mist in the blowby gas flows toward the recess provided above the extension chamber by inertia force and adheres to the recess to form droplets, so the oil mist is separated from the blowby gas. It will be easier.

  Here, above the gas inlet of the PCV valve in the extension chamber, an inclined wall connecting the extension and the recess is provided. For this reason, the oil in the blowby gas adhering to the concave portion and becoming droplets drops down to the lower portion of the expansion portion along the inclined wall portion. Therefore, it can suppress that oil mist is attracted | sucked by a PCV valve.

Sectional drawing of a blowby gas processing apparatus. The perspective view which shows the shape of the 1st gas passage of blow-by gas treatment equipment.

Hereinafter, an embodiment of a blowby gas processing apparatus will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the blowby gas processing apparatus 1 includes a blowby gas passage 2 through which the blowby gas flows. The blowby gas passage 2 includes a first gas passage 20 provided in a cylinder head 10 of an internal combustion engine and a second gas passage 40 provided in an intake manifold 30. The second gas passage 40 communicates with an intake passage (not shown) provided separately from the second gas passage 40 inside the intake manifold 30. The blowby gas in the crankcase (not shown) sequentially passes through the first gas passage 20 and the second gas passage 40 and flows into the intake passage. In addition, the second gas passage 40 has an enlarged diameter portion 40a whose passage sectional area is enlarged at the upstream end in the flow direction of the blowby gas.

  The cylinder head 10 and the intake manifold 30 are fixed by bolts 70 in a state where the joint surface 10 a of the cylinder head 10 and the joint surface 30 a of the intake manifold 30 are in contact with each other. A seal portion (not shown) is provided at the joint portion 3 where the cylinder head 10 and the intake manifold 30 are jointed, and the seal portion suppresses the leakage of blowby gas from the joint portion 3.

  As shown in FIGS. 1 and 2, the first gas passage 20 is opposite to the gas introduction passage 21 through which the blowby gas flows from the crankcase and one of both end portions of the gas introduction passage 21 opposite to the end on the crankcase side. And an expansion chamber 50 connected to the downstream end in the flow direction of the blowby gas. The gas introduction passage 21 has a substantially circular passage cross section and extends upward of the cylinder head 10.

Hereinafter, the outer side (right side of FIG. 1) and the inner side (left side of FIG. 1) of the cylinder head 10 in FIG. 1 will be described simply as the outer side and the inner side, respectively.
The expansion chamber 50 has an expansion portion 51 defined by a bottom wall 51a where the downstream end of the gas introduction passage 21 opens and a side wall 51b as an inner wall extending upward from the bottom wall 51a. The enlarged cross section of the expanded portion 51 is larger than that of the gas introduction path 21. A communication hole 52 communicating with the enlarged diameter portion 40a of the second gas passage 40 is provided in an upper portion on the outer side of the side wall 51b. The communication holes 52 are inclined so as to be positioned outward as going upward, and extend to the joint surface 10 a.

  As shown in FIG. 2, an inclined wall portion 53 inclined with respect to the extending direction of the gas introduction passage 21 is provided above the side wall 51 b. The inclined wall portion 53 includes an inner inclined wall portion 53 a connected to the inner side of the side wall 51 b and an outer inclined wall portion 53 b connected to the upper portion of the communication hole 52. The inner inclined wall portion 53a is inclined so as to be positioned outward from the inside to the upper side of the side wall 51b. The outer inclined wall portion 53 b is inclined so as to be positioned inward as it goes upward from the communication hole 52. Therefore, the passage cross-sectional area of the expansion chamber 50 is made smaller toward the upper side from the expansion portion 51. A recess 54 is provided above the expansion chamber 50, and the inner wall of the recess 54 is connected to the inner inclined wall 53a and the outer inclined wall 53b.

  The joint 3 is provided with a PCV valve 60. More specifically, the PCV valve 60 is inserted into and fixed to the communication hole 52 of the first gas passage 20 and the enlarged diameter portion 40 a of the second gas passage 40.

The PCV valve 60 is a differential pressure operated adjusting valve whose opening degree is adjusted by the difference between the internal pressure of the first gas passage 20 and the internal pressure of the second gas passage 40.
The gas inlet 61 of the PCV valve 60 is located in the expansion chamber 50 and below the recess 54 of the expansion chamber 50, and the gas outlet 62 is located in the second gas passage 40. There is. In addition, the PCV valve 60 is inclined and disposed such that the gas inlet 61 is located below the gas outlet 62.

Here, the inclined wall portion 53 of the expansion chamber 50 described above is inclined so as to be away from the gas inlet 61 as it goes downward in the expansion chamber 50.
A seal member 63 is provided on a portion of the outer peripheral surface of the PCV valve 60 that contacts the inner wall of the communication hole 52, and a portion that contacts the inner wall of the enlarged diameter portion 40a of the second gas passage 40. Is provided.

The operation and effects of the present embodiment will be described.
The PCV valve 60 is provided at a joint 3 between the cylinder head 10 and the intake manifold 30. Therefore, the heat generated in the cylinder head 10 is transmitted to the PCV valve 60, whereby the inside of the PCV valve 60 is heated. Therefore, it is possible to suppress the water contained in the blowby gas from freezing in the PCV valve 60.

  When the internal pressure of the first gas passage 20 is higher than the internal pressure of the second gas passage 40, the differential pressure causes the PCV valve 60 to open. Then, the blowby gas leaked into the crankcase flows into the expansion chamber 50 from the gas introduction passage 21 and flows from the cylinder head 10 side to the intake manifold 30 side.

  Here, the expanded portion 51 of the first gas passage 20 has an expanded passage cross-sectional area than the gas introduction passage 21 into which the blowby gas flows. For this reason, the blowby gas is dispersed in the expansion chamber 50 by the flow velocity of the blowby gas decreasing in the expansion portion 51. At this time, most of the oil mist in the blowby gas flows toward the recess 54 of the expansion chamber 50 by the inertia force and adheres to the recess 54 to be droplets.

  Here, the extension chamber 50 is provided with an inclined wall 53 connecting the recess 54 and the extension 51. For this reason, the oil in the blowby gas adhering to the recess 54 and becoming droplets drops down to the lower part of the expansion chamber 50 along the inclined wall portion 53. Therefore, it can suppress that oil mist is attracted | sucked by the PCV valve | bulb 60. FIG.

The present embodiment can be modified as follows. The present embodiment and the following modifications can be implemented in combination with one another as long as there is no technical contradiction.
The number and shape of the recesses 54 are appropriately changed.

In place of the differential pressure actuated PCV valve 60 in the present embodiment, a solenoid valve is employed. In this case, control may be performed so that the opening degree of the solenoid valve is adjusted according to the operating state of the internal combustion engine.
In the present embodiment, the gas outlet 62 of the PCV valve 60 is located in the second gas passage 40. However, the entire PCV valve 60 may be incorporated in the cylinder head 10.

  DESCRIPTION OF SYMBOLS 1 ... blow-by gas processing apparatus, 2 ... blow-by gas passage, 3 ... junction part, 10 ... cylinder head, 10 a ... junction surface, 20 ... 1st gas passage, 21 ... gas introduction passage, 30 ... intake manifold, 30 a ... junction surface 40: second gas passage 40a: enlarged diameter portion 50: expanded chamber 51: expanded portion 51a: bottom wall 51b: side wall 52: communicating hole 53: inclined wall 53a: inner inclined wall , 53b: outer inclined wall portion, 54: recess, 60: PCV valve, 61: gas inlet, 62: gas outlet, 63: sealing portion, 64: sealing portion, 70: bolt.

Claims (1)

A first gas passage provided in a cylinder head, a second gas passage provided in an intake manifold, and a site where the intake manifold of the cylinder head is joined, the first gas passage and the first gas passage And a PCV valve communicating with the second gas passage, the blow-by gas processing device comprising:
The first gas passage is connected to a gas introduction passage extending upward, a downstream end of the gas introduction passage connected, and an expanded portion whose passage sectional area is expanded more than the gas introduction passage, and an upper portion of the expansion portion An expansion chamber having a recess provided in the
The PCV valve has a gas inlet located lower than the recess in the expansion chamber, and a gas outlet located in the second gas passage, and the gas inlet is closer to the gas outlet than the gas outlet. It is placed inclined to be located below,
The expansion chamber connects an inner wall of the expansion portion and an inner wall of the recess, and includes an inclined wall portion inclined so as to be away from the gas inlet as moving downward in the expansion chamber.
Blow-by gas processing equipment.