JP2012163085A - Pcv valve and internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PCV valve capable of suppressing the aggregation of oil contained in blow-by gas when the blow-by gas passes through the PCV valve, and to provide an internal combustion engine capable of suppressing the generation of a deposit in an intake passage.SOLUTION: The PCV valve 1 is disposed at a second ventilation passage recirculating the blow-by gas in a crank chamber of the internal combustion engine into the intake passage. The PCV valve 1 has a valve element 5 disposed in the PCV valve 1 along a flow passage of the blow-by gas so as to be displaceable, and is displaced upstream of the flow passage to close an inlet port 41 of the blow-by gas. An upstream end face 53 of the valve element 5 has an inclination face formed to be gradually inclined from its center toward an outer periphery thereof to be positioned downstream of the blow-by gas.

Description

  The present invention relates to a PCV valve provided in a blow-by gas passage for returning blow-by gas in a crank chamber to an intake passage, and an internal combustion engine including the PCV valve.

  In an internal combustion engine, a part of the air-fuel mixture existing in the combustion chamber may leak into the crank chamber as so-called blow-by gas. Blow-by gas may deteriorate the oil in the internal combustion engine. Therefore, in order to burn such blow-by gas again in the combustion chamber, the internal combustion engine is provided with a blow-by gas processing device for returning the blow-by gas to the intake passage (see, for example, Patent Document 1).

  The blow-by gas processing device is configured by a blow-by gas passage for returning the blow-by gas in the crank chamber to the intake passage, a PCV valve provided in the blow-by gas passage and adjusting the flow rate of the blow-by gas returned through the passage. ing.

  The PCV valve has a valve body that is displaceable along the flow path of the blow-by gas inside the main body, and is closed when the valve body is displaced upstream to close the inlet of the blow-by gas. The Here, the entire upstream end face of the valve body is flat because the valve body can be easily brought into contact with the member forming the inlet without a gap or the valve body is easily processed. It is made into a shape.

Japanese Utility Model Publication No. 3-17215

  By the way, in the PCV valve, blow-by gas flows into the inside from the inflow port and collides with the upstream end surface of the valve body. However, in the conventional PCV valve, since the entire upstream end face of the valve body is flat, the blow-by gas loses much kinetic energy at the time of collision. As a result, the mist-like oil contained in the blow-by gas aggregates and adheres to the intake passage of the internal combustion engine, so that deposits are easily generated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a PCV valve that can prevent oil contained in blow-by gas from aggregating when blow-by gas passes through the PCV valve. There is. Another object of the present invention is to provide an internal combustion engine that can suppress the generation of deposits in the intake passage.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
The invention according to claim 1 is a PCV valve provided in a blow-by gas passage for returning blow-by gas in a crank chamber of an internal combustion engine to an intake passage, and is displaced along the flow path of the blow-by gas inside the PCV valve. In a PCV valve having a valve body that can be provided and that is displaced upstream of the flow path to close the blow-by gas inlet, the upstream end surface of the valve body is blowby-by as it is spaced from the center to the outer peripheral side. The gist is that an inclined surface is formed so as to be located on the downstream side of the gas.

  According to this configuration, the angle when blow-by gas collides with the upstream end face of the valve body can be made small, and the kinetic energy lost during the collision can be reduced. Therefore, the oil contained in the blowby gas can be prevented from aggregating when the blowby gas passes through the PCV valve.

The gist of the invention according to claim 2 is that, in the PCV valve according to claim 1, the inclined surface is formed on the entire upstream end face of the valve body.
According to this configuration, since the entire upstream end face of the valve body is inclined, the kinetic energy lost from the blow-by gas can be reduced regardless of the part where the blow-by gas collides with the end face. Therefore, it is possible to accurately suppress the oil contained in the blowby gas from aggregating when the blowby gas passes through the PCV valve.

The gist of the invention according to claim 3 is that, in the PCV valve according to claim 1 or claim 2, the entire upstream end face of the valve body is spherical.
According to this configuration, the valve body is seated with no gap on the member forming the inflow port. For this reason, an inflow port can be suitably closed with a valve element.

  The gist of the invention described in claim 4 is provided with a blow-by gas passage for returning the blow-by gas in the crank chamber to the intake passage, and the PCV valve according to any one of claims 1 to 3. Yes.

  According to the configuration, it is possible to suppress the oil contained in the blow-by gas from aggregating when the blow-by gas passes through the PCV valve, and thus it is possible to suppress the generation of deposits in the intake passage.

1 is a cross-sectional view of an internal combustion engine to which a PCV valve according to an embodiment of the present invention is applied. Sectional drawing of the PCV valve | bulb of the embodiment. (A) Side view of the valve body of the PCV valve of the embodiment, (b) Front view of the valve body Explanatory drawing for demonstrating the effect | action of the PCV valve | bulb of the embodiment. Explanatory drawing for demonstrating the effect | action of the conventional PCV valve | bulb. The graph which shows the ratio of the oil of each state in a PCV valve | bulb.

  1 to 5, the internal combustion engine and the PCV valve according to the present invention are embodied as an in-line four-cylinder direct injection gasoline engine (hereinafter, internal combustion engine 90) and a PCV valve mounted on the engine. One embodiment will be described.

FIG. 1 shows a cross-sectional structure of the internal combustion engine 90.
As shown in FIG. 1, an air cleaner 94, a throttle valve 95, a surge tank 96, and an intake manifold 97 are provided in the intake passage 93 of the internal combustion engine 90 in order from the upstream side.

  The internal combustion engine 90 is provided with a blow-by gas processing device 80 that returns the blow-by gas in the crank chamber 91 to the intake passage 93. A connection passage 83 is provided between the crank chamber 91 and the inner space of the head cover 92 to connect them. A first ventilation passage 81 is provided between the internal space of the head cover 92 and a portion of the intake passage 93 between the air cleaner 94 and the throttle valve 95. A second ventilation passage 82 is provided between the interior space of the head cover 92 and the surge tank 96 to connect them. In addition, a negative pressure type PCV valve 1 that adjusts the flow rate of blow-by gas returned to the intake passage 93 via the second ventilation passage 82 is provided at the upstream end of the second ventilation passage 82. A ventilation case 84 is provided inside the head cover 92 so as to be connected to the upstream end of the PCV valve 1. The second ventilation passage 82 corresponds to a blow-by gas passage.

  FIG. 2 shows a longitudinal sectional structure of the PCV valve 1. Hereinafter, the head cover 92 side in the PCV valve 1 will be referred to as the upstream side, and the second ventilation passage 82 side, that is, the surge tank 96 side will be described as the downstream side.

  As shown in FIG. 2, the main body 2 of the PCV valve 1 has a substantially cylindrical shape, and the upstream end 21 is connected to the head cover 92 and the downstream end 22 is connected to the second ventilation passage 82. ing.

  An internal passage 3 is formed inside the main body 2 to accommodate the valve body 5 and serve as a flow path for blow-by gas. The internal passage 3 connects the upstream passage 31 located on the upstream side, the downstream passage 32 located on the downstream side and having a diameter smaller than that of the upstream passage 31, and the upstream passage 31 and the downstream passage 32. In addition, the connecting passage 33 is made smaller in diameter than the downstream passage 32.

  A substantially disk-shaped sheet member 4 is fixed to the inner wall of the upstream end 21 of the main body 2. An inflow port 41 is formed through the sheet member 4 on the same axis as the internal passage 3. The upstream portion of the inlet 41 is tapered toward the downstream side.

  The shaft portion 51 of the valve body 5 has a substantially cylindrical shape, and an upstream end 52 having a diameter larger than that of the shaft portion 51 is formed on the upstream side. The valve body 5 is provided so that the center axis thereof coincides with the center axis of the internal passage 3 and can be displaced along the internal passage 3, that is, the flow path of blow-by gas.

  The upstream passage 31 is provided with a spring 6 that urges the valve body 5 toward the upstream side (right side in FIG. 2). The valve body 5 is displaced to the upstream side by the urging force of the spring 6, and the upstream end surface 53 can be brought into contact with the edge of the inlet 41 of the sheet member 4. The inlet 41 is closed by the upstream end face 53 of the valve body 5, so that the PCV valve 1 is closed.

  The downstream passage 32 is provided with a regulating spring 7 that regulates excessive displacement of the valve body 5 toward the downstream side. The restriction spring 7 biases the valve body 5 toward the upstream side when the amount of displacement of the valve body 5 toward the downstream side becomes a predetermined amount or more.

Here, with reference to FIG. 3, the structure of the valve body 5 is demonstrated.
As shown in FIGS. 3A and 3B, the entire upstream end surface 53 of the valve body 5 has a spherical shape that is inclined so as to be positioned on the downstream side as the distance from the center C to the outer peripheral side increases. Moreover, as shown in FIG.3 (b), the upstream edge part 52 has comprised the substantially hexagonal shape by the front view. Specifically, the upstream end 52 is a portion sandwiched between three chords g located at equiangular intervals and an arc k corresponding to the chord g from a virtual circle indicated by a two-dot chain line in a front view. The shape is cut off.

Next, the operation of this embodiment will be described.
A force that urges the PCV valve 1 to the upstream side by the spring 6 acts on the valve body 5. Further, a downstream force is applied to the upstream end surface 53 of the valve body 5 based on the pressure in the crank chamber 91. On the other hand, an upstream force acts on the back surface of the upstream end 52 of the valve body 5 based on the pressure (intake pressure) in the surge tank 96. For this reason, the opening degree of the PCV valve 1 is changed by the valve body 5 being displaced according to the position where these forces are balanced. And the recirculation | reflux amount of blowby gas is changed according to the opening degree.

  As shown in FIG. 4, in this embodiment, since the upstream end surface 53 of the valve body 5 has a spherical shape, the blow-by gas that has flowed into the PCV valve 1 from the inflow port 41 flows into the upstream end surface 53. The angle at the time of collision is small. For this reason, the kinetic energy lost from blow-by gas at the time of a collision becomes small. For this reason, when blow-by gas passes through the PCV valve 1, oil contained in the blow-by gas is less likely to aggregate.

  On the other hand, as shown in FIG. 5, in the conventional PCV valve, since the entire upstream end surface 153 of the valve body 105 is flat, the angle when the blow-by gas collides with the upstream end surface 153 is large. Become. For this reason, blowby gas loses much kinetic energy at the time of a collision, and the oil contained in blowby gas tends to aggregate.

As shown in FIG. 6, according to the present embodiment, the ratio of liquid oil in the PCV valve is reduced as compared with the prior art shown in FIG.
According to the PCV valve and the internal combustion engine according to the present embodiment described above, the following operational effects can be obtained.

  (1) The PCV valve 1 is provided in the second ventilation passage 82 for returning the blowby gas in the crank chamber 91 of the internal combustion engine 90 to the intake passage 93. The PCV valve 1 is provided inside the PCV valve 1 so as to be displaceable along the flow path of the blow-by gas and is displaced to the upstream side of the flow path to close the valve body 5 that closes the inlet 41 of the blow-by gas. Have. Further, the upstream end surface 53 of the valve body 5 is formed with an inclined surface that is inclined so as to be positioned on the downstream side of the blow-by gas as the distance from the center to the outer peripheral side increases. Therefore, the generation of deposits in the intake passage 93 can be suppressed.

  (2) An inclined surface is formed on the entire upstream end face 53 of the valve body 5. According to such a configuration, since the entire upstream end face 53 of the valve body 5 is inclined, the kinetic energy lost from the blowby gas can be reduced regardless of the part where the blowby gas collides with the upstream end face 53. it can. Therefore, when the blowby gas passes through the PCV valve 1, the oil contained in the blowby gas can be accurately suppressed.

  (3) The entire upstream end face 53 of the valve body 5 is spherical. The valve body 5 is seated on the seat member 4 forming the inflow port 41 without a gap. For this reason, the inflow port 41 can be suitably closed by the valve body 5.

  Note that the PCV valve and the internal combustion engine according to the present invention are not limited to the configurations exemplified in the above-described embodiment, and can be implemented as, for example, the following forms appropriately modified.

  In the above embodiment, the PCV valve 1 and the ventilation case 84 are provided on the head cover 92. However, instead of this, the PCV valve and the ventilation case may be provided on the side wall of the crankcase.

In the above embodiment, the negative pressure type PCV valve 1 is illustrated, but the present invention may be applied to an electric type PCV valve instead.
In the above embodiment, the entire upstream end face 53 of the valve body 5 is illustrated as having a spherical shape, but the inclined surface according to the present invention is not limited to the spherical shape. In addition, for example, the inclined surface can be configured by a polyhedral shape in which the entire upstream end surface of the valve body is formed of a plurality of planes.

  -In above-mentioned embodiment, although the inclined surface was formed in the whole upstream end surface 53 of the valve body 5, this invention is not limited to this, An inclined surface is formed in the part or several part of the upstream end surface of a valve body. May be formed.

  DESCRIPTION OF SYMBOLS 1 ... PCV valve, 2 ... Main body, 21 ... Upstream side end, 22 ... Downstream side end, 3 ... Internal passage, 31 ... Upstream side passage, 32 ... Downstream side passage, 33 ... Connection passage, 4 ... Seat member, DESCRIPTION OF SYMBOLS 41 ... Inlet, 5,105 ... Valve body, 51 ... Shaft part, 52 ... Upstream end part, 53, 153 ... Upstream end surface, 6 ... Spring, 7 ... Restriction spring, 80 ... Blow-by gas processing apparatus, 81 ... 1st ventilation passage, 82 ... 2nd ventilation passage (blow-by gas passage), 83 ... Connection passage, 84 ... Ventilation case, 90 ... Internal combustion engine, 91 ... Crank chamber, 92 ... Head cover, 93 ... Intake passage, 94 ... Air cleaner 95 ... Throttle valve, 96 ... Surge tank, 97 ... Intake manifold.

Claims (4)

A PCV valve provided in a blow-by gas passage for returning a blow-by gas in a crank chamber of an internal combustion engine to an intake passage, and is provided inside the PCV valve so as to be displaceable along a flow path of the blow-by gas. In a PCV valve having a valve body that is displaced upstream and closes the inlet of blow-by gas,
A PCV valve characterized in that an inclined surface is formed on the upstream end face of the valve body so as to be located on the downstream side of the blow-by gas as the distance from the center to the outer peripheral side increases. The PCV valve according to claim 1, wherein
The PCV valve, wherein the inclined surface is formed on the entire upstream end surface of the valve body. The PCV valve according to claim 1 or 2,
The entire upstream end surface of the valve body is formed into a spherical shape.   An internal combustion engine comprising a blow-by gas passage for returning blow-by gas in the crank chamber to an intake passage, and the PCV valve according to any one of claims 1 to 3.

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