JPH0663810U - Blow-by gas reduction device - Google Patents

Abstract

(57) [Summary] [Objective] By connecting the communication passage that connects the space where the blow-by gas of the internal combustion engine is stored with the intake passage to the portion of the intake passage where the pressure fluctuation due to the intake pulsation is small, To provide a blow-by gas reducing device capable of reducing high-frequency vibration of a PCV valve caused by the above as much as possible, preventing an abnormal increase in crankcase internal pressure, and improving durability of the PCV valve. [Composition] In a blow-by gas reducing apparatus provided with a communication passage that connects a space where blow-by gas is accumulated in an internal combustion engine and the intake passage 1 and a valve mechanism 8 that opens and closes the communication passage, the communication passage is the intake passage 1 A blow-by gas reduction device, characterized in that guide members (11, 15) are provided so as to communicate with a portion of the inside where pressure fluctuation due to intake pulsation is small.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a blowby gas returning device for sending blowby gas from the inside of a crankcase or a cylinder head cover to an intake passage.

[0002]

[Prior art]

 During engine operation, some exhaust gas and unburned gas leak from the combustion chamber into the crankcase. Therefore, the engine oil becomes thinner or deteriorates due to the influence of heat, moisture in the combustion gas, or fuel components to generate sludge. In order to prevent this, a ventilator called a breather was conventionally installed in the crankcase to release it into the atmosphere, but this blow-by gas contains a large amount of hydrocarbons and becomes a source of air pollution. Therefore, there is provided a blow-by gas reduction device (PCV device) which is forcibly introduced into the intake system and again fed into the combustion chamber for combustion.

There are three types of this PCV device, a shield system, an open system, and a closed system, but the closed system is generally adopted in many cases. In the closed system, the inside of the crankcase communicates with the intake passage on the one hand, and the inside of the cylinder head cover communicates with the intake passage on the other, so that blow-by gas is sucked from one of the passages in response to a change in load. At the same time, the atmosphere is introduced from the other communication passage to limit the pressure fluctuation in the crankcase and prevent blow-by gas from being released into the atmosphere. A ventilation valve (PCV valve) is provided in the middle of the communication passage communicating with the intake passage in order to adjust the flow rate of the blow-by gas according to the load.

[0004]

[Problems to be solved by the device]

 As the PCV valve, the one shown in FIG. 3 is generally used. That is, a ventilation hole 2 is formed in the intake manifold 1, and a cover 4 having a breathing hole 3 is attached to the outside of the intake manifold 1 so as to cover the ventilation hole 2 and a valve body is provided inside the cover 4. A diaphragm 5 that is formed and can close the ventilation hole 2, a spring seat 6 that abuts on the diaphragm 5, and a spring 7 that is interposed between the spring sheet 6 and the cover 4 are provided. It constitutes the PCV valve 8.

By the way, in the intake passage such as the intake manifold 1 in which the intake air is flowing, pressure fluctuations due to intake pulsation of a few millisecond cycle occur, and therefore the pulsating pressure acts on the diaphragm 5. As a result, high-frequency vibration occurs, and as a result, the pressure regulating function is lost and the internal pressure of the crankcase rises abnormally. Further, there is a problem that the diaphragm 5, which is generally made of rubber, is fatigued and deteriorates in a short period of time due to the vibration of the high frequency.

In view of the above problems, the present invention provides a communication passage, which communicates the space where blow-by gas is accumulated in the internal combustion engine and the intake passage, with a portion of the intake passage where pressure fluctuation due to intake pulsation is small. Thus, a blow-by gas reducing device is provided which can reduce the high frequency vibration of the PCV valve caused by the intake pulsation as much as possible, prevent the abnormal increase in the crankcase internal pressure, and improve the durability of the PCV valve. That is the purpose.

[0007]

[Means for Solving the Problems]

 The blow-by gas returning apparatus of the present invention for achieving the above object is a blow-by gas provided with a communication passage for communicating a space where blow-by gas of an internal combustion engine is stored with an intake passage, and a valve mechanism for opening and closing the communication passage. In the reducing device, a guide member is provided so that the communication passage communicates with a portion of the intake passage where pressure fluctuation due to intake pulsation is small.

The space where the blow-by gas is stored is a space formed inside the crankcase, the cylinder head cover, etc., and the intake passage is the intake manifold, the intake pipe, or the air cleaner case. This is the flow path for inhaled air. The guide member guides the communication passage to a portion in the intake passage where the pressure fluctuation due to the intake pulsation is relatively small. For example, a plate-shaped member or a tubular member can be used.

[0009]

[Work]

 Since the blow-by gas returning device of the present invention has the above-mentioned configuration, the guide member allows the communication passage to communicate with a portion in the intake passage where pressure fluctuation due to intake pulsation is small, and the intake pulsation is reduced. The influence on the valve mechanism can be reduced as much as possible.

[0010]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. The same members as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. The blow-by gas returning apparatus according to the first embodiment of the present invention shown in FIG. 1 has a vent hole 2 so that one end has a closed end 9 and the other end has an open end 10 in an intake manifold 1 to which a PCV valve 8 is attached. A baffle plate 11 is attached so that the open end 10 is positioned in the intake manifold 1 where the pressure fluctuation due to the intake pulsation is small, that is, where the flow velocity of the intake air is relatively slow.

When the blow-by gas is not very much accumulated in the space inside the crankcase or the space inside the cylinder head cover, the internal pressure of these spaces is relatively low, and the spring 7 applies the valve in the valve closing direction. The diaphragm 5 of the PCV valve 8 which is energized keeps the ventilation hole 2 of the intake manifold 1 closed. When the blow-by gas accumulated in the space reaches a predetermined pressure, the diaphragm 5 separates from the valve seat 12 against the elastic force of the spring 7, and the blow-by gas passes through the ventilation hole 2 formed in the intake manifold 1, It is fed into the intake manifold 1 toward the open end 10 as guided by the baffle plate 11.

By the way, in the intake manifold 1 through which the intake air flows, the pressure fluctuation due to the intake pulsation occurs as described above, and the portion where the intake pulsation is the largest is the resonance supercharging pipe 13 and each intake port 14. It is a place that connects and in a substantially straight line. In this embodiment, the baffle plate 11 is attached, and the open end 10 is located at a portion where the influence of the intake pulsation is relatively small, so that the influence of the intake pulsation on the PCV valve 8 is minimized. You can do it.

Therefore, it is possible to prevent high-frequency vibration from occurring in the diaphragm 5 as much as possible, and it is possible to normally maintain the pressure regulating function of the PCV valve 8. Then, it is possible to prevent the crankcase internal pressure from abnormally rising, reduce fatigue of the diaphragm 5 due to high frequency vibration, and improve its durability. In this embodiment, since the baffle plate 11 is arranged in a direction similar to the direction of intake pulsation, the volumetric efficiency of intake air is not deteriorated, and a sufficient blowby gas passage is secured. it can.

Next, in the blow-by gas reducing apparatus according to the second embodiment of the present invention shown in FIG. 2, a rubber or synthetic resin hose 15 is provided in the intake manifold 1 to which a PCV valve 8 is attached, and one end of this hose 15 is provided. Is fixed to the pipe 17 press-fitted into the ventilation hole 2, and the other end is placed as the open end 10 in the intake manifold 1 at a portion where pressure fluctuation due to intake pulsation is small, and fixed by the clip 18. It is a thing.

When blow-by gas flows in from a space formed inside the crankcase or the cylinder head cover, the blow-by gas flows through the ventilation hole 2 formed in the intake manifold 1, is guided by the hose 15, and is opened from the open end 10 to the intake manifold 1. Even in the inside, it is sent to the part where the influence of inspiration pulsation is comparatively small. In this embodiment, since the open end 10 of the hose 15 is arranged as far as possible from the position where the resonance supercharging pipe 13 is attached, the influence of intake pulsation on the PCV valve 8 can be minimized, The intake pulsation can be damped in the hose 15.

From the above, generation of high-frequency vibrations in the diaphragm 5 can be avoided as much as possible, and the pressure regulating function of the PCV valve 8 can be normally maintained.

[0017]

[Effect of device]

 The blow-by gas returning apparatus of the present invention is a blow-by gas returning apparatus provided with a communication passage for connecting a space for accumulating blow-by gas of an internal combustion engine and an intake passage, and a valve mechanism for opening and closing the communication passage. Since the guide member is provided so as to communicate with a portion where the pressure fluctuation due to the intake pulsation in the intake passage is small, the following effects can be obtained.

With the guide member, the communication passage can be communicated with a portion in the intake passage where the pressure fluctuation due to the intake pulsation is small, and the influence of the intake pulsation on the valve mechanism can be reduced as much as possible. it can. Therefore, the high frequency vibration of the valve mechanism due to the intake pulsation can be reduced as much as possible, the abnormal increase in the crankcase internal pressure can be prevented, and the durability of the valve mechanism can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a blow-by gas returning apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a blow-by gas returning apparatus according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a conventional blow-by gas returning apparatus.

[Explanation of symbols]

1 intake passage (intake manifold) 8 valve mechanism (P
CV valve) 11 Guide member (baffle plate) 15 Guide member (hose)

Claims (1)

[Scope of utility model registration request] 1. A blow-by gas returning apparatus provided with a communication passage that communicates a space where blow-by gas of an internal combustion engine is stored with an intake passage, and a valve mechanism that opens and closes the communication passage.
A blow-by gas returning apparatus, wherein a guide member is provided so that the communication passage communicates with a portion of the intake passage where pressure fluctuation due to intake pulsation is small.