JP5936476B2 - Engine blow-by gas reduction device - Google Patents

Description

  The present invention relates to a blow-by gas reduction device for an engine in which blow-by gas leaking into a crankcase from a gap between a piston and a cylinder is reduced to an intake system and recombusted.

  As this type of blow-by gas reduction device, for example, in Patent Document 1, the crankcase (1) and the downstream side of the throttle valve (S) of the intake pipe (2) are communicated by a blow-by gas passage (3). There is disclosed a structure in which a PCV valve (4) opened by intake negative pressure is connected to the blow-by gas passage (3).

JP 2000-8828 A

  By the way, in the conventional blow-by gas reducing device, the PCV valve is opened by the negative pressure accompanying the lowering of the piston during the intake stroke. For this reason, for example, when the throttle valve is suddenly closed, the intake negative pressure increases, and the inside of the crankcase may be excessively reduced. As a result, there is a concern that the lubricity of the oil in the crankcase deteriorates.

  The present invention has been made in view of the above-described conventional situation, and provides an engine blow-by gas reduction device capable of avoiding deterioration of oil lubricity due to excessive decompression of the crankcase. It is an issue.

The invention of claim 1 is an engine blow-by gas reduction device in which a crankcase and an intake passage including an air cleaner and a throttle valve communicating with a combustion chamber are connected by a blow-by gas reduction passage.
A one-way valve that allows only a flow from the crankcase to the intake passage is interposed in the blow-by gas reduction passage, and a negative pressure in the crankcase is disposed upstream of the one-way valve in the blow-by gas reduction passage. Is provided with a relief valve that allows external air to flow when the air pressure exceeds a predetermined value.
The relief valve includes a cylinder in which a relief passage is formed, a piston that is movably inserted into the cylinder, opens and closes the relief passage, and a spring that normally biases the piston in a closing direction.
The cylinder has an outer cylinder formed with an external air outlet communicating with the relief passage, an external air inlet communicating with the relief passage, and is moved in the axial direction with respect to the outer cylinder. An inner cylinder capable of adjusting the biasing force of the spring;
The piston has a valve shaft portion and a valve portion formed in the valve shaft portion, and the valve portion is installed between the valve portion and an opening edge portion of an external air outlet of the outer cylinder. The relief passage is closed by abutting against the downstream end face of the relief passage of the inner cylinder by the biasing force of the spring, and the relief passage is opened when moved against the biasing force of the spring, Further, the valve portion is supported on an inner peripheral surface of the relief passage of the outer cylinder so as to be slidable in the axial direction, and the valve shaft portion is pivoted on an inner peripheral surface of an insertion hole formed in a bottom portion of the outer cylinder. It is characterized by being slidably supported in the direction .

According to a second aspect of the invention, the blow-by gas returning device for an engine according to claim 1, the relief passage of the outer cylinder is restricted from moving in the opening direction of the piston by the valve portion of the piston comes into contact The stopper part to be formed is formed.

According to a third aspect of the present invention, in the blow-by gas reduction device for an engine according to the first or second aspect , an air filter for filtering external air is detachably attached to the relief valve, and the relief valve is The one-way valve is integrally connected via a joint member.

  According to the blow-by gas reduction device of the first aspect of the present invention, the relief valve is provided on the upstream side of the one-way valve in the blow-by gas reduction passage to allow external air to flow when the negative pressure in the crankcase exceeds a predetermined value. Therefore, when the decompression in the crankcase increases, external air flows from the relief valve into the crankcase case. As a result, excessive decompression of the crankcase can be avoided, and deterioration of oil lubricity can be prevented.

In the first aspect of the invention, the relief valve has a cylinder in which a relief passage is formed, a piston that opens and closes the relief passage, and a spring that biases the piston in the closing direction. By setting the force to a value corresponding to the reduced pressure state in the crankcase, the reduced pressure value of the crankcase can be adjusted with a simple structure.

In the first aspect of the invention, the cylinder has an outer cylinder in which an external air outlet communicating with the relief passage is formed, and an inner cylinder in which an external air inlet communicating with the relief passage of the outer cylinder is formed. The relief passage is closed when the valve portion of the piston is brought into contact with the downstream end surface of the relief passage of the inner cylinder by the biasing force of the spring and moved against the biasing force of the spring. Since the spring is installed between the valve portion and the opening edge of the external air outlet of the outer cylinder, the relief valve can be configured with the minimum number of parts, which increases the cost. And can be provided to users at low cost.

In the first aspect of the present invention, the urging force of the spring can be adjusted by moving the inner cylinder in the axial direction with respect to the outer cylinder. It becomes easy to set the value, and versatility with respect to the vehicle type can be enhanced.

In the invention of claim 2 , since the stopper portion for restricting the movement of the piston in the opening direction is formed in the relief passage of the outer cylinder, the stroke amount of the piston can be restricted with a simple structure.

In the invention of claim 3 , since the air filter for filtering external air is detachably attached to the relief valve and the one-way valve is integrally connected through the joint member, the one-way valve and the relief valve are unitized. As a result, the assembling work can be easily performed, and as a result, the labor required for assembling can be reduced.

It is a schematic block diagram of the engine provided with the blowby gas reduction apparatus by Example 1 of this invention. It is a perspective view of the one-way valve and the relief valve of the blowby gas reducing device in a unitized state. It is a figure which shows each principal part of the said relief valve. It is a figure of the piston of the relief valve. It is a partial sectional view of the one-way valve. It is a perspective view of the one-way valve. It is sectional drawing of the said one-way valve.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 7 are views for explaining an engine blow-by gas reduction device according to Embodiment 1 of the present invention.

  In the figure, reference numeral 1 denotes a 4-cycle engine mounted on an automobile or the like. The engine 1 includes a crankcase 3 in which a crankshaft 2 is accommodated, a cylinder block 4 having a cylinder bore 4 a formed therein, a cylinder head 5 connected to the cylinder block 4, and a head cover 6 attached to the cylinder head 5. It has an attached schematic structure.

  A piston 7 is slidably inserted into the cylinder bore 4 a of the cylinder block 4, and the piston 7 is connected to the crankpin 2 a of the crankshaft 2 through a connecting rod 8.

  The cylinder head 5 is formed with an intake port 5b and an exhaust port 5c communicating with a combustion recess 5a formed on the lower mating surface thereof. A space surrounded by the combustion recesses 5 a, the cylinder bores 4 a and the top surfaces of the pistons 7 is a combustion chamber 14.

  The cylinder head 5 is provided with an intake valve 9 and an exhaust valve 10 that open and close the openings communicating with the combustion recesses 5a of the intake port 5b and the exhaust port 5c. The intake valve 9 and the exhaust valve 10 are driven to open and close by an intake camshaft 11 and an exhaust camshaft 12 that are rotationally driven by a crankshaft 2 via a cam chain (not shown), respectively.

  A spark plug 13 is mounted on the cylinder head 5 so as to face the combustion recess 5a.

  An exhaust pipe 15 is connected to the exhaust port 5 c of the cylinder head 5, and a muffler 16 is connected to the downstream end of the exhaust pipe 15. A catalyst (not shown) for purifying exhaust gas is interposed in the middle of the exhaust pipe 15.

  An intake pipe 18 is connected to the intake port 5 b of the cylinder head 5, and an air cleaner 19 is connected to the upstream end of each intake pipe 18. An air filter 19c for filtering air is disposed between the air inlet 19a and the air outlet 19b in the air cleaner 19.

  An intake passage communicating with the combustion chamber 14 is formed by the air cleaner 19, the intake pipe 18, and the intake port 5b.

  A butterfly valve type throttle valve 20 that changes the passage area of the intake pipe 18 is disposed at the downstream end of the intake pipe 18. An accelerator pedal (not shown) is connected to the throttle valve 20.

  A fuel injection valve 21 is mounted on the intake pipe 18 downstream of the throttle valve 20. The fuel injection valve 21 is arranged to inject and supply fuel into the intake port 5b.

  The engine 1 reduces the blow-by gas composed of unburned gas and combustion gas that has entered the crankcase 3 from between the piston 7 and the cylinder bore 4a of the cylinder block 4 from the intake pipe 18 to the combustion chamber 14 and re-combusts it. A blow-by gas reduction device 25 is provided.

  Here, the inside of the head cover 6 communicates with the inside of the crankcase 3 via a cam chain arrangement chamber in which a cam chain for connecting the intake and exhaust camshafts 11 and 12 and the crankshaft 2 is arranged. . Accordingly, part of the blow-by gas that has entered the crankcase 3 enters the head cover 6 through the cam chain placement chamber.

  As shown in FIG. 1, the blow-by gas reduction device 25 includes a first reduction path 25a and a second reduction path 25b.

  The first reduction path 25a includes a first blow-by gas reduction hose 40 that connects the inside of the crankcase 3 and the vicinity of the downstream side of the throttle valve 20 of the intake pipe 18, and a middle portion of the first blow-by gas reduction hose 40. And a PCV valve 41 that allows only the flow of blow-by gas from the crankcase 3 to the intake pipe 18 (see arrow b in FIG. 1).

  Although not shown, the PCV valve 41 has a structure in which a valve body that opens and closes an opening of the valve body is slidably disposed in the valve body, and the valve body is urged in a closing direction by a spring. The valve element is opened when a pressure difference exceeding the biasing force of the spring is generated.

  The second reduction path 25 b is provided in the middle of the second blow-by gas reduction hose 26 and the second blow-by gas reduction hose 26 that connect the inside of the head cover 6 and the upstream side of the throttle valve 20 of the intake pipe 18. And a one-way valve 27 that allows only the flow of blow-by gas from the head cover 6 to the intake pipe 18 (see arrow a in FIGS. 1, 2, and 5).

  During the deceleration operation in which the throttle valve 20 is suddenly closed or in the idling operation state in which the throttle valve 20 is fully closed, the pressure in the crankcase 3 increases due to the lowering of the piston 7 and the downstream side portion of the throttle valve 20 in the intake pipe 18. The negative pressure increases. As a result, the PCV valve 41 is opened, and the blow-by gas in the crankcase 3 flows into the combustion chamber 14 from the intake pipe 18 through the first blow-by gas reduction hose 40 and is recombusted in the combustion chamber 14. . In this way, the crankcase 3 is forcibly ventilated using the negative pressure in the intake pipe 18.

  On the other hand, when the throttle valve 20 is substantially fully opened, the pressure in the crankcase 3 increases due to the lowering of the piston 7 and the entire intake pipe 18 has a relatively weak negative pressure. The one-way valve 27 is opened, and the blow-by gas in the head cover 6 flows into the combustion chamber 14 from the intake pipe 18 via the second blow-by gas reduction hose 26 and is recombusted.

  As described above, since the first reduction path 25a and the second reduction path 25b are provided, the blow-by gas can be reduced to the intake system during the deceleration operation of the engine 1 or in a wide operation range from the idling operation to the high-speed operation. This prevents the blow-by gas from being discharged to the outside of the engine, and avoids problems such as engine oil deterioration and rust.

  Further, when the PCV valve 41 is damaged due to an abnormal increase in the internal pressure of the crankcase 3 for some reason, the one-way valve 27 functions as a safety valve that releases the pressure in the crankcase 3. As a result, it is possible to avoid major engine troubles.

  5 to 7, the one-way valve 27 includes a valve case 33, a valve main body 30 accommodated in the valve case 33, and an O-ring (not shown) in a connection opening 30i of the valve main body 30. An upstream valve sleeve 34 that is detachably screwed with a valve interposed therebetween, and a downstream valve sleeve 35 that is detachably screwed with an O-ring 37 interposed in a downstream opening 33 c of the valve case 33.

  The valve case 33 has a rectangular tube shape having an upstream opening 33b and a downstream opening 33c. The valve body 30 is detachably screwed into the upstream opening 33b of the valve case 33 with an O-ring 36 interposed.

  The upstream and downstream valve sleeves 34 and 35 have cylindrical body portions 34a and 35a and hexagonal portions 34b and 35b formed in the body portions 34a and 35a. Further, an external connection portion 35c is formed in the hexagonal portion 35b of the downstream side valve sleeve 35 (see FIG. 5).

  An upstream end 26b of the blow-by gas reduction hose 26 on the intake pipe 18 side is detachably connected and fixed to the external connection portion 35c of the downstream valve sleeve 35 by a fastening band (not shown).

  In the valve body 30, there are an inlet 30a that opens to the crankcase 3 side, an outlet 30b that opens to the intake pipe 18, and a blow-by gas passage 30c that communicates the outlet 30b and the inlet 30a. Is formed.

  The outlet 30b of the valve body 30 is opened and closed by a valve plate 31, and the opening degree of the valve plate 31 is regulated by a stopper 32. Specifically, the following structure is provided.

  The valve body 30 includes a triangular pyramid portion 30h formed to have a substantially triangular pyramid shape, and a cylindrical portion 30g formed integrally with the triangular pyramid portion 30h.

  The outlet 30b is formed on three side surfaces of the triangular pyramid portion 30h of the valve body 30, and the common inlet 30a is formed on the cylindrical portion 30g following the triangular pyramid portion 30h. Has been.

  The valve plate 31 is disposed on the three side surfaces of the triangular pyramid portion 30 h of the valve body 30 so as to cover the outlets 30 b, and the stopper 32 is disposed so as to cover the valve plate 31. One end of the valve plate 31 is fastened and fixed to the upstream edge of the outlet 30b by a screw 38.

  Each of the valve plates 31 is made of a steel plate and has a strip shape. Specifically, the thickness of the valve plate 31 is, for example, about 0.08 mm so that the outlet 30b can be opened even by a slight pressure difference that increases on the crankcase side. Is set to When the pressure on the crankcase side is low, the valve plate 31 reliably closes the outlet 30b to prevent backflow of air or the like.

  Each stopper 32 is bent so as to curve outward from the upstream end to the downstream end, so that the valve plate 31 is fully opened so as to follow the curved shape of the stopper 32. The position is restricted.

  On the inner peripheral surface of the blow-by gas passage 30c of the valve body 30, three grooves 30d extending in a generally spiral shape from the inlet 30a toward each outlet 30b are formed at intervals of 120 degrees in the circumferential direction. ing. As a result, the blow-by gas flowing in from the inflow port 30a flows out of the outflow port 30b while being rotated by being twisted by the grooves 30d.

  External air is allowed to flow into the upstream side of the one-way valve 27 of the second blow-by gas reduction hose 26 when the negative pressure in the crankcase 3 exceeds a predetermined value (see arrow c in FIG. 3D). ) A relief valve 45 is provided.

  Specifically, the relief valve 45 is integrally attached to the upstream side valve sleeve 34 of the one-way valve 27 via a joint member 46, whereby the relief valve 45 and the one-way valve 27 are unitized. Yes.

  A downstream end 26a of the head cover 6 side portion of the blow-by gas reduction hose 26 is detachably connected to the external connection portion 46a of the joint member 46 by a fastening band (not shown).

  As shown in FIGS. 3A to 3D, the relief valve 45 includes a cylindrical cylinder 47 in which downstream and upstream relief passages 50 a and 51 a extending in the axial direction are formed. The piston 48 is inserted and arranged, and opens and closes the upstream relief passage 51a, and a coil spring 49 that constantly biases the piston 48 in the closing direction.

  The cylinder 47 has a bottomed cylindrical outer cylinder 50 in which the downstream relief passage 50a is formed, and is inserted into the downstream relief passage 50a of the outer cylinder 50, and communicates with the downstream relief passage 50a. And an inner cylinder 51 in which an upstream relief passage 51a is formed.

  An insertion hole 50c through which the valve shaft 48a of the piston 48 is inserted is formed at the center of the bottom 50b of the outer cylinder 50, and an outer peripheral portion of the insertion hole 50c communicates with the downstream relief passage 50a. A plurality of external air outlets 50d are formed at predetermined intervals in the circumferential direction.

  A downstream end 50e of the outer cylinder 50 is detachably screwed to the upstream valve sleeve 34 of the one-way valve 27 with an O-ring 53 interposed.

  A circular recess 50g is formed in the upstream end 50f of the outer cylinder 50, and a spacer 55 is screwed into the recess 50g with an O-ring 54 interposed.

  The inner cylinder 51 is integrally formed with a cylindrical external air inlet 51b extending outward after the upstream relief passage 51a.

  An air filter 57 that filters external air is detachably attached to the external air inlet 51 b of the inner cylinder 51. As shown in FIG. 2, the air filter 57 has a filter (not shown) disposed in a filter case 57b having a wire mesh 57a through which external air passes, and the air that has passed through the filter on the bottom wall of the filter case 57b. Is connected to a rubber tube 57c. The air filter 57 is attached to the relief valve 45 by fitting the rubber tube 57c into the external air inlet 51b in an airtight manner.

  The inner cylinder 51 is screwed into the spacer 55 of the outer cylinder 50 so as to be movable in the axial direction with an O-ring 52 interposed therebetween, and the axial position with respect to the outer cylinder 50 can be adjusted. . The biasing force of the coil spring 49 can be adjusted by adjusting the amount of insertion of the inner cylinder 51 into the outer cylinder 50.

  A lock nut 56 is screwed to the upstream end 51 c of the inner cylinder 51, and the inner cylinder 51 is fixed so as not to move by tightening the lock nut 56 to the spacer 55.

  As shown in FIGS. 4A and 4B, the piston 48 is inserted and arranged in the outer cylinder 50, and passes through the insertion hole 50c of the outer cylinder 50 and protrudes outward. And a valve part 48b formed integrally with the valve shaft part 48a.

  The valve portion 48b of the piston 48 is in contact with the downstream end surface 51d of the upstream relief passage 51a of the inner cylinder 51 by the urging force of the coil spring 49, and thereby the relief passage 51a is always closed ( (Refer FIG.3 (b)).

  A large number of recessed flow channels 48c are formed at predetermined intervals in the circumferential direction at the outer peripheral edge of the valve portion 48b. When the piston 48 moves backward against the urging force of the coil spring 49, the downstream relief passage 50a and the upstream relief passage 51a communicate with each other through the flow passages 48c (see FIG. 3D). As a result, the external air flows from the relief valve 45 through the second blow-by gas reducing hose 26 and flows into the crankcase 3 through the head cover 6.

  The coil spring 49 is installed between the valve portion 48 b and the bottom portion 50 b of the outer cylinder 50. The biasing force of the coil spring 49 is set so as to open the piston 48 when the inside of the crankcase 3 becomes an excessive negative pressure.

  In addition, the valve portion 48b of the piston 48 abuts in the vicinity of the bottom portion 50b of the downstream relief passage 50a of the outer cylinder 50, whereby a stopper portion 50h that regulates the amount of movement of the piston 48 in the opening direction is provided. It is formed in an attached shape (see FIGS. 3B and 3D).

  According to the blow-by gas reduction device of the present embodiment, external air is caused to flow into the upstream side of the one-way valve 27 interposed in the second blow-by gas reduction hose 26 when the negative pressure in the crankcase 3 exceeds a predetermined value. Since the relief valve 45 is provided, for example, when the decompression in the crankcase 3 increases due to forced ventilation of the PCV valve 41 in the first reduction path 25a, external air flows from the head cover 6 into the crankcase case 3 via the relief valve 45. As a result, the reduced pressure in the crankcase 3 is relieved, and oil lubricity can be prevented from deteriorating. In this manner, excessive pressure reduction in the crankcase 3 can be suppressed while ensuring the performance and function of the PCV valve 41 of the first reduction path 25a.

  In this embodiment, the relief valve 45 is urged in the closing direction by a cylinder 47 having downstream and upstream relief passages 50a and 51a, a piston 48 for opening and closing the relief passage 51a, and the piston 48 in the closing direction. Since the coil spring 49 is provided, the urging force of the coil spring 49 can be adjusted to a value corresponding to the decompressed state in the crankcase 3, thereby reducing the decompression of the crankcase 3 with a simple structure. it can.

  An outer cylinder 50 in which a number of external air outlets 50d are formed to communicate the cylinder 47 with the downstream relief passage 50a, and an outside air inlet 51b that communicates with the downstream relief passage 50a of the outer cylinder 50 are formed. And the valve portion 49b of the piston 49 is brought into contact with the downstream end face 51d of the upstream relief passage 51a of the inner cylinder 51 by the urging force of the coil spring 49. When the passage 51a is closed and moved against the urging force of the coil spring 49, the relief passage 51a is opened. The coil spring 49 is provided between the valve portion 48b and the bottom portion 50b of the outer cylinder 50. The relief valve 45 can be configured with the minimum necessary number of parts, the increase in cost can be suppressed, and the user can be provided at a low cost. Kill.

  In the present embodiment, since the inner cylinder 51 can be moved in the axial direction with respect to the outer cylinder 50, the biasing force of the coil spring 49 can be adjusted. It becomes easy to set the value according to the number of cylinders, the displacement, etc., and the versatility for the vehicle type can be improved.

  In this embodiment, since the stopper portion 50h for restricting the movement of the piston 48 in the opening direction is formed in the vicinity of the bottom portion 50b of the downstream relief passage 50a of the outer cylinder 50, the stroke amount of the piston 48 can be simplified. Can be regulated by structure.

  In the present embodiment, an air filter 57 that filters external air is detachably attached to the relief valve 45, and the one-way valve 27 is integrally connected via the joint member 46. Therefore, the one-way valve 27 and the relief valve 45 are connected together. Can be unitized, the assembling work can be easily performed, and consequently the labor required for assembling can be reduced.

  In addition, since the one-way valve 27 is of a reed valve type, the passage resistance is reduced, and the pulsation of the internal pressure of the crankcase 3 accompanying the vertical movement of the piston 7 can be followed.

  Further, grooves 30d, 30e, 30f extending in a generally spiral shape from the inlet 30a to the outlet 30b are formed on the inner peripheral surface of the valve body 30 of the one-way valve 27, so that the blow-by gas is formed by the grooves 30d-30f. Rotation is applied, the flow of blow-by gas becomes smooth, and the followability to the pulsation of the pressure in the crankcase 3 can be further improved.

  Furthermore, three outlets 30b are formed on three side surfaces of the valve body 30 having a substantially triangular pyramid shape, and a common inlet 30a is formed in the three outlets 30b, so that blow-by gas that has flowed in from the inlet 30a is formed. Will flow out from the three outlets 30b substantially evenly, making the flow of blow-by gas smoother and reducing the passage resistance.

  In the above embodiment, a gasoline engine has been described as an example, but the blow-by gas reduction device of the present invention can also be applied to a gas engine. Further, the scope of application of the present invention is not limited to a single cylinder engine, but can of course be applied to a multi-cylinder engine and a multi-cylinder engine, and can also be applied to an automobile engine and a motorcycle engine.

1 Engine 3 Crankcase 14 Combustion chamber 18 Intake pipe (intake passage)
19 Air cleaner (intake passage)
20 Throttle valve 25 Blow-by gas reduction device 26 Blow-by gas reduction hose (Blow-by gas reduction passage)
27 One-way valve 45 Relief valve 47 Cylinder 48 Piston 49 Coil spring 50 Outer cylinder 50a Downstream relief passage 50d External air outlet 50h Stopper 51 Inner cylinder 51a Upstream relief passage 51b External air inlet

Claims (3)

In a blowby gas reduction device for an engine in which a crankcase and an intake passage including an air cleaner and a throttle valve communicating with a combustion chamber are connected in communication by a blowby gas reduction passage.
The blow-by gas reduction passage is provided with a one-way valve that allows only the flow from the crankcase to the intake passage,
A relief valve is provided on the upstream side of the one-way valve in the blow-by gas reduction passage to allow external air to flow when the negative pressure in the crankcase exceeds a predetermined value.
The relief valve includes a cylinder in which a relief passage is formed, a piston that is movably inserted into the cylinder, opens and closes the relief passage, and a spring that normally biases the piston in a closing direction.
The cylinder has an outer cylinder formed with an external air outlet communicating with the relief passage, an external air inlet communicating with the relief passage, and is moved in the axial direction with respect to the outer cylinder. An inner cylinder capable of adjusting the biasing force of the spring;
The piston has a valve shaft portion and a valve portion formed on the valve shaft portion,
The valve portion is brought into contact with the downstream end surface of the relief passage of the inner cylinder by the urging force of the spring spanned between the valve portion and the opening edge of the outer air outlet of the outer cylinder. The relief passage is closed and configured to open the relief passage when moved against the biasing force of the spring;
Further, the valve portion is supported on an inner peripheral surface of the relief passage of the outer cylinder so as to be slidable in the axial direction, and the valve shaft portion is pivoted on an inner peripheral surface of an insertion hole formed in a bottom portion of the outer cylinder. An engine blow-by gas reduction device characterized by being supported so as to be slidable in a direction . The blow-by gas reduction device for an engine according to claim 1 ,
A blow-by gas reduction device for an engine, wherein a stopper portion for restricting movement of the piston in the opening direction is formed in the relief passage of the outer cylinder by contacting the valve portion of the piston. The blowby gas reduction device for an engine according to claim 1 or 2 ,
The relief valve is detachably mounted with an air filter that filters external air,
The blow-by gas reduction device for an engine, wherein the relief valve is integrally connected to the one-way valve via a joint member.

Images