JP5374889B2 - Engine blow-by gas recirculation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent blow-by gas recirculating performance from being lowered due to an instantaneous pressure variation in crankcases. <P>SOLUTION: A blow-by gas is moved from the first cutout section 11a of the crankcase of a third cylinder and the second cutout section 12a of the crankcase of a fourth cylinder which are formed in the crankcase sidewall surface at the mating portion of an upper block 2 and a lower block 3 at the portion where the upper block and the lower block sandwich a bulkhead 5 to an oil separation space OS through first and second gas passages 11, 12. The blow-by gas introduced into the oil separation space OS is collided with the root portion of a first baffle plate 203, the oil mist contained in the gas is adhered to the baffle plate, and the gas advances toward the PCV valve. With this configuration, a path from the openings 11b, 12b to the blow-by gas introduction opening 14a of the PCV valve can be sufficiently secured, and the pressure variation affecting the opening 14a can be minimized. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an engine blow-by gas recirculation device, and in particular, has an oil separation cover that forms an oil separation space for blow-by gas on one side of the engine body, and a PCV valve attached to the oil separation cover. The present invention also relates to an apparatus for separating oil from blow-by gas introduced into the oil separation space from the inside of the engine and supplying it to the intake system of the engine.

With the internal combustion of the engine, a gas containing unburned components leaked from the combustion chamber , so-called blow-by gas, is generated in the crank chamber inside the cylinder block and the oil pan. The blow-by gas is collected, recirculated to the intake system, and burned again. However, since the collected blow-by gas contains oil mist from lubricating oil and the like, oil components are not separated. If it is sufficient, there is a possibility that adverse effect on the exhaust system catalyst.

From the above, an oil separator chamber separating the oil from the blow-by gas is provided in the engine body, the configuration of the Positive Crankcase Ventilation valve to be opened against the oil separator chamber biasing force of Sprint grayed (hereinafter, PCV valve) And a PCV valve and an intake system are connected by a PCV hose, and a device that guides blow-by gas from which oil has been separated to the intake system according to intake negative pressure is generally known. In such an apparatus, the PCV valve, the PCV hose, and the like are cooled by running air at an extremely low temperature and the moisture contained in the blow-by gas is frozen, which may adversely affect the reflux performance.

  In recent years, in order to reduce costs, there is a tendency to form a lightweight and compact layout while forming the intake manifold and oil separator chamber with synthetic resin, but in this case, the heat conduction from the engine is smaller than that of metal. As the freezing tendency increases, the reflux performance deteriorates further.

As a countermeasure against such a problem, for example, a structure disclosed in JP-A-2002-106429 is known. That is, in this publication, the engine is placed horizontally so that the resin intake manifold faces the front side of the vehicle with respect to the vehicle longitudinal direction, and the oil separator chamber communicated with the crank chamber through a single passage is disposed in the engine. The PCV valve and the PCV hose are formed in the concave portion on the side surface and can be accommodated in the projection surface of the intake manifold as viewed from the front side of the vehicle.

JP 2002-106429 A

  In the device of Patent Document 1, the PCV valve and the PCV hose are accommodated in the projection surface of the intake manifold located on the front side of the vehicle. This prevents a reduction in the reflux performance of blow-by gas.

However, as a factor that affects the recirculation performance of blow-by gas, in addition to the above-described freezing in the passage, it is necessary to consider the linkage between the recirculation amount of blow-by gas and the intake negative pressure , that is , the throttle valve opening. . In the crank chamber where the oil separator chamber communicates, momentary pressure fluctuation occurs due to the vertical movement of the piston or the rotational movement of the crankshaft accompanying the combustion stroke, and the amount of blow-by gas recirculation controlled by the PCV valve It has an influence.

Further, for the purpose of reducing vibration of the engine, provided with a bulkhead for partitioning the inside of the crank chamber for each inter-cylinder, also it has been made to so-called lattice structure to bridge the crankshaft bearing between the preceding and succeeding blocks. Along with this, the communication area of the crank chamber corresponding to each cylinder decreases, and the influence of the combustion stroke in the cylinder on the oil separator chamber becomes more remarkable.

  An object of the present invention is to prevent a reduction in the reflux performance of blow-by gas due to instantaneous pressure fluctuations in the crank chamber.

An engine blow-by gas recirculation device according to claim 1 includes an oil separation cover that forms an oil separation space on one side of an engine body in which a plurality of cylinders are arranged in a row, and a PCV valve mounted on the oil separation cover. A gas passage that communicates the crank chamber of the engine body with an oil separation space, and a vibration of the engine. In order to reduce the cylinder head, a bulkhead section that divides the inside of the cylinder block for each cylinder is provided, and a plurality of the gas passages are provided across the bulkhead section, and the plurality of gas passages have a piston phase of 180 °. provided so as to correspond to the pair of cylinders adjacent different, and communicates with the same of the oil separation space that It is characterized.

  According to the first aspect of the present invention, the pressure fluctuation in the oil separation space corresponding to the specific cylinder is suppressed. Moreover, it can communicate between a pair of adjacent cylinders whose piston phases differ by 180 °, and pressure fluctuations in the oil separation space are further suppressed.

  According to a second aspect of the present invention, there is provided a blow-by gas recirculation device for an engine according to the first aspect, wherein the gas introduction opening of the PCV valve opens into the oil separation space, and the gas introduction opening of the PCV valve and the downstream end of the gas passage. A baffle plate is provided between the two.

  According to invention of Claim 2, the pressure fluctuation with respect to the gas introduction opening part of a PCV valve is reduced.

  The blow-by gas recirculation device for an engine according to claim 3 is the invention according to claim 2, wherein the baffle plate is integrally formed in a recess on one side surface of the engine body toward the outside of the engine body, and the downstream end portion of the gas passage Is arranged on the base side of the baffle plate.

  According to the invention of claim 3, the pressure fluctuation with respect to the gas introduction opening of the PCV valve is further reduced.

According to the first aspect of the present invention, the crank chambers of a pair of adjacent cylinders separated by a bulkhead and having a piston phase difference of 180 ° are communicated in the same oil separation space. The instantaneous pressure fluctuation is released to the oil separation space and further to the crank chamber of the other cylinder, and different pressure fluctuations for each cylinder cancel each other.
Therefore, the pressure fluctuation in the crank chamber that affects the opening / closing operation of the PCV valve can be reduced, and the flow quantity fluctuation of the blow-by gas can be suppressed.

  According to the second aspect of the present invention, even when the gas introduction opening of the PCV valve is opened in the oil separation space, the pressure fluctuation proceeding from the gas passage can be attenuated by colliding with the baffle plate. Thus, fluctuations in the flow rate of blow-by gas can be suppressed.

  According to the invention of claim 3, in addition to the effect of claim 3, by making the travel path of the blow-by gas longer, the pressure fluctuation is attenuated, and further the flow-by fluctuation of the blow-by gas can be suppressed.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

First, an outline of an engine according to the present invention will be described with reference to FIG.
The engine body ENG is composed of a cylinder head 1, an upper block 2, a lower block 3, and an oil pan 4 constituting a cylinder block, and a plurality of cylinders, specifically, four cylinders are arranged in the vehicle width direction. This is a so - called four-cylinder horizontal engine laid out in the engine room.

  The upper block 2 and the lower block 3 are fastened and fixed in a state where a crankshaft (not shown) is rotatably supported, and is placed on the oil pan 4. In the present invention, as a countermeasure for preventing vibration of the engine ENG, a bulkhead 5 is formed as a vertical wall that cuts off between the cylinders on the upper block 2 side, and a bearing for the crankshaft is formed on the lower block 3 side. The structure which takes a lattice structure which connects a surface is taken.

  An intake unit IU that supplies air to a combustion chamber (not shown) of the engine is formed by a throttle body 6, a surge tank 7 that constitutes an intake passage, a branch intake passage 8, and the like.

Air sucked from the air cleaner is guided to an intake duct (not shown) upstream of the throttle body 6 and supplied to a surge tank 7 forming a volume chamber. The throttle body 6 is a so-called electronically controlled throttle whose outer periphery is formed of a metal casing, the control unit of the engine calculates the control amount based on the operation amount of the accelerator pedal, and the throttle valve is controlled by an internal motor.
The air supplied to the surge tank 7 is connected to the cylinder head 1 by the branch intake passage 8 and supplied to the combustion chamber of each cylinder. The branch intake passage 8 is formed of a synthetic resin such as polyamide, and has a shape curved upward from the lower side of one side surface of the engine body in the forward direction of the vehicle. The intake unit IU is supported on the engine ENG by connecting to the cylinder head 1 described above, fastening to the upper block 2 via the stay 9, and cooperating with one side of the upper block 2 described later. This is performed by attaching to the oil separation cover 10 that forms the separation space OS.

  Next, the blow-by gas recirculation device will be described with reference to FIGS.

  2 is a side view of the upper block 2 as viewed from the intake unit IU side, FIG. 3 is a bottom view of the upper block 2, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 6 is a view showing a cross section taken along line VV in FIG. 2, and FIG. 6 is a view showing a cross section taken along line VI-VI in FIG.

  As shown in FIG. 2, an oil separation portion that forms an oil separation space OS in cooperation with the oil separation cover 10 along with a number of reinforcing ribs on the surface of the intake unit IU of the upper block 2 that is one side of the engine body. 200 is formed. The oil separation unit 200 is located in a concave portion corresponding to the cylinder bore of the intake unit IU side upper block 2. The cylinder arrangement is the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder in order from the left side of the drawing.

  The oil separation part 200 has a cover attachment part 201 to which the attachment flange part 101 of the oil separation cover 10 is fastened, and six attachment bolt holes 202a to which the attachment flange part 101 of the oil separation cover 10 is fastened and fixed by bolts or the like. , 202b, 202c, 202d, 202e, 202f are provided at three locations on the left and right. The first, second, and third baffle plates 203, 204, and 205 for separating the oil contained in the blow-by gas are attached to the inner portion of the cover mounting portion 201. It is integrally formed outward from the unit IU side surface.

  The first baffle plate 203 located at the lowermost position is formed at a substantially middle portion in the vertical direction of the upper block 2 continuously from the left cover mounting portion 201 to the vicinity of the right cover mounting portion. Further, the front end portion in the direction of the intake unit IU extends to a position exceeding the intermediate portion of the oil separation space OS.

  The second baffle plate 204 located at the intermediate portion is formed at a substantially middle portion between the first baffle plate 203 and the upper end portion of the upper block 2 continuously from the right cover attaching portion 201 to a substantially middle portion of the oil separation space OS. Has been. The length of the second baffle plate 204 in the direction of the intake unit IU is about ¼ of that of the first baffle plate 203. Since the lower part of the upper block 2 forms the upper part of the crank chamber and the position corresponding to the cylinder bore is a recess, the tip part of the second baffle plate 204 is a position corresponding to the root part of the first baffle plate 203.

  The uppermost third baffle plate 205 is formed at a substantially middle portion between the second baffle plate 204 and the upper end of the upper block 2 from the right cover attaching portion 201 to a substantially middle portion of the second baffle plate 204. The length in the direction of the intake unit IU is less than half of the second baffle plate 204.

  Inside the upper block 2, the first gas passage 11 and the second gas passage 12 are located in a portion of the bulkhead 5 between the third cylinder and the fourth cylinder with the crankshaft bearing portion and the bulkhead 5 sandwiched therebetween. It is formed so as to penetrate the crank chamber CR and the oil separation space OS. The order of the ignition timing of the engine in the present invention is the order of the first cylinder → the third cylinder → the fourth cylinder → the second cylinder, and the phase difference of the combustion stroke between the third cylinder and the fourth cylinder is 180. °.

  As shown in FIG. 3, first and second cutout portions 11a and 12a are provided at the lower end portions of the first gas passage 11 and the second gas passage 12, and cranks are provided via the cutout portions 11a and 12a. The blow-by gas of the chamber CR is introduced into the gas passages 11 and 12.

  Upper end openings 11 b and 12 b of the first and second gas passages 11 and 12 are opened at the base portion of the first baffle plate 203 and are provided upward so as to face the lower surface of the first baffle plate 203.

  The bottom surface portion of the oil separation space OS is formed so as to be positioned gradually downward in the vertical direction along the longitudinal direction of the engine, and the opening 13b below the upper end openings 11b, 12b of the first and second gas passages 11, 12. An oil return passage 13 is provided on the engine longitudinal direction side of the first and second gas passages 11 and 12.

  4 to 6, the oil separation cover 10 forms an oil separation space OS by covering the oil separation portion 200 provided on the intake unit IU side surface of the upper block 2 described above. The oil separation cover 10 is provided with a first rib 102 that extends toward the tip of the first baffle plate 203 and a second rib 103 that extends to the vicinity of the root of the first baffle plate 203. Yes.

  A PCV valve 14 is provided in the oil separation cover 10 with the upstream side protruding into the oil separation space OS, and the blow-by gas introduction opening 14a and the upper end openings 11b of the first and second gas passages 11 and 12, The first baffle plate 203 and the second rib 103 are interposed between the two b. The PCV valve 14 has a general structure in which a spring is installed in a cylindrical casing, and a valve body that opens against the urging force of the spring is attached to the tip of the PCV valve 14.

  In addition, a chamber 300 is formed integrally with the oil separation cover 10 in the vertical direction on the downstream side of the PCV valve 14 and in the vicinity thereof. The chamber 300 and the surge tank 7 are communicated with each other through the third gas passage 15, and the opening 15 a of the third gas passage 15 is vertically lower than the downstream end of the PCV valve 14 and is vertically lower in the chamber 300. In place. The third gas passage 15 is composed of an upstream portion 15 b formed in the oil separation cover 10 and a downstream portion 15 c formed in the surge tank 7.

  Based on FIG.7 and FIG.8, the connection form of the oil separation cover 10 and the surge tank 7 which concerns on this invention is demonstrated.

  FIG. 7 is a perspective view in which the oil separation cover 10 is mounted on the intake unit IU side of the upper block 2, and FIG. 8 is a view showing a cross-section of the main part where the oil separation cover 10 and the surge tank 7 are connected in communication.

  The oil separation cover 10 has a mounting flange portion 101 on its outer peripheral edge, and has five openings 104a, 104b, 104c, 104d, and 104f provided on the mounting flange portion 101 and mounting bolt holes 202a on the upper block side. , 202b, 202c, 202d, 202f are fastened with bolts or the like.

  On the right mounting flange portion 101, a surge tank mounting portion 400 having a cross-sectional cam-like column having substantially the same height as the oil separation space OS is formed integrally with the oil separation cover 10. The upper surface of the surge tank mounting portion 400 is a flat mounting seat surface 401 and is configured to come into contact with the mounting seat surface 7a of the surge tank 7 in a surface contact state.

  The mounting seat surface 401 of the surge tank mounting portion 400 is provided with a support opening 402 for fastening and supporting the surge tank 7 to the oil separation cover 10 with a bolt or the like. Further, the support opening 402 is positioned coaxially with the central mounting bolt hole 202e among the three mounting bolt holes provided on the right side of the cover mounting portion 201 of the upper block, and is connected to the surge tank 7 and the upper block side. The mounting bolt holes 202e are configured to be fastened together with bolts or the like via the oil separation cover 10.

  A first opening 403 that forms a gas passage from the chamber 300 is formed in the vicinity of the support opening 402 of the mounting seat surface 401. The second opening 7b, which is the upstream end of the downstream portion 15c of the third gas passage 15 formed on the mounting seat surface 7a of the surge tank, and the first opening 403 are in contact with each other, so that the blow-by gas is surged. A third gas passage 15 to be supplied to the tank 7 is formed to penetrate therethrough.

  Next, the structure of the oil separation cover 10 according to the present invention will be described with reference to FIGS.

  9 is a front view of the oil separation cover 10, FIG. 10 is a side view of the oil separation cover 10, FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG. 9, and FIG. FIG. 13 is a view showing a cross section taken along line XII-XII, and FIG. 13 is a view showing a cross section taken along line XIII-XIII in FIG.

  As shown in FIG. 9, the oil separating cover 10 includes a bulging portion 500, a mounting flange portion 101, a surge tank mounting portion 400, and a chamber 300 that are integrally formed of synthetic resin.

  The bulging portion 500 bulges toward the intake unit IU in a range extending over the upper portion of the oil separation cover 10 and the right side portion where the chamber 300 is installed, and cooperates with the oil separation portion 200 to form the oil separation space OS. Configure. A second rib 103 is extended below the bulging portion 500 and at an intermediate portion of the oil separation cover 10, and a first rib 102 is installed below the second rib 103.

  The mounting flange portion 101 is provided on the outer peripheral edge portion of the oil separation cover 10 and has five openings 104a used for fastening at positions corresponding to the mounting bolt holes 202a, 202b, 202c, 202d, 202f provided in the upper block 2. 104 b, 104 c, 104 d, 104 f are provided at substantially the middle positions of the four corners of the upper, lower, left and right sides and the left mounting flange 101.

  The surge tank mounting portion 400 is a columnar cam-shaped column, and is formed to extend from the right mounting flange portion 101 along the bulging portion 500 in the direction of the intake unit IU. A mounting seat surface 401 that forms a flat portion toward the intake unit IU is formed on the upper end surface of the surge tank mounting portion 400. The mounting seat surface 401 has a support opening 402 that is coaxial with the mounting bolt hole 202 e provided in the upper block 2.

  A first opening 403 is formed at a substantially intermediate portion between the support opening 402 and the upper right opening 104f so as to be in contact with the second opening 7a at a position facing the second opening 7a of the surge tank. Has been. The first opening 403 forms an upstream portion 15 b of the third gas passage 15 that supplies blow-by gas from the chamber 300.

  A PCV valve 14 is mounted inside the wall of the bulging portion 500 in the vicinity of the opening 104f on the upper right side, and a chamber 300 is formed around the downstream side thereof. As shown in FIGS. 10 and 11, the PCV valve 14 is disposed so that the introduction opening 14 a faces the second rib 103, so that blow-by gas supplied from the crank chamber CR is not directly introduced into the PCV valve 14. Is arranged.

  As shown in FIG. 13, the valve support member 16 is fastened and fixed from the back surface of the oil separation cover 10 so that the downstream portion of the PCV valve 14 is accommodated in the chamber 300.

  As shown in FIG. 12, the upstream portion 15 b of the third gas passage on the oil separation cover 10 side uses the inside of the wall of the oil separation cover 10 from the chamber 300 to the first opening 403 provided in the mounting seat surface 401. Communicate. In addition, the upstream opening 15a to the chamber 300 of the upstream portion 15b of the third gas passage is installed vertically below the end of the PCV valve 14 in the vehicle-mounted state and at an intermediate position vertically below the chamber 300. ing.

  Next, the operation and effect of the blow-by gas recirculation apparatus will be described.

  In the idling state or low load state, a negative pressure is generated downstream of the throttle valve, and the PCV valve 14 is opened against the urging force of the spring so that the crank chamber CR and the throttle valve downstream, specifically, Is connected to the surge tank 7 and blow-by gas in the crank chamber CR is sucked in by the negative intake pressure.

The blow-by gas is supplied from the first notch 11a of the crank chamber of the third cylinder and the second notch 12a of the crank chamber of the fourth cylinder formed on the crank chamber side wall surface of the mating surface portion of the upper block 2 and the lower block 3. It moves to the oil separation space OS through the first and second gas passages 11 and 12.
In the case of adopting a lattice structure using a bulkhead 5 in the upper block 2 and a crankshaft bearing on the lower block 3 side for the purpose of reducing vibration as in this embodiment, the communication of the crank chamber CR of each cylinder is established. Since the area is small and the pressure fluctuation in the crank chamber CR of each cylinder becomes particularly remarkable, the third cylinder crank chamber CR and the first cylinder are different in phase by 180 ° with the same bulkhead 5 interposed therebetween so that the interval is the shortest distance. It communicates with the 4-cylinder crank chamber CR. As a result, it is possible to further suppress the pressure fluctuation transmitted to the oil separation space OS.

The blow-by gas introduced into the same oil separation space OS from the upper end openings 11b and 12b of the first and second gas passages collides with the root portion of the first baffle plate 203 disposed opposite to the upper end openings 11b and 12b. The oil mist contained in the gas advances toward the PCV valve while adhering to the baffle plate. The first, second and third baffle plates 203, 204 and 205 and the first and second ribs 102 and 103 are alternately arranged between the upper end openings 11b and 12b and the PCV valve introduction opening 14a. It has a maze structure.
With the above-described configuration, a sufficient path from the openings 11b and 12b to the blow-by gas introduction opening 14a of the PCV valve can be ensured, and the pressure fluctuation affecting the opening 14a can be minimized and the flow from the blow-by gas can be reduced. Improves oil separation performance.

  On the other hand, the oil adhering to the baffle plate and the ribs flows down to the oil separation portion bottom surface 200 along the upper block wall surface and the oil separation cover inner wall surface, and enters the inside of the crank chamber CR from the oil return passage opening 13b formed at the lowest portion. Refluxed.

  The blow-by gas that has passed through the PCV valve 14 is discharged into the chamber 300 formed in the oil separation cover 10, passes through an opening 15 a provided in the chamber 300, and the upstream portion 15 b and the downstream of the third gas passage 15. The side portion 15c is advanced.

  Since the installation position of the opening 15a in the chamber is vertically downward from the downstream end of the PCV valve in the on-vehicle state, even when moisture contained in the blow-by gas condenses and flows backward from the third gas passage 15. It is possible to prevent adhesion to the downstream end portion of the PCV valve.

  In addition, since the installation position of the opening 15a is an intermediate position in the vertical direction of the chamber in a vehicle-mounted state, the casing of the PCV valve 14 can be used as a weir, and condensed moisture can be retained in the chamber. Even at a low temperature, the downstream end of the PCV valve or the opening 15a in the chamber can be prevented from being blocked by freezing of moisture.

  The upstream portion 15b of the third gas passage extends to the mounting seat surface 401 of the surge tank mounting portion 400 using the wall portion of the oil separation cover 10, and in the vicinity of the mounting portion between the oil separation cover 10 and the surge tank 7. The first opening 403 of the oil separation cover 10 and the second opening 7b that is the upstream end of the downstream portion 15c of the third gas passage of the surge tank 7 are in contact with each other. That is, the third gas passage 15 is formed by using an attachment portion between the oil separation cover 10 and the surge tank 7, and blow-by gas is returned to the surge tank 7 through this passage. A member to be externally connected is not required, and a reflux failure due to an assembly failure during manufacturing can be prevented.

  According to this embodiment, the oil separation space OS, the PCV valve, and the third gas passage 15 can be positioned on the back surface of the intake unit IU, and icing can be prevented.

  Further, according to the present embodiment, it is possible to maintain a strong attachment property of a heavy object such as the electronically controlled throttle 6 even if the branched intake passage 8 is made of synthetic resin.

  As mentioned above, although the Example applied to the horizontal 4-cylinder engine was described, from the main point of this invention, the blowby gas recirculation apparatus of the engine of this invention is not limited to the said embodiment.

1 is a side view of an engine according to an embodiment of the present invention. It is the side view which looked at the upper block from the intake unit side. It is a bottom view of the upper block. It is a figure which shows the IV-IV sectional view in FIG. It is a figure which shows the VV sectional view in FIG. It is a figure which shows the VI-VI line cross section in FIG. FIG. 6 is a perspective view in which an oil separation cover is mounted on the intake unit side of the upper block. It is a figure which shows the principal part cross section by which the oil separation cover and the surge tank were connected by communication. It is a front view of an oil separation cover. It is a side view of the oil separation cover. It is a figure which shows the XI-XI line cross section of FIG. It is a figure which shows the XII-XII line cross section of FIG. It is a figure which shows the XIII-XIII line cross section of FIG.

ENG Engine IU Intake unit OS Oil separation space CR Crank chamber 2 Upper block 200 Oil separation section 203 First baffle plate 204 Second baffle plate 205 Third baffle plate 5 Bulkhead 6 Throttle body 7 Surge tank 8 Branch intake passage 10 Oil separation Cover 102 First rib 103 Second rib 11 First gas passage 11a First notch 11b Upper end opening 12 Second gas passage 12a Second notch 12b Upper end opening 14 PCV valve 14a Blow-by gas introduction opening

Claims (3)

An oil separation cover that forms an oil separation space on one side of an engine body in which a plurality of cylinders are arranged in a row, and a PCV valve attached to the oil separation cover, and a blow-by generated from the crank chamber of the engine In an engine blow-by gas recirculation device that supplies gas to the engine intake system after separating the oil into oil,
A gas passage communicating the crank chamber of the engine body with an oil separation space;
In order to reduce the vibration of the engine, a bulkhead section that divides the inside of the cylinder block for each cylinder is provided,
A plurality of the gas passages are provided across the bulkhead portion,
The blow-by gas recirculation device for an engine, wherein the plurality of gas passages are provided so as to correspond to a pair of adjacent cylinders whose piston phases are different by 180 ° and communicate with the same oil separation space .   The gas introduction opening of the PCV valve opens into an oil separation space, and a baffle plate is provided between the gas introduction opening of the PCV valve and the downstream end of the gas passage. The blowby gas recirculation device for an engine according to 1.   The baffle plate is integrally formed in a recess on one side of the engine body toward the outside of the engine body, and the downstream end of the gas passage is disposed on the root side of the baffle plate. Item 3. The blowby gas recirculation device for an engine according to Item 2.