JP2008075630A - Multi-cylinder engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-cylinder engine capable of providing a sufficient oil separating function even when an oil mist amount becomes large. <P>SOLUTION: In the multi-cylinder engine, a breather chamber 4 facing a fore and aft direction is formed along a ceiling wall 3 of a head cover 2, a breather chamber inlet 5 is provided on a front end of the breather chamber 4, a breather chamber outlet 6 is provided on a rear end of the breather chamber 4, and a plurality of bulkheads 7 is provided in the breather chamber 4. Blow-by gas is passed through a breather chamber 4 interior along the bulkheads 7, and oil mist included in the blow-by gas is condensed on surfaces of the bulkheads 7 to carry out oil separation. A front stage oil separation chamber 9 facing a vertical direction is provided along a front end wall 8 of the head cover 2, an oil trap 10 with a three dimensional mesh structure is housed in the front stage oil separation chamber 9, a separation chamber inlet 9a is provided in a lower end of the front stage oil separation chamber 9, a front end corner space of the head cover 2 positioned above the front stage oil separation chamber 9 is used as a separation chamber outlet 9b, and the separation chamber outlet 9b is communicated with the breather chamber inlet 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multi-cylinder engine, and more particularly to a multi-cylinder engine that can provide a sufficient oil separation function even when the amount of oil mist increases.

  As a conventional multi-cylinder engine, as in the present invention, the longitudinal direction of the head cover attached to the cylinder head is the front-rear direction, one is the front, the height direction of the head cover is the vertical direction, and the longitudinal direction is along the ceiling wall of the head cover. A breather chamber inlet, a breather chamber inlet at the front end of the breather chamber, a breather chamber outlet at the rear end of the breather chamber, a plurality of partition walls in the breather chamber, and along the partition walls. There is one in which blow-by gas is passed through a breather chamber and oil mist contained in the blow-by gas is condensed on the surface of a partition wall to perform oil separation (see, for example, Patent Document 1).

  However, the conventional multi-cylinder engine has a problem because there is no means for assisting oil separation in the breather chamber.

Japanese Patent Laying-Open No. 2005-48601 (see FIGS. 1 and 2)

The above prior art has the following problems.
<< Problem >> When the amount of oil mist increases, a sufficient oil separation function may not be obtained.
Since there is no means for assisting oil separation in the breather chamber, if the amount of oil mist increases, oil separation may not be in time just by condensation on the surface of the partition wall, and the oil mist may blow through the breather chamber. Also, in the case of a breather chamber along the ceiling wall of the head cover, if a large oil discharge port is provided on the bottom wall, there is a problem that blow-by gas is short-circuited from here to the breather chamber, so a large oil discharge port cannot be provided, When the amount of oil condensed in the breather chamber increases, the condensed oil cannot be discharged efficiently, and the condensed oil may be re-misted and taken out of the breather chamber. For this reason, if the amount of oil mist increases, a sufficient oil separation function may not be obtained.

  An object of the present invention is to provide a multi-cylinder engine that can solve the above-described problems, that is, a multi-cylinder engine that can provide a sufficient oil separation function even when the amount of oil mist increases.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 1A, the head cover (2) attached to the cylinder head (1) has a longitudinal direction as the front and rear direction, one side as the front, and the height direction of the head cover (2) as the vertical direction. 2) A breather chamber (4) directed in the front-rear direction is formed along the ceiling wall (3), and a breather chamber inlet (5) is provided at the front end of the breather chamber (4). The breather chamber (4) A breather chamber outlet (6) is provided at the rear end portion, a plurality of partition walls (7) are provided in the breather chamber (4), and the blow-by gas passes through the partition wall (7) in the breather chamber (4). In the multi-cylinder engine in which oil mist contained in the blow-by gas is condensed on the surface of the partition wall (7) to perform oil separation,
A front oil separation chamber (9) is provided in the vertical direction along the front end wall (8) of the head cover (2), and the oil catcher (10) having a three-dimensional mesh structure is accommodated in the front oil separation chamber (9). A separation chamber inlet (9a) is provided at the lower end of the front oil separation chamber (9), and the front end corner space of the head cover (2) located above the front oil separation chamber (9) is separated from the separation chamber outlet (9b). The multi-cylinder engine is characterized in that the separation chamber outlet (9b) communicates with the breather chamber inlet (5).

(Invention according to Claim 1)
<Effect> Even if the amount of oil mist increases, a sufficient oil separation function can be obtained.
As illustrated in FIG. 1A, a front oil separation chamber (9) is provided along the front end wall (8) of the head cover (2) in the vertical direction, and a three-dimensional mesh is formed in the front oil separation chamber (9). The oil trapping body (10) having the structure is accommodated, and a separation chamber inlet (9a) is provided at the lower end portion of the upstream oil separation chamber (9), and the head cover (2) located above the upstream oil separation chamber (9) is provided. Since the front end corner space is the separation chamber outlet (9b), and this separation chamber outlet (9b) communicates with the breather chamber inlet (5), before the blow-by gas containing oil mist flows into the breather chamber (4). The oil catcher (10) separates the oil to some extent, and most of the separated oil naturally falls from the separation chamber inlet (9a) and does not enter the breather chamber (4). For this reason, the oil catcher (10) assists the oil separation in the breather chamber (4), the separated oil is efficiently discharged, and a sufficient oil separation function can be obtained even if the amount of oil mist increases. .

(Invention according to Claim 2)
In addition to the effect of the invention according to claim 1, the following effect is achieved.
<Effect> High oil separation function.
As illustrated in FIG. 1B, the blow-by gas that has entered the front space (17) of the separation chamber outlet (9b) from the vent outlet hole (19) of the lower end portion (16) of the presser (13) becomes a ventilation gap. The oil mist contained in the blow-by gas, which has entered the breather chamber inlet (5) through the rear space (18) and the rear space (18), flows into the breather chamber (4) before the presser (13). Passes through the front and rear spaces (17) and (18) partitioned by (5) and condenses on the surface of the presser (13). Thus, since the oil mist that has passed through the oil catcher (10) is separated on the surface of the presser (13) before entering the breather chamber (4), the oil separating function is high.

<Effect> The presser can be effectively used as an oil separating means.
As illustrated in FIG. 1 (A), the presser (13) is plate-shaped, and its upper end (15) is bent backward to contact the ceiling wall (3) of the head cover (2), and its lower end. (16) is folded forward and brought into contact with the upper surface of the oil catcher (10), and the separation chamber outlet (9b) is divided into a front space (17) and a rear space (18) at the intermediate portion (20). As shown in FIG. 1 (B), a vent outlet hole (19) is formed in the lower end (16) of the presser (13), and as shown in FIG. 1 (C), the presser (13) A ventilation gap (23) is provided between the lateral edge (21) of the intermediate portion (20) and the lateral wall (22) of the head cover (2), and the breather chamber entrance is located on the opposite side of the ventilation gap (23) in the left-right direction. Since (5) is arranged, as shown in FIG. 1 (B), the blow-by gas is allowed to pass in an inverted manner along the front space (17) and the rear space (18) partitioned by the pressing tool (13). Can be pressed Ingredients (13) can be effectively used as an oil separating means.

(Invention according to claim 3)
In addition to the effect of the invention according to claim 1 or claim 2, the following effect is achieved.
<Effect> High oil separation function.
As shown in FIG. 3, a gas swirl chamber (24) is provided in the ceiling wall (3) of the head cover (2), and the start end (26) of the swirl chamber inlet (25) communicates with the breather chamber outlet (6). As shown in FIG. 1 (E), the end portion (27) of the swirl chamber inlet (25) is set along the tangential direction of the inner peripheral surface of the swirl chamber peripheral wall (28), and the swirl chamber inlet (25) Since the blow-by gas that has entered the gas swirl chamber (24) from the end portion (27) of the swirl swirls along the inner peripheral surface of the swirl chamber peripheral wall (28), the oil mist that has passed through the breather chamber (4) Centrifugation is performed in the gas swirl chamber (24). Thus, since the oil mist that has passed through the breather chamber (4) is separated later in the gas swirl chamber (24), the oil separation function is high.

(Invention of Claim 4)
In addition to the effect of the invention according to claim 3, the following effect is achieved.
<Effect> High oil separation function.
As illustrated in FIG. 3, blow-by gas that has passed through the gas swirl chamber (24) passes between the valve surface (33) and the valve seat (31) where the valve is opened, and enters the valve seat outlet passage (34). The oil mist that has passed through the gas swirl chamber (24) is oil-separated by the passage resistance between the valve face (33) and the valve seat (31). In this way, the oil mist is separated even when it flows out of the gas swirl chamber (24), so the oil separation function is high.

(Invention according to claim 5)
In addition to the effect of the invention according to claim 4, the following effect is achieved.
<Effect> The specification can be easily changed to an engine having a specification without a swirl chamber.
As illustrated in FIG. 3, instead of the swirl chamber peripheral wall (28), the periphery of the diaphragm valve (32) can be mounted on the swirl chamber mount seat (35). 35), when the peripheral portion of the diaphragm valve (32) is attached instead of the swirl chamber peripheral wall (28), the valve surface (33) of the diaphragm valve (32) is provided on the upper surface of the outlet passage front peripheral wall (36). Since the diaphragm valve (32) can be used as a breather valve, the swirl chamber peripheral wall (28) is removed from the swirl chamber mounting seat (35), and the diaphragm valve ( By simply replacing 32), it is possible to easily change the specification to an engine without a swirl chamber.

<Effect> It is possible to share the head cover and the engine without the swirl chamber.
As illustrated in FIG. 3, the swirl chamber mounting seat (35) can also be used as a valve mounting seat for the diaphragm valve (32), and the upper surface of the outlet passage front peripheral wall (37) is formed on the diaphragm valve (32). Therefore, it is possible to share the head cover (2) with the engine having no swirl chamber.

(Invention of Claim 6)
In addition to the effects of the invention according to any one of claims 1 to 5, the following effects are provided.
<Effect> High oil separation function.
As illustrated in FIG. 1A, an oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4), and a lower end (42) of the oil discharge pipe (41) is connected to the U Since the oil is collected at the lower end (42) of the oil discharge pipe (41), blow-by gas is short-circuited from the lower end opening (44) of the oil discharge pipe (41) to the breather chamber (4). The internal diameter of the oil discharge pipe (41) can be made sufficiently large. For this reason, the oil can be efficiently discharged from the breather chamber (4), the condensed oil hardly accumulates in the breather chamber (4), and the take-out from the breather chamber (4) due to the re-misting of the condensed oil is suppressed. High oil separation function.

(Invention of Claim 7)
In addition to the effects of the invention according to any one of claims 1 to 5, the following effects are provided.
<Effect> High oil separation function.
As illustrated in FIG. 2C, an oil sump (43) is provided on the upper surface of the cylinder head (1), and the oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4). Since the lower end opening (44) of the oil discharge pipe (41) is immersed in the oil (45) stored in the oil reservoir (43), the blow-by gas flows into the lower end opening (44) of the oil discharge pipe (41). Therefore, the oil discharge pipe (41) can have a sufficiently large inner diameter. For this reason, the oil can be efficiently discharged from the breather chamber (4), the condensed oil hardly accumulates in the breather chamber (4), and the take-out from the breather chamber (4) due to the re-misting of the condensed oil is suppressed. High oil separation function

(Invention of Claim 8)
In addition to the effects of the invention according to any one of claims 1 to 7, the following effects are provided.
<Effect> By forming the breather chamber, the overall height of the engine does not increase.
As illustrated in FIG. 1A, a breather chamber (4) is formed only in the front half (3a) of the front half (3a) and the rear half (3b) of the ceiling wall (3) of the head cover (2). By doing so, the second half (3b) of the ceiling wall (3) of the head cover (2) is made lower than the first half (3b) of the ceiling wall (3), and the second half of the ceiling wall (3) of the head cover (2). Since the supercharged pipe (47) is arranged along the part (3b), the position of the supercharged pipe (47) is high even if the breather chamber (4) is formed on the ceiling wall (3) of the head cover (2). In addition, there is no possibility that the overall height of the engine is increased by the formation of the breather chamber (4).

  Embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are diagrams for explaining a multi-cylinder engine according to an embodiment of the present invention. In this embodiment, a 4-cylinder vertical diesel engine will be explained.

The outline of the embodiment of the present invention is as follows.
As shown in FIG. 4, the cylinder head (1) is assembled to the upper part of the cylinder block (48), and the head cover (2) is assembled to the upper part of the cylinder head (1). A winding transmission (49) is disposed at the front of the cylinder block (48), and a timing gear train (not shown) is disposed at the rear of the cylinder block (48). An oil pan (50) is assembled to the lower part of the cylinder block (48). An intake distribution passage wall (51) is provided on the left and right sides of the cylinder head (1), and an exhaust merging passage wall (52) is provided on the other side. Although the intake distribution passage wall (51) is generally called an intake manifold, it is expressed as an intake distribution passage wall because it has a box structure without a branch pipe. The exhaust merging passage wall (52) is generally called an exhaust manifold, but is expressed as an exhaust merging passage wall according to the expression of the intake distribution passage wall. An EGR cooler (53) and an EGR valve case (54) are arranged above the intake distribution passage wall (51). A valve actuator (55) is assembled to the upper part of the EGR valve case (54). A supercharger (46) is assembled to the upper part of the exhaust merging passage wall (52). The head cover (2) is provided with a breather device.

The outline of the breather device is as follows.
As shown in FIG. 1 (A), the longitudinal direction of the head cover (2) attached to the cylinder head (1) is the front-rear direction, one is the front, and the height direction of the head cover (2) is the vertical direction. A breather chamber (4) directed in the front-rear direction is formed along the ceiling wall (3). A breather chamber inlet (5) is provided at the front end of the breather chamber (4), a breather chamber outlet (6) is provided at the rear end of the breather chamber (4), and a plurality of partition walls are provided in the breather chamber (4). (7) is provided, and blow-by gas is allowed to pass along the partition wall (7) in the breather chamber (4), and oil mist contained in the blow-by gas is condensed on the surface of the partition wall (7) for oil separation. I am doing so. As shown in FIG. 2 (A), the partition wall (7) is directed in the left-right direction and arranged side by side in the front-rear direction. It is divided into two compartments. Adjacent partition walls (7) are provided with communication ports (54) on opposite sides in the horizontal direction so that blow-by gas passes through the breather chamber (4) while meandering.

The oil separation structure upstream of the breather chamber is as follows.
As shown in FIG. 1 (A), a front oil separation chamber (9) is provided in the vertical direction along the front end wall (8) of the head cover (2), and a three-dimensional network structure is provided in the front oil separation chamber (9). The oil trapping body (10) is accommodated, a separation chamber inlet (9a) is provided at the lower end of the preceding oil separation chamber (9), and the front end of the head cover (2) located above the preceding oil separation chamber (9) The corner space is defined as a separation chamber outlet (9b), and the separation chamber outlet (9b) communicates with the breather chamber inlet (5). The oil catcher (10) is steel wool.

The oil trapping body fixing structure is as follows.
As shown in FIG. 1 (A), a receptacle (12) is provided at the separation chamber inlet (9a), an oil catcher (10) is placed on the receptacle (12), and a presser is placed at the separation chamber outlet (9b). (13) is housed, and the oil catcher (10) is sandwiched between the presser (13) and the receiver (12), so that the oil catcher (10) in the preceding oil separation chamber (9). To fix.

The device for the fixing is as follows.
As shown in FIG. 2 (A), a vent inlet hole (14) is made in the receiving tool (12), and as shown in FIG. 1 (A), the pressing tool (13) is plate-shaped and its upper end (15 ) Is bent backward and is brought into contact with the ceiling wall (3) of the head cover (2), and its lower end portion (16) is bent forward and brought into contact with the upper surface of the oil catcher (10). 1), the separation chamber outlet (9b) is divided into a front space (17) and a rear space (18), and a vent outlet hole (19) is formed in the lower end (16) of the presser (13). ), A ventilation gap (23) is provided between the lateral edge (21) of the intermediate part (20) of the presser (13) and the lateral wall (22) of the head cover (2). 23) The breather chamber entrance (5) is arranged on the opposite side in the left-right direction. As a result, as shown in FIG. 1 (B), blow-by gas that has entered the front space (17) of the separation chamber outlet (9b) from the vent outlet hole (19) of the lower end (16) of the presser (13) The breather chamber entrance (5) is entered through the ventilation gap (23) and the rear space (18).

The oil separation structure downstream of the breather chamber is as follows.
As shown in FIG. 3, a gas swirl chamber (24) is provided in the ceiling wall (3) of the head cover (2), and the start end (26) of the swirl chamber inlet (25) communicates with the breather chamber outlet (6). As shown in FIG. 1E, the end portion (27) of the swirl chamber inlet (25) is set along the tangential direction of the inner peripheral surface of the swirl chamber peripheral wall (28), and the end of the swirl chamber inlet (25) is formed. The blow-by gas that has entered the gas swirl chamber (24) from the section (27) swirls along the inner peripheral surface of the swirl chamber peripheral wall (28).

The structure of the gas swirl chamber is as follows.
As shown in FIG. 3, a valve mounting seat (29) is formed on the upper surface of the swirl chamber peripheral wall (28), and a valve seat peripheral wall (30) is disposed at the center of the gas swirl chamber (24). The valve seat (31) is formed on the upper surface of the valve seat peripheral wall (30), and the peripheral portion of the diaphragm valve (32) serving as a breather valve is formed on the valve mounting seat (29). The valve face (33) of the diaphragm valve (32) is seated on the valve seat (31), and a valve seat outlet passage (34) is formed in the valve seat peripheral wall (30). As a result, the blow-by gas that has passed through the gas swirl chamber (24) passes between the valve surface (33) and the valve seat (31), and flows into the valve seat outlet passage (34). Yes.

  As shown in FIG. 3, a swirl chamber mounting seat (35) is provided on the ceiling wall (3) of the head cover (2), and a swirl chamber peripheral wall (28) is mounted on the swirl chamber mounting seat (35). An outlet passage front peripheral wall (36) is provided at the center of the seat (35), and the axis of the outlet passage front peripheral wall (36) is directed in the vertical direction so that the outlet passage front peripheral wall (36) and the side wall (22) of the head cover (2) ), The outlet passage rear-stage peripheral wall (37) is erected, and the axis of the outlet passage rear-stage peripheral wall (37) is directed in the horizontal direction.

As shown in FIG. 3, an outlet passage front wall (36) and an outlet passage front wall (37) provided with an outlet passage (38) bent in an L shape are formed on the upper surface of the outlet passage front wall (37). The starting end of the outlet passage (38) is connected to the end of the valve seat outlet passage (34), and the end of the outlet passage (38) formed at the end of the rear peripheral wall (37) of the outlet passage is sucked through the breather pipe (39). In communicating with the passageway, the following is done.
Instead of the swirl chamber peripheral wall (28), the periphery of the diaphragm valve (32) can be mounted on the swirl chamber mounting seat (35), and the swirl chamber peripheral wall (28) is attached to the swirl chamber mount seat (35). When the peripheral portion of the diaphragm valve (32) is attached instead of the diaphragm valve (32), the valve surface (33) of the diaphragm valve (32) is seated on the upper surface of the outlet passage front peripheral wall (36), and the diaphragm valve (32 ) Can be used as a breather valve.

The oil discharge structure from the breather chamber is as follows.
As shown in FIG. 1 (A), the oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4), and the lower end (42) of the oil discharge pipe (41) is U-shaped. It is folded back into a shape. As shown in FIG. 2 (C), an oil sump (43) is provided on the upper surface of the cylinder head (1), and the oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4). The lower end opening (44) of the oil discharge pipe (41) may be immersed in the oil (45) stored in the oil reservoir (43).

The arrangement of the supercharging pipe is as follows.
As shown in FIG. 4, when the supercharger pipe (47) for supercharging the intake passage from the supercharger (46) is disposed along the ceiling wall (3) of the head cover (2), FIG. As shown in FIG. 4, a breather chamber (4) is formed only in the front half (3a) of the front half (3a) and the rear half (3b) of the ceiling wall (3) of the head cover (2). 2) The second half (3b) of the ceiling wall (3) is made lower than the first half (3b) of the ceiling wall (3), along the second half (3b) of the ceiling wall (3) of the head cover (2). The supercharging pipe (47) is arranged.

It is a figure explaining components, such as a head cover, used for the diesel engine which concerns on embodiment of this invention, FIG. 1 (A) is a vertical side view of a head cover, FIG.1 (B) is from the B arrow direction of FIG. FIG. 1C is a plan view of the pressing tool viewed from the direction of arrow C in FIG. 1A, and FIG. 1D is a cross-sectional view taken along the line DD in FIG. 1A. FIG. 1 (E) is a plan view of the gas swirl chamber viewed from the direction of arrow E in FIG. 1 (A). FIG. 2A is a bottom view of the head cover, FIG. 2B is a bottom view of the bottom wall of the breather chamber, and FIG. 2B is a view for explaining components such as a head cover used in the diesel engine according to the embodiment of the present invention. C) is an explanatory view of a modified example of the oil discharge pipe. It is a vertical side view of the gas swirl chamber used for the diesel engine which concerns on embodiment of this invention, and its peripheral part. 1 is a perspective view of a diesel engine according to an embodiment of the present invention.

Explanation of symbols

(1) Cylinder head
(2) Head cover
(3) Ceiling wall
(3a) First half
(3b) Second half
(4) Breezer room
(5) Breezer room entrance
(6) Breezer room exit
(7) Bulkhead
(8) Front end wall
(9) Front oil separation chamber
(9a) Separation chamber entrance
(9b) Separation chamber exit
(10) Oil catcher
(11)
(12) Receiver
(13) Presser
(14) Venting hole
(15) Upper end
(16) Lower end
(17) Front space
(18) Back space
(19) Vent outlet hole
(20) Middle part
(21) Horizontal edge
(22) Horizontal wall
(23) Ventilation gap
(24) Gas swirl chamber
(25) Swirl room entrance
(26) Start end
(27) Termination
(28) Swirling chamber wall
(29) Valve mounting seat
(30) Valve seat wall
(31) Valve seat
(32) Diaphragm valve
(33) Valve face
(34) Valve seat outlet passage
(35) Swivel chamber mounting seat
(36) Exit passage front wall
(37) Exit passage rear wall
(38) Exit passage
(39) Breather pipe
(40) Bottom wall
(41) Oil discharge pipe
(42) Lower end
(43) Oil sump
(44) Lower end opening
(45) Oil
(46) Turbocharger
(47) Supercharged pipe

Claims (8)

Along the ceiling wall (3) of the head cover (2), the longitudinal direction of the head cover (2) attached to the cylinder head (1) is the front-rear direction, one is the front, and the height direction of the head cover (2) is the vertical direction. A breather chamber (4) directed in the front-rear direction is formed, a breather chamber inlet (5) is provided at the front end of the breather chamber (4), and a breather chamber outlet (6) is disposed at the rear end of the breather chamber (4). A plurality of partition walls (7) are provided in the breather chamber (4), blow-by gas is passed through the breather chamber (4) along the partition wall (7), and oil mist contained in the blow-by gas is removed. In a multi-cylinder engine that is condensed on the surface of the partition wall (7) to perform oil separation,
A front oil separation chamber (9) is provided in the vertical direction along the front end wall (8) of the head cover (2), and the oil catcher (10) having a three-dimensional mesh structure is accommodated in the front oil separation chamber (9). A separation chamber inlet (9a) is provided at the lower end of the front oil separation chamber (9), and the front end corner space of the head cover (2) located above the front oil separation chamber (9) is separated from the separation chamber outlet (9b). The multi-cylinder engine is characterized in that the separation chamber outlet (9b) communicates with the breather chamber inlet (5). The multi-cylinder engine according to claim 1,
A receptacle (12) is provided at the separation chamber inlet (9a), an oil catcher (10) is placed on the receptacle (12), and a pressing tool (13) is received at the separation chamber outlet (9b). In fixing the oil catcher (10) in the preceding oil separation chamber (9) by sandwiching the oil catcher (10) between (13) and the receiver (12),
Vent inlet hole (14) is made in receptacle (12), presser (13) is plate-shaped, and its upper end (15) is bent backward to contact the ceiling wall (3) of head cover (2). The lower end portion (16) is bent forward and brought into contact with the upper surface of the oil capturing body (10), and the separation chamber outlet (9b) is connected to the front space (17) and the rear space (18) at the intermediate portion (20). A vent outlet hole (19) is formed in the lower end (16) of the presser (13), and the lateral edge (21) of the intermediate part (20) of the presser (13) and the head cover (2) are formed. By providing a ventilation gap (23) between the lateral wall (22) and disposing the breather chamber inlet (5) on the opposite side of the ventilation gap (23) in the left-right direction,
Blow-by gas that has entered the front space (17) of the separation chamber outlet (9b) from the vent outlet hole (19) of the lower end (16) of the presser (13) passes through the ventilation gap (23) and the rear space (18). A multi-cylinder engine characterized in that it enters the breather chamber entrance (5). The multi-cylinder engine according to claim 1 or 2,
A gas swirl chamber (24) is provided on the ceiling wall (3) of the head cover (2), and the start end (26) of the swirl chamber inlet (25) is communicated with the breather chamber outlet (6). The blow-by gas that has entered the gas swirl chamber (24) from the end portion (27) of the swirl chamber inlet (25) is aligned along the tangential direction of the inner peripheral surface of the swirl chamber peripheral wall (28). A multi-cylinder engine characterized by swirling along an inner peripheral surface of a swirl chamber peripheral wall (28). The multi-cylinder engine according to claim 3,
A valve mounting seat (29) is formed on the upper surface of the swirl chamber peripheral wall (28), a valve seat peripheral wall (30) is disposed at the center of the gas swirl chamber (24), and the axis of the valve seat peripheral wall (30) is moved up and down. A valve seat (31) is formed on the upper surface of the valve seat peripheral wall (30), and a peripheral portion of a diaphragm valve (32) serving as a breather valve is attached to the valve mounting seat (29), and the diaphragm valve (32 ) Is seated on the valve seat (31), and the valve seat outlet passage (34) is formed in the valve seat peripheral wall (30).
The blow-by gas that has passed through the gas swirl chamber (24) passes between the valve surface (33) and the valve seat (31) opened, and flows into the valve seat outlet passage (34). A featured multi-cylinder engine. The multi-cylinder engine according to claim 4,
A swirl chamber mounting seat (35) is provided on the ceiling wall (3) of the head cover (2), and a swirl chamber peripheral wall (28) is mounted on the swirl chamber mounting seat (35). An outlet passage front-stage peripheral wall (36) is provided in the outlet passage, and the axis of the outlet passage front-stage peripheral wall (36) is directed vertically, so that the outlet passage is between the outlet passage front-stage peripheral wall (36) and the lateral wall (22) of the head cover (2). A rear peripheral wall (37) is installed, and the axis of the rear peripheral wall (37) of the outlet passage is directed in the horizontal direction,
The outlet passage front wall (36) and the outlet passage front wall (37) are provided with an outlet passage (38) bent in an L-shape, and the start of the outlet passage (38) formed on the upper surface of the outlet passage front wall (37). Is connected to the end of the valve seat outlet passage (34), and the end of the outlet passage (38) formed at the end of the rear peripheral wall (37) of the outlet passage is connected to the intake passage via the breather pipe (39).
Instead of the swirl chamber peripheral wall (28), the periphery of the diaphragm valve (32) can be mounted on the swirl chamber mounting seat (35), and the swirl chamber peripheral wall (28) is attached to the swirl chamber mount seat (35). When the peripheral portion of the diaphragm valve (32) is attached instead of the diaphragm valve (32), the valve surface (33) of the diaphragm valve (32) is seated on the upper surface of the outlet passage front peripheral wall (36), and the diaphragm valve (32 ) Can be used as a breather valve. The multi-cylinder engine according to any one of claims 1 to 5,
The oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4), and the lower end portion (42) of the oil discharge pipe (41) is folded in a U-shape. Multi-cylinder engine. The multi-cylinder engine according to any one of claims 1 to 5,
An oil sump (43) is provided on the upper surface of the cylinder head (1), an oil discharge pipe (41) is led downward from the bottom wall (40) of the breather chamber (4), and a lower end opening of the oil discharge pipe (41) is provided. A multi-cylinder engine wherein the portion (44) is immersed in oil (45) stored in an oil reservoir (43). The multi-cylinder engine according to any one of claims 1 to 7,
When the supercharger pipe (47) for supercharging the intake passage from the supercharger (46) is arranged along the ceiling wall (3) of the head cover (2),
By forming the breather chamber (4) only in the front half (3a) of the front half (3a) and the rear half (3b) of the ceiling wall (3) of the head cover (2), the ceiling wall of the head cover (2) The rear half (3b) of (3) is made lower than the front half (3b) of the ceiling wall (3), and a supercharged pipe (3b) is provided along the rear half (3b) of the ceiling wall (3) of the head cover (2). 47), a multi-cylinder engine.

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