JP4977675B2 - Multi-cylinder engine - Google Patents

Description

  The present invention relates to a multi-cylinder engine, and more particularly to a multi-cylinder engine that can improve output performance and exhaust gas performance.

  As a conventional multi-cylinder engine, as in the present invention, an intake distribution passage is provided on the side surface of the cylinder head, with the crankshaft installation direction being the front-rear direction and the width direction of the cylinder head perpendicular to the crankshaft installation direction being the horizontal direction The EGR valve case, the EGR gas introduction passage, and the intake introduction pipe are arranged in order from the front above the intake distribution passage, and the introduction passage gas inlet of the EGR gas introduction passage is connected to the valve case gas outlet of the EGR valve case. The EGR gas introduction passage has an introduction passage gas outlet communicated with the intake inlet pipe on the front side of the peripheral wall of the intake introduction pipe, and flows into the intake air introduced along the axial length direction of the intake introduction pipe from the front side of the peripheral wall of the intake introduction pipe There is one in which gas is mixed and the intake air mixed with the EGR gas is distributed to the intake port of each cylinder in an intake distribution passage (see, for example, Patent Document 1).

  However, in the conventional multi-cylinder engine, the valve mounting frame protrudes from the valve case gas outlet of the EGR valve case into the EGR gas introduction passage, and the EGR gas flows backward from the EGR gas introduction passage to the EGR valve case in the valve mounting frame. There is a problem because a reed valve for preventing the EGR gas is attached, the distance of the EGR gas introduction passage downstream of the reed valve is short, and there is no EGR gas rectifying function.

JP 2008-75632 A (see FIGS. 1 and 2)

The above prior art has the following problems.
<Problem> Output performance and exhaust gas performance may deteriorate.
Output performance and exhaust gas performance may deteriorate.
The reason is estimated as follows.
A valve mounting frame protrudes from the valve case gas outlet of the EGR valve case into the EGR gas introduction passage, and a reed valve for preventing a backflow of EGR gas from the EGR gas introduction passage to the EGR valve case is attached to the valve mounting frame. Since the distance of the EGR gas introduction passage downstream of the reed valve is short and there is no EGR gas rectifying function, the EGR gas immediately after passing through the reed valve flows into the intake introduction pipe without aligning the direction. For this reason, the penetration force of the EGR gas along the radial direction of the intake pipe is weak, the EGR gas is mixed into the intake air only near the EGR gas inlet, and the EGR gas is not uniformly distributed throughout the intake air and is supplied to each cylinder. The EGR gas concentration in the intake air differs and the output performance and exhaust gas performance deteriorate.

  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 improve output performance and exhaust gas performance.

Invention specific matters of the invention according to claim 1 are as follows.
The installation direction of the crankshaft (1) is the front-rear direction, and the width direction of the cylinder head (2) perpendicular to the installation direction of the crankshaft (1) is the lateral direction.
As illustrated in FIG. 1 (A), an intake distribution passage (3) is provided on the lateral side surface of the cylinder head (2), and an EGR valve case (5) is disposed above the intake distribution passage (3) in order from the front. An EGR gas introduction passage (6) and an intake introduction pipe (7) are arranged, and an introduction passage gas inlet (11) of the EGR gas introduction passage (6) is connected to the valve case gas outlet (10) of the EGR valve case (5). The inlet passage gas outlet (12) of the EGR gas inlet passage (6) communicates with the intake inlet pipe (7) on the front side of the peripheral wall of the inlet inlet pipe (7).
EGR gas (15) flowing from the front side of the peripheral wall of the intake air introduction pipe (7) is mixed into the intake air (14) introduced along the axial length direction of the intake air introduction pipe (7), and this EGR gas (15) is mixed. In the multi-cylinder engine in which the intake air (14) is distributed to the intake ports (16) and (16) of each cylinder in the intake air distribution passage (3),
As illustrated in FIG. 1A, the EGR gas introduction passage is provided downstream of the reed valve (17) for preventing the backflow of the EGR gas (15) from the EGR gas introduction passage (6) to the EGR valve case (5). (6) includes a rectifying plate (39) oriented in the front-rear direction, and the EGR gas (15) is guided to the intake air introduction pipe (7) while being rectified in the straight forward direction along the rectifying plate (39). And
As illustrated in FIGS. 1A and 1B, a rectifying plate (39) includes a plurality of downward rectifying plates (41) protruding downward from the upper wall (40) of the EGR gas introduction passage (6). A plurality of upward rectifying plates (43) protruding upward from the lower wall (42) of the EGR gas introduction passage (6),
Each section passage (46) comprising an upper section passage (44) sectioned by the downward rectifying plate (41) and a lower section passage (45) sectioned by the upward rectifying plate (43) is divided into an upper section passage (44). ) And the upper opening (48) of the lower section passage (45).
As illustrated in FIG. 1B, the downward rectifying plate (41) protrudes toward the lower section passage (45), and the upward rectifying plate (43) protrudes toward the upper section passage (44). A multi-cylinder engine characterized by

<Effect> Output performance and exhaust gas performance can be improved.
Output performance and exhaust gas performance can be improved. The reason is estimated as follows.
As illustrated in FIG. 1A, the EGR gas introduction passage is provided downstream of the reed valve (17) for preventing the backflow of the EGR gas (15) from the EGR gas introduction passage (6) to the EGR valve case (5). (6) includes a rectifying plate (39) oriented in the front-rear direction, and the EGR gas (15) is guided to the intake air introduction pipe (7) while being rectified in the straight forward direction along the rectifying plate (39). Since the EGR gas (15) having passed through the reed valve (17) is aligned in the direction of the EGR gas introduction passage (6), the intake introduction pipe (7) is introduced from the introduction passage gas outlet (12). Flow into. Therefore, the penetration force of the EGR gas (15) along the radial direction of the intake air intake pipe (7) is strong, and the EGR gas (15) is mixed into the intake air (14) in a wide range in the radial direction of the intake air intake pipe (7). The EGR gas (15) is uniformly distributed throughout the intake air (14), the concentration of the EGR gas (15) in the intake air (14) supplied to each cylinder is equalized, and the output performance and exhaust gas performance are improved. Can be increased.

<Effect> High function to enhance output performance and exhaust gas performance.
High function to enhance output performance and exhaust gas performance.
The reason is estimated as follows.
As illustrated in FIGS. 1A and 1B, a rectifying plate (39) includes a plurality of downward rectifying plates (41) protruding downward from the upper wall (40) of the EGR gas introduction passage (6). The EGR gas introduction passage (6) is composed of a plurality of upward rectifying plates (43) protruding upward from the lower wall (42) of the EGR gas introduction passage (6), so that the EGR gas (15) is the EGR gas introduction passage (6). Is rectified on both the upper side and the lower side, and the penetration force of the EGR gas (15) along the radial direction of the intake air introduction pipe (7) is strengthened.
Further, as illustrated in FIG. 1 (B), an upper section passage (44) divided by a downward rectifying plate (41) and a lower section passage (45) divided by an upward rectifying plate (43). Since each section passage (46) communicates with each other via the lower opening (47) of the upper section passage (44) and the upper opening (48) of the lower section passage (45), each section passage ( The amount of EGR gas passing through 46) is equalized.
For these reasons, the EGR gas (15) is uniformly dispersed throughout the intake air (14) passing through the intake air intake pipe (7), and the EGR gas concentration in the intake air (14) supplied to each cylinder is equalized. , Output performance and exhaust gas performance can be enhanced.

<Effect> High function to enhance output performance and exhaust gas performance.
High function to enhance output performance and exhaust gas performance.
The reason is estimated as follows.
As illustrated in FIG. 1B, the downward rectifying plate (41) protrudes toward the lower section passage (45), and the upward rectifying plate (43) protrudes toward the upper section passage (44). Therefore, the gap between the projecting ends of the downward rectifying plate (41) and the upward rectifying plate (43) is larger than when the downward rectifying plate (41) and the upward rectifying plate (43) are projected in abutment with each other. Through this gap, the amount of EGR gas passing through each section passage (46) is equalized, and the EGR gas (15) is uniformly distributed throughout the intake air (14) passing through the intake air intake pipe (7). Dispersed and the EGR gas concentration in the intake air (14) supplied to each cylinder is equalized, and the output performance and exhaust gas performance can be improved.

  Embodiments of the present invention will be described with reference to the drawings. 1 to 8 are diagrams for explaining a multi-cylinder engine according to an embodiment of the present invention. In this embodiment, a vertical four-cylinder diesel engine will be described.

The outline of the embodiment of the present invention is as follows.
As shown in FIG. 6, the cylinder head (2) is assembled to the upper part of the cylinder block (61), the oil pan (62) is assembled to the lower part of the cylinder block (61), and the front of the cylinder block (61) is assembled. A water pump (63) and an oil pump (64) are assembled, and a flywheel housing (65) is assembled at the rear of the cylinder block (61).
A crankshaft (1) is installed in a crankcase (66) formed in the lower part of the cylinder block (61).

The installation direction of the crankshaft (1) is the front-rear direction, and the width direction of the cylinder head (2) perpendicular to the installation direction of the crankshaft (1) is the lateral direction.
As shown in FIG. 5, an exhaust merging passage (67) is provided on one of the lateral sides of the cylinder head (2), and an intake air distribution passage (3) is provided on the other side. The exhaust merge passage (67) is provided in the exhaust merge passage wall (68), and the intake distribution passage (3) is provided in the intake distribution passage wall (69). As shown in FIG. 1 (A), the intake distribution passage wall (69) is used to distribute intake air to the intake port (16) of each cylinder, and is called a so-called intake manifold. As shown in FIGS. 4 (A) to (E) and FIG. 4, this embodiment has a box shape without branch pipes, and is therefore referred to as an intake distribution passage wall (69) and an intake distribution passage (3). ing. As shown in FIG. 5, the exhaust merging passage (67) is for merging exhaust from the exhaust port (70) of each cylinder, and the exhaust merging passage wall (68) is a so-called exhaust manifold. However, they are referred to as an exhaust merging passage wall (68) and an exhaust merging passage (67) in order to match the part name of the intake distribution passage wall (69).

The configuration of the EGR device is as follows.
As shown in FIG. 1 (A), an EGR valve (71) is accommodated in an EGR valve case (5), the EGR valve (71) is opened, and an EGR gas is supplied from the exhaust side to the intake distribution passage (3). (15) is refluxed. The EGR valve (71) is biased in the valve closing direction by the spring force of the valve spring (72), and the EGR valve (71) is linked to the pneumatic valve actuator (73). The air pressure chamber (74) communicates with the intake air distribution passage (3), and the intake air distribution passage (3) is supercharged by a supercharger (75) driven by exhaust energy. As shown in FIGS. 6 and 7, the intake air distribution passage (3) is supercharged via an intake air supply pipe (95).

As shown in FIG. 5, the intake pressure chamber (74) of the valve actuator (73) is communicated with the intake distribution passage (3) via the intake pressure introduction pipe (76), and the intake pressure introduction pipe (76) is sensed. At the time of cold start when the engine temperature is less than a predetermined value, the intake pressure cutoff valve (77) is closed and the boost pressure in the intake distribution passage (3) is arranged. Regardless of this, the EGR valve (71) is maintained in the fully closed state, and the intake pressure shut-off valve (77) is opened at the time of warm start when the engine temperature is equal to or higher than a predetermined value or during normal operation, and the intake distribution passage (3 The opening degree of the EGR valve (71) is adjusted according to the supercharging pressure in the bracket.
The intake pressure cutoff valve (77) is attached to the EGR valve case (5), and the heat input portion (78) of the intake pressure cutoff valve (77) faces the valve cooling water passage (79) in the EGR valve case (5). It is out. The intake pressure shut-off valve (77) includes temperature-sensitive deformation means such as bimetal inside, and opens and closes the valve using deformation due to the temperature as a driving force. The valve cooling water channel (79) shown in FIG. 5 is formed in a U shape in plan view.

The arrangement of each part of the EGR device is as follows.
As shown in FIG. 1 (A), an intake distribution passage (3) is provided on the lateral surface of the cylinder head (2), and an EGR cooler (4) and an EGR valve are sequentially provided above the intake distribution passage (3) from the front. A case (5), an EGR gas introduction passage (6), and an intake introduction pipe (7) are arranged, and a valve case gas inlet (9) of the EGR valve case (5) is connected to a cooler gas outlet (8) of the EGR cooler (4). Are communicated, and the introduction gas inlet (11) of the EGR gas introduction passage (6) is communicated with the valve case gas outlet (10) of the EGR valve case (5), and the introduction passage gas outlet of the EGR gas introduction passage (6). (12) communicates with the intake inlet pipe (7) on the front side of the peripheral wall of the intake inlet pipe (7).
The intake intake pipe (7) is vertically raised at the rear end of the intake distribution passage wall (69). The longitudinal direction (front-rear direction) of the intake distribution passage (3) is a horizontal direction, and the EGR gas introduction passage (6) is inclined downward toward the intake introduction pipe (7) at a depression angle of 10 ° with reference to the horizontal direction. is doing. This depression angle is preferably less than 30 ° and more preferably less than 15 ° from the viewpoint of imparting the radial penetration force of the intake pipe (7) to the EGR gas (15).
As shown in FIG. 1A, EGR gas (15) flowing from the front side of the peripheral wall of the intake air introduction pipe (7) is mixed into the intake air (14) introduced along the axial length direction of the intake air introduction pipe (7). The intake air (14) mixed with the EGR gas (15) is distributed to the intake ports (16) and (16) of the respective cylinders through the intake air distribution passage (3).

  As shown in FIG. 1A, at the boundary between the valve case gas outlet (10) of the EGR valve case (5) and the introduction passage gas inlet (11) of the EGR gas introduction passage (6), the EGR gas introduction passage ( A reed valve (17) for preventing the backflow of the EGR gas (15) from 6) to the EGR valve case (5) is disposed. Therefore, the distance until the EGR gas (15) that has passed through the reed valve (17) is guided to the intake air introduction pipe (7) through the EGR introduction passage (6) can be made relatively long, and the reed valve (17 The EGR gas (15) that has passed through) is aligned in the passage formation direction in the EGR gas introduction passage (6), and then flows into the intake introduction pipe (7) from the introduction passage gas outlet (12).

The configuration of the reed valve is as follows.
As shown in FIGS. 2 (B) and 2 (C), the plate member (25) (26) is provided with the valve element (18) of the reed valve (17) and its valve port (19), and this plate member (25) (26). ) Are sandwiched between the valve case gas outlet peripheral portion (22) of the EGR valve case (5) and the introduction passage gas inlet peripheral portion (23) of the EGR gas introduction passage (6). Gaskets 29 and 30 are provided. For this reason, the reed valve (17) can be arranged in a space-saving manner. In addition, a dedicated gasket part is not necessary, and the number of parts of the engine can be reduced.
As shown in FIGS. 2 (B) and 2 (C), the plate members (25) and (26) include a plate member (25) with a valve body including a valve body (18) and a valve port including a valve port (19). It is comprised with the board | plate material (26) with attached. For this reason, the reed valve (17) can be manufactured easily and inexpensively.

As shown in FIG. 2 (D), the gaskets (29) and (30) of the peripheral portions (27) and (28) of the plate member (25) with a valve body and the plate member (26) with a valve port are both steps. The shape is a half bead. For this reason, as illustrated in FIG. 2 (G), the joint portion at the boundary between the valve case gas outlet (10) of the EGR valve case (5) and the introduction passage gas inlet (11) of the EGR gas introduction passage (6). The sealing properties of the gaskets (29) and (30) are high.
As shown in FIG. 2 (B), the plate member (25) with a valve element is provided with a slit (31) along the outer shape of the valve element (18) in the plate member (25), and is surrounded by the slit (31). The plate member portion is a valve body (18), and the plate member (26) with a valve opening is provided with a valve port (19) in the plate member (26), and the plate member portion at the peripheral portion of the valve port (19) is The valve seat (32) is used. For this reason, the reed valve (17) can be manufactured easily and inexpensively.
As shown in FIGS. 2 (C) and 2 (E), a plurality of valve ports (19) and (19) are arranged side by side on a plate (26) with valve ports, and the peripheral portions of the valve ports (19) are stepped. Of the formed valve body side step surfaces (33) and (34), the surface (33) closer to the valve body is the valve seat (32). For this reason, the rigidity of the valve seat (32) is high, and the sealing performance when the reed valve is closed is high.

As shown in FIGS. 2B and 2C, the valve seat (32) is always provided with an opening (35), and the EGR gas (15) ejected from the valve opening (19) opens the valve body (18). Before the valve is operated, the valve body peripheral portion (36) receives pressure in the valve opening direction by the EGR gas (15) ejected from the normally open port (35). For this reason, the valve opening delay of the valve body (18) by the sticking of the valve body (18) to the valve seat (32), the stationary inertia of the valve body (18), etc. is prevented.
As shown in FIG. 2 (F), the normally open port (35) is formed in a circular shape, and the valve body peripheral portion (36) is concentric with the normally open port (35) and smaller in diameter than the normally open port (35). An arc-shaped notch (37) is provided so that the EGR gas (15) ejected from the always-opening opening (35) blows to the peripheral portion (38) of the arc-shaped notch (37). For this reason, the valve opening delay prevention function of the valve body (18) is high.
The reason is estimated as follows.
Of the EGR gas (15) ejected from the normally open port (35), the gas ejected from the center of the normally open port (35) having the fastest flow velocity passes through the notch (37), and the normally opened port has a slow flow rate. Since the jet gas from the peripheral edge of (35) blows to the peripheral edge (38) of the arc-shaped cutout (37), the rebound of the jet gas to the always-opening opening (35) is gentle and the peripheral edge of the valve body (36) The occurrence of turbulent flow of the EGR gas (15) in the vicinity is suppressed, the vibration of the valve body (18) due to turbulence is less likely to occur, the delay in valve opening due to vibration is prevented, and the opening of the valve body (18) is prevented. High valve delay prevention function.

As shown in FIGS. 1 (A) and 1 (B), the EGR gas introduction passage (6) includes a rectifying plate (39) oriented in the front-rear direction, and the EGR gas (15) is moved along the rectifying plate (39). While being straightened in the straight direction, it is guided to the intake air introduction pipe (7).
As shown in FIGS. 1A and 1B, a rectifying plate (39) includes a plurality of downward rectifying plates (41) protruding downward from the upper wall (40) of the EGR gas introduction passage (6); A plurality of upward rectifying plates (43) projecting upward from the lower wall (42) of the EGR gas introduction passage (6).
As shown in FIG. 1 (B), each divided passage comprising an upper divided passage (44) divided by a downward rectifying plate (41) and a lower divided passage (45) divided by an upward rectifying plate (43). (46) communicate with each other via the lower opening (47) of the upper section passage (44) and the upper opening (48) of the lower section passage (45).
As shown in FIG. 1 (B), the downward rectifying plate (41) protrudes toward the lower section passage (45), and the upward rectifying plate (43) protrudes toward the upper section passage (44). .

As shown in FIG. 2 (G), an extension part (49) is provided on the upper front side of the downward rectifying plate (41), and this extension part (49) serves as a valve opening stopper (50) and a valve of the valve body (18). The valve body restraining part (51) is disposed above the valve opening stopper (50), and the valve body gas outlet (10) of the valve body restraining part (51) and the EGR valve case (5) is provided. ) Is sandwiched by the upper opening edge portion (56), and the valve body portion (53) below the base portion (52) of the valve body (18) is bent. The valve is opened. For this reason, damage to the reed valve (17) due to slight vibration of the base (52) of the valve body (18) and excessive opening of the valve body (18) is suppressed, and durability of the reed valve (17) is increased. be able to.
As shown in FIG. 2 (H), both lateral edges (54) and (54) of the extension (49) are disposed inwardly of the lateral edges (55) and (55) of the valve element (18). ing. For this reason, the fall of an EGR rate is prevented.
The reason is estimated as follows.
As illustrated in FIG. 2 (H), both lateral edges (54) and (54) of the extension (49) are disposed more inward than the lateral edges (55) and (55) of the valve element (18). Therefore, the valve body (18) is moved until the both lateral edges (55) (55) of the valve body (18) are located rearward of the valve opening stopper (50) and the valve body restraining portion (51). Even if there is room for twisting and the gas pressure distribution of the EGR gas (15) received by the valve body (18) is not uniform left and right, the valve body (18) opens smoothly while twisting, and the EGR rate decreases. Is prevented.
As shown in FIG. 2 (G), a solid content falling space (57) is formed below the lower valve body portion (53) in the introduction passage gas inlet (11) of the EGR gas introduction passage (6). ing. For this reason, since the solid content such as carbon that has reached the lower valve body portion (53) falls downward through the solid content drop space (57), the solid content is caught in the reed valve (17). Can be prevented.
The intake distribution passage wall (69), the intake introduction pipe (7), the passage wall of the EGR gas introduction passage (6), the downward rectifying plate (41), its extension (49), and the upward rectifying plate (43) are a series of This is a cast integrated product.

The configuration of the EGR gas cooling device is as follows.
As shown in FIG. 5, the cylinder head (2) is provided with an in-head EGR passage (80) that passes through the water-cooling jacket. A connecting pipe (94) is attached to the side surface of the cylinder head (2) in front of the intake distribution passage (3), and the EGR cooler (4) is connected to the EGR passage (80) in the head via the connecting pipe (94). The EGR gas (15) is introduced into the tank.
As shown in FIG. 5, a cooler jacket (81) is formed in the EGR cooler (4), a valve cooling water passage (79) is formed in the EGR valve case (5), and the cooler jacket (81) and the valve cooling are formed. The water channel (79) is connected in series via the cooling water relay pipe (83). As shown in FIG. 6, the cooler jacket inlet (84) of the cooler jacket (81) communicates with the cylinder jacket outlet (86) via the cooling water inlet pipe (85). The cooler jacket outlet (87) of the cooler jacket (81) communicates with the water channel inlet (88) of the valve cooling water channel (82) via the cooling water relay pipe (83). The water passage outlet (89) of the valve cooling water passage (82) communicates with the passage inlet (91) of the cooling water suction passage (not shown) via the cooling water outlet pipe (90). A passage outlet (not shown) of the cooling water suction passage communicates with a suction port (not shown) of the water pump (63). The cooling water in the cylinder jacket is cooled by the suction force of the water pump (63), the cylinder jacket outlet (86), the cooler jacket (81), the valve cooling water passage (82), the cooling water outlet pipe (90), and the cooling water suction passage. Are sequentially sucked into the water pump (63), merged with the other cooling water, pumped to the radiator (not shown), and returned to the cylinder jacket again.

  As shown in FIGS. 1 (A) and 5, an out-head EGR passage (92) passing outside the cylinder head (2) is led out from the exhaust merging passage (67), and downstream of the out-head EGR passage (92). The EGR cooler (4) is disposed in the EGR cooler (4) so that EGR gas is introduced into the EGR cooler (4) from both the in-head EGR passage (80) and the outside-head EGR passage (92).

  As shown in FIGS. 6 to 8, an EGR passage (92) outside the head is disposed behind the engine cooling fan (93), and the engine cooling caused by the engine cooling fan (93) is caused in the EGR passage outside the head (92). The wind blows. As shown in FIG. 8, when viewed in a direction parallel to the installation direction of the crankshaft (1), the EGR passage (92) outside the head is slightly shifted from the position overlapping the engine cooling fan (93). Since the engine cooling air blowing area is larger than the locus of the outer periphery of the engine cooling fan (93), the engine cooling air blows against the head outside EGR passage (92).

1A and 1B are diagrams illustrating a multi-cylinder engine according to an embodiment of the present invention. FIG. 1A is a partially longitudinal side view of an intake distribution passage and its periphery, and FIG. 1B is a cross-sectional view taken along line BB in FIG. It is line sectional drawing. FIG. 2A is a front view of an intake air distribution passage wall, FIG. 2B is a front view of a plate member with a valve body, and FIG. 2C is a view illustrating a multi-cylinder engine according to an embodiment of the present invention. Front view of plate with valve opening, Fig. 2 (D) is a longitudinal side view of the stacked gasket, Fig. 2 (E) is a cross-sectional view taken along the line EE of Fig. 2 (C), and Fig. 2 (F) is a stack. Fig. 2 (G) is a longitudinal side view of the vicinity of the reed valve, Fig. 2 (H) is an introduction passage gas inlet of the EGR gas introduction passage, a plate member with a valve body, and a valve case gas outlet. It is the front view which piled up the upper opening edge part. 3A and 3B are views for explaining an intake distribution passage wall used in the multi-cylinder engine according to the embodiment of the present invention, in which FIG. 3A is a side view, FIG. 3B is a plan view, and FIG. 3 (D) is a rear view, and FIG. 3 (E) is a cross-sectional view taken along the line EE of FIG. 3 (A). FIG. 4 is a side view of the intake distribution passage wall of FIG. 3 as viewed from the cylinder head side. It is a figure explaining the multicylinder engine which concerns on embodiment of this invention, and is a top view of a cylinder head and its peripheral components. 1 is a side view of a multi-cylinder engine according to an embodiment of the present invention. 1 is a plan view of a multi-cylinder engine according to an embodiment of the present invention. 1 is a front view of a multi-cylinder engine according to an embodiment of the present invention.

Explanation of symbols

(2) Cylinder head
(3) Intake distribution passage
(5) EGR valve case
(6) EGR gas introduction passage
(7) Intake inlet pipe
(10) Valve case gas outlet
(11) Inlet passage gas inlet
(12) Introduction passage gas outlet
(13) EGR gas inlet
(14) Inhalation
(15) EGR gas
(16) Intake port
(17) Reed valve
(39) Current plate
(40) Upper wall
(41) Downward current plate
(42) Lower wall
(43) Upward current plate
(44) Upper section passage
(45) Lower section passage
(46) Each section passage
(47) Lower opening
(48) Upper opening

Claims (1)

The installation direction of the crankshaft (1) is the front-rear direction, and the width direction of the cylinder head (2) perpendicular to the installation direction of the crankshaft (1) is the lateral direction.
An intake distribution passage (3) is provided on the lateral surface of the cylinder head (2), and an EGR valve case (5), an EGR gas introduction passage (6), and an intake introduction pipe are sequentially arranged above the intake distribution passage (3) from the front. (7) is disposed, the introduction gas inlet (11) of the EGR gas introduction passage (6) is communicated with the valve case gas outlet (10) of the EGR valve case (5), and the EGR gas introduction passage (6) The introduction passage gas outlet (12) communicates with the intake introduction pipe (7) on the front side of the peripheral wall of the intake introduction pipe (7).
EGR gas (15) flowing from the front side of the peripheral wall of the intake air introduction pipe (7) is mixed into the intake air (14) introduced along the axial length direction of the intake air introduction pipe (7), and this EGR gas (15) is mixed. In the multi-cylinder engine in which the intake air (14) is distributed to the intake ports (16) and (16) of each cylinder in the intake air distribution passage (3),
Rectification in which the EGR gas introduction passage (6) is directed in the front-rear direction downstream of the reed valve (17) for preventing the backflow of the EGR gas (15) from the EGR gas introduction passage (6) to the EGR valve case (5) A plate (39), and the EGR gas (15) is guided to the intake air introduction pipe (7) while being rectified in the straight line direction along the rectifying plate (39) .
The rectifying plate (39) includes a plurality of downward rectifying plates (41) protruding downward from the upper wall (40) of the EGR gas introduction passage (6), and the lower wall (42) of the EGR gas introduction passage (6). And a plurality of upward rectifying plates (43) protruding upward from
Each section passage (46) comprising an upper section passage (44) sectioned by the downward rectifying plate (41) and a lower section passage (45) sectioned by the upward rectifying plate (43) is divided into an upper section passage (44). ) And the upper opening (48) of the lower section passage (45) .
A multi-cylinder engine characterized in that a downward rectifying plate (41) protrudes toward the lower section passage (45) and an upward rectifying plate (43) protrudes toward the upper section passage (44).

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