JP5756776B2 - 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 suppress thermal deterioration of engine components disposed below an exhaust manifold.

Conventionally, as a multi-cylinder engine, there is one in which an exhaust manifold is attached to one side of a cylinder head and the exhaust manifold is covered with a heat insulating cover (see, for example, Patent Document 1).
According to this type of multi-cylinder engine, there is an advantage that the heat radiation from the exhaust manifold can be shielded by the heat shield cover.
However, this conventional technique has a problem because there is no means for blocking heat radiation downward from the exhaust manifold.

JP 2001-303951 A (see FIG. 3)

<< Problem >> When engine parts are arranged below the exhaust manifold, thermal deterioration cannot be suppressed.
Since there is no means for blocking heat radiation downward from the exhaust manifold, thermal degradation cannot be suppressed when engine parts are arranged below the exhaust manifold.

  The subject of this invention is providing the multicylinder engine which can suppress the thermal deterioration of the engine components arrange | positioned under the exhaust manifold.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIGS. 1 to 5, in a multi-cylinder engine in which an exhaust manifold (2) is attached to one side of the cylinder head (1) and the exhaust manifold (2) is covered with a heat shield cover (3).
As shown in FIGS. 1 to 5, the engine component (7) is disposed below the exhaust manifold (2), and the exhaust outlet pipe (9) is connected to the combined exhaust outlet (8) of the exhaust manifold (2). In doing so,
Cover the lower side of the exhaust manifold (2) with the lower heat shield cover plate (5), and extend the lower heat shield cover plate (5) diagonally downward from the lateral outer edge (5a) on the side opposite to the cylinder head. The heat shield cover plate (10) is led out, and the extended heat shield cover plate (10) is interposed between the exhaust lead pipe (9) and the engine component (7) ,
The upper side of the exhaust manifold (2) is covered with the upper heat shield cover plate (4), the front side and the rear side of the exhaust manifold (2) are covered with the front and rear heat shield cover plates (11), (12), and the exhaust manifold (2 ) Cover the lateral outer side with the lateral outer heat shield cover plate (6),
The lateral outer edge (5a) of the lower heat shield cover plate (5) and the lower edge (6a) of the lateral outer heat shield cover plate (6) are lateral outer lower gaps (6b) between them. )
A combined exhaust outlet (8) is provided at the top of the exhaust manifold (2), and the combined exhaust outlet (8) protrudes upward from the notch (4a) of the upper heat shield cover plate (4).
The combined exhaust outlet (8) and the upper heat shield cover plate (4) are separated by an upper gap (4b) along the outer peripheral surface of the combined exhaust outlet (8) and the inner periphery of the notch (4a),
An outlet flange (8a) is arranged on the laterally outer side of the combined exhaust outlet part (8), and this outlet flange (8a) is located on the laterally outer side of the upper gap (4b) and the cylinder head cover with the flange surface on top of the cylinder head (1). (15) Along the horizontal peripheral wall, orient in the vertical direction, connect the exhaust outlet pipe (9) to the outlet flange (8a),
A multi-cylinder engine having an exhaust sensor (13) attached to an exhaust outlet pipe (9).

(Invention of Claim 1)
The invention according to claim 1 has the following effects.
<Effect> It is possible to suppress the thermal deterioration of the engine component disposed below the exhaust manifold.
As shown in FIGS. 1 to 5, the lower side of the exhaust manifold (2) is covered with the lower heat shield cover plate (5), and the lateral outer edge of the lower heat shield cover plate (5) on the side opposite to the cylinder head The extended heat shield cover plate (10) is led out from the portion (5a) obliquely downward laterally outside, and the extended heat shield cover plate (10) is interposed between the exhaust lead pipe (9) and the engine component (7). Therefore, the heat radiation from the exhaust manifold (2) to the engine part (7) is shielded by the lower heat shield cover plate (5), and the heat radiation from the exhaust outlet pipe (9) to the engine part (7) is extended heat shield. It is possible to suppress thermal deterioration of the engine component (7) which is shielded by the cover plate (10) and is arranged below the exhaust manifold (2).

<Effect> It is possible to suppress the thermal deterioration of the engine component disposed below the exhaust manifold.
As illustrated in FIGS. 1 to 3, the lateral outer edge (5a) of the lower heat shield cover plate (5) and the lower edge (6a) of the lateral outer heat shield cover plate (6) Therefore, the heat of the lateral outer heat shield cover plate (6) is not transmitted to the lower heat shield cover plate (5). Further, the merged exhaust outlet portion (8) and the upper heat shield cover plate (4) are separated by an upper gap (4b) along the outer peripheral surface of the merged exhaust outlet portion (8) and the inner periphery of the notch (4a). Therefore, the heated air in the heat shield cover (3) is discharged from the upper gap (4b) to the upper side of the upper heat shield cover plate (4) by convection, and the heat shield cover (3) has a laterally lower side. Outside air is introduced from the side gap (6b), and the lower heat shield cover plate (5) is cooled. For this reason, the temperature of the lower heat shield cover plate (5) can be kept relatively low, and thermal deterioration of the engine component (7) disposed below the exhaust manifold (2) can be suppressed.
<Effect> The exhaust sensor can be easily attached and maintained.
As illustrated in FIGS. 1 to 5, since the exhaust sensor (13) is attached to the exhaust lead-out pipe (9), the exhaust sensor (13) can be attached and maintained without being interrupted by the heat shield cover (3). Can be easily performed.

(Invention of Claim 2 )
The invention according to claim 2 has the following effect in addition to the effect of the invention according to claim 1 .
<Effect> It is possible to suppress the thermal deterioration of the engine component disposed below the exhaust manifold.
As illustrated in FIGS. 1 to 3, the front and rear side edges (5 b) and (5 c) of the lower heat shield cover plate (5) and the lower side edges of the front and rear heat shield cover plates (11) and (12). (11a) and (12a) are separated by the front and rear lower gaps (11b) and (12b) between these edges (5b), (11a), (5c), and (12a). (11) The heat of (12) is not transmitted to the lower heat shield cover plate (5). Also, by the convection of heated air in the heat shield cover (3), outside air is introduced into the heat shield cover (3) from the front and rear lower gaps (11b) and (12b), and the lower heat shield cover plate (5). Is cooled. For this reason, the temperature of the lower heat shield cover plate (5) can be kept relatively low, and thermal deterioration of the engine component (7) disposed below the exhaust manifold (2) can be suppressed.

(Invention of Claim 3 )
The invention according to claim 3 has the following effect in addition to the effect of the invention according to claim 1 or claim 2 .
<Effect> A heat shield cover can be easily manufactured.
As illustrated in FIGS. 1 to 3, the lateral outer heat shield cover plate (6) and the front and rear heat shield cover plates (11) and (12) 4c) and the front and rear side edges (4d) and (4e), respectively, and are formed by bending downward, and the extended heat-insulating cover plate (10) is a lateral outer edge (5a) of the lower heat-insulating cover plate (5). The heat shield cover (3) can be easily manufactured by bending a sheet metal.

It is the perspective view which looked at the thermal insulation cover of the multicylinder engine which concerns on embodiment of this invention, and its peripheral part from diagonally behind. FIG. 2 is a side view of a heat insulating cover of the engine of FIG. 1 and its peripheral portion. FIG. 2 is a rear view of a heat shield cover of the engine of FIG. 1 and its peripheral part. It is the perspective view which looked at the engine of FIG. 1 from diagonally behind. It is the perspective view which looked at the engine of FIG. 1 from diagonally forward.

FIGS. 1 to 5 are diagrams for explaining a multi-cylinder engine according to an embodiment of the present invention. In this embodiment, a water-cooled vertical in-line multi-cylinder spark ignition engine will be described.
The configuration of this engine is as follows.
4 and 5, the cylinder head (1) is assembled to the upper part of the cylinder block (14), the cylinder head cover (15) is assembled to the upper part of the cylinder head (1), and the front part of the cylinder block (1) is assembled. The gear case (16) is assembled with the engine cooling fan (17), the flywheel (18) is disposed at the rear of the cylinder block (14), and the oil pan (19) is disposed below the cylinder block (14). It is assembled.

As shown in FIGS. 4 and 5, the exhaust manifold (2) is assembled on one side of the cylinder head (1), the exhaust manifold (2) is covered with a heat shield cover (3), and the side of the cylinder head (1) is covered. An intake manifold (20) is assembled on the other side.
A coil integrated side plug cap (23) is attached to the surge tank (21) of the intake manifold (20) via a stay (22), and the coil integrated side plug cap (23) is assembled to the cylinder head (1). A spark plug (not shown) is fitted.

As shown in FIGS. 1 to 5, the engine component (7) is disposed below the exhaust manifold (2), and the exhaust outlet pipe (9) is connected to the combined exhaust outlet portion (8) of the exhaust manifold (2). In doing so, it is as follows.
Cover the lower side of the exhaust manifold (2) with the lower heat shield cover plate (5), and extend the lower heat shield cover plate (5) diagonally downward from the lateral outer edge (5a) on the side opposite to the cylinder head. The heat shield cover plate (10) is led out, and the extended heat shield cover plate (10) is interposed between the exhaust lead pipe (9) and the engine component (7).
This engine component (7) is a starter motor (24).

As shown in FIGS. 1 to 5, the upper side of the exhaust manifold (2) is covered with an upper heat shield cover plate (4), and the front side and the rear side of the exhaust manifold (2) are front and rear side heat shield cover plates (11). (12) and the lateral outside of the exhaust manifold (2) is covered with a laterally outer heat shield cover plate (6).
As shown in FIGS. 1 to 3, the lateral outer edge (5a) of the lower heat shield cover plate (5) and the lower edge (6a) of the lateral outer heat shield cover plate (6) They are separated by a lateral outer lower gap (6b) that is in between.
A combined exhaust outlet portion (8) is provided at the upper portion of the exhaust manifold (2), and the combined exhaust outlet portion (8) protrudes upward from the notch (4a) of the upper heat shield cover plate (4).
The combined exhaust outlet portion (8) and the upper heat shield cover plate (4) are separated by an upper clearance (4b) along the outer peripheral surface of the combined exhaust outlet portion (8) and the inner peripheral edge of the notch (4a). .
An outlet flange (8a) is arranged on the laterally outer side of the combined exhaust outlet part (8), and this outlet flange (8a) is located on the laterally outer side of the upper gap (4b) and the cylinder head cover with the flange surface on top of the cylinder head (1). The exhaust outlet pipe (9) is connected to the outlet flange (8a) so as to be oriented in the vertical direction along the horizontal peripheral wall of (15).

  As shown in FIGS. 1 to 5, the outlet flange (8a) of the combined exhaust outlet portion (8) is directed laterally outward, and an exhaust outlet pipe (9) is connected to the outlet flange (8a). (9) extends horizontally outward from the outlet flange (8a), curves downward, and then extends vertically downward.

  As shown in FIGS. 1 to 3, the front and rear side edges (5b) and (5c) of the lower heat-insulating cover plate (5) and the lower side edge parts of the front and rear-side heat insulating cover plates (11) and (12) ( 11a) and 12a are separated by a front and rear lower gap 11b and 12b between these edges 5b 11a 5c 12a.

  As shown in FIGS. 1 to 3, the lateral outer heat shield cover plate (6) and the front and rear heat shield cover plates (11) and (12) are formed from the lateral outer edge (4 c) of the upper heat shield cover plate (4). ) And front and rear side edges (4d) and (4e), respectively, and the extended heat shield cover plate (10) is formed from the lateral outer edge (5a) of the lower heat shield cover plate (5). It is formed by bending the laterally outer side obliquely downward.

  As shown in FIGS. 1 to 5, an exhaust sensor (13) is attached to the exhaust outlet pipe (9). The exhaust sensor (13) is an oxygen sensor (25), and manages the air-fuel ratio of the air-fuel mixture by detecting the oxygen concentration in the exhaust gas in cooperation with the engine ECU (not shown).

(1) Cylinder head
(2) Exhaust manifold
(3) Heat shield cover
(4) Upper heat shield cover plate
(4a) Notch
(4b) Upper gap
(4c) Lateral outer edge
(4d) Front edge
(4e) Rear edge
(5) Lower heat shield cover plate
(5a) Lateral outer edge
(5b) Front edge
(5c) Rear edge
(6) Lateral outer heat shield cover plate
(6a) Lower edge
(6b) Horizontal outer bottom gap
(7) Engine parts
(8) Merged exhaust outlet
(9) Exhaust outlet pipe
(10) Extended heat shield cover plate
(11) Front heat shield cover plate
(11a) Lower edge
(11b) Front lower gap
(12) Rear heat shield cover plate
(12a) Lower edge
(12b) Rear lower gap
(13) Exhaust sensor

Claims (3)

In a multi-cylinder engine in which an exhaust manifold (2) is attached to one side of the cylinder head (1) and the exhaust manifold (2) is covered with a heat shield cover (3),
When placing the engine part (7) below the exhaust manifold (2) and connecting the exhaust outlet pipe (9) to the combined exhaust outlet (8) of the exhaust manifold (2),
Cover the lower side of the exhaust manifold (2) with the lower heat shield cover plate (5), and extend the lower heat shield cover plate (5) diagonally downward from the lateral outer edge (5a) on the side opposite to the cylinder head. The heat shield cover plate (10) is led out, and the extended heat shield cover plate (10) is interposed between the exhaust lead pipe (9) and the engine component (7) ,
The upper side of the exhaust manifold (2) is covered with the upper heat shield cover plate (4), the front side and the rear side of the exhaust manifold (2) are covered with the front and rear heat shield cover plates (11), (12), and the exhaust manifold (2 ) Cover the lateral outer side with the lateral outer heat shield cover plate (6),
The lateral outer edge (5a) of the lower heat shield cover plate (5) and the lower edge (6a) of the lateral outer heat shield cover plate (6) are lateral outer lower gaps (6b) between them. )
A combined exhaust outlet (8) is provided at the top of the exhaust manifold (2), and the combined exhaust outlet (8) protrudes upward from the notch (4a) of the upper heat shield cover plate (4).
The combined exhaust outlet (8) and the upper heat shield cover plate (4) are separated by an upper gap (4b) along the outer peripheral surface of the combined exhaust outlet (8) and the inner periphery of the notch (4a) ,
An outlet flange (8a) is arranged on the laterally outer side of the combined exhaust outlet part (8), and this outlet flange (8a) is located on the laterally outer side of the upper gap (4b) and the cylinder head cover with the flange surface on top of the cylinder head (1). (15) Along the horizontal peripheral wall, orient in the vertical direction, connect the exhaust outlet pipe (9) to the outlet flange (8a),
A multi-cylinder engine having an exhaust sensor (13) attached to an exhaust outlet pipe (9). The multi-cylinder engine according to claim 1 ,
The front and rear side edges (5b) and (5c) of the lower heat shield cover plate (5) and the lower edges (11a) and (12a) of the front and rear heat shield cover plates (11) and (12) A multi-cylinder engine characterized by being separated by front and rear lower gaps (11b) and (12b) between the edges (5b), (11a), (5c) and (12a). The multi-cylinder engine according to claim 1 or 2 ,
The lateral outer heat shield cover plate (6) and the front and rear heat shield cover plates (11) and (12) are the lateral outer edge portion (4c) and the front and rear side edge portion (4d) of the upper heat shield cover plate (4). 4e) and bent downward from each other,
The extended heat-insulating cover plate (10) is formed by bending the laterally outer edge (5a) of the lower heat-insulating cover plate (5) diagonally downward laterally outward.

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