JP7700630B2 - Engine superstructure - Google Patents

Description

The technology disclosed here belongs to the technical field of engine superstructures.

Nowadays, engines generally have multiple cylinders. The engine has a fuel rail to supply fuel to each of the multiple cylinders. In engines that inject fuel from above the cylinders, the fuel rail is installed in the upper part of the engine to minimize the distance between the fuel rail and each injector.

For example, Patent Document 1 discloses a configuration in which a fuel rail is placed above the engine on the intake side, and each injector provided for each cylinder is connected to the fuel rail by a fuel supply pipe.

In Patent Document 1, the connection between the fuel rail and the fuel pipe (guide pipe) that guides the fuel pumped from the fuel pump to the fuel rail is provided below the fuel rail.

JP 2019-132249 A

However, if the connection between the fuel rail and the fuel pipe is located below the fuel rail, as in Patent Document 1, the visibility of the connection is reduced and it is difficult to insert tools during the connection work. For this reason, from the viewpoint of maintainability, it is preferable that the connection is provided above the fuel rail. However, if the connection is provided above the fuel rail, there is a risk that the bonnet, cowl, tower bar, engine cover, dash panel, etc. will deform in the event of a vehicle collision, and a load will be applied from above to the connection. If a load is applied to the connection, the load will be applied to the fuel rail via the connection, and the fuel rail may be damaged.

The technology disclosed here has been developed in light of these issues, and its purpose is to improve engine maintainability and prevent damage to the fuel rail in the event of a vehicle collision.

In order to solve the above problem, the technology disclosed herein is directed to an upper structure of an engine with multiple cylinders arranged in series, and is configured to include a cylinder head cover disposed on the upper side of a cylinder head of the engine, the cylinder head cover having a recess extending along the cylinder row direction and recessed downward, and a protrusion disposed adjacent to the recess on both sides of the recess and extending along the cylinder row direction, a fuel rail disposed on the upper side of the cylinder head cover and at the position of the recess so as to extend along the cylinder row direction, a fuel pipe extending across the protrusion and supplying fuel to the fuel rail, and a connection portion connecting the fuel pipe and the fuel rail, the connection portion connecting the fuel pipe to the fuel rail from above, and positioned so as to overlap the corner between the recess and the protrusion when viewed from above.

With this configuration, the connection part is located above the fuel rail, as the fuel pipe is connected from above the fuel rail. This improves visibility of the connection part and makes it easier to position tools during connection work, improving engine maintainability.

In addition, when viewed from above, the connection portion is positioned so that it overlaps with the corner between the recess and protrusion of the cylinder head cover, and so the corner is located directly below the connection portion. When a load is applied to the connection portion from above due to deformation of the bonnet or the like during a vehicle collision, the connection portion interferes with the corner. Because the corner has a relatively high rigidity, it is difficult for it to deform even if the connection portion interferes. This makes it possible to suppress displacement of the connection portion relative to the fuel rail. As a result, it is possible to suppress damage to the fuel rail.

This improves engine maintainability and prevents damage to the fuel rail in the event of a vehicle collision.

In one embodiment of the engine upper structure, the cylinder head cover has a rib on the cylinder head side of the protrusion that extends to include the corner, and the connection portion is located above the rib.

With this configuration, the ribs increase the rigidity of the corners, so that deformation of the cylinder head cover can be more effectively prevented when the connection portion and the cylinder head cover interfere with each other. This makes it possible to more effectively prevent damage to the fuel rail.

In one embodiment, the engine may be arranged vertically in an engine room so that the cylinder row direction is in the vehicle front-rear direction, and the rib may be located forward of the center of the cylinder row direction at the connection portion when viewed from the outside in the vehicle width direction.

In other words, if the engine is mounted vertically, the engine will move backward in the event of a frontal collision. At this time, when the connection part and the vehicle part come into contact with each other, a diagonal load directed toward the front and downward is input to the connection part. This load causes the connection part to move diagonally toward the front and downward. If the rib is positioned slightly forward of the connection part as in the above configuration, the rib can appropriately bear the load of the connection part. This makes it possible to more effectively prevent damage to the fuel rail.

In the upper structure of the engine, the cylinder head cover may have a protrusion that protrudes upward from the lower portion of the connection portion of the protrusion.

With this configuration, in the event of a vehicle collision, the connection portion and the protrusion interfere with each other, so that the displacement of the connection portion can be more effectively suppressed. This makes it possible to more effectively suppress damage to the fuel rail.

In the engine upper structure, the connection portion may include a flare nut, and the distance between the opposing ends of the flare nut on its outer shape may be greater than the outer diameter of the fuel pipe.

With this configuration, the connection portion can be located as close as possible to the corner portion, and displacement of the connection portion can be more effectively suppressed. In addition, the rigidity of the connection portion itself can be improved, and deformation of the connection portion can be suppressed. This makes it possible to more effectively suppress damage to the fuel rail.

In the upper structure of the engine, the cylinder head cover may be made of an aluminum alloy.

This configuration makes it possible to maximize the rigidity of the cylinder head cover and suppress deformation of the cylinder head cover. This makes it possible to more effectively suppress displacement of the connection portion and more effectively suppress damage to the fuel rail.

As described above, the technology disclosed herein improves engine maintainability and prevents damage to the fuel rail in the event of a vehicle collision.

FIG. 1 is a plan view of an engine to which an upper structure according to an exemplary embodiment is applied. FIG. 2 is an enlarged perspective view of the periphery of the connection portion. FIG. 3 is a cross-sectional view taken along a plane corresponding to line III-III in FIG. FIG. 4 is a cross-sectional view taken along a plane corresponding to line IV-IV in FIG. FIG. 5 is a view equivalent to FIG. 3 of an upper structure according to a modified example. FIG. 6 is a view equivalent to FIG. 4 of an upper structure according to a modified example.

Below, an exemplary embodiment will be described in detail with reference to the drawings. In the following description, the front, rear, left, right, top, and bottom of the vehicle will simply be referred to as front, rear, left, right, top, and bottom, respectively. With respect to the left-right direction, the left side when looking from the rear to the front will be referred to as the left, and the right side will be referred to as the right.

Figure 1 shows an engine 1 to which the upper structure according to this embodiment is applied. This engine 1 is an in-line six-cylinder engine with six cylinders arranged in line. The engine 1 is placed vertically in the engine room so that the cylinders are aligned in the front-to-rear direction. When the engine 1 is placed in the engine room, the left side is the intake side and the right side is the exhaust side.

The engine 1 has a cylinder head 3 with an intake port 3a, and a cylinder head cover 4 (hereafter referred to as head cover 4) arranged on the upper side of the cylinder head 3. The head cover 4 is fixed onto the cylinder head 3 with multiple bolts. The head cover 4 is made of an aluminum alloy.

As shown in Figures 1 to 3, the head cover 4 has a recess 41 in the left-right center that extends in the front-rear direction and is recessed downward. The head cover 4 has a pair of protrusions 42 on both the left and right sides of the recess 41, which are adjacent to the recess 41 and extend along the cylinder row direction. The recesses 41 are located above each cylinder. An intake camshaft (not shown) for opening and closing the intake valve is disposed below the left protrusion 42, and an exhaust camshaft (not shown) for opening and closing the exhaust valve is disposed below the right protrusion 42.

As shown in FIG. 3, the recess 41 and the pair of protrusions 42 are formed continuously. Specifically, the head cover 4 has a pair of outer wall portions 4a located on the outside in the left-right direction and extending in the vertical direction, a pair of inner wall portions 4b facing the outer wall portions 4a in the left-right direction and extending in the vertical direction, a pair of upper wall portions 4c connecting the upper end portions of the outer wall portions 4a and the upper end portions of the inner wall portions 4b on the left and right sides, respectively, and a lower wall portion 4d connecting the lower end portions of the pair of inner wall portions 4b. The recess 41 is composed of a pair of inner wall portions 4b and a lower wall portion 4d. The protrusion portion 42 is composed of the outer wall portion 4a, the inner wall portion 4b, and the upper wall portion 4c. Note that FIG. 3 shows only the left outer wall portion 4a, and the right outer wall portion 4a is omitted from the illustration.

As shown in FIG. 1, a fuel rail 51 is disposed at the position of the recess 41 in the left-right direction so as to extend along the cylinder row direction. The fuel rail 51 is a fuel distribution pipe that distributes fuel pumped from the fuel pump 5 attached to the left side surface of the engine 1 to the injectors disposed for each cylinder. Although not shown, each injector is disposed in the recess 41 along the cylinder row direction. Both longitudinal ends of the fuel rail 51 are closed. The fuel rail 51 is supported by a bracket 41a disposed in the recess 41. As shown in FIG. 3, when the fuel rail 51 is supported by the bracket 41a, its lower half is located below the upper wall portion 4c of the head cover 4, while its upper half is located above the upper wall portion 4c. In other words, the lower half of the fuel rail 51 is located in the recess 41, while its upper half protrudes from the recess 41. As shown in FIG. 1, a fuel pressure sensor 59 that detects the pressure of the fuel is provided in the front portion of the fuel rail 51. Wiring (not shown) is connected to the fuel pressure sensor 59.

The fuel pump 5 and the fuel rail 51 are connected by a fuel pipe 52. The fuel pipe 52 extends upward from the fuel pump 5, passes through the left side of the cylinder head 3 and the head cover 4, and then extends upward so as to straddle the protrusion 42 of the head cover 4 from above. As shown in Figures 2 and 3, the fuel pipe 52 extends above the head cover 4, slanting downward toward the right side.

2 and 3, the fuel rail 51 and the fuel pipe 52 are connected by a flare nut 53. Specifically, the rear part of the fuel rail 51 is provided with an inlet 51a for allowing fuel to flow into the rail, and the inlet 51a and the end of the fuel pipe 52 opposite the fuel pump 5 are connected by a flare nut 53. Since the inlet 51a is provided to extend obliquely upward toward the left side, the flare nut 53 connects the fuel pipe 52 to the fuel rail 51 from above, more specifically, from the diagonally upward side. The upper part of the flare nut 53 is located above the top of the upper side of the fuel rail 51 when attached to the inlet 51a. The distance between the facing surfaces of the flare nut 53 in its outer shape is greater than the outer diameter of the fuel pipe 52. Also, the distance between the facing surfaces of the flare nut 53 in its outer shape is greater than the outer diameter of the fuel rail 51. The flare nut 53 is made of metal, more specifically, iron. The inlet portion 51a and the flare nut 53 form the connection portion.

As shown in Figures 3 and 4, the flare nut 53 is positioned vertically away from the head cover 4. This makes it easier to position tools when installing the flare nut 53.

As shown in FIG. 1, the flare nut 53 is located in a position overlapping the corner 43 between the recess 41 and the left protrusion 42 when viewed from above. More specifically, as shown in FIG. 3, the flare nut 53 is located directly above the corner 43 between the left inner wall 4b of the recess 41 and the upper wall 4c of the left protrusion 42.

2 and 4, a recess 43a is provided slightly behind the flare nut 53 at the corner 43, more specifically, at the same front-to-rear position as the rear half of the flare nut 53 at the corner 43, which is recessed downward. This recess 43a is provided to make it easier to operate tools when connecting the fuel rail 51 (strictly speaking, the inlet portion 51a) and the fuel pipe 52 with the flare nut 53.

3 and 4, a rib 44 is provided on the lower side (cylinder head 3 side) of the left protrusion 42, which extends to include the corner 43. The rib 44 extends along the inner wall 4b, the upper wall 4c, and the outer wall 4a. The rib 44 is provided at a position that overlaps with the flare nut 53 in the vertical direction. More specifically, the rib 44 is located forward of the center position of the flare nut 53 in the longitudinal direction when viewed from the outside in the vehicle width direction, specifically from the left side, and overlaps with the front half of the flare nut 53 in the vertical direction. The rib 44 is also provided adjacent to the recess 43a in the longitudinal direction. The rib 44 may be provided not only at the lower position of the flare nut 53 but also in other parts of the lower part of the protrusion 42.

Here, as in this embodiment, if the fuel rail 51 is disposed above the head cover 4 and the flare nut 53 is disposed so that the fuel pipe 52 is connected from above the fuel rail 51, the visibility of the flare nut 53 is improved and it is easy to place tools when attaching and detaching the flare nut 53. This improves the maintainability of the engine 1. However, if the flare nut 53 is disposed above the head cover 4, there is a risk that the bonnet or cowl panel may deform and interfere with the flare nut 53 in the event of a collision, particularly a frontal collision. If the bonnet or the like interferes with the flare nut 53, a load may be applied to the fuel rail 51 via the flare nut 53 and the inlet portion 51a, which may damage the fuel rail 51.

In contrast, in this embodiment, the flare nut 53 that forms the connection between the fuel rail 51 and the fuel pipe 52 is positioned so that it overlaps with the corner 43 between the recess 41 and the protrusion 42 when viewed from above. As a result, in the event of a frontal collision, when a load is applied to the flare nut 53 from above due to deformation of the bonnet or the like, the flare nut 53 interferes with the corner 43. Because the corner 43 has a relatively high rigidity, it is not easily deformed even if the flare nut 53 interferes. This makes it possible to suppress displacement of the flare nut 53 relative to the fuel rail 51. As a result, it is possible to suppress damage to the fuel rail 51.

In addition, by arranging the flare nut 53 above the corner 43, the gap between the flare nut 53 and the head cover 4 can be made smaller than when the flare nut 53 is arranged to the left or right of the corner 43. This makes it possible to minimize the amount of displacement of the flare nut 53, and to prevent damage to the fuel rail 51.

In addition, in this embodiment, the head cover 4 has a rib 44 that extends to include the corner 43 on the cylinder head 3 side of the protrusion 42, and the flare nut 53 is located above the rib 44. This rib 44 improves the rigidity of the corner 43, so that deformation of the head cover 4 can be more effectively prevented when the flare nut 53 and the head cover 4 interfere with each other. This makes it possible to minimize the amount of displacement of the flare nut 53, and more effectively prevent damage to the fuel rail 51.

In particular, in this embodiment, the rib 44 is located forward of the center position of the flare nut 53 in the front-to-rear direction when viewed from the left side. That is, in the event of a frontal collision, the engine moves backward. At this time, when the flare nut 53 and the bonnet or the like are buffered, a diagonal load toward the front and downward is input to the flare nut 53. This load causes the flare nut 53 to move diagonally toward the front and downward. If the rib 44 is located slightly forward of the flare nut 53, when the flare nut 53 interferes with the corner portion 43, the rib 44 is more likely to be located at the interference position. This allows the rib 44 to appropriately receive the load. As a result, damage to the fuel rail 51 can be more effectively suppressed.

In addition, in this embodiment, the distance between the opposing sides of the outer shape of the flare nut 53 is greater than the outer diameter of the fuel pipe 52. This makes it possible to minimize the gap between the flare nut 53 and the corner portion 43, and to minimize the amount of displacement of the flare nut 53. In addition, the rigidity of the flare nut 53 itself can be improved, and deformation of the flare nut 53 can be suppressed. As a result, damage to the fuel rail 51 can be more effectively suppressed.

In addition, in this embodiment, the lower half of the fuel rail 51 is located below the upper wall portion 4c, and the distance between the opposing sides of the flare nut 53 in its outer shape is greater than the outer diameter of the fuel rail 51. As a result, even if the flare nut 53 is displaced and comes into contact with the corner portion 43, the upper portion of the flare nut 53 is located above the fuel rail 51. As a result, it is possible to prevent the bonnet, etc. from directly interfering with the fuel rail 51, and it is possible to more effectively prevent damage to the fuel rail 51.

In addition, in this embodiment, the upper half of the fuel rail 51 is located above the upper wall portion 4c. This makes it possible to make the inclination angle of the inlet portion 51a with respect to the horizontal plane as shallow as possible while suppressing the amount of protrusion of the fuel rail 51 from the upper wall portion 4c as much as possible. As a result, it is possible to suppress direct interference between the bonnet, etc. and the fuel rail 51, and to make the displacement amount of the flare nut 53 as small as possible. That is, if the amount of protrusion of the fuel rail 51 with respect to the upper wall portion 4c is reduced, the inclination angle of the inlet portion 51a with respect to the horizontal plane becomes large, so that the gap between the flare nut 53 and the protruding portion 42 becomes large, and the displacement amount of the flare nut 53 at the time of a frontal collision becomes large. Also, if the inclination angle of the inlet portion 51a with respect to the horizontal plane becomes large, there is a risk that a load will be applied in the shear direction of the fuel rail 51 through the inlet portion 51a. On the other hand, if the amount of protrusion of the fuel rail 51 with respect to the upper wall portion 4c is increased, there is a risk that the bonnet, etc. will directly interfere with the fuel rail 51 at the time of a frontal collision. Therefore, if the upper half of the fuel rail 51 is positioned above the upper wall portion 4c, damage to the fuel rail 51 in the event of a frontal collision can be effectively prevented.

In addition, in this embodiment, the head cover 4 is made of an aluminum alloy. This increases the rigidity of the head cover 4 as much as possible, and suppresses deformation of the head cover 4 when the head cover 4 interferes with the flare nut 53. This more effectively suppresses displacement of the flare nut 53, and more effectively suppresses damage to the fuel rail 51.

(Modification)
5 and 6 show a modified example of the upper structure of the engine 1, in which the head cover 4 has a protruding portion 45 that protrudes upward from a portion of the convex portion 42 below the flare nut 53. The protruding portion 45 may be formed integrally with the head cover 4, or may be formed separately from the head cover 4. If the protruding portion 45 is formed separately from the head cover 4, the protruding portion 45 can be removed during maintenance, which is advantageous in terms of maintainability.

As shown in FIG. 5, the protrusion 45 is provided along the lower portion of the flare nut 53 at the corner 43. The portion of the protrusion 45 opposite the corner 43 forms an inclined surface that is approximately parallel to the lower surface of the flare nut 53.

As shown in FIG. 6, the protrusion 45 is provided at a position that overlaps with the rib 44 in the vertical direction. A protrusion 45a that protrudes upward is formed at the front end of the protrusion 45.

By forming the protrusion 45 in this way, the amount of displacement of the flare nut 53 can be more effectively suppressed by causing interference between the flare nut 53 and the protrusion 45 during a collision. This makes it possible to suppress damage to the fuel rail 51.

In addition, by forming a protrusion 45a at the front end of the protruding portion 45, when the flare nut 53 is displaced forward and downward during a frontal collision, the protrusion 45a interferes with the flare nut 53, thereby preventing the flare nut 53 from displacing forward as much as possible. This makes it possible to more effectively prevent damage to the fuel rail 51.

The technology disclosed herein is not limited to the above-described embodiments, and may be substituted without departing from the spirit of the claims.

For example, in the above-described embodiment, the rib 44 is located forward of the center position in the fore-and-aft direction of the flare nut 53 when viewed from the left side. However, the present invention is not limited to this, and the rib 44 may be located in the center position in the direction of the flare nut 53 when viewed from the left side.

In addition, in the above embodiment, the engine 1 was placed vertically in the engine room, but it may be placed horizontally so that the cylinder rows are aligned left-right. In this case, it is advantageous in the event of a frontal collision if the rib 44 is positioned in the center of the flare nut 53 in the left-right direction when viewed from the front-rear direction.

In addition, in the above embodiment, the engine 1 is an engine having six cylinders, but the number of cylinders may be seven or more, or five or less.

The above-described embodiments are merely examples and should not be interpreted as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and variations that fall within the scope of equivalence of the claims are within the scope of the present disclosure.

The technology disclosed here is useful as the upper structure of an engine with multiple cylinders arranged in series.

REFERENCE SIGNS LIST 1 Engine 3 Cylinder head 4 Cylinder head cover 41 Recess 42 Protrusion 43 Corner 44 Rib 45 Protrusion 51 Fuel rail 52 Fuel pipe 53 Flare nut (connection part)

Claims (6)

An upper structure of an engine having a plurality of cylinders arranged in series,
a cylinder head cover disposed on an upper side of a cylinder head of the engine, the cylinder head cover having a recess extending along a cylinder row direction and recessed downward, and protrusions provided adjacent to the recess on both sides of the recess and extending along the cylinder row direction;
a fuel rail disposed above the cylinder head cover and at the position of the recess so as to extend along the cylinder row direction;
a fuel pipe extending across the protruding portion and supplying fuel to the fuel rail;
a connection portion that connects the fuel pipe and the fuel rail,
an engine upper structure, characterized in that the connection portion connects the fuel pipe to the fuel rail from above and is located at a position overlapping a corner between the recessed portion and the protruding portion when viewed from above. The upper structure of the engine according to claim 1,
the cylinder head cover has a rib that extends to include the corner portion on a portion of the protrusion that faces the cylinder head,
An engine upper structure, characterized in that the connection portion is located above the rib. The upper structure of an engine according to claim 2,
The engine is disposed vertically in an engine room such that the cylinder row direction corresponds to the front-rear direction of the vehicle,
The upper structure of an engine, wherein the rib is located further forward of the vehicle than a center position of the connection portion in the cylinder row direction when viewed from the outside in the vehicle width direction. In the upper structure of the engine according to any one of claims 1 to 3,
13. An engine upper structure, comprising: a cylinder head cover having a protrusion that protrudes upward below the connecting portion of the convex portion. In the upper structure of the engine according to any one of claims 1 to 4,
The connection portion includes a flare nut,
a distance between opposing ends of the flare nut in its outer shape is greater than an outer diameter of the fuel pipe. In the upper structure of the engine according to any one of claims 1 to 5,
13. An engine upper structure, wherein the cylinder head cover is made of an aluminum alloy.