Upper structure of the engine

Abstract

To suppress the breakage of a fuel rail during vehicle collision while improving the maintainability of an engine.SOLUTION: An upper structure for an engine includes a head cover 4 having a recessed part 41 extending in a cylinder row direction and recessed toward the lower side and a protruded parts 42 provided on both sides of the recessed part 41, a fuel rail 51 arranged on the upper side of the head cover 4 and at the position of the recessed part 41 while extending in the cylinder row direction, a fuel pipe 52 for supplying fuel to the fuel rail 51, and a connection part connecting the fuel pipe 52 and the fuel rail 51, the connection part connecting the fuel pipe 52 to the fuel rail 51 from the upper side, and located at a position of overlap with an angular portion 43 between the recessed part 41 and the protruded part 42 in view from the upper side.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The technology disclosed herein belongs to the technical field related to the upper structure of an engine.

Background Art

[0002] In recent years, engines generally have a plurality of cylinders. The engine has a fuel rail for supplying fuel to each of the plurality of cylinders. In an engine of the type that injects fuel from above the cylinders, the fuel rail is provided in the upper part of the engine in order to make the distance between the fuel rail and each injector as short as possible.

[0003] For example, Patent Document 1 discloses a configuration in which a fuel rail is arranged above the engine and on the intake side, and each fuel rail is connected to each injector provided corresponding to each cylinder by a fuel supply pipe.

[0004] In Patent Document 1, the connection portion between the fuel pipe (guide pipe) that guides the fuel pumped from the fuel pump to the fuel rail and the fuel rail is provided below the fuel rail.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, as in Patent Document 1, when the connection part between the fuel rail and the fuel pipe is located below the fuel rail, the visibility of the connection part is reduced, and it becomes difficult to insert tools during the connection work. Therefore, from the viewpoint of maintainability, it is preferable that the connection part is provided above the fuel rail. However, when the connection part is provided above the fuel rail, in the event of a vehicle collision, the bonnet, cowl, tower bar, engine cover, dash panel, etc. may be deformed and a load may be applied to the connection part from above. When a load is applied to the connection part, a load may be applied to the fuel rail via the connection part, and the fuel rail may be damaged.

[0007] The technology disclosed herein has been made in view of such points, and its object is to improve the maintainability of the engine and suppress the fuel rail from being damaged during a vehicle collision.

Means for Solving the Problems

[0008] In order to solve the above problems, in the technology disclosed herein, for the upper structure of an engine in which a plurality of cylinders are arranged in series, a cylinder head cover disposed above the cylinder head of the engine, the cylinder head cover having a recess extending along the cylinder row direction and recessed downward, and convex portions 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 extending along the cylinder row direction at the position of the recess; a fuel pipe extending so as to straddle the convex portion and supplying fuel to the fuel rail; and a connection portion connecting the fuel pipe and the fuel rail, wherein the connection portion connects the fuel pipe to the fuel rail from above and is located at a position overlapping the corner between the recess and the convex portion when viewed from above.

[0009] According to this configuration, since the connection part connects the fuel pipe from above the fuel rail, it is located above the fuel rail. As a result, the visibility of the connection part is improved, and it becomes easier to place tools during the connection work, so the maintainability of the engine is improved.

[0010] Also, since the connection part is arranged at a position overlapping with the corner part between the concave part and the convex part in the cylinder head cover when viewed from above, a corner part is located directly below the connection part. When a vehicle collides, when a load is applied to the connection part from above due to deformation of the bonnet or the like, the connection part interferes with the corner part. Since the corner part has relatively high rigidity, it is difficult to deform even if the connection part interferes. Thereby, it is possible to suppress the relative displacement of the connection part with respect to the fuel rail. As a result, it is possible to suppress the fuel rail from being damaged.

[0011] Therefore, it is possible to improve the maintainability of the engine and suppress the fuel rail from being damaged during a vehicle collision.

[0012] In one embodiment of the upper structure of the engine, the cylinder head cover has a rib that extends to include the corner part at a portion on the cylinder head side of the convex part, and the connection part is located above the rib.

[0013] According to this configuration, since the rigidity of the corner part is improved by the rib, it is possible to more effectively suppress the cylinder head cover from deforming when the connection part and the cylinder head cover interfere with each other. Thereby, it is possible to more effectively suppress the fuel rail from being damaged.

[0014] In the above embodiment, the engine may be vertically installed in the engine room such that the cylinder row direction is the vehicle front-rear direction, and the rib may be located on the vehicle front side of the central position in the cylinder row direction of the connection part when viewed from the outside in the vehicle width direction.

[0015] That is, when the engine is longitudinally mounted, the engine moves backward during a frontal vehicle collision. At this time, when the connection part and the vehicle component buffer, an oblique load directed forward and downward is input to the connection part. Due to this load, the connection part tends to move obliquely forward and downward. If the rib is located slightly in front of the connection part as in the above configuration, the rib can appropriately receive the load of the connection part. Thereby, it is possible to more effectively suppress the fuel rail from being damaged.

[0016] In the upper structure of the engine, the cylinder head cover may have a protruding portion protruding upward at a portion below the connection portion in the convex portion.

[0017] According to this configuration, during a vehicle collision, by interfering the connection part and the protruding portion, the displacement of the connection part can be more effectively suppressed. Thereby, it is possible to more effectively suppress the fuel rail from being damaged.

[0018] In the upper structure of the engine, the connection part may include a flare nut, and the distance between the facing surfaces in the outer shape of the flare nut is larger than the outer diameter of the fuel pipe.

[0019] According to this configuration, the connection part can be made to approach the corner as much as possible, and the displacement of the connection part can be more effectively suppressed. In addition, the rigidity of the connection part itself can be improved, and the deformation of the connection part can be suppressed. Thereby, it is possible to more effectively suppress the fuel rail from being damaged.

[0020] In the upper structure of the engine, the cylinder head cover may be made of an aluminum alloy.

[0021] According to this configuration, the rigidity of the cylinder head cover can be made as high as possible, and deformation of the cylinder head cover can be suppressed. Thereby, displacement of the connecting portion can be more effectively suppressed, and breakage of the fuel rail can be more effectively suppressed.

Advantages of the Invention

[0022] As described above, according to the technology disclosed herein, the maintainability of the engine can be improved, and breakage of the fuel rail during a vehicle collision can be suppressed.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0024] Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. In the following description, front, rear, left, right, up, and down with respect to the vehicle are simply referred to as front, rear, left, right, up, and down, respectively. The left-right direction means that the left side when viewed from the rear side toward the front side is the left, and the right side is the right.

[0025] FIG. 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 in which six cylinders are arranged in series. The engine 1 is vertically installed in the engine room so that the cylinder row direction is the front-rear direction. In the state where the engine 1 is arranged in the engine room, the left side is the intake side and the right side is the exhaust side.

[0026] The engine 1 has a cylinder head 3 having an intake port 3a and a cylinder head cover 4 (hereinafter referred to as the head cover 4) disposed above the cylinder head 3. The head cover 4 is fixed to the cylinder head 3 with a plurality of bolts. The head cover 4 is made of an aluminum alloy.

[0027] As shown in FIGS. 1 to 3, the head cover 4 has a recess 41 that extends in the front-rear direction and is recessed downward at the center in the left-right direction. The head cover 4 has a pair of convex portions 42 provided adjacent to the recess 41 on both the left and right sides of the recess 41 and extending along the cylinder row direction. The recess 41 is located above each cylinder. An intake camshaft (not shown) for opening and closing the intake valve is disposed below the left convex portion 42, and an exhaust camshaft (not shown) for opening and closing the exhaust valve is disposed below the right convex portion 42.

[0028] As shown in FIG. 3, the recess 41 and the pair of convex portions 42 are continuously formed. Specifically, the head cover 4 has a pair of outer wall portions 4a located on the outer side in the left-right direction and extending in the up-down direction, a pair of inner wall portions 4b facing the outer wall portions 4a in the left-right direction and extending in the up-down 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 the lower wall portion 4d. The convex portion 42 is composed of the outer wall portion 4a, the inner wall portion 4b, and the upper wall portion 4c. In FIG. 3, only the left outer wall portion 4a is shown, and the right outer wall portion 4a is omitted from the illustration.

[0029] 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 the fuel pumped from a 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, in a state where 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. That is, the lower half of the fuel rail 51 is located within the recess 41, while the upper half protrudes from the recess 41. As shown in Fig. 1, a fuel pressure sensor 59 for detecting the fuel pressure is provided at the front portion of the fuel rail 51. A wiring (not shown) is connected to the fuel pressure sensor 59.

[0030] 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, then extends upward through the left side of the cylinder head 3 and the head cover 4, and then extends so as to straddle the convex portion 42 of the head cover 4 from above. As shown in Figs. 2 and 3, the fuel pipe 52 extends obliquely downward toward the right side above the head cover 4.

[0031] As shown in FIGS. 2 and 3, the fuel rail 51 and the fuel pipe 52 are connected by a flare nut 53. Specifically, an inlet portion 51a for allowing fuel to flow into the rail is provided at the rear portion of the fuel rail 51, and the inlet portion 51a and the end portion of the fuel pipe 52 opposite to the fuel pump 5 are connected by the flare nut 53. Since the inlet portion 51a is provided so as to obliquely extend upward toward the left side, the flare nut 53 connects the fuel pipe 52 to the fuel rail 51 from above, more specifically, from obliquely above. The upper portion of the flare nut 53 is located above the upper top portion of the fuel rail 51 in a state of being attached to the inlet portion 51a. The distance between the opposing faces in the outer shape of the flare nut 53 is larger than the outer diameter of the fuel pipe 52. Also, the distance between the opposing faces in the outer shape of the flare nut 53 is larger than the outer diameter of the fuel rail 51. The flare nut 53 is made of metal, specifically iron. The inlet portion 51a and the flare nut 53 constitute a connecting portion.

[0032] As shown in FIGS. 3 and 4, the flare nut 53 is arranged at a vertical distance from the head cover 4. This makes it easier to place tools during the attachment operation of the flare nut 53.

[0033] As shown in FIG. 1, the flare nut 53 is located at a position overlapping with the corner portion 43 between the concave portion 41 and the convex portion 42 on the left side when viewed from above. More specifically, as shown in FIG. 3, the flare nut 53 is located directly above the corner portion 43 between the inner side wall portion 4b on the left side of the concave portion 41 and the upper wall portion 4c of the convex portion 42 on the left side.

[0034] As shown in FIGS. 2 and 4, a recessed portion 43a that is recessed downward is provided at a position slightly behind the flare nut 53 at the corner portion 43, more specifically, at the same front-rear position as the rear half portion of the flare nut 53 at the corner portion 43. This recessed portion 43a is a portion for facilitating the operation of tools when connecting the fuel rail 51 (strictly speaking, the inlet portion 51a) and the fuel pipe 52 by the flare nut 53.

[0035] As shown in FIGS. 3 and 4, a rib 44 that extends to include a corner portion 43 is provided in a lower portion (on the side of the cylinder head 3) of the left convex portion 42. The rib 44 extends along the inner wall portion 4b, the upper wall portion 4c, and the outer wall portion 4a. The rib 44 is provided at a position that vertically overlaps with the flare nut 53. More specifically, when viewed from the outside in the vehicle width direction, specifically from the left side, the rib 44 is located in front of the center position in the front-rear direction of the flare nut 53 and vertically overlaps with the front half portion of the flare nut 53. Further, the rib 44 is provided adjacent to the recessed portion 43a in the front-rear direction. Note that the rib 44 may be provided not only at the position below the flare nut 53 but also at other portions in the lower portion of the convex portion 42.

[0036] Here, when the fuel rail 51 is arranged above the head cover 4 and the flare nut 53 is arranged so that the fuel pipe 52 is connected from above the fuel rail 51 as in the present embodiment, the visibility of the flare nut 53 is improved and it becomes easier to arrange a tool when attaching and detaching the flare nut 53. As a result, the maintainability of the engine 1 is improved. However, when the flare nut 53 is arranged above the head cover 4, there is a risk that the bonnet or the cowl panel may be deformed and interfere with the flare nut 53 during a collision, particularly during 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, and the fuel rail 51 may be damaged.

[0037] In contrast, in the present embodiment, the flare nut 53 that constitutes the connection portion between the fuel rail 51 and the fuel pipe 52 is arranged at a position overlapping with the corner portion 43 between the concave portion 41 and the convex portion 42 when viewed from above. Thereby, during 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 portion 43. Since the corner portion 43 has relatively high rigidity, it is difficult to deform even if the flare nut 53 interferes. Thereby, it is possible to suppress the relative displacement of the flare nut 53 with respect to the fuel rail 51. As a result, it is possible to suppress the fuel rail 51 from being damaged.

[0038] Also, by arranging the flare nut 53 above the corner portion 43, the gap between the flare nut 53 and the head cover 4 can be made smaller compared to the case where the flare nut 53 is arranged on the left or right side of the corner portion 43. Thereby, the displacement amount of the flare nut 53 can be made as small as possible, and it is possible to suppress the fuel rail 51 from being damaged.

[0039] Further, in the present embodiment, the head cover 4 has a rib 44 that extends to include the corner portion 43 at the portion on the cylinder head 3 side of the convex portion 42, and the flare nut 53 is located above the rib 44. Due to this rib 44, the rigidity of the corner portion 43 is improved, so that when the flare nut 53 and the head cover 4 interfere with each other, it is possible to more effectively suppress the deformation of the head cover 4. Thereby, the displacement amount of the flare nut 53 can be suppressed as much as possible, and it is possible to more effectively suppress the fuel rail 51 from being damaged.

[0040] In particular, in the present embodiment, the rib 44 is positioned in front of the center in the front-rear direction of the flare nut 53 when viewed from the left side. That is, during a frontal collision, the engine moves backward. At this time, when the flare nut 53 and the bonnet or the like buffer, an oblique load directed forward and downward is input to the flare nut 53. Due to this load, the flare nut 53 tends to move obliquely forward and downward. If the rib 44 is positioned slightly in front of the flare nut 53, when the flare nut 53 interferes with the corner portion 43, the rib 44 is likely to be positioned at the interference position. Thereby, the load on the rib 44 can be appropriately received. As a result, it is possible to more effectively suppress the fuel rail 51 from being damaged.

[0041] Also, in the present embodiment, the distance between the opposing surfaces in the outer shape of the flare nut 53 is larger than the outer diameter of the fuel pipe 52. Thereby, the gap between the flare nut 53 and the corner portion 43 can be made as small as possible, and the displacement amount of the flare nut 53 can be suppressed as much as possible. 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, it is possible to more effectively suppress the fuel rail 51 from being damaged.

[0042] Also, in the present embodiment, the lower half portion of the fuel rail 51 is positioned below the upper wall portion 4c, and the distance between the opposing surfaces in the outer shape of the flare nut 53 is larger than the outer diameter of the fuel rail 51. Thereby, even if the flare nut 53 is displaced and abuts against the corner portion 43, the upper portion of the flare nut 53 is positioned above the fuel rail 51. As a result, it is possible to suppress the bonnet or the like from directly interfering with the fuel rail 51, and it is possible to more effectively suppress the fuel rail 51 from being damaged.

[0043] Also, in the present embodiment, the upper half of the fuel rail 51 is located above the upper wall portion 4c. As a result, while suppressing the protrusion amount of the fuel rail 51 from the upper wall portion 4c as much as possible, the inclination angle of the inlet portion 51a with respect to the horizontal plane can be made as shallow as possible. As a result, it is possible to suppress direct interference between the bonnet or the like and the fuel rail 51, and to make the displacement amount of the flare nut 53 as small as possible. That is, if the protrusion amount 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 increases, so that the gap between the flare nut 53 and the convex portion 42 becomes large, and the displacement amount of the flare nut 53 during a frontal collision becomes large. In addition, if the inclination angle of the inlet portion 51a with respect to the horizontal plane increases, there is a possibility that a load is applied in the shearing direction of the fuel rail 51 via the inlet portion 51a. On the other hand, if the protrusion amount of the fuel rail 51 with respect to the upper wall portion 4c is increased, there is a possibility that the bonnet or the like directly interferes with the fuel rail 51 during a frontal collision. Therefore, if the upper half of the fuel rail 51 is positioned above the upper wall portion 4c, it is possible to more effectively suppress damage to the fuel rail 51 during a frontal collision.

[0044] Also, in the present embodiment, the head cover 4 is made of an aluminum alloy. Thereby, the rigidity of the head cover 4 can be made as high as possible, and when the head cover 4 and the flare nut 53 interfere with each other, deformation of the head cover 4 can be suppressed. Thereby, the displacement of the flare nut 53 can be more effectively suppressed, and damage to the fuel rail 51 can be more effectively suppressed.

[0045] (Modification example) Figs. 5 and 6 show a modified example of the upper structure of the engine 1. In this modified example, the head cover 4 has a protruding portion 45 that protrudes upward at the lower portion of the flare nut 53 in the convex portion 42. The protruding portion 45 may be integrally formed 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, it can be removed during maintenance, which is advantageous in terms of maintainability.

[0046] As shown in Fig. 5, the protruding portion 45 is provided along the corner portion 43 at the lower portion of the flare nut 53 in the corner portion 43. The portion of the protruding portion 45 opposite to the corner portion 43 is an inclined surface substantially parallel to the lower surface of the flare nut 53.

[0047] As shown in Fig. 6, the protruding portion 45 is provided at a position overlapping the rib 44 in the vertical direction. A protrusion 45a that protrudes upward is formed at the front end portion of the protruding portion 45.

[0048] In this way, by forming the protruding portion 45, the displacement amount of the flare nut 53 can be more effectively suppressed by causing interference between the flare nut 53 and the protruding portion 45 during a collision. Thereby, it is possible to suppress the fuel rail 51 from being damaged.

[0049] Also, by forming the protrusion 45a at the front end portion of the protruding portion 45, when the flare nut 53 is displaced forward and downward during a frontal collision, the displacement of the flare nut 53 toward the front side can be suppressed as much as possible by causing interference between the protrusion 45a and the flare nut 53. Thereby, it is possible to more effectively suppress the fuel rail 51 from being damaged.

[0050] The technology disclosed herein is not limited to the foregoing embodiments, and substitutions are possible without departing from the gist of the claims.

[0051] For example, in the above-described embodiment, the rib 44 was positioned in front of the center in the front-rear direction of the flare nut 53 when viewed from the left side. However, the rib 44 may be positioned at the center in the direction of the flare nut 53 when viewed from the left side.

[0052] Also, in the above-described embodiment, the engine 1 was vertically installed in the engine room, but it may be installed horizontally so that the cylinder row direction becomes the left-right direction. In this case, if the rib 44 is positioned at the center in the left-right direction of the flare nut 53 when viewed from the front-rear direction, it is advantageous for frontal collision.

[0053] Also, in the above-described embodiment, the engine 1 was an engine having six cylinders, but the number of cylinders may be seven or more, or five or less.

[0054] The above-described embodiments are merely examples, and the scope of the present disclosure should not be construed restrictively. The scope of the present disclosure is defined by the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present disclosure.

Industrial Applicability

[0055] The technology disclosed herein is useful as an upper structure of an engine in which a plurality of cylinders are arranged in series.

Explanation of Reference Numerals

[0056] 1 Engine 3 Cylinder Head 4 Cylinder Head Cover 41 Recess 42 Projection 43 Corner 44 Rib 45 Protrusion 51 Fuel Rail 52 Fuel Pipe 53 Flare Nut (Connection Part)

Claims

1. An upper structure of an engine in which a plurality of cylinders are arranged in series, A cylinder head cover disposed above the cylinder head of the engine, the cylinder head cover having a recess extending along the cylinder row direction and recessed downward, and convex portions 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 extending along the cylinder row direction at the position of the recess, A fuel pipe extending across the convex portion and supplying fuel to the fuel rail, A connection portion connecting the fuel pipe and the fuel rail, and The connection portion connects the fuel pipe to the fuel rail from above, and is located at a position overlapping with a corner between the recess and the convex portion when viewed from above. An upper structure of an engine characterized by this.

2. In the upper structure of the engine according to Claim 1, The cylinder head cover has a rib extending so as to include the corner at a portion of the convex portion on the cylinder head side, The connection portion is located above the rib. An upper structure of an engine characterized by this.

3. In the upper structure of the engine according to Claim 2, The engine is vertically installed in the engine room such that the cylinder row direction becomes the vehicle front-rear direction, The rib is located on the vehicle front side of a central position in the cylinder row direction of the connection portion when viewed from the outside in the vehicle width direction. An upper structure of an engine characterized by this.

4. In the upper structure of the engine according to any one of Claims 1 to 3, The cylinder head cover has a protruding portion protruding upward at a portion of the convex portion below the connection portion. An upper structure of an engine characterized by this.

5. In the upper structure of the engine according to any one of Claims 1 to 4, The connection portion includes a flare nut, The distance between the opposing surfaces in the outer shape of the flare nut is larger than the outer diameter of the fuel pipe. An upper structure of an engine characterized by this.

6. In the upper structure of the engine according to any one of Claims 1 to 5, The cylinder head cover is made of an aluminum alloy. An upper structure of an engine characterized by this.

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