Oil supply port structure of engine

Abstract

This oil supply port structure, provided to a cylinder head cover (1) of an engine, is provided with: a cylindrical part (3) constituting an oil supply port (2) into which a nozzle (13) of an oil mug is inserted, the cylindrical part (3) having a filler cap which is detachably mounted to an upper end portion; a bottom wall part (6) formed integrally with the cylindrical part (3) so as to cover the lower end of the cylindrical part (3); an opening (8) formed at the lower side surface of the cylindrical part (3) along the bottom wall part (6); and a plate-shaped rib (11) raised upright from an upper surface (6a) of the bottom wall part (6). The bottom wall part (6) is provided so that oil droplets of lubricating oil scattered by a camshaft do not easily go into the oil supply port (2) when the filler cap is forgotten to be mounted. During oiling, the tip of the nozzle (13) of the oil mug abuts the rib (11), and is regulated to be at a height position separated from the upper surface (6a), so that excellent oiling performance can be obtained.

Description

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[0001] This invention relates to a fuel filler structure provided on the upper surface portion of an engine housing.

[0002] A fuel filler for replenishing lubricating oil is arranged on the upper surface portion of the engine housing, generally on the cylinder head cover, and a filler cap is detachably attached to the upper end thereof.

[0003] In such a fuel filler of an engine, if the engine is started with the filler cap left closed after refueling, the lubricating oil will scatter outside from the fuel filler.

[0004] Patent Document 1 discloses a configuration in which a shielding wall is attached adjacent to the lower end opening of a fuel filler that opens toward the internal space of the cylinder head cover in order to suppress such scattering of lubricating oil from the inside. This shielding wall is attached in a shape that hangs downward from the lower surface of the cylinder head cover so as to partition between the rotating camshaft and the lower end opening of the fuel filler.

[0005] However, a configuration in which such a shielding wall made of a separate part is attached to the cylinder head cover has a complicated structure and is not preferable. Also, since the shielding wall becomes large, it cannot be applied to a cylinder head cover with little space.

[0006] Japanese Patent Application Laid-Open No. 2020-122421

[0007] This invention is a fuel filler structure provided on the upper surface portion of an engine housing, comprising: a fuel filler into which the nozzle of an oil can is inserted, and a filler cap is detachably attached to the upper end thereof, and a cylindrical portion whose lower part is exposed to the space inside the housing; a bottom wall portion integrally formed with the cylindrical portion so as to cover the lower end of the cylindrical portion; an opening formed on the lower side surface of the cylindrical portion along the bottom wall portion; and a protrusion formed to project from the upper surface of the bottom wall portion or the inner wall surface of the cylindrical portion and supporting the tip of the nozzle of the oil can at a height position away from the upper surface.

[0008] In this configuration, the lower end of the cylindrical part that constitutes the fuel filler opening is covered by the bottom wall, so if the filler cap is forgotten to be installed, the scattering of lubricating oil from inside the housing is suppressed. Since the bottom wall is formed integrally with the cylindrical part, the structure is simple and no additional installation space is required.

[0009] Furthermore, when the nozzle of the oil jug is inserted into the fuel filler opening, the position of the nozzle tip of the oil jug is restricted by the protrusion to a position away from the bottom wall. Therefore, the nozzle tip is not covered by the bottom wall, resulting in good oiling performance.

[0010] A cross-sectional view along the longitudinal direction of the fuel filler port showing the fuel filler port structure of one embodiment. A cross-sectional view along line A-A in Figure 1. A cross-sectional view along line B-B in Figure 1. An explanatory diagram similar to Figure 1 when the nozzle of the oil jug is inserted.

[0011] Hereinafter, an embodiment of this invention will be described in detail with reference to the drawings. Figures 1 to 3 show the fuel filler port structure of an engine according to one embodiment. In this embodiment, for example, the fuel filler port structure is provided on the upper surface portion of a cylinder head cover 1, which is part of the housing of an in-line multi-cylinder engine. The cylinder head cover 1 is mounted on the upper surface of a cylinder head (not shown) and forms a space between itself and the cylinder head for housing, for example, a pair of camshafts. In the illustrated example, the entire cylinder head cover 1, including the fuel filler port structure, is integrally molded by, for example, injection molding of a hard synthetic resin material.

[0012] The cylinder head cover 1 includes a cylindrical portion 3 that constitutes an oil filler port 2 into which the nozzle of an oil jug is inserted during refueling. The cylindrical portion 3 is substantially cylindrical in shape and extends in the vertical direction, and a filler cap (not shown) is detachably attached to its upper end. Specifically, as shown in Figures 1 and 2, the inner circumferential surface of the upper end of the oil filler port 2 is provided with a threaded portion 4 (details of the threads are not shown) into which the filler cap is screwed. The lower part of the cylindrical portion 3 protrudes downward from the upper wall of the cylinder head cover 1 and is exposed to the internal space of the cylinder head cover 1.

[0013] The cylindrical portion 3, which is roughly cylindrical in shape, has an appropriate length so that the nozzle of the oil jug can be fully inserted. It is equipped with a bottom wall portion 6 that is integrally formed with the cylindrical portion 3 so as to cover the lower end of the cylindrical portion 3 that protrudes into the internal space of the cylinder head cover 1. The bottom wall portion 6 is a flat disc shape aligned in a direction perpendicular to the center line of the cylindrical portion 3. In other words, the lower end of the oil filler port 2 into which the nozzle of the oil jug is inserted is closed off by the bottom wall portion 6.

[0014] As described above, an opening 8 is formed on the lower side surface of the cylindrical portion 3, which is closed by the bottom wall portion 6, at a height along the bottom wall portion 6. When unfolded in the circumferential direction, this opening 8 has an elongated rectangle shape with an aspect ratio in which the horizontal (circumferential) dimension is larger than the vertical (up and down) dimension of the cylindrical portion 3. As shown in Figure 3, the opening 8 consists of a single opening that extends over an angular range exceeding 180° of the cylindrical portion 3. For example, in the illustrated example, the opening 8 is formed over an angular range of about 200°.

[0015] A plate-shaped rib 11 is provided on the upper surface 6a of the bottom wall portion 6 as a projection for supporting the tip of the oil jug nozzle at a height away from this upper surface 6a. As shown in Figure 2, this rib 11 is a flat plate-like shape of a certain height that rises from the upper surface 6a along the vertical direction of the cylindrical portion 3 (in other words, along the center line of the cylindrical portion 3). Furthermore, as shown in Figure 3, the rib 11 extends along the diametrical direction of the cylindrical portion 3, which has a circular cross-section. And, as shown in Figure 3, the opening 8 extending in the circumferential direction is provided over an angular range that is roughly symmetrical with respect to the rib 11.

[0016] Furthermore, as shown in Figure 2, one end of the rib 11, which is provided along the diametrical direction of the cylindrical portion 3, on the side of the opening 8, is set back so as to move away from the inner wall surface 3a of the cylindrical portion 3 (more precisely, the extension of the inner wall surface 3a). In other words, it has a notch 12 such that a radial gap is created between it and the inner wall surface 3a. Therefore, the circumferentially long opening 8 is not substantially divided into two by the rib 11, and the flow of lubricating oil is ensured through the notch 12 even in the portion of the opening 8 that overlaps with the rib 11.

[0017] In contrast, the other end of the rib 11, which is provided along the diametrical direction of the cylindrical portion 3, is connected to the inner wall surface 3a of the cylindrical portion 3 and is firmly integrated with the cylindrical portion 3. The lower edge of the rib 11 is integrally connected to the bottom wall portion 6.

[0018] Furthermore, as shown in Figure 2, the upper edge 11a of the rib 11 is at the same height as the upper edge 8a of the opening 8.

[0019] The cylindrical portion 3 having the opening 8, ribs 11, and bottom wall portion 6 is formed as part of the cylinder head cover 1 by mold molding (e.g., injection molding) of a rigid synthetic resin. The opening 8 can be formed simultaneously by using a slide core.

[0020] With the above configuration, the tip of the cylindrical part 3 which serves as the fuel filler port 2 is covered by the bottom wall 6, making it difficult for oil droplets scattered by the high-speed rotating camshaft to enter the fuel filler port 2. Therefore, even if the engine is operated without the filler cap installed, the scattering of lubricating oil from the fuel filler port 2 is sufficiently suppressed.

[0021] Furthermore, its simple structure and the elimination of the need to attach separate parts make it highly suitable for mass production.

[0022] During refueling, the position of the nozzle tip of the oil jug, which is appropriately inserted into the refueling port 2, is restricted when it comes into contact with the rib 11. Figure 4 is an explanatory diagram showing the state in which the nozzle 13 is inserted into the refueling port 2 in the cross-section shown in Figure 1. As shown in the figure, the tip of the nozzle 13 comes into contact with the upper edge 11a of the rib 11 and is kept away from the upper surface 6a of the bottom wall portion 6. In other words, the tip of the nozzle 13 is not covered by the bottom wall portion 6. In particular, in the above embodiment, the tip opening of the nozzle 13 is aligned at the height of the upper edge 8a of the opening 8, and the outer surface of the nozzle 13 does not narrow the opening area of ​​the opening 8. Therefore, if the oil jug is tilted and refueling is performed in the state shown in Figure 4, the lubricating oil flows smoothly through the opening 8 on the circumferential surface of the cylindrical portion 3.

[0023] Furthermore, since the bottom wall portion 6 and the cylindrical portion 3 are connected via the rib 11, the opening 8 along the circumferential direction can be provided in a wide angular range exceeding 180°. In other words, even if the opening 8 is formed in a wide angular range, the support rigidity of the bottom wall portion 6 can be ensured because the bottom wall portion 6 is connected to the inner wall surface 3a of the cylindrical portion 3 via the rib 11. Therefore, good lubrication is obtained by the opening 8 spanning a wide angular range.

[0024] Here, the shape of the opening 8 is advantageous to be an elongated rectangle with a small aspect ratio, as in the above embodiment, which provides good lubrication. For example, when comparing an elongated rectangular opening with a small aspect ratio and a square opening with a large aspect ratio, both with the same opening area, the elongated rectangular opening allows for better lubrication flow.

[0025] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various modifications are possible. For example, the projection that supports the tip of the nozzle of the oil jug at a height away from the upper surface is not limited to the configuration of the above embodiment, but can take any form as long as it can support the tip of the nozzle of the oil jug. For example, a configuration in which a plate-shaped rib is positioned along the chord of a circle slightly off-center from the diameter line, a configuration in which two plate-shaped ribs are arranged in a cross shape, a configuration in which a pair of short plate-shaped ribs facing each other are arranged at a circumferential position that does not overlap with the opening 8, etc. Furthermore, the projection that supports the tip of the nozzle of the oil jug may be formed on the inner wall surface 3a of the cylindrical portion 3 in a form away from the upper surface 6a of the bottom wall portion 6. For example, the projection can be formed by a plurality of ribs that protrude inward from the inner wall surface 3a of the cylindrical portion 3.

[0026] The height of a protrusion, such as a rib, does not necessarily have to be equal to the upper edge of the opening.

[0027] Furthermore, the opening may be configured to have multiple openings.

[0028] Furthermore, in the above embodiment, the cylinder head cover 1, which includes the cylindrical portion 3, is made of a hard synthetic resin, but it may also be a metal cylinder head cover such as a die-cast aluminum alloy. Also, the engine housing may be made of a component other than the cylinder head cover.

Claims

1. An engine fuel filler structure provided on the upper surface of the engine housing, comprising: a cylindrical portion that constitutes a fuel filler into which the nozzle of an oil jug is inserted, and into which a filler cap is detachably attached at the upper end, with the lower part of which is exposed to the space inside the housing; a bottom wall portion formed integrally with the cylindrical portion so as to cover the lower end of the cylindrical portion; an opening formed on the lower side surface of the cylindrical portion along the bottom wall portion; and a projection portion formed to protrude from the upper surface of the bottom wall portion or the inner wall surface of the cylindrical portion, and to support the tip of the nozzle of an oil jug at a height away from the upper surface.

2. The engine fuel filler port structure according to claim 1, wherein the projection consists of a plate-shaped rib rising from the upper surface along the vertical direction of the cylindrical portion.

3. The engine fuel filler port structure according to claim 1, wherein the projection consists of a plate-shaped rib extending along the diametrical direction of the cylindrical portion.

4. The engine fuel filler port structure according to claim 1, wherein the opening consists of a single opening extending in an angular range exceeding 180° at the lower part of the cylindrical portion.

5. The engine fuel filler port structure according to claim 4, wherein the projection consists of a plate-shaped rib extending along the diametrical direction of the cylindrical portion, one end of the rib that overlaps with the angular range is recessed inward so as to move away from the inner wall surface of the cylindrical portion, and the other end of the rib is connected to the inner wall surface of the cylindrical portion.

6. The engine fuel filler port structure according to claim 1, wherein the upper end of the projection is provided at a height equal to the upper edge of the opening.

7. The above housing is a cylinder head cover that covers the camshaft, the fuel filler port structure for the engine according to claim 1.

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