The present application claims priority to Japanese Patent Application number 2023-084372, filed on May 23, 2023 contents of which are incorporated herein by reference in their entirety.
The present disclosure relates to a head cover of an engine.
The engine is provided with a head cover that covers an upper surface of a cylinder head. Japanese Unexamined Patent Application Publication No. 2000-54912 discloses a rib connecting two convex portions provided on the head cover's upper surface to prevent vibration.
It has been proposed to place a weight, such as a component for facilitating smooth engine operation, on the head cover's upper surface. In such cases, where the head cover needs to support the weight, enhancing its rigidity becomes desirable. However, the structure disclosed in Japanese Unexamined Patent Application Publication No. 2000-54912 has difficulty in adequately supporting the weight.
Accordingly, the present disclosure has been made in view of these points, and its object is to achieve increased rigidity in a head cover that supports a weight.
An aspect of the present disclosure provides a head cover covering a cylinder head of an engine, the head cover including: a support part that is provided on an upper surface of a cover body and supports a weight; and a plurality of upper surface ribs extending radially from the support part on the upper surface.
Hereinafter, the present disclosure will be described through exemplary embodiments, but the following exemplary embodiments do not limit the invention according to the claims, and not all of the combinations of features described in the exemplary embodiments are necessarily essential to the solution means of the invention.
A configuration of a head cover according to the present embodiment will be described with reference to
The head cover 1 is provided to an engine of a vehicle or the like. The head cover 1 covers a cylinder head of an engine having a plurality of cylinders. Specifically, the head cover 1 covers a valve train (a mechanism for opening and closing an intake valve and an exhaust valve) provided to the cylinder head. The head cover 1 has a function of reducing the operating noise of a piston in the engine and combustion noise in a combustion chamber.
As shown in
As shown in
The cover body 10 is a portion constituting the main body of the head cover 1, and is formed in a rectangular flat plate shape. Here, the cover body 10 is a casting. The weight 50 is placed on an upper surface 12 of the cover body 10. A back surface 14 that opposes the upper surface 12 covers the cylinder head. As shown in
The support part 20 is a pedestal on which the weight 50 is placed, and supports the weight 50. As shown in
As shown in
As shown in
As shown in
As described above, it is possible to increase the rigidity of the cover body 10 by providing the upper surface ribs 31 to 34 extending from the support part 20 such that they become orthogonal to each other. Therefore, even though the weight 50 is placed on the support part 20, it is possible to prevent deformation of the cover body 10 caused by a load from the weight 50. Further, the upper surface ribs 31 to 34 extending from the support part 20 to the ends on the upper surface 12 make it possible to increase the rigidity of the cover body 10 across a wide range.
The upper surface ribs 31 to 34 are formed such that the heights of the upper surface ribs 31 to 34 become greater as they get closer to the support part 20. Specifically, the upper surface ribs 31 to 34 are inclined such that their heights decrease as they extend farther from the support part 20. Here, the upper surface ribs 31 to 34 may be inclined such that their heights decrease at a constant angle. That is, the upper surface ribs 31 to 34 have a triangular shape as shown in
Normally, in the cover body 10, as a portion gets closer to the weight 50, a bending moment to deform the cover body 10 increases due to the inertial force of the weight 50 caused by the vibration of the engine. In such a case, the upper surface ribs 31 to 34 formed in the above-described triangular shape can increase the rigidity of portions of the cover body 10 where the bending moment is large. As a result, it is possible to prevent deformation of the cover body 10 due to the weight 50.
It should be noted that the heights of the upper surface ribs 31 to 34 decrease as they extend farther from the support part 20 in the above description, but the present embodiment is not limited to this. For example, the heights of the upper surface ribs 31 to 34 may be constant. Further, although the four upper surface ribs 31 to 34 are provided on the upper surface 12 in the above description, the present embodiment is not limited to this. For example, three upper surface ribs or five or more upper surface ribs may be provided on the upper surface 12. Further, although the four upper surface ribs 31 to 34 (a plurality of upper surface ribs) are provided at regular intervals in the circumferential direction in the above description, the present embodiment is not limited to this. For example, the plurality of upper surface ribs may be provided at irregular intervals.
In the present embodiment, in addition to the upper surface ribs 31 to 34, back surface ribs are provided also on the back surface 14 that opposes the upper surface 12. The back surface ribs are formed at predetermined intervals on the back surface 14. As shown in
As shown in
On the basis of simulation results, the first back surface ribs 42a to 42d are provided at portions where the cover body 10 is likely to deform.
As shown in
As shown in
Some ribs among the first back surface ribs 42a to 42d and the second back surface ribs 44a to 44d are formed at the same positions as the upper surface ribs 31 to 34 when the head cover 1 is viewed in a plane. In other words, some ribs among the first back surface ribs 42a to 42d and the second back surface ribs 44a to 44d are positioned just behind the upper surface ribs 31 to 34, sandwiching the cover body 10. Specifically, the first back surface rib 42c is formed at the same position as the upper surface ribs 33 and 34. Also, the second back surface rib 44c is formed at the same position as the upper surface ribs 31 and 32. Further, the first back surface rib 42c is connected to the upper surface ribs 33 and 34 via the cover body 10, and the second back surface rib 44c is connected to the upper surface ribs 31 and 32 via the cover body 10. This makes it possible to increase the cross-sectional secondary moment of the first back surface rib 42c and the upper surface ribs 33 and 34, and the cross-sectional secondary moment of the second back surface rib 44c and the upper surface ribs 31 and 32. As a result, it is possible to prevent bending of the cover body 10 effectively.
In the present embodiment, the heights of the second back surface ribs 44a to 44d are constant, but the heights of the first back surface ribs 42a to 42d are not constant. The heights of the first back surface ribs 42a to 42d are lower at the center in the traverse direction and higher at their ends in the traverse direction. Specifically, the first back surface ribs 42a to 42d are formed in an arch shape as shown in
Further, forming the first back surface ribs 42a to 42d in an arch shape gives the following effects.
In a case where the heights of the first back surface ribs 42a to 42d are constant, unlike the present embodiment, a vertical load received by the cover body 10 from the weight 50 is transmitted to the first back surface ribs 42a to 42d as the load of the bending moment. This induces flexural deformation of the cover body 10, causing the cover body 10 to become the source of noise.
In contrast, in a case where the first back surface ribs 42a to 42d are in an arch shape as described in the present embodiment, a vertical load received by the cover body 10 from the weight 50 is converted into compressive force (or tensile force) in the longitudinal direction of the cover body 10. As a result, it is possible to prevent flexural deformation of the cover body 10 that generates noise. In other words, it is possible to reduce noise caused by flexural deformation of the cover body 10.
The first back surface ribs 42a to 42d and the second back surface ribs 44a to 44d are integrally formed with the cover body 10, but the present embodiment is not limited to this. For example, the first back surface ribs 42a to 42d and the second back surface ribs 44a to 44d may be separate members from the cover body 10, and may be fixed to the cover body 10.
The head cover 1 of the above-described embodiment includes the support part 20 that is provided on the upper surface 12 of the cover body 10 and supports the weight 50, and the plurality of upper surface ribs 31 to 34 that extend radially from the support part 20 on the upper surface 12.
Providing the upper surface ribs 31 to 34 extending radially from the support part 20 can increase the rigidity of the cover body 10. Therefore, even though the weight 50 is placed on the support part 20, the cover body 10 having high strength can prevent deformation of the cover body 10 due to a load from the weight 50.
The present disclosure is explained on the basis of the exemplary embodiments. The technical scope of the present disclosure is not limited to the scope explained in the above embodiments and it is possible to make various changes and modifications within the scope of the invention. For example, all or part of the apparatus can be configured with any unit which is functionally or physically dispersed or integrated. Further, new exemplary embodiments generated by arbitrary combinations of them are included in the exemplary embodiments. Further, effects of the new exemplary embodiments brought by the combinations also have the effects of the original exemplary embodiments.
Number | Date | Country | Kind |
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2023-084372 | May 2023 | JP | national |