JP2016118113A - Piston cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piston cooling structure which inhibits diffusion of an engine oil from being caused by turbulence of flow of the engine oil when the engine oil is jetted and thereby increases an amount of the engine oil flowing into a cavity of a piston to attain desired cooling effect.SOLUTION: A cavity 2a having an oil inflow port 2b is formed in a piston 2. An oil jet 5 has an oil passage 10, in which an engine oil EO for cooling the piston 2 flows, and jets the engine oil EO from a tip of the oil passage 10 to the oil inflow port 2b of the piston 2. The oil jet 5 has a flow straightener 6 which is disposed in at least a part of the oil passage 10 and divides the oil passage 10 into divided passages 11 arranged along a circulation direction of the engine oil EO.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piston cooling structure.

  Patent Document 1 describes a piston cooling structure that includes an oil jet that injects engine oil, and that cools the piston by flowing engine oil injected from the oil jet into a cavity formed in the piston. In such a piston cooling structure, the cooling performance can be enhanced by increasing the amount of engine oil flowing into the cavity of the piston.

JP 2009-293587 A

  In the piston cooling structure of Patent Document 1, the injection amount of engine oil increases by expanding the oil flow path in the oil jet. However, the expansion of the oil flow path causes a disturbance in the flow of engine oil, and there is a possibility that the injected engine oil will diffuse. When the injected engine oil diffuses, the amount of engine oil that flows into the cavity of the piston with respect to the injection amount decreases, and a desired cooling effect cannot be obtained.

  Therefore, the present invention can suppress the diffusion at the time of jetting of the engine oil due to the disturbance of the flow of the engine oil, and increase the amount of the engine oil flowing into the piston cavity to obtain a desired cooling effect. The object is to provide a piston cooling structure.

  In order to achieve the above object, a piston cooling structure for an engine of the present invention includes a cavity and an oil jet. The cavity has an oil inlet opening and is formed inside the piston. The oil jet has an oil passage through which engine oil for cooling the piston flows, and injects engine oil from the tip of the oil passage toward the oil inlet of the piston. The oil jet has a rectifier that is disposed in at least a part of the oil flow path and divides the oil flow path into a plurality of divided flow paths along the flow direction of the engine oil.

  In the above configuration, the engine oil flowing through the oil flow path passes through the rectifier, so that the flow of turbulent engine oil is adjusted, the diffusion of the engine oil during injection is suppressed, and the straightness of the injected engine oil is improved. To do. For this reason, a desired cooling effect can be obtained by increasing the amount of engine oil flowing from the oil inlet into the cavity of the piston in accordance with the expansion of the oil passage.

  According to the piston cooling structure of the present invention, a desired cooling effect is obtained by suppressing diffusion at the time of jetting of engine oil caused by disturbance of the flow of engine oil and increasing the amount of engine oil flowing into the cavity of the piston. be able to.

It is a principal part perspective view of the engine which employ | adopted the piston cooling structure which concerns on 1st Embodiment of this invention. It is a perspective view of the oil jet with which the engine of FIG. 1 is provided. It is a perspective view of the rectifier with which the oil jet of FIG. 2 is provided. It is a figure explaining the state of the spreading | diffusion of the engine oil which the oil jet injected, (a) shows 1st Embodiment of this invention, (b) shows the comparative example which employ | adopted the conventional structure, respectively. It is a perspective view of the oil jet with which the engine which employ | adopted the piston cooling structure which concerns on 2nd Embodiment of this invention is provided, (a) shows the disassembled state and (b) shows the assembled state, respectively. It is a perspective view of the rectifier with which the engine which adopted the piston cooling structure concerning a 3rd embodiment of the present invention is provided.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the engine 1 includes a piston 2 that reciprocates in an engine block (not shown) and a connecting rod 3 that transmits the reciprocating motion of the piston 2 to a crankshaft (not shown). Is done. The engine 1 employs a piston cooling structure for cooling the piston 2.

  The piston cooling structure includes a cavity 2a formed inside the piston 2 and an oil jet 5 having an oil flow path 10 (see FIG. 2) through which engine oil EO for cooling the piston 2 flows. The cavity 2a of the piston 2 has an oil inlet 2b that opens toward the base end side (crankshaft side) of the connecting rod 3, and the oil jet 5 is engine oil from the oil outlet 2b to the cavity 2a of the piston 2. Inject EO.

  The oil jet 5 is provided in an engine block (not shown) and injects engine oil EO toward the oil inlet 2 b of the piston 2. As shown in FIG. 2, the oil jet 5 includes an oil jet main body 7 to which engine oil EO is supplied from an oil pump (not shown) and an oil passage 10 through which the engine oil EO from the oil jet main body 7 flows. The pipe 8 and the rectifier 6 are provided, and the engine oil EO is injected from the tip 8a of the pipe 8 (tip of the oil flow path 10).

  The rectifier 6 is incorporated in the oil jet 5 and fixed to the root of the pipe 8, and defines the oil flow path 10 together with the pipe 8. That is, the rectifier 6 is disposed at the upstream end of the oil flow path 10. As shown in FIG. 3, the rectifier 6 includes a large-diameter pipe 6a and a plurality (seven in this embodiment) of small-diameter pipes 6b placed inside the large-diameter pipe 6a. The axis of each small-diameter pipe 6b is substantially parallel to the axis of the large-diameter pipe 6a (the flow direction of engine oil EO), and the engine oil EO flowing into the rectifier 6 flows into the divided flow path 11 defined by the plurality of small-diameter pipes 6b. Divide and flow. That is, the rectifier 6 partitions the oil flow path 10 into a plurality of divided flow paths 11 along the flow direction of the engine oil EO.

  Next, the flow of engine oil EO injected by the oil jet 5 will be described.

  In the case of the oil jet 5 shown in FIG. 4A incorporating the rectifier 6 (see FIG. 2), diffusion of the engine oil EO injected from the tip 8a of the pipe 8 is suppressed. On the other hand, in the case of the oil jet 35 of the comparative example shown in FIG. 4B in which the rectifier is not incorporated, the engine oil EO injected from the tip 38a of the pipe 38 is obtained when the rectifier 6 is incorporated (FIG. 4A). Compared to diffusion. Thus, by incorporating the rectifier 6, the straightness of the injected engine oil EO is improved, and the amount of the engine oil EO collected at the oil inlet 2 b of the piston 2 is increased.

  According to the present embodiment, the engine oil EO flowing through the oil flow path 10 passes through the rectifier 6 so that the turbulent flow of the engine oil EO is adjusted, and the diffusion at the time of injection of the engine oil EO is suppressed and injected. The straightness of engine oil EO is improved. For this reason, the amount of engine oil EO that reaches and flows into the cavity 2a of the piston 2 can be increased in accordance with the enlargement of the oil flow path 10 to obtain a desired cooling effect.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that the piston cooling structure according to the second embodiment includes an oil jet 15 instead of the oil jet 5 according to the first embodiment, and a place where the rectifier 6 is incorporated is changed. The same components as those in FIG.

  An oil jet 15 shown in FIGS. 5A and 5B includes an oil jet main body 17 and a pipe 18.

  The rectifier 6 is incorporated in the oil jet 15 by the cap 19 and is provided at the tip 18 a of the pipe 18 so as to constitute a part of the pipe 18. The cap 19 is formed so that an accommodation hole 19 a for accommodating the rectifier 6 and an injection hole 19 b that tapers from the accommodation hole 19 a toward the tip end are continuous. That is, the rectifier 6 is disposed at the downstream end of the oil flow path 10.

  The engine oil EO injected by the oil jet 15 is injected from the tip 18 a of the pipe 18 through the cap 19.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings. The engine (not shown) according to the third embodiment includes a rectifier 26 instead of the rectifier 6 according to the first embodiment, and the description of the same configuration as that of the first embodiment is omitted. To do.

  As shown in FIG. 6, the rectifier 26 is a cylindrical member in which a plurality of processed holes 26 b penetrating both end surfaces are formed, and the processed holes 26 b serve as the branch flow path 11.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it should be added that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, the rectifiers 6 and 26 may be provided in the middle of the pipes 8 and 18 (intermediate part of the oil flow path 10) instead of the tips 8 a and 18 a or the roots of the pipes 8 and 18.

2 Piston 2a Cavity 2b Oil inlet 5 Oil jet 6, 26 Rectifier 7, 17 Oil jet body 8, 18 Pipe 8a, 18a Tip 10 Oil flow path 11 Split flow path EO Engine oil

Claims (1)

A cavity formed in the piston, having an oil inlet opening;
An oil passage through which engine oil for cooling the piston flows, and an oil jet that injects engine oil from the tip of the oil passage toward the oil inlet of the piston,
The oil jet has a rectifier that is disposed in at least a part of the oil flow path and divides the oil flow path into a plurality of divided flow paths along a flow direction of engine oil. .

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