JP7219643B2 - oil recovery structure - Google Patents

Description

The present invention relates to an oil recovery structure provided within a case.

A vehicle such as an automobile is equipped with a transmission, an engine, and the like. Cases of these transmissions, engines, and the like store oil to be supplied to lubricating parts, actuators, and the like (see Patent Documents 1 to 3). An oil strainer is provided in the lower part of the case, and the oil in the lower part of the case is sucked by the oil strainer.

Japanese Utility Model Laid-Open No. 2-50110 Japanese Utility Model Laid-Open No. 54-53158 Japanese Utility Model Laid-Open No. 5-27212

By the way, a large amount of oil mist floats inside a case of a transmission or the like, and a part of the oil mist adheres to the wall surface inside the case. As described above, since the oil adhering to the wall surface inside the case does not easily fall to the lower part of the case, it is necessary to increase the amount of oil injected into the case in consideration of the amount of oil adhering to the wall surface. However, increasing the amount of injected oil causes an increase in the weight of the transmission and the like, so it is required to collect the oil adhering to the wall surface inside the case.

SUMMARY OF THE INVENTION An object of the present invention is to collect oil adhering to a wall surface.

An oil recovery structure according to the present invention is an oil recovery structure provided in a case in which oil is stored, comprising: a plurality of projections formed on a wall surface inside the case; and a base formed thereon, the base having a higher oil repellency than the projection.

According to the present invention, there are a plurality of projections formed on the wall surface inside the case, and a base portion formed on the wall surface adjacent to the projections, the base having higher oil repellency than the projections. have. As a result, the oil adhering to the wall surface can be slid off, and the oil adhering to the wall surface can be recovered.

It is a figure which shows the powertrain mounted in a vehicle. FIG. 2 is a cross-sectional view simply showing a transmission case along line AA of FIG. 1; FIG. 3 is a cross-sectional view simply showing the transmission case along line AA of FIG. 2; It is a figure explaining oil repellency and lipophilicity. (A) to (C) are diagrams showing an example of how oil moves on the inner wall surface of the transmission case. (A) is an enlarged view showing an example of how oil is moved by the oil recovery structure of the embodiment provided with an oil-repellent layer, and (B) is an example of how oil is moved by an oil-recovery structure of a comparative example that is not provided with an oil-repellent layer. is an enlarged view showing the. (A) to (C) are diagrams showing an example of the manufacturing process of the oil recovery structure. FIG. 4 is a cross-sectional view of a transmission case provided with an oil recovery structure according to another embodiment of the invention; (A) and (B) are perspective views showing a separator plate provided with an oil recovery structure according to another embodiment of the present invention. (A) and (B) are perspective views showing a separator plate provided with an oil recovery structure according to another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Power train]
FIG. 1 is a diagram showing a powertrain 10 mounted on a vehicle. A transmission case (case) 12 of a transmission 11 that constitutes a powertrain 10 shown in the figure is provided with an oil recovery structure 13 that is an embodiment of the present invention.

As shown in FIG. 1, powertrain 10 has engine 14 and transmission 11 . A transmission case 12 of the transmission 11 accommodates a torque converter 15 , a forward/reverse switching mechanism 16 and a continuously variable transmission mechanism (transmission mechanism) 17 . A secondary shaft 18, which is the output shaft of the continuously variable transmission mechanism 17, is connected to a front wheel output shaft 20 via a gear train 19. Front wheels (not shown) are connected to the front wheel output shaft 20 via a differential mechanism 21. concatenated. A rear wheel output shaft 24 is connected to the front wheel output shaft 20 via a gear train 22 and a transfer clutch 23. Rear wheels are connected to the rear wheel output shaft 24 via a differential mechanism (not shown). be done. Furthermore, an oil pump 27 is connected to the pump impeller 25 of the torque converter 15 via a chain mechanism 26 .

The transmission case 12 includes a main case 30 that houses the continuously variable transmission mechanism 17 and the like, and a transfer case 31 that houses the transfer clutch 23 and the like. A separator plate 32 is sandwiched between the main case 30 and the transfer case 31 , and the separator plate 32 and the main case 30 define a breather chamber 33 . A breather port 34 that opens to the breather chamber 33 is formed in the main case 30 , and the breather chamber 33 communicates with the outside through the breather port 34 . A hose 35 is connected to the breather port 34 .

Oil X is stored in the lower portion of the transmission case 12 to be supplied to the forward/reverse switching mechanism 16, the continuously variable transmission mechanism 17, and the like. An oil strainer 36 connected to the intake port 27i of the oil pump 27 is provided in the lower portion of the transmission case 12 . When the oil pump 27 is driven by engine power, the oil X stored in the lower portion of the transmission case 12 is sucked from the oil strainer 36 toward the oil pump 27 . The oil X sucked by the oil pump 27 is supplied to the forward/reverse switching mechanism 16, the continuously variable transmission mechanism 17 and the like from the discharge port 27o through a valve body (not shown). The oil level OL, which is the height of the oil level in the transmission case 12, is set to a height at which the oil strainer 36 is sufficiently immersed in the oil X, that is, at a height at which the oil strainer 36 does not suck in air.

[Oil recovery structure]
By the way, since many rotating bodies are housed in the transmission case 12, minute amounts of oil are scattered from the rotating bodies when the vehicle is running. In other words, a large amount of oil mist floats inside the transmission 11 , and some of this oil mist adheres to the wall surface inside the transmission case 12 . Thus, the oil adhering to the wall surface inside the mission case 12 is a factor that reduces the amount of oil flowing down to the bottom of the mission case 12 and is a factor that lowers the oil level inside the mission case 12 . For this reason, an oil recovery structure 13, which will be described later, is provided in the transmission case 12, and the oil adhering to the wall surface is recovered by the oil recovery structure 13.

The oil recovery structure 13 inside the transmission case 12 will be described below. 2 is a cross-sectional view simply showing the transmission case 12 along line AA of FIG. 1, and FIG. 3 is a cross-sectional view simply showing the transmission case 12 along line AA of FIG. be.

As shown in the enlarged portions of FIGS. 2 and 3, a base portion 42 having an oil-repellent layer 41 is provided on an inner wall surface (wall surface) 40 of the transmission case 12, and a plurality of protrusions projecting from the base portion 42. 43 are provided. That is, the inner wall surface 40 of the transmission case 12 is formed with a base portion 42 and a projection portion 43 adjacent to each other. The transmission case 12 is made of metal such as aluminum, and the oil-repellent layer 41 is made of fluororesin such as polytetrafluoroethylene (PTFE). That is, the base portion 42 covered with the oil repellent layer 41 has higher oil repellency than the protruding portion 43 where the metal material is exposed. In the enlarged portion of FIG. 3, the portions covered with the oil-repellent layer 41 are indicated by dots, and the portions not covered by the oil-repellent layer 41 are indicated by white.

FIG. 4 is a diagram for explaining oil repellency and lipophilicity. As shown in FIG. 4, the oil repellency and oleophilicity in this specification are defined by the contact angle θ between the surfaces α and β of the protrusion 43 and the base portion 42 and the oil X adhering thereto. That is, the larger the contact angle θ, the higher the oil repellency, and the smaller the contact angle θ, the higher the lipophilicity. In other words, the larger the contact angle θ, the lower the lipophilicity, and the smaller the contact angle θ, the lower the oil repellency.

As shown in FIG. 4, when the oil X is adhered to the surface α of the base portion 42, the oil repellent layer 41 repels the oil X, so the contact angle is large indicating high oil repellency (that is, low oleophilicity). becomes "θ1". On the other hand, when the oil X is attached to the surface β of the projection 43, the oil X spreads along the metal surface, so that the contact angle becomes small "θ2" indicating low oil repellency (that is, high oil lipophilicity). Become. Thus, since the contact angle θ1 of the base portion 42 is larger than the contact angle θ2 of the projection portion 43, the base portion 42 has higher oil repellency than the projection portion 43. In other words, since the contact angle θ2 of the projection 43 is smaller than the contact angle θ1 of the base 42, the projection 43 has higher lipophilicity than the base 42.

[Oil movement status]
Next, how the oil X moves on the inner wall surface 40 of the transmission case 12 will be described. 5A to 5C are diagrams showing an example of how oil moves on the inner wall surface 40 of the transmission case 12. FIG. FIG. 6A is an enlarged view showing an example of the movement of oil by the oil recovery structure 13 of the embodiment provided with the oil repellent layer 41, and FIG. 4 is an enlarged view showing an example of how oil is moved by the oil recovery structure 100; FIG. 6A and 6B show the movement of the oil X in chronological order.

As shown in FIG. 5A, the oil mist Xm floating in the transmission case 12 adheres to the projections 43 having high oleophilicity. Subsequently, as shown in FIG. 5B, the oil mist Xm adheres to the protrusion 43 repeatedly, and the mass of the oil X adhering to the protrusion 43 gradually grows. When the end of the oil X reaches the oil-repellent layer 41, the oil X slides down the oil-repellent layer 41 due to its own weight, as shown in FIG. 5(C). In other words, since the oil X slides on the oil-repellent layer 41 without staying on the protrusion 43, it is possible to prevent the oil X from adhering to the inner wall surface 40 and staying there, and the oil X is actively applied to the lower part of the transmission case 12. can be collected at As a result, the amount of oil injected into the transmission case 12 can be reduced, and the weight of the transmission 11 can be reduced.

That is, as shown in FIG. 6A, in the oil recovery structure 13 provided with the oil-repellent layer 41, the mass of the oil X adhering to the protrusion 43 grows, and the end of the oil X grows as indicated by symbol a1. When the part reaches the oil-repellent layer 41, the oil X slides down on the oil-repellent layer 41 due to its own weight. That is, even if the mass of the oil X is small and the downward movement force is small, the oil X is repelled on the oil-repellent layer 41, so that the oil X slides without staying on the oil-repellent layer 41. - 特許庁On the other hand, as shown in FIG. 6B, in the oil recovery structure 100 without the oil-repellent layer 41, although the mass of the oil X adhering to the protrusion 43 gradually grows, it has high lipophilicity. Since the oil X is not repelled on the metal surface, the oil X stays on the metal surfaces of the protrusions 43 and the base portion 42 .

[Manufacturing process]
A manufacturing process of the oil recovery structure 13 having the oil-repellent layer 41 will be described below. 7A to 7C are diagrams showing an example of the manufacturing process of the oil recovery structure 13. FIG. As shown in FIG. 7A, a base portion 42 and projections 43 are formed on the inner wall surface 40 of the transmission case 12 when casting the transmission case 12 using a metal material such as aluminum. Subsequently, as shown in FIG. 7B, the inner wall surface 40 of the transmission case 12 is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) to form an oil-repellent layer 41 on the entire inner wall surface 40. be. Then, as shown in FIG. 7C, the inner peripheral surface of the transmission case 12 is polished with a file or the like, and the oil-repellent layer 41 is removed from the tips of the protrusions 43 . As a result, it is possible to obtain the oil recovery structure 13 including the base portion 42 covered with the oil-repellent layer 41 and the plurality of projecting portions 43 exposing the metal surface.

[Other embodiments (inner wall surface of mission case)]
In the example shown in FIG. 3, the hemispherical protrusion 43 is formed on the inner wall surface 40 of the transmission case 12, but the present invention is not limited to this, and a linearly extending protrusion may be formed. good. Here, FIG. 8 is a sectional view of a transmission case 12 having an oil recovery structure 50 according to another embodiment of the invention. 8 shows the same parts as those shown in FIG.

As shown in the enlarged portion of FIG. 8, a base portion 52 having an oil-repellent layer 51 is provided on an inner wall surface (wall surface) 40 of the transmission case 12, and a plurality of protrusions 53 are provided to protrude from the base portion 52. It is Each protrusion 53 has a substantially triangular cross-sectional shape and extends annularly along the inner wall surface 40 of the transmission case 12 . In addition, the projecting portion 53 is installed along the vertical direction on the side portion of the transmission case 12 .

Thus, the inner wall surface 40 of the transmission case 12 is formed with the base portion 52 and the projection portion 53 adjacent to each other. The transmission case 12 is made of metal such as aluminum, and the oil-repellent layer 51 is made of fluororesin such as polytetrafluoroethylene (PTFE). That is, the base portion 52 covered with the oil-repellent layer 51 has higher oil repellency than the protruding portion 53 where the metal material is exposed. In the enlarged portion of FIG. 8, the portions covered with the oil-repellent layer 51 are indicated by dots, and the portions not covered by the oil-repellent layer 51 are indicated by white.

As described above, even when the protrusion 53 extending linearly is formed, it can function in the same manner as the oil recovery structure 13 described above. In other words, the oil mist floating in the transmission case 12 adheres to the highly oleophilic projections 53 . After that, the oil mist adheres to the protrusion 53 repeatedly, and the mass of the oil X adhering to the protrusion 53 gradually grows. When the ends of the oil X reach the oil-repellent layers 51 on both sides, the oil X slides down the oil-repellent layers 51 due to its own weight. In this way, since the oil slides on the oil-repellent layer 51 without remaining on the protrusion 53, it is possible to prevent the oil X from adhering to the inner wall surface 40 and staying there. can be recovered.

[Another embodiment (separator plate)]
In the above description, the oil recovery structure 13 is formed on the inner wall surface 40 of the transmission case 12. However, the present invention is not limited to this. may be formed.

As shown in FIG. 1 , a separator plate 32 that partitions a breather chamber 33 is provided inside the transmission case 12 . That is, the surface 32 a of the separator plate 32 functions as a wall surface inside the transmission case 12 facing the breather chamber 33 . By providing an oil recovery structure on the surface 32a of the separator plate 32, the oil mist in the breather chamber 33 can be captured and returned to the lower part of the transmission case 12, and the oil mist can be prevented from being discharged from the breather chamber 33 to the outside. can be prevented.

Here, FIGS. 9A and 9B are perspective views showing a separator plate 61 provided with an oil recovery structure 60 according to another embodiment of the invention. 10A and 10B are perspective views showing a separator plate 71 having an oil recovery structure 70 according to another embodiment of the invention. The separator plates 61 and 71 shown in FIGS. 9 and 10 are attached at the same positions as the separator plate 32 shown in FIG. In FIGS. 9B and 10B, the portions covered with the oil-repellent layers 62 and 72 are hatched, and the portions not covered with the oil-repellent layers 62 and 72 are outlined. It is

As shown in FIGS. 9A and 9B, a base portion 63 having an oil-repellent layer 62 is provided on a surface 61a of a separator plate 61, which is a wall surface inside the mission case 12, and protrudes from the base portion 63. A plurality of protrusions 64 are provided for the purpose. That is, the surface 61a of the separator plate 61 has a base portion 63 and a projection portion 64 adjacent to each other. The separator plate 61 is made of metal such as iron or stainless steel, and the oil-repellent layer 62 is made of fluororesin such as polytetrafluoroethylene (PTFE). That is, the base portion 63 covered with the oil repellent layer 62 has higher oil repellency than the protruding portion 64 where the metal material is exposed.

As shown in FIGS. 10A and 10B, a base portion 73 having an oil-repellent layer 72 is provided on a surface 71a of a separator plate 71, which is a wall surface inside the transmission case 12, and protrudes from the base portion 73. A plurality of projections 74 are provided for the purpose. Each protrusion 74 has a substantially triangular cross-sectional shape and extends linearly along the vertical direction. That is, the surface 71a of the separator plate 71 has a base portion 73 and a projection portion 74 adjacent to each other. The separator plate 71 is made of metal such as iron or stainless steel, and the oil-repellent layer 72 is made of fluororesin such as polytetrafluoroethylene (PTFE). That is, the base portion 73 covered with the oil repellent layer 72 has higher oil repellency than the protruding portion 74 where the metal material is exposed.

As described above, even when the oil recovery structures 60, 70 are provided on the surfaces 61a, 71a of the separator plates 61, 71, the oil mist is captured and the transmission case is removed, similarly to the oil recovery structures 13, 50 described above. It can be returned to the bottom of 12. That is, the oil mist floating in the breather chamber 33 adheres to the protrusions 64 and 74 having high oleophilicity. After that, the oil mist adheres to the protrusions 64 and 74 repeatedly, and the mass of oil adhering to the protrusions 64 and 74 gradually grows. Then, when the ends of the oil reach the oil-repellent layers 62, 72, the oil slides down the oil-repellent layers 62, 72 due to its own weight. Since the oil slides on the oil-repellent layers 62 and 72 without remaining on the protrusions 64 and 74, it is possible to prevent the oil from adhering to the separator plates 61 and 71 and staying there. oil can be actively recovered. Moreover, since the oil mist that has entered the breather chamber 33 can be captured, it is possible to prevent the oil mist from being discharged to the outside from the breather port 34 .

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In the above description, the transmission case 12 is used as the case in which the oil recovery structures 13, 50, 60, 70 are provided. 60 and 70 may be provided. Further, although the illustrated transmission case 12 accommodates a continuously variable transmission mechanism 17 as a transmission mechanism, it is not limited to this. As the transmission mechanism accommodated in the mission case 12, for example, a planetary gear type automatic transmission mechanism or a manual transmission mechanism may be used.

Further, the shape and arrangement of the protrusions 43, 53, 64, and 74 constituting the oil recovery structures 13, 50, 60, and 70 are not limited to those shown in FIGS. Needless to say, other shapes and arrangements may be used instead. 2 and 3, the projections 43 and 53 are formed on the entire inner wall surface 40 of the transmission case 12, but the present invention is not limited to this. You may form the protrusion parts 43 and 53 in a part of . Moreover, it goes without saying that the projections 43 and 53 may be formed on the inner wall surface 40 of the transmission case 12 that defines the breather chamber 33 .

In the manufacturing process described above, the oil-repellent layer 41 is removed from the tip of the protrusion 43 by polishing the inner peripheral surface of the transmission case 12 with a file or the like to expose the metal surface, but the present invention is not limited to this. When the oil-repellent layer 41 is formed by applying a fluororesin, the fluororesin may be applied while avoiding the protrusions 43 by performing a masking process. Further, in the above description, in order to increase the oil repellency of the base portions 42, 52, 63, 73 rather than the protrusions 43, 53, 64, 74, the base portions 42, 52, 63, 73 are provided with an oil repellent layer made of fluorine resin. Although 41, 51, 62 and 72 are formed, the oil-repellent layers 41, 51, 62 and 72 may be formed using other materials without being limited to this.

In the example shown in FIG. 4, the contact angle θ1 of the base portion 42 provided with the oil-repellent layer 41 exceeds 90°. It may be less than °. Further, in the example shown in FIG. 4, the contact angle θ2 of the protrusion 43 is less than 90°, but the contact angle θ2 of the protrusion 43 may be 90° or more. That is, in order for the base portion 42 to have a higher oil repellency than the projection portion 43 , the contact angle θ1 of the base portion 42 should be larger than the contact angle θ2 of the projection portion 43 .

12 mission case (case)
13 Oil recovery structure 17 Continuously variable transmission mechanism (transmission mechanism)
32 separator plate 32a surface (wall surface)
33 breather chamber 40 inner wall surface (wall surface)
41 oil-repellent layer 42 base portion 43 protrusion 50 oil recovery structure 51 oil-repellent layer 52 base portion 53 protrusion 60 oil recovery structure 61 separator plate 61a surface (wall surface)
62 oil-repellent layer 63 base portion 64 protrusion 70 oil recovery structure 71 separator plate 71a surface (wall surface)
72 oil-repellent layer 73 base portion 74 protrusion X oil

Claims (4)

An oil recovery structure provided in a case in which oil is stored,
a plurality of protrusions formed on a wall surface within the case;
a base portion formed on the wall surface adjacent to the protrusion;
has
The base portion has higher oil repellency than the projection portion,
Oil recovery structure. The oil recovery structure of claim 1, wherein
The base portion is provided with an oil-repellent layer,
Oil recovery structure. In the oil recovery structure according to claim 1 or 2,
the wall surface faces a breather chamber communicating with the outside of the case;
Oil recovery structure. In the oil recovery structure according to any one of claims 1 to 3,
The case is a transmission case that houses a transmission mechanism,
Oil recovery structure.

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