JP2019183925A - Breather structure and breather cover - Google Patents

Abstract

To surely suppress a rise of the internal pressure of a case, and to prevent the flow-out of a lubricant.SOLUTION: A ventilation path 17 has a vertical circulation space 16 at least at a part, and makes an internal opening 14 which is arranged above a liquid level of a lubricant in an in-case space 2 and opened at the in-case space 2 and an external opening which is opened at the outside of a case 1 communicate with each other via the vertical circulation space 16. The vertical circulation space 16 is partitioned by a peripheral face 18 including a first region 20 and a second region 21 which oppose each other, and extends in a vertical direction. A first barrier part 22 is arranged while intersecting with the vertical circulation space 16 in the vertical direction, and protrudes toward the second region 21 from the first region 20. A second barrier part 23 is arranged while intersecting with the vertical circulation space 16 in the vertical direction above the first barrier part 22, and protrudes toward the first region 20 from the second region 21. In the vertical circulation space 16, air circulates between the first barrier part 22 and the second region 21, and between the second barrier part 23 and the first region 20.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a breather structure and a breather cover for suppressing a variation in internal pressure of a case in which lubricating oil is stored in a case internal space.

  Patent Document 1 describes an air breather device attached to a through hole of a housing that houses a transmission therein. The air breather device has a cylindrical portion that is inserted into the through hole of the housing. Both ends of the tube portion are open, and the tube portion forms a breather chamber inside. The breather chamber is an area for separating a liquid such as oil and air, discharging the air to the outside, and guiding the liquid such as oil to the inside. A lid portion is provided at one end of the tube portion, and the other end of the tube portion communicates with a space inside the transmission unit.

  The lid is formed with an air escape hole for adjusting the internal pressure, for example, by connecting the inside and outside of the housing to prevent the pressure in the housing from increasing during operation. A plate member is provided in the breather chamber of the cylindrical portion. A plurality of plate members are provided along the extending direction of the cylindrical portion, and a through hole is formed at the tip of the plate member. The plate member has a function of separating air and oil in order to discharge the internal air to the outside and circulate the lubricating oil inside.

JP 2015-48926

  In the structure of Patent Document 1, since a through hole formed in the plate member is used as a ventilation portion, high-viscosity lubricating oil scraped up by a gear or the like in the case (housing) adheres to the plate member so as to block the through hole. there's a possibility that. In this case, if the hole diameter of the through hole is small, the through hole is blocked by the lubricating oil, and the function of reducing the internal pressure of the case is impaired. On the other hand, if the through hole is formed to have a large diameter so that the through hole is not blocked by the lubricating oil, the lubricating oil scraped up by the gear or the like may flow out of the case from the through hole. That is, in the structure in which the through hole of the plate member is a ventilation portion, it is difficult to prevent the lubricant from flowing out without impairing the function of suppressing the increase in the internal pressure of the case.

  Therefore, an object of the present disclosure is to provide a breather structure and a breather cover capable of reliably suppressing an increase in the internal pressure of the case and preventing outflow of lubricating oil.

  In order to achieve the above object, a first aspect of the present invention is a breather structure for suppressing fluctuations in the internal pressure of a case in which lubricating oil is stored in a space in the case. A first barrier portion and a plate-like second barrier portion are provided. The ventilation path has at least a part of the vertical flow space, and is disposed above the liquid level of the lubricating oil and has an internal opening that opens to the space in the case and an external opening that opens to the outside of the case. Communicate through. The vertical distribution space is partitioned by the peripheral surfaces including the first region and the second region facing each other, and extends in the vertical direction. The first barrier portion is arranged in the vertical distribution space so as to cross the vertical direction, and protrudes from the first region toward the second region. The second barrier portion is disposed above the first barrier portion in the vertical flow space so as to cross the vertical direction, and protrudes from the second region toward the first region. In the vertical flow space, air flows between the first barrier portion and the second region and between the second barrier portion and the first region.

  In the above configuration, an increase in the internal pressure of the case (pressure in the case internal space) is suppressed by discharging air in the internal space of the case from the air passage to the outside of the case.

  Most of the lubricating oil scraped up by the gears and the like in the case internal space toward the internal opening is prevented from moving toward the external opening by the first barrier portion and the second barrier portion, and returns to the case internal space. Accordingly, the outflow of the lubricating oil from the external opening can be prevented by the first barrier portion and the second barrier portion.

  Since the ventilation portion is between the first barrier portion and the second region, and between the second barrier portion and the first region, respectively, compared with a structure in which the through hole formed in the plate-like member is the ventilation portion. Therefore, it is difficult to generate a closed state in which the ventilation portion is blocked by the attached lubricating oil. Therefore, ventilation from the internal opening to the external opening can be maintained, and an increase in the internal pressure of the case can be reliably suppressed.

  A second aspect of the present invention is the breather structure according to the first aspect, wherein the second barrier portion is inclined downward toward the first region.

  In the above configuration, even when the lubricating oil enters the external opening side beyond the second barrier portion, the lubricating oil flows down the upper surface of the second barrier portion that is inclined downward toward the first region. It is easy to move to the internal opening side. Accordingly, it is possible to more reliably prevent the lubricating oil from flowing out from the external opening.

  A third aspect of the present invention is the breather structure according to the first or second aspect, wherein the leading edge of the first barrier portion and the leading edge of the second barrier portion are linearly continuous in the vertical direction. The penetrating region to be formed is formed in the vertical distribution space.

  In the above configuration, since the through region that is linearly continuous along the vertical direction from the lower side of the first barrier portion to the upper side of the second barrier portion is provided in the vertical flow space, air can be smoothly circulated in the vertical flow space. It is possible to suppress the increase in the internal pressure of the case more reliably.

  According to a fourth aspect of the present invention, there is provided a breather structure according to any one of the first to third aspects, wherein the breather structure is provided in an air passage closer to the external opening than the second barrier portion, and is external to the second barrier portion. A buffer space is provided in which the lubricating oil that has entered the opening side can be retained.

  In the above configuration, since the buffer space in which the lubricating oil that has entered the external opening side beyond the second barrier portion can stay is provided, the lubricating oil is less likely to move to the external opening side than the buffer space. Accordingly, it is possible to more reliably prevent the lubricating oil from flowing out from the external opening.

  According to a fifth aspect of the present invention, there is provided a breather cover that is attached to a breather hole of the case in order to suppress fluctuations in the internal pressure of the case in which lubricating oil is stored in a case internal space that accommodates the vehicle drive device. The breather structure according to any one of the first to fourth aspects is provided.

  A sixth aspect of the present invention is the breather cover according to the fifth aspect, wherein the drive device is a differential gear, and the case is an axle case that houses the differential gear.

  In the above configuration, the breather structure according to any one of the first to fourth aspects can be provided in the case by attaching the breather cover to the breather hole of the case. Therefore, a breather structure with a desired configuration is provided in the case without complicating the shape of the case, the breather structure is made of a material different from the case, and a breather structure with a different configuration is easily provided in the case with the same shape. In addition, when the breather structure is broken, it is possible to eliminate the need to replace the entire case.

  According to the present disclosure, it is possible to reliably suppress an increase in the internal pressure of the case and to prevent the lubricating oil from flowing out.

It is a side view of the axle case where the breather cover concerning one embodiment of the present invention was attached. It is the top view which looked at the axle case of FIG. 1 from the arrow II direction. FIG. 3 is a cross-sectional view taken along the line III-III of the breather cover of FIG. 2. It is IV-IV arrow sectional drawing of the breather cover of FIG. It is the bottom view which looked at the breather cover of Drawing 3 from arrow V direction.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIGS. 1 and 2, an internal space (case internal space) 2 of an axle case (case) 1 that accommodates a differential gear (differential device) 3 of a vehicle has a high height for lubricating the differential gear 3. The viscous lubricating oil 4 is stored. The axle case 1 has a lubricating oil discharge port 5 communicating with the outside at the bottom of the case internal space 2, and a lubricating oil supply port 6 communicating with the case internal space 2 and the outside at a higher position than the lubricating oil discharge port 5. The lubricating oil discharge port 5 and the lubricating oil supply port 6 are closed by the closing lids 7 and 8 except when the lubricating oil 4 is supplied and discharged. By supplying the lubricating oil 4 from the lubricating oil supply port 6 with the lubricating oil discharge port 5 closed, the lubricating oil 4 is stored in the case inner space 2. The differential gear 3 rotates with at least a portion immersed in the lubricating oil 4, and the lubricating oil 4 is scraped up by the rotating differential gear 3. Note that the detailed shape of the differential gear 3 is not shown.

  In the axle case 1, a breather hole 10 (see FIG. 3) is formed above the liquid level 9 of the lubricating oil 4 to communicate the case internal space 2 with the outside. A breather cover 11 is attached to the breather hole 10 to prevent fluctuation of the internal pressure of the axle case 1 (pressure in the case internal space 2) while preventing the scraped-up lubricating oil 4 from flowing out to the outside. . In the cover attachment state in which the breather cover 11 is attached to the breather hole 10, the space between the breather hole 10 and the breather cover 11 is sealed with a sealant (not shown) or the like.

  As shown in FIGS. 3 to 5, the breather cover 11 is formed by integrating a cylindrical cover lower portion 12 inserted into the breather hole 10 and a box-shaped cover upper portion 13 communicating with the upper end side of the cover lower portion 12. Thus, a ventilation passage 17 is defined in which the cover lower end opening (inner opening) 14 of the cover lower part 12 and the ventilation pipe connection port (external opening) 15 of the cover upper part 13 communicate with each other through the vertical flow space 16. The vertical distribution space 16 is defined by an inner peripheral surface (peripheral surface) 18 of the cover lower portion 12 and extends in the vertical direction when the cover is attached. The cover lower end opening 14 is above the liquid level 9 of the lubricating oil 4 in the case inner space 2 and opens the lower end of the vertical flow space 16 into the case inner space 2.

  The inner peripheral surface 18 of the cover lower part 12 includes a first region 20 and a second region 21 that face each other. In the vertical flow space 16, a flat plate-like first barrier portion 22 and a flat plate-like second barrier portion 23. And are provided. The first barrier portion 22 is disposed substantially orthogonal to the vertical direction (vertical direction), protrudes from the first region 20 toward the second region 21 and extends substantially horizontally. The second barrier portion 23 is disposed above the first barrier portion 22 so as to cross the vertical direction, protrudes from the second region 21 toward the first region 20, and extends obliquely downward. In the vertical flow space 16, air flows between the first barrier portion 22 and the second region 21 and between the second barrier portion 23 and the first region 20.

  A notch-shaped first recess 24 that is recessed toward the first region 20 at the leading edge of the first barrier portion 22, and a notched second recess that is recessed toward the second region 21 at the leading edge of the second barrier portion 23. Recesses 25 are respectively formed. The first concave portion 24 and the second concave portion 25 form a through region 26 that is linearly continuous along the vertical direction in the vertical flow space 16, and the second barrier portion 23 when the cover lower end opening 14 is viewed from below. The ceiling surface of the upper air passage 17 is exposed through the penetrating region 26 (see FIG. 5). Note that whether or not the front end side of the first barrier portion 22 excluding the first concave portion 24 and the front end side of the second barrier portion 23 excluding the second concave portion 25 overlap in the vertical direction is arbitrary. Both end edges are set so as to substantially overlap in the vertical direction (substantially match when viewed from the vertical direction).

  The vent pipe connection port 15 is provided at an end portion of the cover upper portion 13 away from the communication portion 27 between the cover lower portion 12 and the cover upper portion 13 and opens to the outside of the axle case 1. A vent pipe 28 is connected to the vent pipe connection port 15, and an open end (not shown) of the vent pipe 28 is higher than the vent pipe connection port 15 at a predetermined position (a height position at which the vehicle does not submerge when traveling through a water channel). ) Is supported on the vehicle body side.

  The internal space of the cover upper portion 13 is a space provided in the ventilation path 17 on the side of the vent pipe connection port 15 with respect to the second barrier portion 23, and has entered the vent pipe connection port 15 side beyond the second barrier portion 23. It functions as a buffer space 29 in which the lubricating oil 4 can stay. The bottom surface portion 30 of the cover upper portion 13 has a flat plate shape extending substantially horizontally from the communication portion 27 side toward the vent pipe connection port 15 side, and the lower portion of the buffer space 29 is partitioned by the bottom surface portion 30 of the cover upper portion 13. .

  According to the present embodiment, the increase in the internal pressure of the axle case 1 (the pressure in the case internal space 2) is suppressed by the air in the case internal space 2 being exhausted from the air passage 17 of the breather cover 11 to the outside. .

  The lubricating oil 4 in the case inner space 2 is scraped up by the differential gear 3 and the like, and a part of the lubricating oil 4 may go to the cover lower end opening 14. The barrier 22 and the second barrier 23 are prevented from moving toward the vent pipe connection port 15 and return to the case internal space 2. Therefore, the outflow of the lubricating oil 4 from the air pipe connection port 15 can be prevented by the first barrier portion 22 and the second barrier portion 23.

  Since the ventilation portion is between the first barrier portion 22 and the second region 21 and between the second barrier portion 23 and the first region 20, the through hole formed in the plate-like member is the ventilation portion. Compared to the structure, a closed state in which the ventilation portion is blocked by the attached lubricating oil 4 is less likely to occur. Therefore, ventilation from the cover lower end opening 14 to the vent pipe connection port 15 can be maintained, and an increase in the internal pressure of the axle case 1 can be reliably suppressed.

  Since the second barrier portion 23 on the vent pipe connection port 15 side of the first barrier portion 22 and the second barrier portion 23 is inclined downward toward the first region 20, the lubricating oil 4 is added to the second barrier portion 23. Even when the oil enters the vent pipe connection port 15 side beyond the above, the lubricating oil 4 easily flows down the upper surface of the second barrier portion 23 inclined downward and moves to the cover lower end opening 14 side. Therefore, the outflow of the lubricating oil 4 from the vent pipe connection port 15 can be prevented more reliably.

  Since the vertical flow space 16 is provided in the vertical flow space 16 so as to extend linearly along the vertical direction from the lower side of the first barrier portion 22 to the upper side of the second barrier portion 23, air is smoothly circulated in the vertical flow space 16. The increase in the internal pressure of the axle case 1 can be more reliably suppressed.

  Since the buffer space 29 in which the lubricating oil 4 that has entered the vent pipe connection port 15 side beyond the second barrier portion 23 can stay is provided, the lubricant oil 4 moves from the buffer space 29 to the vent pipe connection port 15 side. It becomes difficult to do. Therefore, the outflow of the lubricating oil 4 from the vent pipe connection port 15 can be prevented more reliably.

  In addition, a breather structure (the air passage 17, the first barrier portion 22, and the second barrier portion 23) is provided in the axle case 1 by forming the breather hole 10 in the axle case 1 and attaching the breather cover 11 to the breather hole 10. Therefore, the breather structure having a desired configuration is provided in the axle case 1 without complicating the shape of the axle case 1, the breather structure is made of a material different from the axle case 1, and the axle case 1 having the same shape is provided. It is possible to simply provide a breather structure having a different configuration, and to replace the breather cover 11 without replacing the axle case 1 when the breather structure is damaged.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the content of the said embodiment, Of course, it can change suitably in the range which does not deviate from this invention. That is, it is needless to say 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 breather cover 11 may be omitted, and the breather structure may be directly formed on the axle case 1.

  Moreover, the barrier part provided in the vertical distribution space 16 is not limited to two stages of the first barrier part 22 and the second barrier part 23, and may be three or more stages, and the shape of each barrier part can be arbitrarily set. It is.

  Further, the case where the breather structure is provided is not limited to the axle case 1 that houses the differential gear 3, and may be a case that houses other driving devices (for example, a transfer, a final drive transmission, etc.).

  The present invention can be applied to a case where lubricating oil is stored in a space in the case.

1: Axle case (case)
2: Space in case 3: Differential gear 4: Lubricating oil 5: Lubricating oil discharge port 6: Lubricating oil supply port 7, 8: Closing lid 9: Liquid level of lubricating oil 10: Breather hole 11: Breather cover 12: Lower part of cover 13: Cover upper part 14: Cover lower end opening (internal opening)
15: Vent pipe connection port (external opening)
16: Vertical distribution space 17: Ventilation path 18: Inner peripheral surface (peripheral surface) under cover
20: 1st area | region 21: 2nd area | region 22: 1st barrier part 23: 2nd barrier part 24: 1st recessed part 25: 2nd recessed part 26: Through area 27: Communication part 28: Vent pipe 29: Buffer space 30: Bottom of the top of the cover

Claims (6)

A breather structure for suppressing fluctuations in the internal pressure of the case in which lubricating oil is stored in the case internal space,
The space in the case has at least part of a vertical flow space that is partitioned by peripheral surfaces including the first region and the second region facing each other and extends in the vertical direction, and is disposed above the liquid level of the lubricating oil. An air passage that communicates an internal opening that opens to the outside and an external opening that opens to the outside of the case through the vertical flow space,
A plate-shaped first barrier portion that is arranged in the vertical distribution space so as to intersect with the vertical direction and protrudes from the first region toward the second region;
A plate-like second barrier portion that is disposed above the first barrier portion in the vertical flow space so as to intersect with the vertical direction and protrudes from the second region toward the first region;
In the up-and-down circulation space, air flows between the first barrier portion and the second region and between the second barrier portion and the first region. The breather structure according to claim 1,
The breather structure, wherein the second barrier portion is inclined downward toward the first region. The breather structure according to claim 1 or 2,
The breather structure characterized in that the leading edge of the first barrier portion and the leading edge of the second barrier portion form a continuous through region in the vertical flow space along the vertical direction. The breather structure according to any one of claims 1 to 3,
A breather provided in the ventilation path closer to the external opening than the second barrier portion and capable of retaining the lubricating oil that has entered the external opening beyond the second barrier portion. Construction. A breather cover that is attached to the breather hole of the case in order to suppress fluctuations in the internal pressure of the case in which lubricating oil is stored in a space in the case that houses the drive device of the vehicle;
A breather cover comprising the breather structure according to any one of claims 1 to 4. The breather cover according to claim 5,
The driving device is a differential gear;
The breather cover, wherein the case is an axle case that accommodates a differential gear.

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