JP2017155921A - Air breather device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simpler connecting structure composed of a breather and a casing when constituting an air breather device by using a structure which is constituted different from the casing.SOLUTION: An air breather device 1 for permitting the passage of air while suppressing the passage of oil to the outside from the inside of a differential housing 3 comprises: a breather case 10 having a breather chamber 11 which is formed of resin differently from the differential housing 3, and a cylindrical neck part 12; and a cap 20 which is connected to the neck part 12 from the outside of the differential housing 3 so as to be removable therefrom. A male screw part 21a (first screw part ) formed at the cap 20 and a female screw part 12b (second screw part) formed at the neck part 12 are screw-connected to each other with an opening part 3a of the differential housing 3 sandwiched therebetween.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an air breather device provided in a casing such as a transmission of a vehicle.

  Various air breather devices configured to control the pressure inside the casing while allowing the passage of air while suppressing the passage of oil from the inside of the casing such as a vehicle transmission to the outside have been proposed. The device disclosed in Patent Document 1 uses a cage filter configured separately from the casing. In addition, there is an air breather device in a conventionally known transmission in which a breather plug that has been subjected to male threading is screwed into a female screw hole provided in a casing.

JP-A-5-172214

  In the air breather device disclosed in Patent Document 1, an exhaust pipe is fixed to a casing (mission case), and a large-diameter inner port is provided on the inner side of the casing of the exhaust pipe. A connection port pipe protruding from the filter is connected. For this reason, there is a problem that the structure is complicated. In the configuration in which the female screw hole is provided in the casing, it is necessary to process the female screw hole, which requires a simplified process.

  An object of the present invention is to provide a simpler coupling structure between a breather case and a casing when an air breather device is configured using a structure formed separately from the casing.

One aspect of the present invention is:
An air breather device configured to allow the passage of air while suppressing the passage of oil from the inside of the casing to the outside,
A breather case formed of resin separately from the casing, wherein the breather chamber defines a space for holding oil communicated with the inside of the casing, and communicates with the breather chamber and is connected to the casing. A breather case having a cylindrical neck portion accessible from the outside of the casing through the provided opening;
A cap removably coupled to the neck portion from the outside of the casing, the cap configured to allow passage of air from the inside of the casing to the outside under a predetermined pressure condition;
A first screw portion formed on the cap and a second screw portion formed on the neck portion are screwed to each other with the opening interposed therebetween.

  According to this aspect, the first screw portion formed on the cap and the second screw portion formed on the neck portion are configured to be screw-coupled with the opening of the casing interposed therebetween. The breather case can be fixed to the casing by co-fastening associated with the screw connection, and a simpler connection structure between the breather case and the casing can be provided.

It is a front view showing a section of a differential gear to which an air breather device concerning a 1st embodiment of the present invention is applied. It is the II-II sectional view taken on the line of the differential device of FIG. It is a front view which shows the principal part of the air breather apparatus of 1st Embodiment. It is a front view which shows the principal part of the modification of 1st Embodiment. It is a front view which shows the principal part of another modification of 1st Embodiment. It is a front view which shows the principal part of the air breather apparatus of 2nd Embodiment. It is a front view which shows the principal part of the modification of 2nd Embodiment.

  Preferred embodiments of the present invention will be described in detail below. In FIG. 1, an air breather device 1 according to a first embodiment of the present invention is an application of the present invention to a differential device 2 of an automobile. The differential device 2 is configured by holding a power train 4 inside a differential housing 3 that is a casing. The power train 4 includes a plurality of rotating bodies such as a drive pinion gear, a ring gear, and a differential gear mechanism that operate while meshing with each other.

  The differential housing 3 includes a differential carrier 5 and a side cover 6. The side cover 6 is fixed to the opening edge of the differential carrier 5 side end by a bolt 7, whereby the differential housing 3 is integrally formed. The differential carrier 5 and the side cover 6 are made of cast iron, but may be an aluminum-based material or a magnesium-based material.

  The air breather device 1 includes a breather case 10 and a cap 20. The breather case 10 is formed of a resin, separate from the casing (the differential housing 3). The breather case 10 includes a breather chamber 11 that defines a space for holding oil, and a cylindrical neck portion 12 that communicates with the breather chamber 11. The breather chamber 11 is formed to a size that does not interfere with the power train. A through hole 13 (see FIG. 2) is provided at the lowest point of the bottom of the breather chamber 11, and the inside of the breather chamber 11 communicates with the inside of the differential housing 3 through the through hole 13.

  As shown in FIG. 3, the neck portion 12 has a cylindrical shape and protrudes upward from the breather chamber 11. The neck portion 12 has an outer peripheral surface 12a that has a tapered frustoconical taper shape. On the other hand, the differential housing 3 is provided with an opening 3a. The shape of the inner peripheral surface of the opening 3a is a taper complementary to the outer peripheral surface 12a of the neck portion 12 (that is, upward in FIG. 3). The taper is smaller in diameter. When the breather case 10 is arranged at the set position of the differential housing 3, the neck portion 12 can be accessed from the outside of the differential housing 3 through an opening 5 a provided in the differential housing 3. Furthermore, the neck part 12 has the internal thread part 12b in the internal peripheral surface.

  The cap 20 has a cap body 21. The cap body 21 includes a cylindrical part 22 extending in the vertical direction in the figure, a disk part 23 extending outward from the outer peripheral surface of the cylindrical part 22, and a downward direction in the figure from the outer peripheral edge of the disk part 23. And an existing short cylindrical portion 24. A flange portion 25 extending outward is formed at the upper end portion of the cylindrical portion 22. The cap body 21 is integrally formed of resin, but may be iron. A head cover 26 is fixed to the flange portion 25 by caulking. The head cover 26 is preferably made of iron or other metal.

  A valve body 27 is arranged at the upper end of the tubular portion 22 so as to seal the inner cavity 22 a of the tubular portion 22, and the valve body 27 is directed toward the upper end surface of the tubular portion 22 by a compression spring 28. Always energized. As a result, the cap 20 allows air to flow from the inside of the differential housing 3 to the outside under a predetermined pressure condition (that is, when the internal pressure of the differential housing 3 exceeds the external pressure by more than a predetermined level). Is allowed to pass through.

  A male screw portion 21 a is formed on the outer peripheral surface of the lower portion of the cylindrical portion 22 of the cap body 21. On the other hand, a female screw portion 12 b is formed on the inner peripheral surface of the neck portion 12 of the breather case 10. The female screw portion 12b and the male screw portion 21a are configured to be complementary, and both can mesh with each other. The male screw portion 21a corresponds to the first screw portion in the present invention. The female screw portion 12b corresponds to the second screw portion in the present invention.

  In the air breather device 1 configured as described above, the male screw portion 21a formed on the cap 20 and the female screw portion 12b formed on the neck portion 12 of the breather case 10 sandwich the opening 3a of the differential housing 3, Removably screwed.

  At this time, the outer peripheral surface 12a of the neck portion 12 is tapered, and the shape of the inner peripheral surface of the opening 3a of the differential housing 3 is a tapered shape complementary to the outer peripheral surface 12a of the neck portion 12. Therefore, the outer peripheral surface 12a of the neck portion 12 is elastically compressed as the cap 20 is tightened. By this elastic force, the outer peripheral surface 12a of the neck portion 12 and the inner peripheral surface of the opening 3a are sealed, and the breather case 10 is firmly fixed to the opening 3a, and the drop-off from the differential housing 3 is suppressed. The

  As described above, the air breather device 1 according to the present embodiment is detachably coupled to the breather case 10 formed of resin separately from the differential housing 3 and the neck portion 12 of the breather case 10 from the outside of the differential housing 3. The male screw portion 21a formed on the cap 20 and the female screw portion 12b formed on the neck portion 12 are screw-coupled with the opening 3a of the differential housing 3 interposed therebetween. ing. Therefore, the breather case 10 can be fixed to the differential housing 3 by co-fastening associated with the screw connection, and a simpler connection structure between the breather case 10 and the differential housing 3 can be provided.

  Further, since the breather case 10 is made of resin, the sealing between the outer peripheral surface 12a of the neck portion 12 and the opening 3a and the breather case by the elastic force due to the compression of the neck portion 12 accompanying the screw connection with the cap 20 Therefore, it is possible to reduce the number of parts and the number of assembly steps.

  Note that an adhesive or a sealing agent may be applied to the outer peripheral surface 12 a of the neck portion 12 when the air breather device 1 is assembled in order to more suitably suppress the breather case 10 from falling off the differential housing 3. Also, as shown in FIG. 4, by providing an engaging claw 12c at the upper end of the outer peripheral surface 12a of the neck 12, and engaging the engaging claw 12c with the shoulder 3b at the upper end of the opening 3a, The breather case 10 may be prevented from dropping after assembly. When the breather case 10 is assembled to the differential housing 3, it is preferable that the engaging claw 12c and the vicinity thereof are configured to be flexible so that the engaging claw 12c can be reduced in diameter and pass through the shoulder 3b. The engagement claw 12c may be provided in a series over the entire circumference of the outer peripheral surface of the neck portion 12, or may be provided with an engagement claw 12c extending over only a part of the outer peripheral surface of the neck portion 12, or a plurality of engagement claws. 12c may be provided at intervals. In order to suppress the protrusion amount of the upper end portion of the neck portion 12 from the upper surface of the differential housing 3, the upper end portion of the opening portion 3a is deep enough to accommodate a part or all of the engaging claw 12c in the height direction. A circumferential groove may be provided.

  Further, as shown in FIG. 5, contrary to the first embodiment, the first threaded portion formed on the cap 20 is the female threaded portion 71a, and the second threaded portion formed on the neck portion 12 is the second threaded portion. It is good also as the external thread part 62b. In this case, the female screw portion 71 a can be provided on the inner peripheral surface of the short cylindrical portion 24. Moreover, the external thread part 62b can extend the front-end | tip part of the neck part 12, and can be provided in the outer peripheral surface. Further, in this case as well, an engagement claw (not shown) for preventing the breather case 10 from falling off (which engages with the shoulder at the upper end of the opening 3a as in the engagement claw 12c shown in FIG. 4). It can be provided in the neck portion 12, and such an engaging claw is preferably provided adjacent to the lower side of the male screw portion 62b.

  Next, a second embodiment of the present invention will be described. The air breather device 101 of the second embodiment shown in FIG. 6 is different from the first embodiment described above in the structure of the neck portion 112 and the opening portion 103a.

  The opening 103a of the differential housing 3 in the second embodiment has a constant inner diameter along its axial direction. On the other hand, the outer peripheral surface 112a of the neck portion 112 of the breather case 10 has a constant outer diameter so that it can be fitted to the opening 103a at least at the upper end thereof, and in the middle portion of the region to be fitted, A groove 112c is provided over the entire circumference. Since the remaining structure of 2nd Embodiment is the same as that of 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  In the air breather device 101 of the second embodiment configured as described above, the male screw portion 21a formed on the cap 20 and the female screw portion 112b formed on the neck portion 112 of the breather case 10 as in the first embodiment. Are detachably screwed across the opening 103a of the differential housing 3. Therefore, the number of parts and the number of assembly steps can be suppressed for the same reason as in the first embodiment.

  Further, since the groove 112c is provided on the outer peripheral surface 112a of the neck portion 112, the adhesive or sealant 115 can be applied to the groove 112c when the air breather device 101 is assembled. The drop-off from the differential housing 3 can be more suitably suppressed.

  Further, in the second embodiment, as shown in FIG. 7, a shoulder 112d to be engaged with the periphery of the opening 103a in the inner peripheral surface of the differential housing 3 is formed at the base of the neck 112 of the breather case 10. An enlarged diameter portion such as may be provided. In this case, when the cap 20 is tightened, the upward movement of the breather case 10 is restricted by the shoulder 112d, and the cap 20 can be tightened firmly.

  Although the invention has been described with a certain degree of particularity, it should be understood that various modifications and changes can be made without departing from the spirit and scope of the claimed invention. Various technical means shown in the above-described embodiment and each modification can be combined with each other as much as possible. For example, you may apply the cyclic | annular enlarged diameter part 3b and the engagement nail | claw 12c of the neck part 12 which were used in the modification shown by FIG. 4 to the air breather apparatus 101 of 2nd Embodiment. Moreover, in 2nd Embodiment and its modification, you may comprise so that a female screw part may be provided in the cap 20, and a tail screw part may be provided in the neck part 112, and both may be screw-coupled. The present invention can also be applied to other types of casings such as engine crankcases, and such applications are also within the scope of the present invention.

1,101 Air breather device 2 Differential device 3 Differential housing (casing)
4 Powertrain 10 Breather Case 11 Breather Chamber 12 Neck Part 12b, 112b, 71a Female Thread Part 20 Cap 21a, 62b Male Thread Part

Claims (1)

An air breather device configured to allow the passage of air while suppressing the passage of oil from the inside of the casing to the outside,
A breather case formed of resin separately from the casing, wherein the breather chamber defines a space for holding oil communicated with the inside of the casing, and communicates with the breather chamber and is connected to the casing. A breather case having a cylindrical neck portion accessible from the outside of the casing through the provided opening;
A cap removably coupled to the neck portion from the outside of the casing, the cap configured to allow passage of air from the inside of the casing to the outside under a predetermined pressure condition;
An air breather characterized in that a first screw portion formed in the cap and a second screw portion formed in the neck portion are screwed together with the opening interposed therebetween. apparatus.

Images