JP7201644B2 - Breather structure - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather structure that enables breathing due to differential pressure between the inside and outside of a case (transmission chamber) housing a transmission.

For example, in a vehicle equipped with a transmission, power from the engine is input to the transmission via a torque converter, and the power changed by the transmission is transmitted to the drive wheels via a differential gear. . As a transmission, a continuously variable transmission (CVT) and a stepped automatic transmission (AT) are widely known.

A transmission case that houses a transmission contains oil (fluid) that is used to operate or lubricate each part. The temperature of the oil in the transmission case changes depending on the running state of the vehicle, and the pressure in the transmission case changes along with the temperature change of the oil. Therefore, a breather hose is connected to the transmission case so that when the pressure inside the transmission case increases, the pressure can be released to the atmosphere via the breather hose.

If the tip of the breather hose is open to the atmosphere, there is concern that water may enter from the tip of the breather hose. Therefore, Patent Document 1 proposes a configuration in which the tip of the breather hose is connected to a torque converter case that houses the torque converter, and the tip of the breather hose is opened in the torque converter case.

JP 2005-291326 A

However, a space around the transmission case and the torque converter case is required for routing the breather hose. Patent Document 1 also proposes a configuration in which a breather passage that communicates the inside of the transmission case with the inside of the torque converter case is formed in the outer peripheral portions of the transmission case and the torque converter case through the same route as the breather hose. However, in this configuration, the transmission case and the torque converter case must be formed with thick outer peripheral portions, which increases the size of these cases in the radial direction of rotation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a breather structure in which a breather hose can be omitted without increasing the size of the case in the radial direction of rotation.

In order to achieve the above object, the breather structure according to the present invention provides a case having a partition wall extending in the rotational radial direction of the torque converter between a torque converter chamber in which the torque converter is accommodated and a transmission chamber in which the transmission is accommodated. The breather structure allows breathing due to the differential pressure between the inside and outside of the transmission chamber, and the breather chamber forming a part of the transmission chamber is formed on the surface of the partition on the transmission chamber side, and the partition A breather passage is formed to communicate the breather chamber and the torque converter chamber, a protrusion is formed on the surface of the partition wall facing the torque converter chamber, one end of the breather passage is connected to the breather chamber, and the other end of the breather passage is connected to the breather chamber. , on the surface facing the torque converter chamber, the opening is located on the side of the projection in the rotation direction of the torque converter and at a position lower than the tip of the projection in the rotation axis direction of the torque converter.

According to this configuration, the partition wall between the torque converter chamber in which the torque converter is accommodated and the transmission chamber in which the transmission is accommodated has a breather chamber formed on the transmission chamber side surface thereof. The breather chamber communicates with the torque converter chamber via a breather passage formed in the partition wall. Therefore, breathing is possible due to the differential pressure between the transmission chamber (breather chamber) and the torque converter chamber, and when the pressure in the transmission chamber increases, the pressure is released from the breather chamber to the torque converter chamber via the breather passage. be able to. Therefore, a conventional breather hose can be omitted.

Moreover, the breather passage is open on the side of the partition wall facing the torque converter chamber, and does not pass through the outer peripheral portion of the case. Therefore, there is no need to increase the thickness of the outer peripheral portion of the case, which does not increase the size of the case in the radial direction of rotation.

The position of the open end of the breather passage is on the side of the projection formed on the torque converter chamber side surface of the partition in the rotational direction of the torque converter, and from the tip of the projection in the rotation axis direction of the torque converter. is also at a lower position. As a result, even if water enters the torque converter chamber, the projection dams up the water and prevents the water from entering the breather passage. Therefore, it is possible to prevent water from entering the breather chamber through the breather passage.

The protruding portion may include a protruding portion protruding from the surface of the partition wall on the torque converter chamber side and surrounding the open end of the breather passage.

In this configuration, the bulging portion can effectively suppress water from entering the breather passage.

The bulging portion may be formed in a C-shape partially cut out from a circle surrounding the open end of the breather passage.

Accordingly, even if water enters the inside of the bulging portion, the water can be removed from the notch portion, so that it is possible to prevent water from accumulating inside the bulging portion. As a result, it is possible to more effectively prevent water from entering the breather passage.

According to the present invention, the breather hose can be omitted without increasing the size of the case in the radial direction of rotation.

It is the figure which looked at the transmission unit to which the breather structure concerning one Embodiment of this invention was applied from the engine side. FIG. 2 is a cross-sectional view of the transmission unit taken along a cross-sectional line AA shown in FIG. 1; FIG. 2 is a cross-sectional view of the transmission unit taken along a cross-sectional line BB shown in FIG. 1; FIG. 2 is an enlarged view of part of the front surface of the partition wall of the first case compared to FIG. 1; FIG. 4 is a perspective view showing a part of the front surface of the partition of the first case;

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

<Breather structure>
FIG. 1 is a diagram of a transmission unit 1 having a breather structure 21 according to an embodiment of the present invention, viewed from the front side (engine side). 2 is a cross-sectional view of transmission unit 1 taken along section line AA shown in FIG. 1, and FIG. 3 is a cross-sectional view of transmission unit 1 taken along section line BB shown in FIG.

The transmission unit 1 is mounted on a vehicle and is a unit that changes the speed of power generated by an engine as a drive source for running. A transmission unit 1 includes a torque converter 2 and a transmission. The transmission may be a continuously variable transmission (CVT) or a stepped automatic transmission (AT).

The transmission unit 1 includes a first case 11 and a second case 12 that constitute the outer shell of the transmission unit 1 . The first case 11 and the second case 12 are arranged in this order from the front side.

The first case 11 integrally has a partition 13 extending in the radial direction of rotation of the torque converter 2 (hereinafter simply referred to as “radial direction”) and a peripheral wall 14 extending forward from the outer periphery of the partition 13 . . A space surrounded by the peripheral wall 14 on the front side of the partition wall 13 accommodates the torque converter 2 as a torque converter chamber 15 .

The second case 12 has a tubular shape surrounding a straight line extending in the rotational axis direction of the torque converter 2 (hereinafter simply referred to as the "axial direction"). A front end of the second case 12 is connected to the partition wall 13 of the first case 11 . A space surrounded by the second case 12 on the rear side of the partition wall 13 serves as a transmission chamber 16 and accommodates a transmission.

As shown in FIG. 3 , the first case 11 is provided with a breather structure 21 that allows breathing due to the differential pressure between the inside and outside of the transmission chamber 16 . Breather structure 21 includes breather chamber 22 and breather passageway 23 .

The breather chamber 22 is formed as a concave portion that is recessed forward in a rear surface 24 of the partition wall 13 on the side of the transmission chamber 16 , opens rearward, and communicates with the transmission chamber 16 .

Breather passage 23 is formed inside partition wall 13 . The breather passage 23 includes a first passage portion 25 radially extending from the breather chamber 22 and a second passage portion 26 branched and connected to the first passage portion 25 and extending axially forward from the first passage portion 25 . have.

The first passage portion 25 has one end connected to the breather chamber 22 and the other end opened at the outer peripheral surface 27 of the partition wall 13 . The open end is liquid-tightly closed by inserting a plug 28 . The second passage portion 26 extends forward in the axial direction from an intermediate portion of the first passage portion 25 and opens at a surface of the partition wall 13 on the torque converter 2 side, that is, a front surface 29 . Thereby, the breather chamber 22 communicates with the torque converter chamber 15 on the front side of the partition wall 13 via the breather passage 23 consisting of the first passage portion 25 and the second passage portion 26 .

FIG. 4 is an enlarged view of part of the front face 29 of the partition wall 13 of the first case 11 compared to FIG. FIG. 5 is a perspective view showing part of the front surface 29. As shown in FIG.

As shown in FIGS. 1 and 4 , a plurality of linear ribs 31 are radially formed around the rotation axis of the torque converter 2 on the front surface 29 of the partition wall 13 . The torque converter 2 rotates clockwise when viewed from the front side when the engine is in operation. The open end 32 of the second passage portion 26 that opens at the front surface 29 is located at the 12 o'clock position in the clockwise direction about the rotation axis of the torque converter 2 when the front surface 29 is viewed from the front side in the axial direction. It is formed on the downstream side with respect to the rib 31 closest to the upstream side and further downstream than the 12 o'clock position. Also, the open ends 32 are formed at positions lower than the tips of the ribs 31 in the axial direction.

On the front surface 29, a cylindrical boss 33 is formed at a position adjacent to the open end 32 on the downstream side in the rotational direction of the torque converter 2 (hereinafter simply referred to as the "rotational direction"). It is Further, the front surface 29 is formed with a bulging portion 34 that bulges forward from the front surface 29 . The bulging portion 34 is centered on the center line of the boss 33 and has a substantially C shape formed by partially cutting out a substantially circular shape that encloses the opening end 32 and the boss 33 together. The notch 35 is formed at a position rotated by approximately 180° from the open end 32 about the boss 33 and faces downstream in the rotational direction. The end portion of the bulging portion 34 on the downstream side in the rotation direction with respect to the notch portion 35 extends linearly downward and to the right when viewed from the front side.

A bolt hole 36 is formed in the center of the boss 33 . As shown in FIG. 5, the bulging portion 34 is covered with a circular plate-like lid 37 from the front side. The lid body 37 is fixed to the bulging portion 34 by screwing a bolt 38 inserted through the center thereof from the front side into the bolt hole 36 .

<Effect>
As described above, the partition wall 13 between the torque converter chamber 15 in which the torque converter 2 is accommodated and the transmission chamber 16 in which the transmission is accommodated has the breather chamber 22 formed on the rear surface 24 on the side of the transmission chamber 16 . It is The breather chamber 22 communicates with the torque converter chamber 15 via a breather passage 23 formed in the partition wall 13 . Therefore, the pressure difference between the transmission chamber 16 (breather chamber 22) and the torque converter chamber 15 allows breathing. can be opened to the torque converter chamber 15. Therefore, the conventional breather hose can be omitted, and the need to provide a space for routing the breather hose around the first case 11 and the second case 12 can be eliminated.

Moreover, the breather passage 23 is open at the front surface 29 of the partition wall 13 on the torque converter chamber 15 side and does not pass through the outer peripheral portion of the first case 11 . Therefore, it is not necessary to form the outer peripheral portion of the first case 11 to be thick, and the size of the first case 11 in the radial direction of rotation does not increase.

The position of the open end 32 of the breather passage 23 is lateral to the rib 31 (an example of the protrusion) formed on the front surface 29 in the rotational direction of the torque converter 2 and in the rotational axis direction of the torque converter 2. This position is lower than the tip of the rib 31 . As a result, even if water enters the torque converter chamber 15 , the ribs 31 dam up the water and prevent the water from entering the breather passage 23 . Therefore, water can be prevented from entering the breather chamber 22 through the breather passage 23 .

A bulging portion 34 (an example of a protrusion) bulging from the front surface 29 is formed on the front surface 29 of the partition wall 13 so as to surround the open end 32 of the breather passage 23 . The bulging portion 34 can effectively prevent water from entering the breather passage 23 .

The bulging portion 34 is formed in a C shape formed by cutting out a circular shape surrounding the open end 32 of the breather passage 23 with a notch portion 35 . Accordingly, even if water enters the inside of the bulging portion 34, the water can be removed from the notch portion 35, so that the accumulation of water inside the bulging portion 34 can be suppressed. As a result, water can be prevented from entering the breather passage 23 more effectively.

A boss 33 is formed inside the bulging portion 34 , and the open end 32 of the breather passage 23 is formed on the opposite side of the notch 35 of the bulging portion 34 with the boss 33 interposed therebetween. there is Therefore, even if water enters the inside of the bulging portion 34 through the notch 35 , the water can be prevented from reaching the open end 32 .

Furthermore, the bulging portion 34 is covered with a lid 37 , and the opening of the bulging portion 34 in the axial direction is closed by the lid 37 . Thereby, it is possible to further prevent water from entering the inside of the bulging portion 34 .

<Modification>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms, and various design changes can be made within the scope of the scope of claims. .

2: Torque converter 11: First case (case)
13: Partition wall 15: Torque converter chamber 16: Transmission chamber 21: Breather structure 22: Breather chamber 23: Breather passage 24: Rear surface 25: First passage 26: Second passage 29: Front 31: Rib (projection)
32: Open end 34: Swelling portion (protruding portion)

Claims (3)

It is set in a case having a partition wall extending in the rotation radial direction of the torque converter between the torque converter chamber in which the torque converter is accommodated and the transmission chamber in which the transmission is accommodated, and the differential pressure between the inside and outside of the transmission chamber is set. A breather structure that allows breathing,
A breather chamber forming a part of the transmission chamber is formed on a surface of the partition wall facing the transmission chamber,
A breather passage for communicating the breather chamber and the torque converter chamber is formed in the partition wall,
A protrusion is formed on a surface of the partition wall on the torque converter chamber side,
one end of the breather passage is connected to the breather chamber,
The other end of the breather passage is positioned on the side of the torque converter chamber side relative to the protrusion in the rotational direction of the torque converter and lower than the tip of the protrusion in the rotational axis direction of the torque converter. A breather structure that opens at 2. The breather structure according to claim 1, wherein said projecting portion includes a bulging portion that bulges from a surface of said partition wall on the torque converter chamber side and surrounds an open end of said breather passage. 3. The breather structure according to claim 2, wherein the bulging portion is formed in a shape partially cut out from a circular shape surrounding the open end of the breather passage.

Images