JP2008180313A - Breather device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a breather device in which water is prevented from being intruded into a transmission case due to the lowering of the inner pressure of the transmission case. <P>SOLUTION: This breather device 20 fitted to a transmission mounted on a vehicle such as an automobile comprises a breather chamber 30 formed at the upper part of the transmission case 10, a breather 40 allowing the breather chamber 30 to communicate with the atmosphere, and a gas filling means 50 for forcibly filling the inside of the breather chamber 30 with a gas from the outside of the transmission case 10. An existing compressor 51 mounted on the vehicle is used as the gas filling means 50. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a breather device provided in a transmission mounted on a vehicle such as an automobile. Vehicle transmissions generally include automatic transmissions, manual transmissions, and the like. For example, a transaxle mounted on a front engine / front drive (FF) vehicle, a front engine / rear drive ( FR) and the like mounted on a vehicle.

Generally, a transmission mounted on a vehicle such as an automobile is provided with a breather device in order to prevent a pressure difference between the inside of a transmission case housing a transmission mechanism and the like and the atmosphere. As such a breather device, there is known a breather device provided with a breather chamber provided at an upper portion in a transmission case, and a breather (air breather) communicating the breather chamber with the atmosphere (for example, Patent Document 1). reference).
JP-A-6-117521

  By the way, in the breather device, since the breather is open to the atmosphere, water or the like may enter the transmission case from the open end of the breather. Conventionally, in order to prevent intrusion of water or the like, a cap is attached to the open end of the breather provided on the transmission case as in the breather device described in Patent Document 1, or a breather hose is connected to the transmission case. The breather hose is routed in the space around the transmission case inside the vehicle.

  However, when the internal pressure of the transmission case becomes lower than the external pressure (atmospheric pressure), gas (air) is sucked into the transmission case through the atmosphere side open end of the breather. For this reason, with the intake air, there is a problem that water (water droplets) existing around the open end of the breather on the atmosphere side is sucked and enters the inside of the transmission case. Such a problem is particularly a concern in the case of water splashing in rainy weather, passage through a submerged channel, and car washing with high-pressure washing water.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a breather device capable of preventing water from entering the transmission case due to a decrease in the internal pressure of the transmission case. And

  In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention is a breather device including a breather chamber provided in an upper part of a transmission case, and a breather communicating the breather chamber with the atmosphere, and is provided in the breather chamber from the outside of the transmission case. A gas injection means for injecting gas is provided.

  Here, the transmission case is not limited to a housing that houses only the transmission mechanism of the transmission, but also includes a housing that also houses equipment (such as a torque converter and a differential mechanism) coupled to the transmission mechanism. is there.

  According to the above configuration, since the gas is forcibly injected into the breather chamber by the gas injection means, the gas in the breather chamber is discharged to the outside through the breather. As a result, as the internal pressure of the transmission case decreases, gas is prevented from being sucked from the open end of the breather into the transmission case, and as a result, water can enter the transmission case. Can be effectively prevented. And, for example, even in the case of water splashing in rainy weather, passage through a submerged channel, and car washing with high-pressure washing water, it is possible to prevent water from entering the inside of the transmission case as the internal pressure of the transmission case decreases. .

  A specific example of the gas injection means is a compressor. An existing compressor mounted on the vehicle can be used as the compressor. In this case, a pipe for gas injection is branched from the existing compressor, and the pipe is led to the breather chamber. In addition, a dedicated compressor can be directly attached to the transmission case.

  In the breather device of the present invention, it is preferable that the gas injection amount into the breather chamber by the gas injection means is set to be equal to or larger than the maximum contraction amount of the gas inside the transmission case.

  In this way, even during the maximum contraction of the gas inside the transmission case, the gas exceeding the contraction amount is injected into the breather chamber by the gas injection means, so that the internal pressure of the transmission case due to the decrease in the internal pressure of the transmission case. A gas injection amount sufficient to compensate for the gas contraction amount is always secured. As a result, even when the internal pressure of the transmission case suddenly decreases, it is possible to completely prevent gas from being sucked into the transmission case from the open end of the breather when the internal pressure of the transmission case decreases. It is possible to completely prevent water from entering the transmission case.

  In the breather device of the present invention, it is preferable that an air filter is provided on an injection path for injecting gas from the gas injection means into the breather chamber.

  In this way, even if foreign matter such as dust is mixed in the gas sent from the gas injection means, the foreign matter is collected by the air filter. Thereby, it is possible to prevent foreign matter from entering the transmission case.

  According to the present invention, since the gas is forcibly injected into the breather chamber by the gas injection means, the gas in the breather chamber is discharged to the outside through the breather. As a result, as the internal pressure of the transmission case decreases, gas is prevented from being sucked from the open end of the breather into the transmission case, and as a result, water can enter the transmission case. Can be prevented.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an upper portion of a transmission case, and shows a breather chamber of a breather device and its periphery. FIG. 2 is a perspective view schematically showing an appearance of a transmission case provided with a breather chamber of the breather device.

  As shown in FIGS. 1 and 2, a breather device 20 is provided in a transmission case 10 that houses a transmission mechanism and the like. The breather device 20 is provided in order to prevent a pressure difference between the inside of the transmission case 10 and the atmosphere (outside). The breather device 20 of this example forcibly injects a gas (air) from the outside of the transmission case 10 into the breather chamber 30, a breather 40 that communicates the breather chamber 30 with the atmosphere, and the breather chamber 30. The gas injection means 50 is provided.

  An example of the transmission case 10 is a housing as shown in FIG. A transmission case 10 shown in FIG. 2 is a housing that houses a transaxle mounted on a front engine / front drive (FF) type vehicle, and includes a torque converter, a forward / reverse switching mechanism, A mechanism, a differential mechanism, and the like are accommodated. The transmission case 10 is mounted horizontally with respect to the vehicle body. More specifically, the transmission case 10 has a structure in which four parts are integrally joined, and a transaxle case 11 disposed in the center and a transformer attached to one side of the transaxle case 11. The axle housing 12, the rear cover 13 attached to the other side of the transaxle case 11, and the oil pan 14 attached to the bottom side of the transaxle case 11 are integrally assembled. The structure of the transmission case 10 may be other than this.

  The transmission case 10 is sealed inside and is in an airtight state, but gas can flow between the inside and the outside of the transmission case 10 via the breather device 20. Hereinafter, the breather device 20 will be described in detail.

  The breather chamber 30 of the breather device 20 is provided on the upper side inside the transmission case 10. Specifically, the breather chamber 30 is configured as a space surrounded by the transmission case 10 and a partition wall portion 31 that is integrally provided inside the transmission case 10. The breather chamber 30 communicates with a space C1 that houses a transmission mechanism and the like inside the transmission case 10. In the transmission case 10 shown in FIG. 2, the breather chamber 30 is formed across the transaxle case 11 and the transaxle housing 12. The shape of the breather chamber 30 is a conventionally known labyrinth shape in order to prevent the lubricating oil in the transmission case 10 from leaking to the outside, but the shape and position of the breather chamber 30 are not particularly limited.

  The breather chamber 30 communicates with the atmosphere via the breather 40. Specifically, the breather 40 includes a substantially cylindrical breather plug 41 attached to the transmission case 10 and a breather hose 42 connected to the breather plug 41. A boss portion 15 having a through hole 15a having a circular cross section is formed in the transmission case 10 constituting the wall portion of the breather chamber 30, and a lower portion of the breather plug 41 is inserted into the through hole 15a. One end of a breather hose 42 is connected to the upper side of the breather plug 41. A male screw is formed on the outer peripheral surface of the lower portion of the breather plug 41, a female screw is formed on the inner peripheral surface of the through hole 15 a of the boss portion 15 of the transmission case 10, and the lower portion of the breather plug 41 is connected to the transmission case 10. The breather plug 41 may be attached to the transmission case 10 by being screwed into the through hole 15 a of the boss portion 15.

  The breather plug 41 is formed with a through hole 41a having a circular cross section, and this through hole 41a is a gas flow path. The lower end of the through hole 41 a communicates with the breather chamber 30. The upper end of the through hole 41a communicates with one end of a breather hose 42 routed in a space around the transmission case 10 inside the vehicle. The other end (open end) 42a of the breather hose 42 is open to the atmosphere. The breather hose 42 extends upward from the transmission case 10 so that water, foreign matter, etc. do not enter from the open end 42a, and the open end 42a is opened downward or obliquely downward. Has been. A ring-shaped seal member 43 is provided on the outer peripheral portion of the breather plug 41. The seal member 43 allows water, foreign matter, and the like to enter the breather chamber 30 from the outside through a gap between the outer peripheral surface of the breather plug 41 and the inner peripheral surface of the through hole 15a of the boss portion 15 of the transmission case 10. In addition, the lubricating oil and the like are prevented from leaking from the breather chamber 30 to the outside.

  Next, the gas injection means 50 provided in the breather device 20 will be described.

  The gas injection means 50 of the breather device 20 is for forcibly sending gas into the breather chamber 30 from the outside of the transmission case 10. In this example, a compressor 51 is provided as the gas injection means 50. ing. As the compressor 51, an existing compressor mounted on a vehicle can be used. In this case, a pipe 52 for gas injection is branched from the existing compressor 51, and the pipe 52 for injection is led to the breather chamber 30. An injection pipe 52 extending from the compressor 51 is introduced into the breather chamber 30 through an opening 16 formed in the transmission case 10 constituting the wall portion of the breather chamber 30. In this way, by using the existing compressor 51 for gas injection, the number of components can be reduced and the cost can be reduced. The compressor 51 is always driven during the operation of the transaxle and injects a gas having a constant flow rate into the breather chamber 30.

  Next, the operation of the breather device 20 will be described.

  The pressure (internal pressure) inside the transmission case 10 rises and falls according to the amount of expansion / contraction of the gas, because the gas inside the transmission case 10 expands / contracts as the temperature changes. On the other hand, the gas is supplied into the breather chamber 30 through the injection pipe 52 by driving the compressor 51 which is the gas injection means 50. Accordingly, the gas in the breather chamber 30 is discharged to the outside through the breather 40.

  When the internal pressure of the transmission case 10 becomes higher than the external pressure (atmospheric pressure), the gas inside the transmission case 10 is released to the outside. At this time, the gas inside the transmission case 10 flows out through the breather chamber 30 and the breather 40. As a result, an increase in internal pressure of the transmission case 10 is prevented, and a pressure difference between the inside of the transmission case 10 and the atmosphere is eliminated.

  At this time, it is preferable that the flow direction of the gas injected by the gas injection means 50 in the breather chamber 30 is set so as not to prevent the gas inside the transmission case 10 from flowing out to the outside. In other words, the gas flow direction is set so that the gas injected by the gas injection means 50 does not enter the space C1 that houses the transmission mechanism of the transmission case 10 from the breather chamber 30. preferable. In this way, when the internal pressure of the transmission case 10 becomes higher than the atmospheric pressure, the gas inside the transmission case 10 is efficiently and smoothly discharged to the outside. It becomes possible to quickly eliminate the pressure difference from the atmosphere. Even if foreign matter such as dust is mixed in the gas sent from the gas injection means 50, the foreign matter may enter the space C <b> 1 that houses the transmission mechanism of the transmission case 10 from the breather chamber 30. It is suppressed.

  The gas flow direction can be set, for example, in a direction where the breather chamber side open end of the breather 40 (the lower end of the through hole 41a of the breather plug 41) is located. That is, it is possible to set the gas flow direction by providing guide means for guiding the gas injected into the breather chamber 30 by the gas injection means 50 toward the breather chamber side open end of the breather 40. Specifically, the shape of the injection pipe 52 introduced into the breather chamber 30 may be a shape in which the outlet 52a is opened toward the direction where the breather chamber side open end of the breather 40 is located. . In addition, the shape of the inner wall surface of the breather chamber 30 located in front of the flow direction of the gas flowing out from the outlet 52a of the injection pipe 52, in this case, the shape of the wall surface of the partition wall 31 is the gas reflected by the wall surface. It is mentioned that it is made into the shape inclined so that the flow direction of this may flow toward the direction where the breather chamber side open end of the breather 40 is located.

  On the other hand, when the internal pressure of the transmission case 10 becomes lower than the atmospheric pressure, as described above, the gas is forcedly injected into the breather chamber 30 by the gas injection means 50. As a result, the transmission As the internal pressure of the case 10 decreases, gas is prevented from being sucked into the transmission case 10 from the open end of the breather 40 (the open end 42a of the breather hose 42). Thereby, the penetration | invasion of the water (water droplet etc.) to the inside of the transmission case 10 can be prevented effectively. And, for example, even in the case of water splashing in rainy weather, passage through a submerged channel, and car washing with high-pressure washing water, preventing water from entering the transmission case 10 due to a decrease in internal pressure of the transmission case 10 Can do.

  Here, the amount of gas injected into the breather chamber 30 by the gas injection means 50 can be set in advance based on the amount of expansion / contraction of the gas accompanying the change in the internal pressure of the transmission case 10. For example, the amount of gas injected into the breather chamber 30 by the gas injection means 50 is preferably set to be equal to or greater than the maximum contraction amount of the gas inside the transmission case 10. In this case, the contraction amount at the time of the maximum contraction of the gas inside the transmission case 10 is measured in advance by a test or calculated in advance by calculation.

  In this way, even when the gas inside the transmission case 10 is maximally contracted, the gas injection means 50 injects more gas than the contraction amount into the breather chamber 30. A gas injection amount sufficient to compensate for the contraction amount of the gas inside the machine case 10 is always secured. As a result, even when the internal pressure of the transmission case 10 suddenly decreases, the suction of gas from the open end of the breather 40 to the inside of the transmission case 10 due to the decrease in the internal pressure of the transmission case 10 is completely performed. Intrusion of water (such as water droplets) into the transmission case 10 can be completely prevented.

  Although the embodiment of the breather device of the present invention has been described above, the embodiment shown here can be variously modified.

  The transmission case is a concept that includes not only a housing that houses only the transmission mechanism of the transmission, but also a housing that houses devices (such as a torque converter and a differential mechanism) coupled to the transmission mechanism. The case that houses the transaxle mentioned in the example is an example. The transmission case may be, for example, a housing that houses a transmission mounted on a front engine / rear drive (FR) vehicle.

  In the above-described example, the case where the breather 40 of the breather device 20 is constituted by the breather plug 41 and the breather hose 42 has been described. However, the breather communicates the breather chamber with the atmosphere, and from the atmosphere-side open end. Any other configuration may be used as long as it can prevent intrusion of water or foreign matter.

  For example, as shown in FIG. 3, it is good also as a structure which provides the breather apparatus 120 which does not use a breather hose in the breather apparatus 120 (modification 1). The breather 140 shown in FIG. 3 has substantially the same configuration as that shown in Patent Document 1 cited as a conventional example. Specifically, the breather 140 includes a substantially cylindrical breather plug 141 that is attached to the transmission case 10 and a cap 142 that is mounted so as to cover the atmosphere-side open end 141 b of the breather plug 141. In the case of a vehicle that can use such a breather 140, it is not necessary to route a breather hose around the transmission case 10 inside the vehicle. In the modification shown in FIG. 3, the configuration other than the portion related to the breather 140 is the same as that in the above-described example (see FIGS. 1 and 2).

  In the above-described example, the case where the gas injection unit 50 of the breather apparatus 20 is the existing compressor 51 has been described. However, if the gas injection unit can ensure a sufficient gas injection amount, Other than the compressor, for example, an existing fan mounted on the vehicle may be used.

  Moreover, it is good also as a structure which provides a dedicated thing as a gas injection | pouring means. For example, as shown in FIG. 4, it is possible to provide a dedicated electric compressor 251 as the gas injection means 250 (Modification 2). In this case, since the electric compressor 251 can be directly attached to the outer wall surface of the transmission case 10, etc., the injection pipe from the electric compressor 251 to the breather chamber can be greatly shortened, which is advantageous. Therefore, it is particularly suitable when it is difficult to route the injection piping from the compressor or the like to the breather chamber around the transmission case 10 inside the vehicle. In the example shown in FIG. 4, the configuration other than the portion related to the gas injection means 250 is the same as the above-described example (see FIGS. 1 and 2).

  In the above example, an air filter can be provided on the injection path for injecting gas from the gas injection means to the breather chamber. FIG. 5 illustrates a case where the present invention is applied to the breather device shown in FIG. 1 (Modification 3). As shown in FIG. 5, in the breather device 320, an air filter 353 is attached to the outlet 352 a of the injection pipe 352. In the example shown in FIG. 5, an air filter 353 is attached to the inner wall surface of the transmission case 10 so as to cover the opening 16. In this way, even if foreign matter such as dust is mixed in the gas sent from the gas injection means, the foreign matter is collected by the air filter 353. As a result, foreign matter can be prevented from entering the transmission case 10. In the example shown in FIG. 5, the configuration other than the portion related to the air filter 353 is the same as the above-described example (see FIGS. 1 and 2).

It is sectional drawing which shows the breather chamber of the breather apparatus which concerns on embodiment, and its periphery. It is a perspective view which shows roughly the external appearance of the transmission case in which the breather chamber of a breather apparatus is provided. It is sectional drawing which shows the modification of the breather of a breather apparatus. It is a perspective view which shows the modification of the gas injection | pouring means of a breather apparatus. It is sectional drawing which shows the modification of the breather apparatus of the structure which provided the air filter on the injection | pouring path | route which inject | pours gas from a gas injection | pouring means to a breather chamber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transmission case 20 Breather apparatus 30 Breather chamber 31 Partition part 40 Breather 41 Breather plug 42 Breather hose 50 Gas injection means 51 Compressor 52 Injection piping

Claims (3)

In a breather device comprising a breather chamber provided in an upper part of a transmission case, and a breather communicating the breather chamber with the atmosphere,
A breather apparatus comprising gas injection means for injecting gas into the breather chamber from the outside of the transmission case.   2. The breather device according to claim 1, wherein an amount of gas injected into the breather chamber by the gas injection unit is set to be equal to or greater than a maximum contraction amount of gas inside the transmission case. .   The breather apparatus according to claim 1 or 2, wherein an air filter is provided on an injection path for injecting gas from the gas injection means into the breather chamber.

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