JP2008164003A - Power transmission device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress water from entering in a case due to deformation of sealing members provided between an input shaft and an output shaft and the case as the case is rapidly cooled when a vehicle crosses a river or the vehicle is washed, in a power transmission device of the vehicle wherein a transmission unit for mechanically transmitting power of the input shaft to the output shaft is stored in the case. <P>SOLUTION: In the power transmission device of the vehicle, a transmission gear unit 24 for mechanically transmitting the power of the input shaft 22 to the output shaft 23 is stored in the case 25 and sealing members 27, 28 are provided between the input shaft 22 and the output shaft 23 and the case 25. If a reduction gradient of pressure in the case 25 estimated based on a detection signal of a pressure sensor 53 is smaller than a predetermined gradient, a communication pipe 60 is closed by an opening/closing mechanism 70. If the reduction gradient is larger than the predetermined gradient, the communication pipe 60 is opened by the opening/closing mechanism 70. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention accommodates in a case a transmission unit that mechanically transmits power of an input shaft to an output shaft, and restricts the lubricating oil supplied to the transmission unit from leaking out of the case. The present invention also relates to a vehicle power transmission apparatus in which a seal member is provided between at least one of output shafts and a case.

  As such a power transmission device, for example, a device described in Patent Document 1 is known. This power transmission device is composed of an input shaft driven by an in-vehicle internal combustion engine, an output shaft that drives a drive shaft of the vehicle via a differential, and a plurality of gears, and transmits the power of the input shaft to the output shaft. A transmission gear unit. In this power transmission device, by changing the meshing of the transmission gear unit based on the running state of the vehicle, the ratio of the rotational speeds of the input shaft and the output shaft is changed, and the power of the internal combustion engine is transmitted via the drive shaft. Is transmitted to the drive wheels of the vehicle.

Further, in the power transmission device, in order to reduce friction generated in the transmission gear unit during traveling of the vehicle, the transmission gear unit is housed in the case, and the transmission gear unit is provided by an oil pump provided in the case. Lubricating oil is supplied to each friction part. A seal member made of rubber or resin is provided between the case and the input shaft and output shaft. As a result, the airtightness of the case is suitably maintained, and leakage of the lubricating oil in the case to the outside of the case is suppressed.
JP 2004-125155 A

  By the way, for example, when the vehicle is crossed or washed, if the case is cooled by water, the pressure in the case decreases as the temperature of the case decreases. Here, for example, when the case is rapidly cooled under the condition that the seal member is submerged, the above-mentioned seal member is deformed due to excessive increase in the internal / external pressure difference of the case, and external water is There is a risk of entering the case from the seal member. If water enters the case in this way, there is a possibility that inconveniences such as a decrease in the lubricating effect of the lubricating oil and the occurrence of rust may occur.

  In addition, although the power transmission device having the transmission gear unit functioning as the transmission unit has been described, the power transmission device is not limited to the same device, and another power transmission device in which the transmission unit that transmits the power of the input shaft to the output shaft is accommodated in the case. Can occur almost in common.

  The present invention has been made in view of such a conventional situation, and an object thereof is a vehicle power transmission device in which a transmission unit that mechanically transmits power of an input shaft to an output shaft is housed in a case. When the vehicle crosses or is washed, the case is cooled rapidly, and the seal member provided between the input shaft and output shaft and the case is deformed, so that water enters the case. It is to suppress.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, a transmission unit that mechanically transmits the power of the input shaft to the output shaft is accommodated in the case, and the lubricant supplied to the transmission unit is restricted from leaking out of the case. Therefore, a vehicle power transmission device in which a seal member is provided between at least one of the input shaft and the output shaft and the case, the estimation means for estimating a pressure decrease gradient in the case, The communication path that is connected to the case and opens in the vertical direction above the seal member, and when the lowering gradient estimated by the estimation means is equal to or less than a predetermined gradient, the communication path is closed, while the estimation means The gist of the present invention is to provide an opening / closing mechanism that opens the communication passage when the estimated lowering gradient is larger than a predetermined gradient.

  According to this configuration, when the pressure decreasing gradient in the case is equal to or lower than a predetermined gradient, that is, when the case is not rapidly cooled, the communication path is closed by the opening / closing mechanism, so that the case is kept airtight. It is possible to prevent the lubricating oil in the case from being scattered outside through the communication path. On the other hand, when the pressure decreasing gradient in the case is larger than a predetermined gradient, the open / close mechanism opens the communication path, so that external air can be introduced into the case through the communication path. It is possible to suppress a decrease in pressure. Therefore, for example, even when the case is rapidly cooled under the condition that the sealing member that ensures the airtightness of the case is submerged by crossing or car washing, the pressure difference between the inside and outside of the case will increase excessively. It becomes possible to suppress the intrusion of water due to the deformation of the seal member. As a result, with the above configuration, for example, when the vehicle crosses or is washed, the case is rapidly cooled, and the seal member provided between the input shaft or the output shaft and the case is deformed. It becomes possible to suppress water from entering the inside.

  In addition, as described in claim 2, it is desirable to adopt a configuration in which the opening of the communication passage is installed vertically above the highest design position of the submerged position of the vehicle. According to such a configuration, when external air is introduced into the case through the communication path, it is possible to suppress water from flowing into the case through the communication path as much as possible.

  According to a third aspect of the present invention, in the vehicle power transmission device according to the first or second aspect, the estimating means includes a pressure sensor that detects a pressure in the case, and based on a detection value of the pressure sensor. The gist is to estimate the pressure decrease gradient in the case.

  According to the same configuration, the pressure in the case is directly detected via the pressure sensor, and the pressure decrease gradient is estimated based on the detected value. Compared with the case of estimating the gradient, the pressure decrease gradient in the case can be estimated more accurately.

  According to a fourth aspect of the present invention, in the vehicle power transmission device according to any one of the first to third aspects, when the pressure in the case is greater than a predetermined pressure, the inside of the case communicates with the outside and is the same. The gist of the invention is to include a decompression means for decompressing the inside of the case.

  During normal traveling of the vehicle, the pressure in the case housing the transmission unit may rise due to heat generated by the transmission unit. Here, when the pressure in the case rises excessively, there is a concern that the lubricating oil in the case leaks to the outside due to deformation of the seal member.

  In this regard, according to the above configuration, when the pressure in the case is larger than a predetermined pressure, the pressure in the case is excessively increased by reducing the pressure in the case by communicating the inside of the case with the outside. Can be suppressed. Therefore, it is possible to suppress the leakage of the lubricating oil due to the increase in the pressure in the case.

  According to a fifth aspect of the present invention, the pressure reducing means includes the communication path and the opening / closing mechanism, and when the pressure in the case is larger than a predetermined pressure, the decreasing gradient estimated by the estimating means is a predetermined value. The gist of the invention is to open the communication path by the opening / closing mechanism even if it is below the gradient.

  According to this configuration, for example, when the pressure in the case is larger than a predetermined pressure, compared to the case where the inside and the outside of the case are communicated by a communication mechanism provided separately from the communication path and the opening / closing mechanism. Thus, it is possible to simplify the configuration of the power transmission device.

Hereinafter, an embodiment in which a power transmission device according to the present invention is applied to an automatic transmission mounted in a drive system of a vehicle will be described with reference to FIGS.
FIG. 1 shows a schematic structure of a vehicle drive system according to the present embodiment. As shown in FIG. 1, in the vehicle drive system 100, an automatic transmission 20 is connected to the internal combustion engine 10. The automatic transmission 20 has an input shaft 22 connected to the output shaft 11 of the internal combustion engine 10 via a torque comparator 21, and an output shaft 23 connected to a vehicle drive shaft 40 via a differential gear 30. Has been. The power of the input shaft 22 is mechanically transmitted to the output shaft 23 through a transmission gear unit 24 constituted by a plurality of gears. A part of the input shaft 22 and the output shaft 23 and the transmission gear unit 24 are accommodated in a case 25 of the automatic transmission 20.

  By changing the meshing relationship of each gear in the transmission gear unit 24, in other words, the gear position of the automatic transmission 20, the ratio of the rotational speed between the output shaft 23 and the input shaft 22, in other words, the input shaft 22 The ratio between the input torque and the output torque of the output shaft 23 is changed.

  Further, the vehicle drive system 100 is provided with an electronic control device 50 that performs overall control of the drive system 100 of the vehicle. The electronic control device 50 includes, for example, a vehicle speed for detecting a vehicle speed. Sensors such as a sensor 51 and a rotation speed sensor 52 that detects the rotation speed of the output shaft 11 of the internal combustion engine 10 are connected. The electronic control unit 50 controls the gear position of the automatic transmission 20 based on the driving state of the vehicle detected by the vehicle speed sensor 51 and the rotation speed sensor 52. Then, the differential gear 30 transmits the torque of the output shaft 23 to each drive wheel 41 of the vehicle via the drive shaft 40. The electronic control device 50 includes a memory 50a that stores programs and data necessary for the control.

  An oil pump 26 is provided in the case 25 of the automatic transmission 20, and lubricating oil is supplied from the oil pump 26 to each friction part of the transmission gear unit 24. Further, seal members 27 and 28 formed of rubber, resin, or the like are provided between the case 25 and the input shaft 22 and the output shaft 23, respectively. Thereby, the airtightness of the case 25 is suitably maintained, and leakage of the lubricating oil in the case 25 to the outside of the case is suppressed.

  By the way, as described above, for example, when the vehicle crosses or is washed, if the case 25 is rapidly cooled with the seal members 27 and 28 being submerged, the pressure difference between the inside and outside of the case 25 increases excessively. As a result, the above-described seal member is deformed, and external water may enter the case 25 from the seal members 27 and 28. When water enters the case 25 in this way, there is a risk that inconveniences such as a decrease in the lubricating effect of the lubricating oil and the occurrence of rust may occur. Therefore, the automatic transmission 20 according to the present embodiment employs a configuration that suitably suppresses such inconvenience. Hereinafter, this configuration will be described in detail.

  As shown in FIG. 1, the case 25 is provided with a pressure sensor 53 that detects the pressure inside the case 25, and a detection signal of the pressure sensor 53 is taken into the electronic control unit 50. Further, the case 25 is connected to a communication pipe 60 that opens in the vertical direction above the design maximum position of the submerged position of the vehicle. An opening / closing mechanism 70 that switches between a closed state and an open state of the opening 60 a is provided in the opening 60 a of the communication pipe 60.

  FIG. 2 is a cross-sectional view showing the cross-sectional structure of the opening / closing mechanism 70. FIG. 2 (a) shows a state in which the opening 60a is closed by the opening / closing mechanism 70, and FIG. A state where the opening 60a is opened is shown.

  As shown in FIG. 2A, the opening / closing mechanism 70 has a housing 71 fixed to the tip of the communication pipe 60, and the bottom of the housing 71 communicates with the inside and outside of the housing 71. A hole 71a is formed. A core 72 is attached to the inner peripheral surface of the housing 71, and a coil 73 is fixed to the core 72. A valve body 74 made of a magnetic material is inserted into a guide portion 72a formed at the center of the core 72. The valve body 74 is slidably supported by the guide portion 72a. A spring 75 is provided between the core 72 and the valve body 74, and the valve body 74 is biased toward the opening 60 a of the communication pipe 60 by the spring 75.

  The energization and the stop of the coil 73 are controlled by the electronic control unit 50 based on the detection result of the pressure sensor 53. Here, when energization to the coil 73 is stopped, the valve body 74 is biased toward the opening 60a by the spring 75 as shown in FIG. 2A, and the opening 60a is closed by the valve body 74. Become so. On the other hand, when the coil 73 is energized, the electromagnetic force generated in the core 72 exceeds the urging force of the spring 75 and the valve body 74 moves upward as shown in FIG. The opening 60a is opened.

  In this embodiment, the elastic coefficient of the spring 75 is set so that the force based on the internal pressure exceeds the urging force of the spring 75 when the internal pressure of the case 25 is larger than a predetermined pressure. Yes. Therefore, when the internal pressure of the case 25 is larger than the predetermined pressure, the opening 60a is opened and the gas inside the case 25 is opened as shown in FIG. 3 even when the power supply to the coil 73 is stopped. 60a and the communication hole 71a are led out to the outside.

  Next, a procedure for controlling the opening / closing valve of the opening / closing mechanism 70 by the electronic control device 50 will be described with reference to the flowchart of FIG. The series of processing shown in this flowchart is repeatedly executed by the electronic control device 50 with a predetermined period.

  In this process, first, the pressure P1 in the case 25 is detected via the pressure sensor 53 (step 10). Based on the pressure P1 in the case 25 detected in the current control cycle and the pressure P0 in the case 25 detected in the previous control cycle, the pressure drop gradient S in the case 25 is calculated as Calculation based on (1) (step 20).

S = (P0−P1) / Δt (1)
Δt: Control cycle

Then, it is determined whether or not the calculated decreasing gradient S is larger than a predetermined gradient S0 stored in advance in the memory 50a (step 30). Here, when the decrease gradient S is larger than the predetermined gradient S0, that is, when the case 25 is rapidly cooled (step 30: YES), the coil 60 of the opening / closing mechanism 70 is energized to open the opening 60a. Release (step 40). Thus, as indicated by the arrow in FIG. 2B, external air flows into the communication pipe 60 through the communication hole 71a and the opening 60a and is introduced into the case 25. On the other hand, when the decrease gradient S is equal to or less than the predetermined gradient S0, that is, when the case 25 is not rapidly cooled (step 30: NO), as shown in FIG. By stopping energization, the opening 60a is closed (step 50).

According to the embodiment described above, the following effects can be obtained.
(1) When the pressure decrease gradient S in the case 25 is equal to or less than the predetermined gradient S0, that is, when the case 25 is not rapidly cooled, the communication pipe 60 is closed by the opening / closing mechanism 70. Therefore, the airtightness of the case 25 can be maintained, and the lubricating oil in the case can be suppressed from being scattered outside through the communication pipe 60. On the other hand, when the pressure decrease gradient S in the case 25 is larger than the predetermined gradient S0, the communication pipe 60 is opened by the opening / closing mechanism 70, so that external air is introduced into the case 25 through the communication pipe 60. It is possible to suppress the pressure drop in the case 25. Therefore, even when the sealing members 27 and 28 for ensuring the airtightness of the case 25 are submerged by crossing or washing the car, the pressure difference between the inside and outside of the case 25 is excessive. The increase can be suppressed, and the intrusion of water due to the deformation of the seal members 27 and 28 can be suppressed. As a result, with the above configuration, for example, when the vehicle crosses or is washed, the case 25 is rapidly cooled, and the seal member provided between the input shaft 22 or the output shaft 23 of the automatic transmission 20 and the case 25 case. It becomes possible to prevent water from entering the case due to the deformation of 27 and 28.

  (2) The opening 60a of the communication pipe 60 is installed vertically above the highest design position of the submerged position of the vehicle. Thus, when external air is introduced into the case 25 via the communication pipe 60, it is possible to suppress water from flowing into the case 25 via the communication pipe 60 as much as possible.

  (3) In order to directly detect the pressure in the case 25 via the pressure sensor 53 and calculate the pressure decrease gradient S based on the detected value, for example, the pressure in the case 25 based on the temperature change outside the case 25 As compared with the case of estimating the decrease gradient, the pressure decrease gradient in the case 25 can be estimated more accurately.

  (4) When the pressure in the case 25 is higher than a predetermined pressure, the inside and the outside of the case 25 are communicated. Therefore, it is possible to prevent the pressure in the case 25 from excessively rising due to heat generated by the transmission gear unit 24 during normal traveling of the vehicle. As a result, it is possible to suppress deformation of the seal members 27 and 28 caused by excessive increase in the pressure in the case 25, and to prevent the lubricating oil in the case 25 from leaking to the outside. become.

  (5) When the pressure in the case 25 is larger than a predetermined pressure, the inside and the outside of the case 25 are communicated by the communication pipe 60 and the opening / closing mechanism 70. Therefore, for example, when the pressure in the case 25 becomes larger than a predetermined pressure, compared to the case where the inside and the outside of the case 25 are communicated by a communication mechanism provided separately from the communication pipe 60 and the opening / closing mechanism 70. Thus, it is possible to simplify the configuration of the power transmission device.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, when the pressure in the case 25 is larger than a predetermined pressure, the inside of the case 25 is communicated with the outside by the communication pipe 60 and the opening / closing mechanism 70 so that the inside of the case 25 is decompressed. Yes. On the other hand, the elastic coefficient of the spring 75 is set so that the internal pressure of the case 25 exceeds the urging force of the spring 75 when the pressure in the case 25 is larger than a predetermined pressure due to, for example, structural design limitations. If this is difficult, a configuration in which the inside of the case 25 is decompressed by a communication mechanism provided separately from the communication pipe 60 and the opening / closing mechanism 70 may be employed. Further, for example, when the transmission gear unit 24 is suitably cooled while the vehicle is running by circulating lubricating oil, and the increase in pressure in the case 25 due to the heat generated by the transmission gear unit 24 can be ignored, the case 25 It is possible to omit a communication mechanism for reducing the pressure inside.

  In the above-described embodiment, the pressure in the case 25 is directly detected via the pressure sensor 53, and the pressure decrease gradient S is calculated based on the detected value. Can be provided at a position in contact with water when the vehicle crosses, and the pressure drop gradient can be estimated based on the temperature detected by the outside air temperature sensor.

  In the above embodiment, the opening 60a of the communication pipe 60 is installed vertically above the design maximum position of the submerged position of the vehicle. However, the opening 60a is freely installed due to space restrictions, for example. If this is difficult, it is not always necessary to install the opening 60a vertically above the highest design position.

  In the above embodiment, the case where the present invention is applied to an automatic transmission mounted on a drive system of a vehicle is illustrated, but the present invention is not limited to this, for example, a manual transmission housed in a case, a differential gear, etc. The present invention can be basically applied to other power transmission devices in the same manner.

The block diagram which shows the schematic structure about the transmission system of the vehicle concerning this embodiment. (A), (b) Sectional drawing which shows the cross-section about the opening-closing mechanism concerning the embodiment. Sectional drawing which shows the cross-sectional aspect about the opening / closing mechanism when the pressure in the case concerning the embodiment is larger than predetermined pressure. The flowchart which shows the process sequence about the on-off valve control of the on-off mechanism concerning the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Output shaft, 20 ... Automatic transmission, 21 ... Torque comparator, 22 ... Input shaft, 23 ... Output shaft, 24 ... Transmission gear unit, 25 ... Case, 26 ... Oil pump, 27 ... Seal Members 28... Seal members 30. Differential gears 40 drive shafts 41 drive wheels 50 electronic control devices 50 a memories 51 vehicle speed sensors 52 rotational speed sensors 53 pressure sensors 60 Communication pipe, 60a ... opening, 70 ... opening / closing mechanism, 71 ... housing, 71a ... communication hole, 72 ... core, 72a ... guide part, 73 ... coil, 74 ... valve body, 75 ... spring, 100 ... drive system.

Claims (5)

A transmission unit that mechanically transmits the power of the input shaft to the output shaft is housed in the case, and the input shaft and the output are controlled to prevent the lubricating oil supplied to the transmission unit from leaking out of the case. A vehicle power transmission device in which a seal member is provided between at least one of the shafts and the case,
Estimating means for estimating a pressure drop gradient in the case, a communication path connected to the case and opening vertically above the seal member, and the drop gradient estimated by the estimating means is a predetermined gradient. An opening / closing mechanism that closes the communication path when the following is established, and opens the communication path when the lowering gradient estimated by the estimation means is greater than a predetermined gradient. . The power transmission device for a vehicle according to claim 1,
The vehicle power transmission device, wherein the opening of the communication path is installed vertically above the highest design position of the submerged position of the vehicle. The power transmission device for a vehicle according to claim 1 or 2,
The power transmission device for a vehicle, wherein the estimation means includes a pressure sensor that detects a pressure in the case, and estimates a pressure decrease gradient in the case based on a detection value of the pressure sensor. In the vehicle power transmission device according to any one of claims 1 to 3,
A vehicle power transmission device comprising: a decompression unit that communicates the inside of the case with the outside and decompresses the inside of the case when the pressure in the case is greater than a predetermined pressure. The vehicle power transmission device according to claim 4,
The pressure reducing means includes the communication path and the opening / closing mechanism, and the opening / closing mechanism when the pressure in the case is greater than a predetermined pressure, even if the decreasing gradient estimated by the estimating means is equal to or less than a predetermined gradient. The vehicle power transmission device according to claim 1, wherein the communication path is opened.

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