JP2008121860A - Oil level adjustment device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil level adjusting device of an automatic transmission, eliminating difference in oil level due to the temperature of oil to surely prevent discharging oil with air by a breather plug to the outside while suppressing the rotational resistance of a final ring, and enough supplying oil for lubrication between the gears. <P>SOLUTION: In this oil level adjusting device of the automatic transmission, an oil pan 2 is provided with a flat plate-like split pan 23 for vertically splitting the content volume into an upper volume part 21 and a lower volume part 22. The split pan 23 is provided with an inlet pipe 24 erected for introducing oil exceeding the oil level X at an ordinary oil temperature out of the oil of the upper volume part 21 stored on the split pan 23 into the lower volume part 22. An oil suction port 42a of a suction pipe 42 for sucking oil by an oil pump is opened to the lower part side in the lower volume part 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an oil level adjusting device that makes the oil level of oil in an oil pan provided at the lower end of a case of an automatic transmission constant.

  Generally, oil is used for shifting operation and lubrication of an automatic transmission, and oil pressure for performing the shifting operation is generated by an oil pump. Oil accumulated in the oil pan is sucked up by the oil pump to become pressure oil, adjusted to a constant hydraulic pressure by the regulator valve, and in response to commands from the manual valve, shift valve, etc., the pressure oil is applied to each clutch brake control element. The oil is divided and sent, and the shift operation is performed. At the same time, the oil is also sent to the torque converter and the lubrication circuit so as to return to the oil pan through the oil passage.

On the other hand, the gears of the automatic transmission, such as the final gear of the differential mechanism, are placed in the oil stored in the oil pan so that the lower part of the gear is immersed, and the oil is scraped along with the rotation of the gear in which the lower part is immersed. There is one in which the raised oil is splashed on other gears in the vicinity so that the oil in the oil pan is also used for lubrication between the gears (for example, see Patent Document 1).
JP-A-8-11560

  By the way, in the case of a small automatic transmission, the outer shape of the oil pan is reduced in order to reduce the size, and the volume of oil in the automatic transmission is also reduced. In this way, when the oil capacity is small, it is easily affected by temperature changes. For example, if the automatic transmission is left in a low temperature atmosphere where the outside air temperature is −20 ° C., the oil in the automatic transmission becomes semi-jelly. The oil level of the oil which contracts and accumulates in an oil pan will fall. On the other hand, when the oil is warmed, the oil itself expands, so that the oil level of the oil accumulated in the oil pan increases.

  In that case, if the gear is arranged so that the lower part is immersed in the oil in the oil pan as in the above-mentioned conventional one, the oil level of the oil stored in the oil pan is affected by the temperature and the difference in height is detected. When this occurs, the position of the oil level with respect to the gear naturally changes. For this reason, when the oil is at a low oil temperature, the oil level of the oil is lowered, so that the oil that has been scraped along with the rotation of the gear cannot be sufficiently splashed on other gears in the vicinity. The oil inside cannot be sufficiently used for lubricating the gears. On the other hand, when the oil is at a high temperature, the oil level of the oil becomes high, so that the rotational resistance of the gear increases and the amount of oil scraped up along with the rotation of the gear increases. There is a risk that the plug may be covered with oil, and when the air is released from the case by the breather plug, there is a concern that the oil is discharged to the outside together with the air.

  The present invention has been made in view of the above points, and an object of the present invention is to eliminate the difference in oil level due to the oil temperature of the oil, and to suppress the external rotation caused by the breather plug while suppressing the rotational resistance of the gear. Another object of the present invention is to provide an oil level adjusting device for an automatic transmission that can reliably prevent oil from being discharged to the oil and can sufficiently provide oil to lubricate gears.

  In order to achieve the above object, according to the present invention, as an oil level adjusting device for an automatic transmission, an oil pan for storing oil is provided at a lower end portion of a case of the automatic transmission, and oil accumulated in a lower portion of the oil pan is provided. Provide an oil suction port for pumping up oil. The oil pan is provided with an introduction pipe that guides oil that exceeds a certain height among the oil in the upper volume portion accumulated on the divided pan to the lower volume portion below.

  According to this specific matter, when the oil accumulated on the divided pan that divides the inner volume of the oil pan into two parts, the upper volume part and the lower volume part, that is, the oil accumulated in the upper volume part exceeds a certain height, The oil exceeding the certain height is guided to the lower volume below the upper end opening of the introduction pipe, and the oil in the upper volume accumulated on the dividing pan is always kept at a certain height and the oil due to the oil temperature. There is no difference in surface height. As a result, even when the oil is at a low temperature, the oil scooped up with the rotation of the gear is sufficiently splashed to other nearby gears, and the oil in the oil pan is sufficiently lubricated between the gears. It becomes possible to provide. On the other hand, even when the oil is hot, the rotational resistance of the gear is suppressed, and the amount of oil that is scraped up with the rotation of the gear is controlled to a uniform amount without being increased. The breather plug is not covered with oil, and it is possible to reliably prevent the oil from being discharged to the outside due to the air when the air is discharged from the case by the breather plug.

  Further, when the introduction pipe is extended upward from the divided pan so that the opening end (upper end opening) matches the oil level at the time of low oil temperature of the oil accumulated in the upper volume portion In the upper volume part, only the capacity below the oil level at the time of low oil temperature is accumulated, and all the oil exceeding the oil level at the low oil temperature is led into the lower volume part through the introduction pipe. Thus, the oil in the lower volume portion is sufficiently secured, and it becomes possible to effectively prevent the biting of air when pumping up the oil from the oil suction port.

  In short, the oil pan that divides the internal volume of the oil pan into the upper volume part and the lower volume part into two parts in the vertical direction is divided into oil that exceeds a certain height accumulated in the upper volume part on the divided pan. By erecting the introduction pipe that leads to the volume section, the oil in the upper volume section is always kept at a constant height without causing a difference in oil level due to the oil temperature, and the rotation of the gear when the oil temperature is low. The oil that is pumped up can be sufficiently splashed to other gears in the vicinity to provide sufficient lubrication between the gears, and the oil accompanying the rotation of the gear while suppressing the rotation resistance of the gear at a high temperature of the oil. It is possible to reliably prevent the oil from being discharged to the outside due to the air by the breather plug by regulating the amount of scooping up to a uniform amount.

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

  FIG. 1 is a cross-sectional view of a case of an automatic transmission provided with an oil level automatic adjusting device as viewed from one side in the left-right direction of the vehicle body. ing. The automatic transmission 1 is mounted laterally with respect to a vehicle body.

  The case 10 includes a transaxle case 11, a rear case joined to one side of the transaxle case 11 in the left-right direction of the vehicle body, and a transaxle housing joined to the other side of the transaxle case 11 in the left-right direction of the vehicle body. Yes. A torque converter is housed inside the transaxle housing, and a speed change mechanism (not shown) is housed inside the transaxle case 11. A shallow box-shaped oil pan 2 for storing oil is provided at the lower end of the case 10 (transaxle case 11). The oil stored in the oil pan 2 is used as an operating oil for the torque converter, as a lubricating oil for the speed change mechanism, and an actuator (not connected to the friction engagement elements such as a clutch and a brake of the speed change mechanism). The hydraulic oil (not shown) is supplied by an oil pump (not shown). The oil supplied by the oil pump is collected through a predetermined oil passage in the torque converter and the actuator, and through the inner wall surface of the case 10 (transaxle case 11) in the transmission mechanism. When the automatic transmission 1 is stopped, the oil in the oil pan 2 is required to have an oil level of a predetermined level or higher, that is, an oil level of a predetermined level or higher. It is necessary to replenish appropriately. If the amount of oil is insufficient, the torque converter and actuator described above may not work well, and the amount of wear of planetary gear rotating elements (sun gear, planetary gear, carrier, ring gear, etc.) constituting the speed change mechanism may increase. become.

  On the upper side in the transaxle case 11, a main transmission mechanism having an output shaft (not shown) connected to a torque converter, a planetary gear, and the like, and a sub-transmission mechanism having a drive pinion (not shown) are disposed. . A differential mechanism 12 is disposed on the lower side in the transaxle case 11. The differential mechanism 12 is provided near the rear side of the vehicle body in the transaxle case 11 (left side in the figure).

  The oil pan 2 is provided near the vehicle body front side (right side in the drawing) of the lower end portion of the transaxle case 11, and a thin box shape attached to the lower end portion of the transaxle case 11 is provided above the oil pan 2. A valve body 3 is provided. The suction side of the oil pump is connected to the valve body 3 via an oil passage 41. The oil passage 41 is connected to the suction pipe 42 through the inside of the valve body 3. The suction pipe 42 penetrates the divided pan 23 (described later) and extends further downward, and an oil suction port 42 a at the lower end thereof is opened at the bottom of the oil pan 2. The oil stored in the oil pan 2 is pumped up through the oil passage 41 after passing through the suction pipe 42 and the inside of the valve body 3 by the oil pump.

  The oil pan 2 includes a flat plate-like divided pan 23 that divides the internal volume into an upper volume portion 21 and a lower volume portion 22 in the vertical direction. In this divided pan 23, oil that exceeds a certain height (oil level X at normal oil temperature described later) of the oil in the upper volume portion 21 accumulated on the divided pan 23 is placed below the lower volume portion 22. An introduction pipe 24 to be introduced is installed upright. The introduction pipe 24 extends upward from the divided pan 23 so that the opening end 24a matches the oil level X of the oil accumulated in the upper volume portion 21 at the normal oil temperature. In this case, the amount of oil stored in the oil pan 2 when the automatic transmission 1 is stopped, that is, the oil level X is located near the lower end portion in the transaxle case 11 beyond the oil pan 2 and the differential mechanism 12 The height is such that the lower portion of the large-diameter finaling gear 12a is immersed. The divided pan 23 and the introduction pipe 24 constitute an oil level adjusting device 5.

  Therefore, in the above embodiment, the oil accumulated on the divided pan 23 that divides the internal volume of the oil pan 2 into the upper volume portion 21 and the lower volume portion 22 in the vertical direction, that is, the oil accumulated in the upper volume portion 21 is usually When the oil level X exceeds the oil level X at the oil temperature, the oil exceeding the oil level X at the normal oil temperature is guided to the lower volume portion 22 below the opening end 24a of the introduction pipe 24 and collected on the divided pan 23. The oil in the upper volume portion 21 is always kept at the oil level X at the normal oil temperature, so that the oil level difference due to the oil temperature does not occur. As a result, even when the oil is at a low oil temperature, the oil scooped up along with the rotation of the final gear 12a of the differential mechanism 12 is sufficiently splashed to other nearby gears, Oil can be sufficiently provided for the lubrication between the gears. On the other hand, even when the oil temperature is high, the rotational resistance of the final ring gear 12a of the differential mechanism 12 can be suppressed without increasing, and the amount of oil scraped up along with the rotation of the final ring gear 12a does not increase. Therefore, the oil is not covered by the breather plug at the upper part of the case 10 of the automatic transmission 1, and the air is discharged from the case 10 by the breather plug. Oil discharge can be reliably prevented.

  In addition, since the introduction pipe 24 extends upward from the split pan 23 so that the opening end 24a matches the oil level X at the normal oil temperature, the upper volume portion 21 has a normal oil temperature at the normal oil temperature. Only the oil level X or less of the oil level X is accumulated, and all the oil exceeding the oil level X at the normal oil temperature is guided into the lower volume portion 22 through the introduction pipe 24, and the oil in the lower volume portion 22 is Is sufficiently secured, and it is possible to effectively prevent air from being bitten when the oil is pumped up from the oil suction port 42a of the suction pipe 42 by the oil pump.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above embodiment, the opening end 24a is made to match the oil level X at the normal oil temperature. However, as shown in FIG. 2, the introduction pipe 25 is a low oil that accumulates in the upper volume portion 21. You may be extended upward from the division | segmentation pan 23 so that it may become the height which the opening end 25a corresponds to the oil level Y at the time of temperature. In that case, only the capacity below the oil level Y at the low oil temperature of the oil is accumulated in the upper volume portion 21, and all the oil exceeding the oil level Y at the low oil temperature falls through the introduction pipe 25. As a result, the oil in the lower volume 22 is more sufficiently secured, and it is more effective to bite the air when the oil is pumped from the oil suction port 42a of the suction pipe 41 by the oil pump. Can be prevented.

It is sectional drawing which looked at the transaxle case of the automatic transmission provided with the oil level adjustment apparatus which concerns on embodiment of this invention from the vehicle body left-right direction one side. It is the FIG. 1 equivalent figure which concerns on the modification of embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 10 Case 2 Oil pan 21 Upper capacity | capacitance part 22 Lower capacity | capacitance part 23 Division | segmentation pans 24 and 25 Introduction pipes 24a and 25a Open end 42a Oil suction port 5 Oil level adjustment apparatus Y Oil level at the time of low oil temperature

Claims (2)

An oil pan for storing oil is provided at the lower end of the case of the automatic transmission, and an oil suction port for pumping up oil accumulated in the lower portion of the oil pan is provided.
The oil pan includes a divided pan that divides the internal volume into an upper volume portion and a lower volume portion in the vertical direction, and the divided pan includes the oil in the upper volume portion that has accumulated on the divided pan. An oil level adjusting device for an automatic transmission, characterized in that an introduction pipe is provided to guide oil exceeding a certain height to a lower volume part below. The oil level adjusting device for an automatic transmission according to claim 1,
The automatic transmission is characterized in that the introduction pipe extends upward from the divided pan so that the opening end matches a level of oil at a low oil temperature of the oil accumulated in the upper volume portion. Oil level adjuster.

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