JP2008151170A - Oil level detection method of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly measure an excess and deficiency amount of oil when the oil in an oil pan is returned to a normal oil level. <P>SOLUTION: In the most ascending position of a cylindrical member 52 for oil level detection in which an upper end opening 52a is positioned above the oil level ascending by the thermal expansion of the oil, an oil level detection method of an automatic transmission comprises a first process to move the cylindrical member for oil level detection from the most ascending position downward after a lower end opening 52b is formed, a second process to stop the moving of the cylindrical member for the oil level detection when the top end opening 52a reaches the oil level, and the oil starts to flow out of the lower end opening, a third process to measure the stop position of the cylindrical member for the oil level detection, and to detect the oil level according the measurement results, and a fourth process to calculate the excess and deficiency of the oil according to a distance moved downward of the cylindrical member for the oil level detection when the top end opening reaches the normal oil level, and the distance moved to the stop position of the cylindrical member for oil level detection. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for detecting an oil level of hydraulic oil stored in an oil reservoir provided in a lower part of an automatic transmission such as an automobile, and more particularly to an operation when returning hydraulic oil in an oil reservoir to a normal oil level. It relates to measures to enable quick measurement of excess and deficiency of oil.

  Generally, in an automatic transmission such as an automobile, hydraulic oil for the automatic transmission is supplied to each part of the automatic transmission for its operation and lubrication. This hydraulic oil is stored in an oil reservoir comprising an oil pan provided at the lower part of the automatic transmission.

  In that case, if too much hydraulic oil is stored in the oil reservoir, it may overflow to the outside when the hydraulic oil thermally expands as the temperature rises.If too little hydraulic oil is stored in each part of the automatic transmission, There is a possibility that it will be difficult to be supplied to. Therefore, an appropriate predetermined amount of hydraulic oil necessary for the operation and lubrication of the automatic transmission is stored in the oil reservoir.

  As described above, when an appropriate predetermined amount of hydraulic oil is stored in the oil reservoir, the oil level of the hydraulic oil in the oil reservoir is conventionally detected. As a detection device for detecting the oil level, for example, as shown in Patent Document 1, an oil level detection hole penetrating the bottom of the oil reservoir in the vertical direction and an upper end opening of the oil level detection hole are provided to be freely opened and closed. A lid that is screwed from below into a female thread portion formed on the inner peripheral surface of the oil level detection hole and closes the lower end opening of the oil level detection hole; A cylindrical member for oil level detection in which a male screw portion on the outer peripheral surface is screwed into a female screw portion formed on the peripheral surface and moves in the vertical direction, and is detachably provided at a lower end opening of the cylindrical member for oil level detection. And a cock for closing the lower end opening at the time of mounting. When detecting the oil level of the hydraulic oil stored in the oil reservoir, after removing the closing cock from the lower end opening of the oil level detection hole and opening the lower end opening, the internal thread portion of the oil level detection hole On the other hand, the oil level detecting cylindrical member screwed with the male screw portion is rotated and moved upward. By moving the oil level detecting cylindrical member upward, the lid of the oil level detecting hole is pushed up to open the upper end opening, and the oil level detecting cylindrical member is moved further upward to reach the highest position.

  In this case, the position at which the oil level detection tubular member reaches the highest position is the position where the upper end opening of the oil level detection tubular member matches the normal oil level of the hydraulic oil stored in the oil reservoir. Therefore, the oil level is detected using this position as the reference position of the oil level detecting tubular member.

  That is, when the cock is removed from the lower end opening of the oil level detecting cylindrical member, the hydraulic oil flows out from the lower end opening along the inner peripheral surface from the upper end opening at the reference position of the oil level detecting cylindrical member, It is detected that the oil level of the hydraulic oil is higher than the normal oil level. At this time, when the hydraulic oil finishes flowing out from the lower end opening of the oil level detection tubular member, the oil level of the hydraulic oil in the oil reservoir is returned to the normal oil level.

On the other hand, when the cock is removed from the lower end opening at the reference position of the oil level detecting cylindrical member, if hydraulic oil does not flow out from the lower end opening along the inner peripheral surface from the upper end opening of the oil level detecting cylindrical member, It is detected that the hydraulic oil level is lower than the normal oil level. At this time, the hydraulic oil is supplied from the oil supply port until the hydraulic oil flows out from the lower end opening through the inner peripheral surface from the upper end opening of the oil level detection cylindrical member, and operates from the lower end opening of the oil level detection cylindrical member. When the oil starts to flow out, the oil level of the hydraulic oil in the oil reservoir is returned to the normal oil level.
JP 2003-172438 A

  By the way, there is a factor in the occurrence of excess and deficiency in the hydraulic oil when the oil level is detected, and there is a demand to measure the amount of hydraulic oil flowing out and the amount of hydraulic oil replenished when the oil level is detected. .

  In that case, in the above-mentioned conventional one, the highest level of the oil level detection tubular member is the reference position, so the oil level of the hydraulic oil in the oil reservoir coincides with the upper end opening of the oil level detection tubular member. Until then, the excess or deficiency of hydraulic oil in the oil reservoir cannot be measured.

  In other words, when the oil level of the hydraulic oil in the oil reservoir is higher than the normal oil level, it is necessary to wait until the excess hydraulic oil finishes flowing out from the lower end opening of the oil level detection tubular member. The excess amount of hydraulic oil cannot be measured until the hydraulic oil has flowed out from the lower end opening of the level detection tubular member. On the other hand, when the oil level of the hydraulic oil in the oil reservoir is lower than the normal oil level, the hydraulic oil is supplied into the oil reservoir, and the hydraulic oil in the oil reservoir reaches the normal oil level and reaches the oil level. It is necessary to wait until it starts to flow out from the lower end opening of the detection cylindrical member, and the shortage of hydraulic oil cannot be measured until the hydraulic oil starts to flow out due to replenishment. For this reason, the excess or deficiency of the hydraulic oil when returning the oil level of the hydraulic oil in the oil reservoir to the normal oil level cannot be measured until the end of the outflow or the start of the outflow. Measurement takes time.

  In addition, when the oil level detection tubular member is at the reference position, the lower end opening of the oil level detection tubular member is provided if the hydraulic oil level in the oil reservoir is higher than the normal oil level. As soon as the cock is removed and the lower end opening is opened, the working oil flows out, and the outflowing working oil stains the operator's hand removing the cock.

  The present invention has been made in view of the above points, and an object of the present invention is to return the working oil in the oil reservoir to a normal oil level while preventing hand oil from being soiled when the oil level is detected. It is an object of the present invention to provide an oil level detection method for an automatic transmission that can quickly measure the excess or deficiency of hydraulic oil at the time.

  In order to achieve the above object, the present invention has an oil level detection hole that vertically penetrates the bottom of an oil reservoir provided at the lower portion of the automatic transmission, and an internal thread portion on the inner peripheral surface of the oil level detection hole. The operation stored in the oil reservoir by the hydraulic oil flowing from the upper end opening of the cylindrical member for detecting the oil level, which is moved in the vertical direction by the male threaded portion of the outer peripheral surface being engaged with the oil, flows from the lower end opening through the inner peripheral surface. As a method for detecting the oil level of an automatic transmission that detects the oil level of oil, the following four steps are provided.

  That is, as the first step, the oil level detection tubular member in which the upper end opening is located above the oil level that is increased by the thermal expansion of the hydraulic oil stored in the oil reservoir is increased. A cock that is detachably attached to the lower end opening of the level detecting tubular member is detached to open the lower end opening. Thereafter, the oil level detecting cylindrical member in which the male screw portion is screwed with the female screw portion of the oil level detecting hole is rotated and moved downward from the highest position.

  Next, as a second step, the upper end opening of the oil level detection tubular member that moves downward in the first step reaches the oil level of the hydraulic oil and travels along the inner peripheral surface of the oil level detection tubular member. When the hydraulic oil starts to flow out from the lower end opening, the downward movement of the oil level detecting cylindrical member is stopped.

  Thereafter, the stop position of the oil level detection tubular member stopped downward in the second step is measured, and the oil of the hydraulic oil is measured based on the measured stop position of the oil level detection tubular member. Detect level.

  Thereafter, when the upper end opening reaches the normal oil level of the hydraulic oil stored in the oil reservoir, the oil level detection tubular member moves downward (hereinafter referred to as the oil level detection tubular member). The reference position of the cylinder member for oil level detection is recognized, and the operation is performed based on the recognized reference position of the cylindrical member for oil level detection and the stop position of the cylindrical member for oil level detection measured in the third step. The excess and deficiency of oil is calculated.

  Due to this specific matter, when detecting the oil level of the hydraulic oil stored in the oil reservoir, the oil level detection tubular member that has released the cock from the lower end opening is located at the highest position, and the upper end opening is the oil The hydraulic oil stored in the reservoir is positioned above the oil level that increases due to thermal expansion. For this reason, the hydraulic oil does not flow out as soon as the cock is removed from the lower end opening of the cylindrical member for detecting the oil level and the lower end opening is opened, and the operator's hand with the cock removed becomes dirty with the hydraulic oil. There is nothing.

  Then, the oil level detection tubular member, in which the male thread portion is screwed into the female thread portion of the oil level detection hole, is rotated and moved downward from the highest position, and the upper end opening of the oil level detection tubular member is activated. An oil level detection tubular member that has stopped moving downward when hydraulic oil begins to flow out from the lower end opening along the inner circumferential surface of the oil level detection tubular member when reaching the oil level of the oil The excess / shortage amount of hydraulic oil is calculated based on the stop position and the reference position of the oil level detecting tubular member. For this reason, when the oil level of the hydraulic oil in the oil reservoir is higher than the normal oil level, it waits until the excess hydraulic oil has completely flown out from the lower end opening of the oil level detection tubular member, and then the excess hydraulic oil is discharged. There is no need to measure the amount, and the excess amount of hydraulic oil is measured in advance when the oil level is detected. In addition, when the oil level of the hydraulic oil in the oil reservoir is lower than the normal oil level, the hydraulic oil is replenished and the oil level of the hydraulic oil in the oil reservoir reaches the normal oil level to detect the oil level. There is no need to measure the shortage of hydraulic oil after waiting until the hydraulic oil starts to flow out from the lower end opening of the cylindrical member, and the shortage of hydraulic oil is measured in advance when the oil level is detected. This makes it possible to measure the excess or deficiency of the hydraulic oil when returning the hydraulic oil in the oil reservoir to the normal oil level at the time of detecting the oil level, and to quickly measure the excess or deficiency of the hydraulic oil. Become.

  In addition, the excess / deficiency amount of the hydraulic oil in the fourth step is calculated based on the reference movement distance downward to the reference position of the oil level detection tubular member and the oil level detection tube measured in the third step. When the movement is performed based on the difference in the downward movement distance to the stop position of the cylindrical member, that is, the detection movement distance to the stop position of the oil level detection tubular member, the excess or deficiency of the hydraulic oil is used to detect the oil level. It is easily calculated from the difference between the reference travel distance and the detection travel distance of the cylindrical member, and it is possible to easily measure the excess or deficiency of the hydraulic oil when returning the hydraulic oil in the oil reservoir to the normal oil level. It becomes.

  In short, the excess or deficiency of the hydraulic oil is based on the reference position of the oil level detection tubular member and the stop position of the oil level detection tubular member stopped when the hydraulic oil starts to flow out from the lower end opening. By calculating the amount, the excess or deficiency of the hydraulic oil can be measured in advance when the oil level is detected, and the excess or deficiency of the hydraulic oil can be quickly measured. In addition, the oil level detection tubular member is positioned above the oil level at which the hydraulic oil stored in the oil reservoir is thermally expanded to increase the oil level by positioning the upper end opening that opens at the highest position of the oil level detection tubular member. As soon as the cock is removed from the lower end opening of the tubular member for detection, the hydraulic oil can be prevented from flowing out, and the operator who has removed the cock can be reliably prevented from getting dirty.

  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 as an oil reservoir for storing oil (operating 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. .

  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 extends 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.

  An oil level detection device 5 that detects the oil level X of the oil stored in the oil pan 2 is provided at the deepest portion of the oil pan 2. As shown in FIGS. 2 to 7, the oil level detection device 5 includes an oil level detection hole 51, an oil level detection tubular member 52, and a bolt-shaped cock 53.

  The oil level detection hole 51 is provided through the center portion of the boss portion 21 protruding upward from the bottom portion of the oil pan 2 in the vertical direction. An internal thread portion 511 is formed on the inner peripheral surface of the oil level detection hole 51. An enlarged diameter portion 512 having an enlarged inner diameter is provided at the upper end portion of the inner peripheral surface of the oil level detection hole 51. An annular sealing material 54 is mounted in the enlarged diameter portion 512.

  The cylindrical member 52 for oil level detection includes a lower portion 522 in which a male screw portion 521 that is screwed into a female screw portion 511 on the inner peripheral surface of the oil level detection hole 51 is formed on the outer peripheral surface, and an upper side of the male screw portion 521. And an upper portion 523 having a diameter slightly smaller than the outer diameter of the lower portion 522 by the step portion 524. Further, an upper end opening 52a that opens into the oil pan 2 is provided at the upper end of the oil level detecting tubular member 52 (the upper end of the upper portion 523), and the lower end (lower end) of the oil level detecting tubular member 52 is provided. A lower end opening 52b that opens to the outside of the oil pan 2 (below the oil pan 2) is provided at the lower end of the side portion 522. The oil level detecting cylindrical member 52 has an oil level detecting cylinder because the male threaded portion 521 on the outer peripheral surface of the lower portion 522 is screwed with the female threaded portion 511 on the inner peripheral surface of the oil level detecting hole 51. The member 52 itself is moved in the vertical direction by rotating it forward and backward. Further, the outer peripheral surface of the upper portion 523 of the oil level detection tubular member 52 is fitted into the upper end portion of the oil level detection hole 51 via a seal material 54, and the oil level detection is performed by the seal material 54. The upper portion 523 is slidably supported when the tubular member 52 is moved in the vertical direction, and the sealing performance with respect to the upper end portion (the enlarged diameter portion 512) of the oil level detection hole 51 is ensured.

  Further, the oil level detecting cylindrical member 52 is provided with a stopper portion 525 having a lower end of the outer peripheral surface of the lower portion 522 expanded outward. The stopper portion 525 contacts the lower surface of the oil pan 2 (the lower surface of the boss portion 21) when the oil level detecting tubular member 52 is rotated forward and moved upward, and the oil level detecting tubular member 52. The oil level detection tubular member 52 is positioned at the highest position (the position shown in FIGS. 2, 4 and 6). The oil level detecting cylindrical member 52 moves in the vertical direction by rotating the stopper 525 forward and backward with a tool. In this case, the oil level detecting tubular member 52 is located at the highest position when the oil level of the oil in the oil pan 2 is not detected, and at this highest position, the oil stored in the oil pan 2 is stored. The upper end opening 52a is positioned above the oil level Y (shown in FIG. 4) that increases due to thermal expansion.

  The cock 53 has a leg portion 531 and a head portion 532. The leg portion 531 is formed with a male screw portion 533 that is screwed into a female screw portion 526 formed at the lower end portion of the inner peripheral surface of the oil level detecting tubular member 52 (the lower end portion of the outer peripheral surface of the lower portion 522). Has been. The cock 53 is detachably attached to the lower end portion of the inner peripheral surface of the oil level detecting tubular member 52 by rotating the head 532 with a tool. In this case, the head 532 of the cock 53 is mounted in a state where it is pressed against the lower surface of the oil level detecting tubular member 52 (the lower surface of the stopper portion 525) via an annular sealing material 55 through which the leg portion 531 is inserted. Has been.

  The oil level detecting cylindrical member 52 has an outer peripheral surface of the oil level detecting cylindrical member 52 when the upper end opening 52a reaches the normal oil level X of the oil stored in the oil pan 2. The downward movement position, that is, the reference position downward of the oil level detection tubular member 52 is clearly indicated by marking the male screw portion 521, and the clearly indicated mark indicates the oil level detection of the boss portion 21. The oil level detecting cylindrical member 52 in which the outer threaded male threaded part 521 is screwed with the female threaded part 511 of the inner circumferential surface of the hole 51 is reversely rotated and moved downward from the highest position to lower the bottom surface of the oil pan 2 ( By appearing from the lower surface of the boss portion 21, the operator can recognize the reference position below the oil level detecting cylindrical member 52 when the upper end opening 52 a reaches the normal oil level X. It has become.

  Here, an example of a method for detecting the oil level of the oil in the oil pan 2 detected by the oil level detection device 5 will be described with reference to FIGS. In this case, when the oil level of the oil in the oil pan 2 is detected, the engine is in a stopped state and the operation of the automatic transmission 1 is also stopped.

  First, an oil level detection method in the case where the oil level X of the oil stored in the oil pan 2 is normal will be described based on FIGS.

  In the oil level detection method of the present embodiment, the detection operation is performed in the order of the first to fourth steps shown below.

  That is, as a first step, as shown in FIG. 2, the head 532 of the cock 53 attached to the lower end opening 52b of the oil level detection tubular member 52 positioned at the highest position is rotated by a tool. The cock 53 is detached from the lower end of the oil level detecting tubular member 52 to open the lower end opening 52b. Thereafter, the oil level detecting cylindrical member 52 in which the external threaded male part 521 is screwed into the female threaded part 511 of the internal peripheral surface of the oil level detecting hole 51 of the boss part 21 is reversely rotated by the tool to be lowered from the highest position. Move to.

  Then, as a second step, as shown in FIG. 3, the upper end opening 52a of the oil level detecting tubular member 52 moved downward in the first step reaches the oil level X of the oil and the oil level detection is performed. When the oil begins to flow out from the lower end opening 52b along the inner peripheral surface of the tubular member 52, the downward movement of the oil level detecting tubular member 52 is stopped.

  Thereafter, as a third step, the downward movement distance to the stop position of the oil level detection tubular member 52 that has stopped moving downward in the second step, that is, the detection movement of the oil level detection tubular member 52. The distance A is measured, and the oil level X of the oil is detected based on the measured movement distance A of the oil level detecting tubular member 52. At this time, a mark specified on the male threaded portion 521 of the oil level detecting tubular member 52 appears from the lower surface of the oil pan 2.

  Thereafter, as the fourth step, the reference movement distance B downward to the reference position of the cylindrical member 52 for detecting the oil level when the upper end opening 52a reaches the normal oil level X, and the measurement by the third step. Based on the detected movement distance A of the oil level detection tubular member 52, the excess or deficiency of the hydraulic oil is calculated.

  At this time, the excess / deficiency amount of oil in the fourth step is determined by the reference movement distance B below the oil level detection tubular member 52 and the oil level detection tubular member 52 measured in the third step. It is calculated based on the difference from the detected movement distance A. In this case, the reference movement distance B downward of the oil level detection tubular member 52 and the detection detection movement distance A of the oil level detection tubular member 52 are the same (A = B). It can be seen that there is no difference between the detected detection moving distance A of the tubular member 52 and the reference moving distance B, and the oil stored in the oil pan 2 is at a normal oil level X.

  Next, an oil level detection method when the oil level Y of the oil stored in the oil pan 2 is higher than the normal oil level X will be described with reference to FIGS. In this case, since the first step is the same as the case where the oil level X of the oil in the oil pan 2 matches the normal oil level X, only the steps after the second step will be described in order.

  As the second step, as shown in FIG. 5 from the most elevated position shown in FIG. 4, the upper end opening 52a of the oil level detecting cylindrical member 52 reaches the oil level Y of the oil and moves to the oil level Y. When oil begins to flow out from the lower end opening 52b along the inner peripheral surface of the detection cylindrical member 52, the downward movement of the oil level detection cylindrical member 52 is stopped.

  After that, as a third step, a downward detection movement distance C to the stop position of the oil level detection tubular member 52 stopped downward in the second step is measured, and the measured oil level is measured. The oil level Y of the oil is detected based on the detection moving distance C of the detection cylindrical member 52.

  Thereafter, as a fourth step, the oil level detection tubular member 52 is moved on the basis of the reference movement distance B of the oil level detection tubular member 52 and the detected movement distance C of the oil level detection tubular member 52 measured in the third step. Calculate excess and deficiency.

  At this time, the excess / deficiency amount of oil in the fourth step is calculated based on the difference between the reference movement distance B of the oil level detection tubular member 52 and the detection movement distance C of the oil level detection tubular member 52. Is done. In this case, since a relationship of B> C is established between the reference movement distance B and the detection movement distance C of the oil level detection tubular member 52, a movement distance difference D between the movement distances B and C is established. (B-C) exists, and it is understood that excessive oil corresponding to the movement distance difference D of the oil level detection tubular member 52 is stored in the oil pan 2. From this result, based on the characteristic diagram of FIG. 8 showing the relationship of the amount of oil (cc) to the moving distance (mm) of the oil level detecting tubular member 52, the difference in moving distance of the oil level detecting tubular member 52 is shown. The excess oil quantity Q (cc) corresponding to D (mm) is found.

  Next, an oil level detection method in the case where the oil level Z of the oil stored in the oil pan 2 is lower than the normal oil level X will be described with reference to FIGS. In this case, since the first step is the same as the case where the oil level X of the oil in the oil pan 2 matches the normal oil level X, only the steps after the second step will be described in order.

  As the second step, as shown in FIG. 7, the upper end opening 52a of the oil level detecting tubular member 52 moved downward from the most elevated position shown in FIG. 6 reaches the oil level Z of the oil, and the oil level When oil begins to flow out from the lower end opening 52b along the inner peripheral surface of the detection cylindrical member 52, the downward movement of the oil level detection cylindrical member 52 is stopped.

  Thereafter, as a third step, a detection movement distance E to the stop position of the oil level detection tubular member 52 whose downward movement is stopped in the second step is measured, and the measured oil level detection tube is measured. The oil level Z of the oil is detected based on the detected moving distance E of the member 52.

  Thereafter, as a fourth step, the excess / deficiency amount of oil is calculated based on the reference movement distance B of the oil level detection tubular member 52 and the detection movement distance E of the oil level detection tubular member 52.

  At this time, the excess or deficiency of oil in the fourth step is calculated based on the difference between the reference movement distance B of the oil level detection tubular member 52 and the detection movement distance E of the oil level detection tubular member 52. Is done. In this case, since the relationship of B <E is established between the reference movement distance B of the oil level detection tubular member 52 and the detection movement distance E of the oil level detection tubular member 52, both movement distances are satisfied. It can be seen that there is a movement distance difference F (B−E) between B and E, and the oil corresponding to the movement distance difference F of the oil level detection tubular member 52 is insufficient in the oil pan 2. From this result, based on the characteristic diagram of FIG. 8 showing the relationship of the amount of oil (cc) to the moving distance (mm) of the oil level detecting tubular member 52, the difference in moving distance of the oil level detecting tubular member 52 is shown. The shortage amount R (cc) of oil corresponding to F (mm) is found.

  Therefore, in the above-described embodiment, when detecting the oil level of the oil stored in the oil pan 2, the oil level detecting cylindrical member 52 in which the cock 53 is separated from the lower end opening 52b is located at the highest position, Since the upper end opening 52a is located above the oil level Y where the oil stored in the oil pan 2 expands due to thermal expansion, the cock 53 is removed from the lower end opening 52b of the oil level detecting tubular member 52. As a result, the oil does not flow out as soon as the lower end opening 52b is opened, and the operator's hand with the cock 53 removed can be prevented from being soiled by the oil.

  Then, the oil level detecting cylinder 52 in which the male threaded portion 521 is engaged with the female threaded portion 511 on the inner peripheral surface of the oil level detecting hole 51 is reversely rotated and moved downward from the highest position. On the basis of the movement distance differences D and F between the detected movement distances A, C and E of the cylindrical member 52 and the reference movement distance B of the oil level detection tubular member 52, the excess and deficiency amounts Q and R of the oil are calculated. The For this reason, when the oil level Y of the oil in the oil pan 2 is higher than the normal oil level X, it waits until the excess oil finishes flowing out from the lower end opening 52b of the oil level detecting tubular member 52, and then the oil level The excess amount Q of oil is measured in advance when the oil level Y is detected. In addition, when the oil level Z of the oil in the oil pan 2 is lower than the normal oil level X, the oil is replenished and the oil after the oil level Z of the oil in the oil pan 2 reaches the normal oil level X There is no need to measure the shortage amount of oil after waiting until the oil starts to flow out from the lower end opening 52b of the level detecting cylindrical member 52, and the shortage amount R of oil is measured in advance when the oil level Z is detected. . As a result, the excess / deficiency amounts Q and R of the oil when the oil in the oil pan 2 is returned to the normal oil level X are measured when the oil levels Y and Z are detected, and the excess and deficiency amounts Q and R of the oil are measured. Can be done quickly and easily.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above-described embodiment, the movement distance differences D and F between the reference movement distance B of the oil level detection tubular member 52 and the detection movement distances A, C, and E of the oil level detection tubular member 52 are determined. The oil excess / deficiency amounts Q and R were calculated. The reference position of the oil level detection tubular member, and the stop position where the oil level detection tubular member was stopped when the oil began to flow out from the lower end opening, The excess / deficiency amount of oil may be calculated based on the rotation amount of the oil level detection tubular member corresponding to the difference in height between the two.

  In the above embodiment, the excess / deficiency amounts Q and R of the oil are calculated based on the relationship between the amount (cc) of the oil and the movement distance (mm) of the oil level detection tubular member 52. The amount may be calculated based on the relationship of the weight (g) of the oil with respect to the moving distance (mm) of the oil level detecting tubular member.

It is sectional drawing which looked at the transaxle case of the automatic transmission provided with the oil level detection apparatus which concerns on embodiment of this invention from the vehicle body left-right direction one side. It is sectional drawing of the oil level detection apparatus in a normal oil level. It is sectional drawing of the oil level detection apparatus which shows the state which moved the cylindrical member for oil level detection below to the stop position which corresponds with an upper end opening in a normal oil level. It is sectional drawing of the oil level detection apparatus in the oil level higher than a normal oil level. It is sectional drawing of the oil level detection apparatus which shows the state which moved the cylindrical member for oil level detection below to the stop position which corresponds to an upper end opening in the oil level higher than a normal oil level. It is sectional drawing of the oil level detection apparatus in the oil level lower than a normal oil level. It is sectional drawing of the oil level detection apparatus which shows the state which moved the cylindrical member for oil level detection downward to the stop position which corresponds to an upper end opening in the oil level lower than a normal oil level. It is a characteristic view which shows the relationship of the quantity of oil with respect to the moving distance of the cylindrical member for oil level detection.

Explanation of symbols

1 Automatic transmission 2 Oil pan (oil reservoir)
51 Oil level detection hole 511 Female thread portion 52 Oil level detection cylindrical member 52a Upper end opening 52b Lower end opening 521 Male screw portion 53 Cocks A, C, E Detection movement distance B of oil level detection cylindrical member B Oil level detection cylindrical shape Reference movement distances D and F of the member Difference in movement distance between the detection movement distance of the cylindrical member for detecting the oil level and the reference movement distance Q Excess amount of oil R Insufficient amount of oil X Normal oil level Y More than normal oil level High oil level Z Oil level lower than normal oil level

Claims (2)

It has an oil level detection hole that penetrates the bottom of the oil reservoir provided in the lower part of the automatic transmission in the vertical direction, and the external thread part is screwed into the internal thread part of the internal surface of the oil level detection hole. The oil level of the hydraulic oil stored in the oil reservoir is detected by the hydraulic oil flowing from the upper end opening of the cylindrical member for detecting the oil level that moves in the vertical direction through the inner peripheral surface and out of the lower end opening. An oil level detection method for a transmission,
The lower end of the oil level detecting cylindrical member at the highest position of the oil level detecting cylindrical member in which the upper end opening is located above the oil level where the hydraulic oil stored in the oil reservoir becomes higher due to thermal expansion. After releasing the cock that is detachably attached to the opening and opening the lower end opening, the oil level detection tubular member in which the male screw part is screwed into the female screw part of the oil level detection hole is rotated. A first step of moving downward from the highest position,
The upper end opening of the oil level detection tubular member moved downward in the first step reaches the oil level of the hydraulic oil, travels along the inner peripheral surface of the oil level detection tubular member, and the hydraulic oil from the lower end opening. A second step of stopping the downward movement of the oil level detection tubular member when the oil begins to flow out,
The stop position of the oil level detection tubular member that has stopped moving downward in the second step is measured, and the oil level of the hydraulic oil is determined based on the measured stop position of the oil level detection tubular member. A third step to detect;
Recognizing the downward movement position of the cylindrical member for detecting the oil level when the upper end opening reaches the normal oil level of the hydraulic oil stored in the oil reservoir, and for detecting the recognized oil level A fourth step of calculating an excess / deficiency amount of hydraulic oil based on the downward movement position of the tubular member and the stop position of the oil level detection tubular member measured in the third step. An oil level detection method for an automatic transmission. In the automatic transmission oil level detection method according to claim 1,
When the upper end opening reaches the normal oil level of the hydraulic oil stored in the oil reservoir, the calculation of the excess / deficiency amount of the hydraulic oil in the fourth step is performed downward. An oil level detection method for an automatic transmission, which is performed based on a difference between a distance and a downward movement distance to the stop position of the oil level detection tubular member measured in the third step.

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