JP2014145408A - Oil temperature raising device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an oil temperature from being raised by stirring oil in a differential ring gear in the case where an oil temperature is equal to or higher than a suitable temperature by assisting oil temperature rising by stirring the oil in the differential ring gear in the case where the oil temperature is lower than the suitable temperature.SOLUTION: An oil temperature raising device comprises: a communication path 72 which is provided by communicating a differential ring gear chamber 7 and an oil storage chamber 9 in order to return oil exceeding a predetermined oil level within the differential ring gear chamber 7 to the oil storage chamber 9 and in which a communication end closer to the differential ring gear chamber 7 is formed at a position higher than a maximum oil level in the oil storage chamber 9; and oil level adjustment means 72a-72d for adjusting the quantity of oil to be passed through the communication path 72, so as to keep the oil level in the differential ring gear chamber 7 high when an oil temperature is low, and to keep the oil level in the differential ring gear chamber 7 low when the oil temperature is high.

Description

  The present invention relates to an oil temperature raising device for an automatic transmission that utilizes the principle that oil temperature rises when a differential ring gear stirs oil.

  It is well known that oil is stored in a differential ring gear chamber containing a differential case, a differential ring gear, etc., and the oil is supplied to each sliding portion such as a bearing by using the differential ring gear. 1 and 2). Patent Document 1 discloses a technique for reducing the agitation resistance of a diff ring gear by lowering the oil level in the def ring gear chamber. Japanese Patent Application Laid-Open No. H10-228561 discloses an oil that efficiently guides oil scraped up by a diff ring gear to an oil receiver.

Japanese Patent No. 4838523 JP 2004-183714 A

  By the way, it has been conventionally known that the oil temperature rises when the oil is stirred by the diffring gear, but when the oil temperature is low, the oil temperature is raised by stirring the oil and the oil temperature is higher than the appropriate temperature. Furthermore, there is no disclosure of the idea of suppressing an increase in oil temperature due to oil agitation. If this idea can be embodied, it is possible to assist the increase in the oil temperature by stirring the oil only when it is cold.

  The present invention was devised in view of such a problem. When the oil temperature is lower than the optimum temperature, the oil temperature of the diff ring gear is agitated to assist the increase in the oil temperature. An object of the present invention is to provide an oil temperature raising device for an automatic transmission that can suppress an oil temperature rise due to oil agitation.

  An oil temperature raising device for an automatic transmission according to the present invention is provided with a communication between a diffring gear chamber and an oil storage chamber in order to return oil exceeding a predetermined oil level in the defling gear chamber to the oil storage chamber. By adjusting the communication passage formed at a position where the communication end on the ring gear chamber side is higher than the maximum oil level of the oil storage chamber, and the amount of oil passing through the communication passage, when the oil temperature is low, Oil level adjustment means for maintaining the oil level at a high level and maintaining the oil level in the diff ring gear chamber at a low level when the oil temperature is high is provided.

  For example, the communication path includes a plurality of small communication paths whose flow area increases from the bottom to the top, and the oil level adjustment means is configured by the plurality of small communication paths.

  Further, for example, the oil level adjustment means may be an on-off valve that opens the communication passage when the oil temperature is equal to or higher than a predetermined temperature and closes the communication passage when the oil temperature is lower than the predetermined temperature.

  Further, for example, the oil level adjustment means opens the communication path regardless of the oil temperature when the vehicle is in the forward drive state, while the oil temperature is above a predetermined temperature when the vehicle is in the reverse drive state. An opening / closing valve that opens the passage and closes the communication passage when the oil temperature is lower than a predetermined temperature may be used.

  According to the present invention, when the oil temperature is lower than the appropriate temperature, the oil temperature is increased by stirring the oil in the diff ring gear, and when the oil temperature is higher than the appropriate temperature, the increase in the oil temperature due to the stirring of the oil in the diff ring gear is suppressed. can do.

It is a figure which shows schematic structure of the drive system of the vehicle carrying the oil temperature rising apparatus of an automatic transmission. It is sectional drawing which shows a diff ring gear chamber, an oil storage chamber, etc. in 1st Embodiment. The lower figure is an enlarged view enlarging a region surrounded by a two-dot chain line in the upper figure. It is A arrow enlarged view of FIG. It is sectional drawing which shows a diff ring gear chamber, an oil storage chamber, etc. in 2nd Embodiment, and the figure which shows the control system of an on-off valve.

<First Embodiment>
Hereinafter, an oil temperature raising apparatus for an automatic transmission according to a first embodiment of the present invention will be described with reference to the drawings. First, prior to the description of the oil temperature raising device for an automatic transmission, a schematic configuration of a drive system of a vehicle equipped with the device will be described.

  The vehicle drive system shown in FIG. 1 is mounted on an FF (front engine / front drive) type vehicle, and includes an engine 1, a torque converter 2, a forward / reverse switching device 3, a belt type continuously variable transmission 4, A reduction gear device 5 and a differential gear device 6 are mounted.

  A crankshaft 11, which is an output shaft of the engine 1, is connected to the torque converter 2, and the output of the engine 1 is transmitted from the torque converter 2 to the forward / reverse switching device 3, the belt type continuously variable transmission 4, and the reduction gear device 5. To the differential gear device 6 and distributed to the left and right drive wheels (not shown).

  The torque converter 2 includes an input shaft side pump impeller 21, an output shaft side turbine runner 22, a stator 23, a one-way clutch 24, and the like, and transmits power between the pump impeller 21 and the turbine runner 22 via oil. . Reference numeral 25 denotes a lock-up clutch, and 26 denotes an oil pump 26 that is driven by a driving force transmitted from the pump impeller 21.

  The forward / reverse switching device 3 is a known device composed of a planetary gear mechanism and friction elements such as a clutch and a brake. The forward / reverse switching device 3 directly connects the turbine shaft 28 and the input shaft 40 of the continuously variable transmission 4 when the vehicle moves forward, and transmits the rotation to the input shaft 40 by reversing and decelerating the rotation of the turbine shaft 28 when the vehicle moves backward. . During neutral, power from the turbine shaft 28 to the input shaft 40 is cut off.

  The belt-type continuously variable transmission 4 includes an input-side primary pulley 41, an output-side secondary pulley 42, and a metal belt 43 wound between the primary pulley 41 and the secondary pulley 42. Yes.

  The primary pulley 41 is a variable pulley having a variable effective diameter, and a fixed sheave 411 fixed to the input shaft 40 and a movable sheave 412 disposed on the input shaft 40 in a state in which sliding is possible only in the axial direction. And is mainly composed. Similarly to the primary pulley 41, the secondary pulley 42 is a variable pulley having a variable effective diameter, and a fixed sheave 421 fixed to the output shaft 44 and a state in which the output shaft 44 can slide only in the axial direction. The movable sheave 422 is mainly configured. A reduction gear mechanism 5 is connected to the output shaft 44, and rotational power is transmitted to the differential gear device 6 via the mechanism 5. Reference numeral 61 denotes a differential ring gear fixed to the outer periphery of a differential case (not shown) of the differential gear device 6.

  FIG. 2 is a view showing the diff ring gear chamber 7, the oil storage chamber 9, and the like. The diff ring gear chamber 7 is provided in the transmission case, and accommodates a differential case (not shown) of the differential gear device 6, a diff ring gear 61, and the like. The oil storage chamber 9 is formed by a lower part 91 of the transmission case and an oil pan 92.

  When the oil pump 26 (see FIG. 1) is driven by the power of the engine 1, the oil stored in the oil storage chamber 9 is supplied to each sliding portion such as a bearing by the oil pump 26. The oil supplied to each sliding portion flows down into the diff ring gear chamber 7 and accumulates in the lower portion of the gear chamber 7, is scraped up by the rotating diff ring gear 61, and is further supplied to other sliding portions.

  A communication passage 72 and an oil drain hole 73 are provided in the partition wall 71 that separates the diff ring gear chamber 7 and the oil storage chamber 9.

  The communication path 72 is provided to return oil exceeding a predetermined oil level in the defring gear chamber 7 to the oil storage chamber 9 when forced lubrication is performed by driving the oil pump 26. The communication path 72 communicates a position higher than the maximum oil level of the oil reservoir chamber 9 with the diffring gear chamber 7 and has a flow path area sufficient to substantially maintain the predetermined oil level. Yes. In the present embodiment, the communication path 72 is formed as described above and illustrated, but this communication path 72 returns oil that exceeds a predetermined oil level in the differential ring gear chamber 7 to the oil storage chamber 9. The communication end on the side of the diff ring gear chamber 7 only needs to be formed at a position higher than the maximum oil level of the oil storage chamber 9, and the communication end on the oil storage chamber 9 side is the maximum oil. It may be formed at a position lower than the surface level.

  The oil drain hole 73 discharges as much oil accumulated in the diff ring gear chamber 7 as possible to the oil pan 92 when the engine is stopped and the vehicle is left, to accurately control the oil level. Is provided. The oil drain hole 73 merely discharges to the oil pan 92 an amount of oil that is significantly smaller than the amount of oil supplied into the diff ring gear chamber 7 during forced lubrication, and the oil collected in the ring gear chamber 7 during forced lubrication. It consists of small holes that have almost no effect on the oil level.

  In the present embodiment, as shown in FIGS. 2 and 3, the communication path 72 includes a plurality of small communication paths 72 a to 72 d, and the flow area of each of the small communication paths 72 a to 72 d increases from the bottom to the top. It has become big. The oil of the continuously variable transmission 4 has a relatively high viscosity, and when the oil temperature is low, the passage area (hole diameter) on the lower side is difficult to pass through the small communication passages 72a and 72b. It is easy to pass through only small communication passages 72c and 72d having a certain flow path area. On the other hand, as the oil temperature approaches the appropriate temperature, the oil gradually passes through the lower small passages 72a, 72b, and when the oil temperature is at the appropriate temperature, the oil level is provided at the lowest position. It becomes substantially the same level as the small passage 72a. That is, the main communication passage 72 composed of a plurality of small communication passages 72a to 72d is a means (oil level level) that keeps the oil level in the diff ring gear chamber 7 higher by decreasing the amount of oil passing as the oil temperature is lower. Function as an adjusting means).

  In the present embodiment, the small communication paths 72 a to 72 d are formed in a plate material 76 having a predetermined plate thickness, and the plate material 76 is fitted and fixed in an opening 75 formed in the partition wall 71. Of course, the small communication paths 72 a to 72 d may be formed directly in the partition wall 71 without providing the plate member 76 and the opening 75. Appropriate values such as the flow channel area (hole diameter), installation position, installation interval, and plate thickness of the plate member 76 (flow channel length of the small communication passages 72a to 72d) are set for each vehicle type. In addition, it can be obtained by desktop calculation, experiment, simulation or the like.

  According to the oil temperature raising device of the automatic transmission having the oil level adjusting means, when the oil temperature is lower than the appropriate temperature, the oil level in the diff ring gear chamber 7 is increased, and the stirring resistance by the diff ring gear 61 is increased. The oil temperature rises. Thereafter, as the oil temperature rises, the oil level in the diff ring gear chamber 7 decreases, and when the oil temperature reaches an appropriate temperature, the oil level becomes substantially the same level as the small communication path 72a provided at the lowest position. Become. Thereby, the oil temperature rise by oil stirring is suppressed.

  As described above, according to the oil temperature raising device of the automatic transmission according to the present embodiment, when the oil temperature is low, the mechanical loss can be reduced by promoting the oil temperature increase due to the oil agitation of the diffring gear 61 and reducing the oil viscosity. . Further, when the oil temperature becomes equal to or higher than the appropriate temperature, an increase in the oil temperature due to the oil agitation of the diff ring gear 61 can be suppressed, and the agitation resistance by the diff ring gear 61 can be reduced to increase the driving force of the vehicle. Moreover, since this apparatus can be realized with a simple structure, it can be realized at a low cost.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is obtained by changing the oil level adjustment means to a different type in the first embodiment. In the following, differences from the first embodiment will be mainly described, and description of the same configuration as that of the first embodiment will be omitted.

  In the second embodiment, the communication path provided for returning the oil exceeding the predetermined oil level in the diff ring gear chamber 7 to the oil storage chamber 9 is constituted by a single communication path 72A. An on-off valve 81 that opens and closes the communication path 72A is installed at the downstream end of the communication path 72A. As the on-off valve 81, an electromagnetic valve that opens and closes the communication passage 72A in accordance with a command from the ECU 8 is used.

  The ECU 8 closes the on-off valve 81 and closes the communication passage 72A when the oil temperature is lower than a predetermined temperature (for example, lower than the appropriate temperature), and on the other hand, when the oil temperature is higher than the predetermined temperature (for example, higher than the appropriate temperature). To open the communication path 72A. For this reason, when the oil temperature is lower than the predetermined temperature, the communication path 72A is closed, so that the oil level in the diff ring gear chamber 7 is increased, and the oil temperature is promoted by the oil stirring of the def ring gear 61. As a result, the mechanical loss is reduced due to a decrease in the viscosity of the oil. Further, when the oil temperature is equal to or higher than the predetermined temperature, the communication path 72A is opened, so that the oil level in the diff ring gear chamber 7 is lowered, and excessive temperature rise of the oil is suppressed and stirring by the def ring gear 61 is performed. The driving force of the vehicle can be increased by reducing the resistance.

  Note that a bimetal valve that opens and closes the valve by deformation of the bimetal due to a temperature change can be used as the on-off valve 81 instead of the electromagnetic valve. In this case, the bimetal valve is closed when the oil temperature is lower than a predetermined temperature (for example, lower than the appropriate temperature) to close the communication path 72A, and is opened when the oil temperature is higher than the predetermined temperature (for example, higher than the appropriate temperature). It is installed to open the communication path 72A.

<Third Embodiment>
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, a change is made to the opening / closing control of the opening / closing valve 81 in the second embodiment. In the following, differences from the second embodiment will be mainly described, and description of the same configuration as that of the second embodiment will be omitted.

  The on-off valve 81 in this embodiment is also an electromagnetic valve, and opens / closes the communication path 72A according to a command from the ECU 8.

  When the ECU 8 determines that the vehicle is in the positive drive state based on the output signal of the engine speed sensor 101, the output signal of the accelerator opening sensor 102, and the output signal of the oil temperature sensor 103, the on-off valve When it is determined that the vehicle is in the reverse drive state while opening 81, the on-off valve 81 is opened when the oil temperature is equal to or higher than a predetermined temperature (for example, an appropriate temperature or higher), and the communication path 72A is opened. On the other hand, when the oil temperature is lower than a predetermined temperature (for example, lower than the appropriate temperature), the on-off valve 81 is closed to close the communication passage 72A. The ECU 8 determines that it is in the reverse drive state when the engine speed is equal to or greater than the predetermined speed Ne1 and is in the accelerator OFF state, and determines that it is in the normal drive state when in any other state. As is well known, the determination of the reverse drive state is the same as the control start condition for engine fuel cut control (the engine speed is equal to or higher than the predetermined speed Ne2 and the accelerator is OFF), but the predetermined speed Ne1. And the predetermined rotation speed Ne2 may be the same or different.

  Thus, when the vehicle is in the positive drive state, the communication path 72A is opened, so that the oil level in the ring gear chamber 7 is lowered, and the stirring resistance that reduces the drive force of the vehicle can be reduced. On the other hand, when the vehicle does not require a driving force and is in a reverse driving state, the communication path 72A is closed only when the oil temperature is lower than a predetermined oil temperature, and the oil level becomes high and the oil of the diff ring gear 61 The oil temperature can be increased by stirring.

7 Defring gear chamber 8 ECU
DESCRIPTION OF SYMBOLS 9 Oil storage chamber 72 Communication path 72a-72d Small communication path 81 On-off valve 101 Engine speed sensor 102 Accelerator opening sensor 103 Oil temperature sensor

Claims (4)

In order to return the oil exceeding the predetermined oil level in the diff ring gear chamber to the oil storage chamber, the def ring gear chamber and the oil storage chamber are connected to each other, and the communication end on the def ring gear chamber side is the maximum oil in the oil storage chamber. A communication path formed at a position higher than the surface level;
By adjusting the amount of oil passing through the communication path, the oil level in the diff ring gear chamber is kept high when the oil temperature is low, and the oil level in the def ring gear chamber is kept low when the oil temperature is high. Adjusting means;
An oil temperature raising device for an automatic transmission, comprising: The oil temperature raising device for an automatic transmission according to claim 1,
The communication path is composed of a plurality of small communication paths whose flow area increases from bottom to top,
The oil level raising device for an automatic transmission, wherein the oil level adjusting means is constituted by the plurality of small passages. The oil temperature raising device for an automatic transmission according to claim 1,
The oil level adjustment means is an on-off valve that opens the communication path when the oil temperature is equal to or higher than a predetermined temperature, and closes the communication path when the oil temperature is lower than the predetermined temperature. Temperature device. The oil temperature raising device for an automatic transmission according to claim 3,
The oil level adjusting means opens the communication path regardless of the oil temperature when the vehicle is in the forward drive state, and opens the communication path when the oil temperature is equal to or higher than a predetermined temperature when the vehicle is in the reverse drive state. An oil temperature raising device for an automatic transmission, characterized in that the oil temperature is an on-off valve that closes the communication passage when the oil temperature is lower than a predetermined temperature.

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