JPH06272529A - Oil level holding mechanism - Google Patents

Abstract

PURPOSE:To always hold an oil level constant by arranging a sub oil pan at a higher place than a main oil pan and providing a bimetallic opening and closing valve to block a first oil drain hole at the time when working oil is high in temperature. CONSTITUTION:A main oil pan 5 to store working oil of an automatic transmission 1 and a sub oil pan 7 to which the working oil in this main oil pan 5 is introduced are furnished, and the sub oil pan 7 is arranged at a higher place than the main oil pan 5. When the working oil is high in temperature, by a bimetallic opening and closing valve 13, a first oil drain hole provided on the sub oil pan 7 and communicated through to the main oil pan 5 is blocked. Consequently, it is possible to always keep an oil level inside of the main oil pan constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil level holding mechanism for keeping the level of hydraulic oil in an oil pan substantially constant, for example, by electronically controlling hydraulic pressure to adjust torque distribution to front and rear wheels. The present invention relates to an oil level holding mechanism suitable for use in various electronically controlled four-wheel drive vehicles.

[0002]

2. Description of the Related Art Conventionally, a four-wheel drive vehicle among the automobiles in which a gear shift operation is performed by an automatic transmission (A / T), in which the hydraulic power adjusted by electronic control is used to adjust the driving force distribution between the front and rear wheels. Then this A /
There is a case where the driving force distribution of the front and rear wheels is adjusted by using the hydraulic oil of T (mission oil).

For example, a center differential (center differential) that allows a differential between front and rear wheels is provided between the front wheel side drive system and the rear wheel side drive system, and the drive is distributed to the front and rear wheels in the vicinity of the center differential. A hydraulic multi-plate clutch mechanism is attached so that the force can be adjusted, and this hydraulic multi-plate clutch mechanism is operated by the mission oil. That is, the hydraulic oil is taken in from an oil pan in which the mission oil is stored by an oil pump or the like, and the hydraulic oil of the hydraulic multi-plate clutch mechanism is supplied or discharged while controlling the hydraulic oil by a solenoid valve or the like, and the hydraulic pressure is controlled. In the hydraulic clutch mechanism, the crimping state of the clutch is adjusted according to the hydraulic pressure to adjust the driving force distribution. The solenoid valve and the like operate in accordance with a control signal from the control unit, whereby the vehicle is configured as an electronically controlled four-wheel drive vehicle.

[0004]

However, when the working oil thermally expands in the oil pan of the conventional mission oil, its volume increases and the oil level rises. When the hydraulic oil reaches the rotating portion (for example, the drum portion) of the drive system due to this thermal expansion, the operating oil is agitated by the rotating portion, the temperature of the operating oil further rises, and the clutch mechanism is seized. Or, the sensors may fail.

On the other hand, if the oil level is set low in advance in consideration of the thermal expansion of the hydraulic oil, the oil level will not reach a sufficient level when the hydraulic oil is still low in temperature. The oil filter sucks air by tilting and the oil pressure drops. Then, when the hydraulic pressure is reduced, a shock may occur in the drive system, and the mechanism of the clutch may still be burnt.

The present invention was devised in view of the above problems, and an object thereof is to provide an oil level holding mechanism capable of always keeping the oil level constant regardless of the change in the oil temperature of the working oil. And

[0007]

Therefore, in the oil level holding mechanism of the present invention according to claim 1, a main oil pan for storing hydraulic oil of an automatic transmission and a hydraulic oil in the main oil pan are introduced. And a first oil drain hole communicating with the main oil pan, the sub oil pan being disposed at a higher position than the main oil pan. A second oil drain hole provided at a position higher than the first oil drain hole and communicating with the main oil pan, and a bimetal type opening / closing for closing the first oil drain hole when the temperature of the working oil is high It is characterized in that a valve is provided.

Further, in the oil level holding mechanism of the present invention according to claim 2, in addition to the structure according to claim 1, a center differential for distributing the output torque of the automatic transmission to the front wheel side and the rear wheel side is provided. The center differential includes a hydraulic torque distribution adjusting mechanism that adjusts the torque distribution state to the front wheel side and the rear wheel side, and a hydraulic control valve mechanism that controls the hydraulic state of the hydraulic torque distribution adjusting mechanism. The hydraulic control valve mechanism is installed in the sub-oil pan, and the hydraulic oil of the hydraulic transmission is configured to be hydraulically controlled by the hydraulic oil of the automatic transmission. .

[0009]

In the oil level holding mechanism of the present invention as set forth in claim 1, the hydraulic oil for the automatic transmission is stored in the main oil pan, and the hydraulic oil is introduced from the main oil pan into the sub oil pan. It When the temperature of the working oil is low, the first oil drain hole is opened by the bimetal on-off valve, and the working oil in the sub oil pan is transferred from the first oil drain hole to the main oil pan. It falls and is stored in the main oil pan.

When the oil temperature of the hydraulic oil is higher than a predetermined temperature, the first oil drain hole is closed by the bimetal. As a result, the hydraulic oil is stored in the sub oil pan, and when the predetermined amount of hydraulic oil is stored, the hydraulic oil is supplied to the main oil through the second oil drain hole provided at a position higher than the first oil drain hole. Stored in bread. As a result, when the temperature of the hydraulic oil is high, the hydraulic oil in the main oil pan is reduced by the amount of the hydraulic oil stored in the sub oil pan, and the increase in oil level due to thermal expansion is suppressed.

Further, in the oil level holding mechanism of the present invention as defined in claim 2, the hydraulic state of the hydraulic torque distribution adjusting mechanism provided for the center differential is controlled by the hydraulic control valve mechanism installed in the sub oil pan. To be done.
Further, at this time, the hydraulic control of the hydraulic torque distribution adjusting mechanism is performed by the hydraulic oil of the automatic transmission.

The output torque from the automatic transmission is distributed via the center differential to the front wheel side and the rear wheel side according to the hydraulic state of the hydraulic torque distribution adjusting mechanism.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An oil level holding mechanism as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view showing the overall structure, and FIG. 3 is a plan view showing an example of essential components, and FIG. 3 is a top view thereof.
FIG. 4 is a side view thereof, and FIG. 5 is a schematic sectional view for explaining its operation.

The oil level holding mechanism of this embodiment is provided in a full-time four-wheel drive vehicle equipped with an automatic transmission (A / T). FIG. 1 shows the engine room of the four-wheel drive vehicle as viewed from the side of the vehicle, and the right side of the figure is the front of the vehicle. In FIG. 1, reference numeral 1 is a transmission, 2 is a center differential (center differential), 3 is a front differential (front differential), 3A is an axis of a front drive shaft, and 4 is an axis of a propeller shaft.

The driving force distribution of the front and rear wheels is adjusted by controlling the differential control state in the center differential 2, and here, it is adjusted by utilizing the operating hydraulic pressure of the A / T. is there. The center differential 2 is composed of, for example, a planetary gear, and by the driven gear connected to the pinion carrier of this planetary gear,
Rotational driving force from an engine (not shown) is input to the center differential 2 via the transmission 1.

The rotation of the planetary gear ring gear is transmitted to the rear differential (not shown) via the propeller shaft 4, and the rotation of the sun gear is transmitted to the front wheel side via the front drive shaft 3A. It is like this. Although not shown, a hydraulic multi-disc clutch mechanism as a hydraulic torque distribution adjusting mechanism is provided, for example, adjacent to the center differential 2. By the hydraulic multi-disc clutch mechanism, a differential between the sun gear and the pinion gear is provided. (Relative rotation) can be restricted.

The torque distribution of the front and rear wheels can be adjusted by limiting the differential between the front wheel side and the rear wheel side by the hydraulic multi-plate clutch.
This hydraulic multi-plate clutch mechanism is provided with, for example, a hydraulic piston mechanism to supply A / T mission oil, and an oil pan (main oil pan) 5 to a solenoid valve 6 are supplied to this piston mechanism. Hydraulic oil (mission oil) is supplied through a valve body 8 as a hydraulic control valve mechanism incorporating the above.

Further, inside the main oil pan 5, an oil cleaner 16 and a valve body 20 as an A / T hydraulic control valve mechanism are provided. Then, impurities and the like of the working oil are removed by the oil cleaner 16, and the working oil is supplied to a required portion through the oil cleaner 16. The valve body 20 is a valve mechanism for controlling the hydraulic pressure of the A / T, and the operation of the valve body 20 controls the shift of the A / T.

The solenoid valve 6 and the like adjust the amount of hydraulic oil in response to a command from a control unit (not shown), and the crimping force of the hydraulic multi-plate clutch mechanism is controlled according to the hydraulic pressure of this hydraulic oil. It is supposed to be done.
Further, as shown in FIG. 1, the valve body 8 is built in the sub oil pan 7, and the sub oil pan 7 is
It is provided above the main oil pan 5.

The main oil pan 5 and the valve body 8 are connected by an oil pipe 10, and the working oil stored in the main oil pan 5 passes through the oil pipe 10 to a valve in the sub oil pan 7. It is designed to guide you to important points on the body 8. The hydraulic oil, the hydraulic pressure of which is controlled by the solenoid valve 6 of the valve body 8 and the like, is supplied to the hydraulic clutch mechanism provided near the center differential 2 through the oil pipe 9 for four-wheel drive control. .

The hydraulic oil discharged from the valve body 8 when the hydraulic oil of the solenoid valve 6 is discharged is stored in the sub oil pan 7 or the main oil pan 5
It is supposed to be returned to. Therefore, in the sub oil pan 7, two drain holes (orifices) for returning the discharged working oil to the main oil pan 5 are provided.

As shown in FIG. 2, the first oil drain hole 11 is provided lower than the second oil drain hole 12. In this example, the first oil drain hole 11 is provided in the separating plate 14 that is interposed between the upper portion and the lower portion of the valve body 8. Further, as shown in FIG. 2, a bimetal on-off valve 13 is provided at a predetermined position in the valve body 8, and the bimetal on-off valve 13 is fitted into the valve body 8 and fixed, for example. ing.

The bimetal type on-off valve 13 is a valve using a bimetal which operates according to the ambient temperature, and when the oil temperature of the working oil is low (or room temperature), the first bimetal type on-off valve 13 is used. Open the oil drain hole 11,
When the oil temperature of the hydraulic oil is high, the first oil drain hole 1
1 is blocked. 3 and 4 are a top view and a side view of such a bimetal on-off valve 13 in an assembled state. The bimetal assembly 13 includes a bimetal body 18 and a bimetal case 1.
It is composed of 9 and 9.

As shown in FIG. 3, the bimetal case 19
A hole portion 17 is provided in the bottom surface portion 19A, and the hole portion 17 is formed at a position where it overlaps with the first oil drain hole 11. Further, the bottom surface portion 19A is configured to be in close contact with the separating plate 14, and the above-mentioned hole portion 17 is opened and closed by a bimetal main body 18 described later, whereby the first oil drain hole 11 is formed.
Is designed to be opened and closed.

As shown in FIGS. 3 and 4, the bimetal case 19 has reinforcing members 19B, 19C, 19D and 19F1 and supporting members 19E, 19F and 19G in a direction perpendicular to the bottom surface 19A. It is provided and by these reinforcing members 19B, 19C, 19D, 19F1,
The rigidity of the bimetal case 19 is ensured.

Support members 19E, 19F, 19G
Are bent in the horizontal direction above them, and when the bimetal assembly 13 is fitted into the valve body 8, these bent portions act as spring members that act in the vertical direction in FIG. The elastic force of this spring member pushes the bimetal assembly 13 against the separating plate 14 so that they are in close contact with each other.

Here, the supporting member 19F and the reinforcing member 19F1 are integrally formed, and while the rigidity of the bimetal case 19 is ensured, it also functions as a spring member. By the way, as shown in FIGS. 3 and 4, the bimetal main body 18 has a bimetal supporting member 19H.
It is attached to the bimetal case 19 via.

The bimetal supporting member 19H is, for example, an L-shaped member.
A bimetal contact portion 19H1 is provided at H.
The bimetal supporting member 19H has a bottom surface portion 19
It is fixed to A and the bimetal main body 18 is attached to the bimetal connecting portion 19H1. Also,
The bimetal main body 18 is composed of an arm portion 18A and a valve body portion 18B, and the arm portion 18A is composed of a bimetal that causes bending deformation in accordance with the ambient temperature.

Further, the valve body portion 18B of the bimetal main body 18
Can be moved while being in contact with the bottom surface portion 19A, and the hole portion 17 can be opened and closed from the fully open state to the fully closed state according to the bending deformation of the arm portion 18A. As shown in FIGS. 3 and 4, the bimetal case 19 is provided with a stopper portion 19J,
When the hole portion 17 is fully closed by the bimetal main body 18, a part of the valve body portion 18B comes into contact with the stopper portion 19J, and the bimetal main body 18 is deformed.
It is regulated within 9.

Then, here, when the temperature around the arm portion 18A becomes higher than a predetermined value, the bimetal main body 18 becomes
By moving to the lower side in FIG. 3, the hole 17 is fully closed as shown by the solid line. As a result, the hydraulic oil in the sub oil pan 7 is stored in the sub oil pan 7 without being supplied to the main oil pan 5.

When the ambient temperature decreases, the bimetal main body 18 moves upward as indicated by the chain double-dashed line in the figure, and when this temperature becomes lower than a predetermined value, The hole 17 is fully opened. At this time, the hydraulic oil discharged from the solenoid valve 6 drops through the hole 17 and is stored in the main oil pan 5.

Since the oil level holding mechanism according to the embodiment of the present invention is constructed as described above, the working oil stored in the main oil pan 5 passes through the oil cleaner 16 and the oil pipe 10. It is supplied to the valve body 8 as a hydraulic control valve mechanism through the inside. The hydraulic oil in the main oil pan 5 is the oil cleaner 1
6 to remove impurities and the like in the hydraulic oil.

Then, the hydraulic oil is controlled to a predetermined hydraulic pressure by the solenoid valve 6 in the valve body 8 and is supplied to the hydraulic multi-plate clutch mechanism provided in the vicinity of the center differential 2. Then, in the hydraulic multi-plate clutch mechanism, the crimping state of the clutch is changed according to the hydraulic pressure of the hydraulic oil to adjust the driving force distribution of the front and rear wheels. Further, since the valve body 8 is provided in the sub oil pan 7, the hydraulic oil discharged from the solenoid valve 6 and the like is first stored in the sub oil pan 7.

When the oil temperature of the hydraulic oil is lower than a predetermined temperature when the engine is started, the bimetal main body 18 in the valve body 8 moves upward in FIG.
Fully open. Therefore, the hydraulic oil in the sub oil pan 7 is discharged from the sub oil pan 7 through the hole 17 and the first oil drain hole 11 provided in the separating plate 14. Then, the hydraulic oil discharged from the sub oil pan 7 falls due to its own weight,
It returns to the main oil pan 5 and is stored in the main oil pan 5.

That is, the temperature of the hydraulic oil is low (or room temperature).
Sometimes the hydraulic oil does not expand thermally, so the oil level in the main oil pan 5 does not rise, and at this time,
By opening the bimetal type on-off valve 13 and returning the working oil into the main oil pan 5, the oil level in the main oil pan 5 can be kept constant. As a result, it is possible to prevent the level of the hydraulic oil from decreasing, and even if the liquid surface of the hydraulic oil in the oil pan 5 tilts during acceleration / deceleration of the vehicle, the oil cleaner 16 does not suck air, and the clutch mechanism The reliability of can be improved.

When the oil temperature of the hydraulic oil is higher than a predetermined temperature, the bimetal body 18 provided in the sub oil pan 7 is thermally deformed and the hole 17 is closed. Therefore, the hydraulic fluid discharged from the solenoid valve 6 is
The oil is not discharged from the oil drain hole 11 and is stored in the sub oil pan 7. Then, as shown in FIG. 5, when a predetermined amount of hydraulic oil is stored in the sub oil pan 7, the hydraulic oil is discharged from the second drain hole 12 provided at a position higher than the first oil drain hole 11. Main oil pan 5
It is discharged to.

That is, when the working oil is in a high temperature state, the bimetal main body 18 is deformed according to the working oil temperature to close the hole 17 and store a predetermined amount of working oil in the sub oil pan 7. . This allows the main oil pan 5
Inside, the oil level is prevented from rising due to thermal expansion of the hydraulic oil. As a result, when the hydraulic oil in the main oil pan 5 thermally expands, the hydraulic oil reaches the rotating portion 15 of the A / T, the hydraulic oil is agitated, and the oil temperature further rises. Disappear.

Further, the reliability of various sensors provided for controlling the hydraulic pressure of the hydraulic oil can be improved. In this embodiment, the valve body portion 18B is arranged above the first oil drain hole 11 and the hole portion 17, so that when the valve body portion 18B is closed, the closed state is strengthened by the weight of the hydraulic oil. As a result, the first oil drain hole 1
1 and the hole 17 can be closed more reliably, and the bimetal on-off valve 13 can be operated very reliably.

Since the bimetal type on-off valve 13 is thermally deformed in accordance with the hydraulic oil temperature, the open / closed state of the first oil drain hole 11 is either fully open or fully closed. It is not limited to this, but it can be in an intermediate state between fully open and fully closed.
It is also possible to make the oil level of the main oil pan 5 more stable while finely adjusting the discharge amount of the hydraulic oil from the.

[0040]

As described in detail above, according to the oil level holding mechanism of the present invention described in claim 1, the main oil pan for storing the hydraulic oil of the automatic transmission and the hydraulic oil in the main oil pan are stored. A sub oil pan to be introduced, the sub oil pan is arranged at a higher position than the main oil pan, and the sub oil pan has a first oil drain hole communicating with the main oil pan. A second metal drain hole which is provided at a higher position than the first oil drain hole and communicates with the main oil pan, and which closes the first oil drain hole when the operating oil temperature is high. With the configuration in which the type opening / closing valve is provided, the hydraulic oil in the main oil pan can be kept substantially constant. Further, by doing so, it is possible to improve the reliability of various sensors provided in the clutch mechanism and the hydraulic system that are operated by the operating hydraulic pressure.

According to the oil level holding mechanism of the present invention as defined in claim 2, a center differential for distributing the output torque of the automatic transmission to the front wheel side and the rear wheel side is provided, and the center differential is provided to the front wheel side. And a hydraulic torque distribution adjusting mechanism for adjusting the torque distribution state to the rear wheel side, and a hydraulic control valve mechanism for controlling the hydraulic state of the hydraulic torque distribution adjusting mechanism,
The hydraulic control valve mechanism is installed in the sub oil pan, and the hydraulic control of the hydraulic torque distribution adjusting mechanism is performed by the hydraulic oil of the automatic transmission. This mechanism can be realized at low cost while using parts. Further, this allows the hydraulic oil of the automatic transmission to be effectively used.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an overall configuration of an oil level holding mechanism as an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a main configuration of an oil level holding mechanism as one embodiment of the present invention.

FIG. 3 is a top view showing an example of essential components of the oil level holding mechanism as one embodiment of the present invention.

FIG. 4 is a side view showing an example of essential components of the oil level holding mechanism as one embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view for explaining the operation of the oil level holding mechanism as one embodiment of the present invention.

[Explanation of symbols]

 1 Transmission 2 Center Diff 3 Front Diff 3A Front Drive Shaft Shaft 4 Propeller Shaft Shaft 5 Main Oil Pan 6 Solenoid Valve 7 Sub Oil Pan 8 Valve Body as Hydraulic Control Valve Mechanism 9 4 Wheel Drive Control Oil Pipe 10 Oil Pipe 11 1st Oil drain hole 12 Second oil drain hole 13 Bimetal on-off valve assembly 14 Separating plate 15 Rotating part (drum part) 16 Oil cleaner 17 Hole part 18 Bimetal body 19 Bimetal case 19A Bottom part 19B, 19C, 19D, 19F1 Reinforcement member 19E, 19F, 19G Support member 19H Bimetal support member 19H1 Bimetal connection part 19J Stopper part 20 A / T valve body

Claims (2)

[Claims] 1. A main oil pan for storing hydraulic oil for an automatic transmission, and a sub oil pan into which hydraulic oil in the main oil pan is introduced, the sub oil pan being higher than the main oil pan. A first oil drain hole communicating with the main oil pan, the first oil drain hole communicating with the main oil pan, and a first oil drain hole communicating with the main oil pan higher than the first oil drain hole. And a bimetal type on-off valve that closes the first oil drain hole when the operating oil has a high temperature. 2. A hydraulic pressure for providing a center differential for distributing the output torque of the automatic transmission to a front wheel side and a rear wheel side, and adjusting the torque distribution state between the front wheel side and the rear wheel side to the center differential. Type torque distribution adjustment mechanism and a hydraulic control valve mechanism for controlling the hydraulic state of the hydraulic torque distribution adjustment mechanism. The hydraulic control valve mechanism is installed in the sub oil pan to operate the automatic transmission. The oil level holding mechanism according to claim 1, wherein the hydraulic control of the hydraulic torque distribution adjusting mechanism is performed by oil.