JPH0366539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an oil amount control device for a vehicle automatic transmission using a hydraulic torque converter.

[Prior Art] In general, automatic transmissions for transmitting engine torque to wheels in vehicles include a hydraulic torque converter and a friction engagement device that can selectively engage multiple gears through hydraulic operation. The hydraulic power for this operation is supplied by pressurizing the oil in the oil pan with a pump to the hydraulic torque converter and the control valve that selects the gear transmission mechanism. I try to circulate and feed it.

However, it is necessary to periodically check the remaining amount of oil, which controls important functions as described above, using an oil level gauge or the like, and to maintain the amount at a specified constant level at all times. In other words, if the remaining oil level is below a certain level, air may be sucked in together with the oil, slowing down the selection operation of the gear transmission mechanism, making it impossible to obtain the required output, and reducing driving performance. In addition, there is a risk of deteriorating the durability of the oil pump, clutch, etc. Also, if the remaining oil level exceeds a certain level, the gear transmission mechanism will directly scrape up the oil, causing damage to the oil as the load increases. This is because, in addition to the increased loss, the oil becomes foamy due to the agitation action, making it more likely to cause a decrease similar to oil shortage.

On the other hand, in line with recent fuel efficiency policies, front-wheel drive vehicles are on the rise, and this has greatly restricted the space occupied by automatic transmissions, so the size of the oil pan itself has been reduced to the utmost. It is desired that the oil storage capacity be kept to a minimum, and in order to satisfy this requirement, conventionally, multiple oil tanks, a main tank and a sub-tank, have been provided, and a passage for the oil stored in the sub-tank has been created. There is a known control means that opens when the temperature is low to supply oil to the main tank, and closes when the temperature is high to cut off the supply.

However, with such conventional means, only the temperature is controlled, regardless of the oil level in the main tank. There was a sense of regret that the product could not be expected to have any effect such as stirring up or preventing stirring.

[Summary of the invention]

In view of these drawbacks of the conventional art, the present invention has been developed based on a preset oil level in the main tank based on multiple external load conditions such as ambient temperature, engine speed, and vehicle angular acceleration. When the external load conditions such as:

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the oil amount control device for a vehicle automatic transmission according to the present invention will be described in detail below with reference to FIGS. 1 and 2.

FIG. 1 is an explanatory diagram showing the outline of the apparatus of this embodiment. In FIG. 1, reference numeral 1 denotes a main tank, 2 a strainer immersed in oil contained in the main tank 1, and 3 a control valve (not shown) that pressurizes the oil sucked up through the strainer 2. , an oil pump that supplies the torque converter 4 and the like, 5 a level sensor that detects the oil level in the main tank 1, 6 a control unit that calculates a level signal from the level sensor 5 and outputs a switching signal, 7 1 is an actuator consisting of a coil 8, a plunger 9, a rod 10, a valve 11, and a spring 12 that always presses the valve 11 in the closing direction; 13 is a sub tank;
Reference numeral 5 designates a flow path from this sub-tank 13 to the actuator 7 and a flow path from this actuator 7 to the main tank 1.

However, in the case of the embodiment shown in FIG. 1, the oil in the main tank 1 is sucked up by the pump 3 through the strainer 2, pressurized, and fed to the control valve, torque converter 4, etc.
After the oil has been used, all of it is returned to the sub-tank 13, or a part of it is returned to the main tank 1 through a route not shown, and is used for circulation.

Now, when the amount of oil in the main tank 1 falls below a predetermined sensing level, a signal from the level sensor 5 that detects this is input to the control unit 6, and the control unit 6 controls the solenoid of the actuator 7. The coil 8 is energized, the valve 11 is opened, and the oil in the sub tank 13 is discharged into the main tank 1.
Furthermore, when the amount of oil in the main tank 1 exceeds a predetermined sensing level due to this discharge, the control unit 6 similarly closes the valve 11 to stop the discharge of oil from the sub-tank 13.

Further, a detailed configuration example of the level sensor 5 and the control unit 6 is shown in FIG. That is,
The level sensor 5 consists of a series of fluid rotors 16 and a contact 1 that are swingably supported around an intermediate portion.
7, and the contactor 17 is connected to the contactors 18a to 18 in correspondence with the float positions 16a to 16e at oil levels a to e in the main tank 1.
e, so that oil levels a to e can be detected. The control unit 6 has AND circuits 19 to 23 that input level detection signals from the contactors 18a to 18e, and the AND circuit 19 includes a low temperature sensor 24 that detects and outputs an ambient temperature of 50°C or less. The H signal is input to the AND circuit 20, the H signal from the high temperature sensor 25 which detects and outputs the ambient temperature of 80°C or higher is input to the AND circuit 21, and the engine rotation speed is input to the AND circuit 21.
The H signal of the low rotation speed sensor 26 which detects and outputs the engine rotation speed of 1300 RPM or less is input, and the H signal of the high rotation speed sensor 27 which detects and outputs the engine rotation speed of 2000 RPM or more is input to the AND circuit 22.
The H signal of the angular acceleration sensor 28 that detects and outputs a sharp turn of the vehicle is input to the AND circuit 23, and these AND circuits 19 to 23
The AND output of is input to the OR circuit 29, and its
The OR output controls the energization of the solenoid coil 8 via the switching circuit 30.

That is, when the oil level exceeds a, each AND
Since the H signal is not input to one terminal of the circuits 19 to 23, even if each sensor 24 to 28 detects each condition and sends out the H signal, the AND circuits 19 to 23
No output signal is generated from 23.

Now, if the oil level reaches a, the H signal is input to one input terminal of the AND circuit 23 via the contactor 18a, so the angular acceleration sensor 28 detects a sharp turn and the other input terminal of the AND circuit 23 is input. When an H signal is input to the input terminal, the AND circuit 23
When the following conditions are met, the solenoid coil 8 is energized via the OR circuit 29 and the switching circuit 30, and oil is discharged from the sub-tank 13 to the main tank 1, increasing the oil level in the main tank.

Next, when the oil level reaches b, an H signal is input to one input terminal of the AND circuit 22 via the contactor 18b. At this time, contactor 1
Since the oil level 8a is below a, the H signal is input to one input terminal of the AND circuit 23 in the same way as above. Therefore, in this state, that is, when the oil level is b, the AND circuit 22 or 23
The high rotation speed sensor 27 is connected to the other input terminal of the
When the H signal from the angular acceleration sensor 28 is input, the solenoid coil is excited via the OR circuit 29 and the switching circuit 30.

Similarly, when the oil level reaches c, one of the sensors 26 to 28 is activated, when the oil level reaches d, one of the sensors 25 to 28 is activated, and when the oil level reaches e, one of the sensors 24 to 28 is activated. When the solenoid coil 8 generates an H signal, the solenoid coil 8 is energized to increase the oil level.

On the other hand, when the oil level increases from a state below e and exceeds e, the H signal of the contactor 18e becomes an L signal, and even if the high temperature sensor 24 outputs an H signal, the AND circuit 19 generates an output. I won't. Similarly, when the oil level increases and exceeds d, AND circuit 20, and when it exceeds c, AND circuit 2
The signals from the contactors 18d to 18a, which are sequentially input to one input terminal of the AND circuits 20 to 23 in the order of 1, become L signals, and when the oil level exceeds a, the outputs of the sensors 24 to 28 become H signals. Also, the AND circuits 19 to 23 no longer generate outputs.

In the above embodiment, the ambient temperature, engine speed, and vehicle angular acceleration were used as external load conditions, and the minimum oil level required under these load conditions was set. For example, the minimum necessary oil level may be set for each gear position of a gear transmission mechanism.Also, although solenoid valves have been described as actuators, vacuum-operated valves may also be used. Of course. Alternatively, a control valve may be provided in the circulation path between the oil pump and the sub-tank, and the oil level in the main tank may be adjusted by controlling this control valve.

〔Effect of the invention〕

As detailed above, according to the present invention, a plurality of oil tanks are used, and in order to maintain the preset oil level in the main tank to the minimum necessary level in accordance with the external load conditions at that time,
Since the amount of oil supplied from the sub-tank or the amount of oil supplied to the sub-tank is controlled,
It has the advantage of being able to reduce the size of the oil tank, that is, its volume, as well as avoid reducing durability and loss of transmission torque due to insufficient or excessive oil.

[Brief explanation of drawings]

FIG. 1 is a schematic structural explanatory diagram showing one embodiment of an oil amount control device according to the present invention, and FIG. 2 is a block diagram showing a detailed structural example of the same control unit. DESCRIPTION OF SYMBOLS 1... Main tank, 3... Oil pump, 5... Level sensor, 6... Control unit, 7... Actuator (control valve), 8... Solenoid coil, 11... Valve, 13... Sub tank, 14 and 15... Channel, 16... float, 1
7...Contactor, 18...Contactor, 19 to 23
...AND circuit, 24 to 28...sensor for external load conditions, 29...OR circuit, 30...switching circuit.

Claims (1)

[Claims] 1. An oil amount control device for an automatic transmission for a vehicle, which includes a fluid torque converter and a gear transmission capable of selectively engaging a plurality of gears of a friction engagement device by hydraulic operation, A main tank and a sub-tank that contain oil, a control valve that opens and closes an oil circulation path between the sub-tank and the main tank, and a detection signal for each of the plurality of preset oil levels detected in the main tank. Detects a level sensor that outputs , and a plurality of preset external load conditions, and operates when the signal representing these external load conditions matches the output signal of the level sensor representing the amount of oil required at this time. 1. An oil amount control device for an automatic transmission for a vehicle, comprising: a control unit that outputs a signal, and the control valve is actuated by the operation signal to adjust the amount of oil in the main tank.