JPS584767B2 - Engine oil supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine oil amount detection device, and more particularly to a device for detecting and displaying whether the amount of engine oil in an oil pan is optimal.

An engine mounted on a vehicle such as an automobile includes many moving parts.

Each of these moving parts generates friction, and this friction causes losses such as power loss, wear, and engine seizure due to frictional heat.

Engine oil is supplied to each moving part to reduce friction.

In addition to reducing friction, engine oil has various functions such as cooling, sealing, and cleaning, and plays an important role in achieving good engine operation.

The cooling effect is an effect of cooling the engine, which is exposed to high temperatures due to heat generation such as combustion heat.

The sealing action is an action that seals the gap between the piston and the cylinder to reduce output loss.

Further, the cleaning action is the action of removing solid matter or foreign matter present in the lubricated portion.

The engine oil that performs the above functions is normally injected into an oil pan that is airtightly fixed to the crankcase.

Engine oil is supplied from within the oil pan to each moving part by an oil pump.

Engine oil in the oil pan gradually burns, leaks, and vaporizes as the engine operates, and the amount of the oil decreases.

The lack of engine oil due to this reduction seriously impedes the various functions mentioned above and paralyzes the engine.

Therefore, it is extremely important to accurately control the amount of engine oil at all times in order to maintain good engine operation.

The most widely used method to measure the amount of engine oil is to use an oil level gauge.

This method estimates the amount of oil in the oil pan by inserting an oil level gauge into the oil pan and observing the position of oil adhering to the gauge.

This conventional method has the drawback that the oil level cannot be automatically detected and displayed, and the oil level cannot be checked in the operator's cabin.

Inspecting the oil level using this method requires inserting an oil level gauge directly into the oil pan, so it is not possible to check the oil level while the vehicle is running.

Furthermore, with this method, when the engine is running, the oil level gauge is covered with droplets of engine oil, making it difficult to distinguish between the oil adhering below the oil surface and the droplets.
The drawback was that it was not possible to accurately determine the amount of oil.

The present invention has been made in view of the above points.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine oil amount detection and display device that always automatically informs whether the amount of engine oil is within a predetermined reference value.

Another object of the present invention is to automatically notify whether the level of engine oil injected into an oil pan is within a predetermined reference value regardless of whether the engine is running or stopped. The present invention provides an oil amount detection and display device.

Another object of the present invention is to provide an engine oil amount detection and display device that allows a driver to accurately know the amount of engine oil from inside the driver's seat at all times.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 shows the outline and configuration of the entire engine.

In the illustrated engine, a cooling fan 11 is rotatably supported at the front of an engine body 10, and an oil pan 12 is bolted and fixed to the lower part of the engine body 10 with a gasket (not shown) in between.

The oil pan 12 is filled with vegetable engine oil.

It is known that the level of the engine oil is different when the engine is running and when the engine is stopped.

Assume that the oil level in the oil pan 12 is at level A with the engine stopped.

When the engine is started in this state, the oil pump operates as the engine rotates.

Engine oil is pumped up and supplied to each moving part by the action of this oil pump.

Therefore, the oil level in the oil pan 12 drops to level C for a period of time after the engine is started.

On the other hand, the pumped engine oil supplies the necessary oil to each moving part, and then returns to the oil pan 12 as excess engine oil.

After this, the oil pump circulates engine oil to each moving part in sequence to reach an equilibrium state of engine cleaning action.

Therefore, the oil level, once lowered to level C, recovers to level B in this equilibrium state.

Level B during steady operation of the engine is a state in which engine oil is supplied to each operating part.

From this, level B is at a lower position than level A when the engine is stopped.

This level difference between levels AB varies depending on the characteristics of the engine and the shape of the oil pan.

Normally, this level difference is approximately 10 to 20 mm.

FIG. 2 shows the above-mentioned engine oil level changes and temperature changes of the engine oil and cooling water over time.

A curve 21 shows a change in oil level, a curve 22 shows a change in engine oil temperature, and a curve 23 shows a change in cooling water temperature.

Temperatures T1 and T2 are the temperatures of the engine oil and cooling water when they reach level B.

As is clear from FIG. 2, when the engine is started from level A, the oil level drops to level C and then reaches the equilibrium state indicated by level B.

The time required to reach this equilibrium state varies depending on the viscosity characteristics of the engine oil, the temperature of the engine, and other factors.

In particular, engine temperature has a large effect on the time required.

That is, when the engine is started from a sufficiently warmed state, the oil level reaches an equilibrium state within a few seconds.

However, on the other hand, when starting an engine that has been left in a cold state such as in winter, it takes several minutes for the oil level to reach an equilibrium state.

These are known empirically. Assume that the minimum oil level required during engine operation is level B, and level B is slightly higher than level B.

Set. Here, level B. In order to determine the oil level up to the height of , a detector for detecting oil level is installed.

After the engine is started, when the oil level reaches an equilibrium state, the state of the oil level can be known by reading the detection signal from the detector.

This detector uses a method that determines when the oil level is in equilibrium after a certain period of time has elapsed after the engine has started.

This is done in order to detect a temporary drop in the oil level after starting the engine and to prevent an erroneous determination that the oil level is insufficient.

Therefore, this detector, before starting the engine,
A lack of oil cannot be detected.

Therefore, with this type of detector, there is a risk of starting the engine in a state where engine oil is insufficient.

This will cause a fatal condition to the engine.

Therefore, the second system detects the oil level while the engine is stopped.
It is conceivable to provide several detectors.

This detector is installed at a position slightly higher than level A.

However, it is not advisable to attach this type of detector due to problems of installation space within the oil pan and economical problems.

So level B.

It is conceivable to use the above-mentioned detector installed in the

If this detector is set to operate while the engine is stopped, the engine oil level will be at level B.

Detection is possible in the following cases.

This is shown by curve 21A in FIG.

In this case, before starting the engine, it is possible to know that the oil level is extremely low, so it is possible to prevent the engine from being erroneously started in this state and causing a malfunction in the engine.

In this way, with the conventional oil level detection method, it was impossible to detect an oil shortage condition at all before the engine started, but with the present invention, an extreme oil shortage condition can be detected without increasing the number of oil level detectors and by using a circuit design. It is configured to detect and issue a warning.

FIG. 3 shows a concrete implementation circuit of the oil amount detection and display device.

The oil amount detection and display device shown in the figure includes a power supply 30, an engine key switch 31, an oil level balance detection circuit 32, an engine start detection circuit 33, an oil level detection circuit 34, and a display element 35.

The power source 30 is an automobile battery.

The oil level balance detection circuit 32 detects the balanced state of the engine oil level during engine operation.

In this embodiment, the oil level balance detection circuit 32 is composed of an oil temperature detection circuit or a cooling water temperature detection circuit.

The former measures the temperature of the engine oil (T2 in FIG. 2) and indirectly determines the equilibrium state.

The latter measures the temperature of cooling water (T1 in FIG. 2), especially in water-cooled engines, and indirectly determines the equilibrium state.

An oil temperature detection circuit or a cooling water temperature detection circuit can obtain similar effects.

In the circuit shown in FIG. 3, the oil level balance detection circuit 32 is composed of a cooling water temperature detection circuit.

This cooling water temperature detection circuit 32 includes a temperature switch 36, a transistor 37, diodes 38, 39, and a resistor 40.
It consists of 41.

The temperature switch 36 indirectly detects the equilibrium state of the engine oil level during engine operation.

This switch 36 is attached at a position where the water temperature in a cooling water circuit such as an engine water jacket can be measured.

For example, this switch 36 becomes a closed circuit and is grounded at a temperature of 60° C. or lower, and is opened at a temperature of 60° C. or higher.

The oil temperature detection circuit also has the same configuration as the cooling water temperature detection circuit.

The engine start detection circuit 33 includes a switch 42, a transistor 43, diodes 44, 45, 46, a resistor 47,
It consists of 48.

Switch 42 detects starting of the engine.

There are various methods for detecting engine starting.

In an automobile, a simple method is to obtain the signal from the voltage regulator of the vehicle charging generator.

The switch 42 has a movable contact 42A and a fixed contact 42A.
B, 42C.

The oil level detection circuit 34 includes a liquid level detector 49, a transistor 50, a diode 51, and a resistor 52.

The liquid level detector 49 is at level S shown in FIG.

Detect.

This detector 49 indicates that the oil level is level S. When the level is higher, it is closed and one terminal is grounded, and when it is lower than the level Bo, it is opened.

The display element 35 is composed of a light emitting element such as a lamp.

Hereinafter, the display element 35 will be referred to as a display lamp 35. Next, the action will be explained.

Suppose now that the engine is stopped and the oil level is higher than level A.

Level A is a level at which there is a sufficient amount of oil in the oil pan that does not interfere with engine operation.

Here, when the engine key switch 31 is turned on, since the liquid level detector 49 is on, the transistor 50 is turned off and the indicator lamp 35 is turned off.

When the liquid level detector 49 is on, the transistor 50 is turned off regardless of whether the transistor 43 is on or off.

In this state, the engine is started and the contact 42A is connected to the contact 42A.
This continues regardless of whether the temperature switch 36 is turned off due to a rise in the cooling water temperature.

Next, with the engine stopped, the oil level is at level A and level B.

Suppose it is between. In this state, the indicator lamp 35 is off when the engine key switch 31 is turned on.

When the engine starts, a power supply voltage is applied to the cathode side of the diode 44.

While the cooling water temperature is low, the transistor 37 is turned on, so power supply voltage is similarly applied to the anode side of the diode 39.

As a result, the transistor 43 turns on, and the liquid level detector 49
Regardless of whether it is on or off, the transistor 50 is turned off and the display lamp 35 is kept in an extinguished state.

When the cooling water temperature rises and the oil level reaches an equilibrium state, the temperature switch 36 opens and the transistor 37 turns on.

Therefore, transistor 43 is turned off. At this time, the oil level is level B.

Since the oil level has decreased further, the liquid level detector 49 opens and the indicator lamp 35 lights up to warn of insufficient oil amount.

Next, assume that the oil level is further lowered.

For example, the oil level is level B while the engine is stopped. This is the case when the value decreases to below.

In this case, since the transistor 43 and the liquid level detector 49 are both turned off when the engine key switch 31 is turned on, the indicator lamp 35 lights up, and a clear oil shortage is alerted before the engine is started.

This effect is clear from the above explanation.

FIG. 4 shows a specific embodiment of the engine start detector 42. As shown in FIG.

This circuit includes a power supply 30, an engine key switch 31,
It consists of a phase alternating current generator 60, a voltage regulator 61, an ignition coil 62, and a charge warning lamp 63.

Three-phase alternator 60 is driven by the engine.

This generator 60 is composed of power generation coils 64, 65, 66, a rectifying diode group 67, and a field coil 68.

The power generation coils 64, 65.66 are Y-connected, and the power generation output of each coil 64, 65.66 is three-phase full-wave rectified by a rectifier diode group 67.

Field coil 68 generates a DC magnetic field.

The field current of this field coil 68 is controlled by a voltage regulator 61 to keep the output voltage constant.

The voltage regulator 61 includes excitation coils 69 and 70 and a movable contact 7.
1, 42A, fixed contacts 42B, 42C, and a resistor 72.

The movable contact 71 is actuated by the excitation coil 69.

The movable contact 42A is operated by the excitation coil 70.

The fixed contact 42B is grounded, and the other fixed contact 42C is connected to the output terminal of the generator 60 and to the positive side of the power source 30.

Excitation coil 70 is connected to neutral point N of power generation coils 64, 65, and 66.

At this neutral point N, when the engine speed exceeds the idling speed, a DC voltage that is approximately 1/2 of the output voltage is obtained.

Excitation coil 69 is connected to movable contact 42A.

This coil 69 is grounded by contact 42B when the engine is stopped.

When the engine is operated and the generator 60 starts generating electricity, the coil 69 is connected to the contact 42C by the action of the excitation coil 70.
The output terminal voltage is supplied through the terminal.

Therefore, the movable contact 71 performs a switching operation depending on the magnitude of the output voltage applied to the excitation coil 69.

As a result, the connection of the current adjusting resistor 72 of the filled coil 68 is switched, and the output voltage is controlled to be constant.

The charge warning lamp 63 is grounded through the movable contact 42A and the fixed contact 42B and is turned on.

When power generation is started, both terminals of the lamp 63 become at the same potential and turn off.

As explained above, according to the present invention, by utilizing the fluctuation characteristics of the oil level in the oil pan, it is possible to detect a lack of oil amount during engine operation, and at the same time, detect a lack of oil amount early before starting the engine. be able to.

Detection can be performed by installing one liquid level detector in the oil pan.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the engine, Fig. 2 is an explanatory diagram showing oil level characteristics, Fig. 3 is a circuit diagram showing an embodiment of the oil amount detection and display device of the present invention, and Fig. 4 is an engine start detection circuit. FIG. 32... Oil level balance detection circuit, 33... Engine start detection circuit, 34... Oil level detection circuit, 35...
・Display element, 36... Temperature switch, 37, 43, 5
0...Transistor, 42...Start detector, 49.
...Oil level detector, 60... Generator, 61... Voltage regulator, 42A... Movable contact, 42B, 42C... Fixed contact.

Claims (1)

[Claims] 1 After the engine is started, at least one of the engine cooling water temperature and the engine oil temperature is detected, and the detected engine cooling water temperature or engine oil temperature reaches a known predetermined temperature at the time when the engine oil level reaches an equilibrium state. an oil level balance detection circuit that determines that the engine oil level is in an equilibrium state and outputs an electrical signal when the engine an oil level detection circuit that detects whether the oil level of oil is above a predetermined value and generates an electric signal; and an oil level detection circuit that detects that the engine oil level is lower than a predetermined oil level connected to the oil level detection circuit. After the engine has started and the oil level has not reached an equilibrium state,
An engine oil amount detection and display device, characterized in that the oil balance detection circuit and the engine start detection circuit are connected to the display element so as to prohibit operation of the display element.