JPS6237931Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an engine oil amount reduction warning device that warns of a reduction in engine oil.
The purpose is to not issue a warning when the engine oil temperature is below a certain temperature.

Conventionally, a device is known in which a float with a built-in magnet is installed inside the engine's oil pan, and this magnet operates a reed switch to warn of a decrease in the engine oil level. When the temperature of the oil is low and the viscosity is high, the amount of oil that returns from the oil circulation path to the oil pan is small, so there is a problem in that a warning is issued that the oil is decreasing even though there is sufficient oil. In addition, as a means to solve this problem, there is a function that uses a timer to limit the operation of the warning circuit for a certain period of time, and a function that uses a thermoferrite magnet as the magnet and operates the reed switch until the temperature of the oil rises. There have been proposals to make the oil lose its temperature, but the time it takes for the oil to reach the specified temperature is not constant,
Thermoferrite magnets had the disadvantage of increasing the size of the device, and were not sufficient.

Furthermore, in the specification of Japanese Utility Model Application Publication No. 51-126164, a reed switch storage tube and a thermistor case are provided that extend downward from the support body, and the reed switch and thermistor are housed in these, and a float is placed around the reed switch storage tube. A liquid level detecting device having a structure has been proposed, which solves the above-mentioned drawbacks that occur at low temperatures. However, if the reed switch and thermistor both hang downward from the support, the thermistor will be located above the float, and the thermistor will not be immersed in the oil.
There may be cases where the desired effect is not obtained, and therefore the conventional problems will not be completely resolved.
In addition, with this structure, the thermistor case that houses the thermistor hangs down from the support plate, that is, protrudes downward, which makes installation unstable, and also causes problems such as engine vibrations when installing or inspecting the device. There is a risk of damage due to

Therefore, this invention consists of a support body having an inverted concave cross section, which has a mounting part, a chamber extending laterally from the mounting part and opening at the bottom, and a cylindrical chamber erected at the tip of the support body. A reed switch is housed in the cylindrical chamber, a float with a magnet is inserted around the outer periphery of the cylindrical chamber, and a critical temperature register is placed in the chamber of the support.
Resistor is hereinafter referred to as CTR. ) and two lead wires, one end of one lead wire to one end of the reed switch, and one end of the other lead wire to one end of the reed switch.
It is configured to be connected to the other end of the reed switch via the CTR. As a result, the CTR is constantly immersed in engine oil within the movement range of the float. Moreover, by arranging the CTR within the chamber of the support, the CTR can be protected from the risk of damage.

To describe an embodiment, the engine oil amount warning device is constructed by mounting a detecting body 9 upright on the tip of a support 3 extending laterally from a mounting portion 8 to a side wall of an oil pan 1. The support 3 has an inverted concave cross section and has a chamber 10 that is open at the bottom. The detection body 9 has a reed switch 2 in a cylindrical chamber 11 that is erected upward at the tip of the support body 3.
A donut-shaped float 4 having a magnet 5 is inserted into the outer periphery of the cylindrical chamber 11. Inside the chamber 10 of the support 3 are CTR and CTR.
One lead wire 7 and the other lead wire 7 connected
and will be provided. One end of both lead wires 7, 7 is connected to both ends of the reed switch 2 of the detection body 9, and the other end is connected to Tr ₁ of the circuit shown in FIG.
connected to the base side and ground side of the In the warning circuit of FIG. 2, the series circuit of the CTR 6 and the reed switch 2 is connected between the collector and base of the PNP transistor Tr ₁ , while the series circuit is connected between the collector and base of the PNP transistor Tr ₁ ;
Connect a series circuit of a resistor R and a warning lamp A between the emitter and base of PNP transistor Tr ₁ , and
Connect the anode of power supply B to the connection point of warning lamp A. The reed switch 2 is of a type in which the contact is turned on when the magnet 5 is opposed to it.

In the above embodiment, when the oil level in the oil pan 1 reaches the warning level L, the float 4 is also positioned at that height and the reed switch 2 is turned on.
Make it. In this case, the warning circuit operates in the following two ways depending on the temperature of the engine oil. First, the temperature of the engine oil is the set temperature (50~
60℃), the resistance value of CTR6 is high (10 ³ Ω or more), and therefore the potential difference between the emitter and base of PNP transistor Tr ₁ is small, and as a result, the emitter and collector are cut off and a warning is generated. Do not turn on lamp A. When the engine oil temperature is higher than the set temperature, the resistance value of CTR6 changes critically and becomes low (below 10Ω).
As a result of a potential difference occurring between the emitter and the base of the PNP transistor _Tr1 , the emitter and collector are turned on, causing the warning light A to light up. In the above circuit, instead of PNP type transistor Tr ₁
When using NPN transistors, CTR
6 and reed switch 2 are connected in series,
A similar operation can be achieved by replacing the resistor R.

In addition, if the reed switch 2 is of a type that turns off the contact when the magnet 5 faces it, the circuit connecting the CTR 6 and the warning lamp A in series is connected to an NPN transistor as shown in Figure 3.
While installing between the collector and base of Tr ₂ , reed switch 2 is connected by forming a circuit in parallel with resistor R.
By connecting the emitter and base of the NPN transistor Tr ₂ and connecting the anode of the power source B to the connection point between the CTR 6 and the warning lamp A, the same operation as described above can be achieved.

That is, when the oil level reaches the warning oil level L and the reed switch 2 is turned off, the following operation occurs depending on the temperature of the engine oil. First, if the engine oil temperature is below the set temperature,
Since the resistance value of CTR6 is high, the potential difference between the base and emitter is small, and the warning lamp A will not light up when the collector and emitter are cut off. When the engine oil temperature is higher than the set temperature and the resistance value of CTR6 is low, a potential difference is generated between the base and emitter, turning on the collector and emitter, causing warning lamp A to light up. In this circuit as well, if a PNP transistor is used instead of the NPN transistor Tr ₂ , the circuit of CTR6,
Replace the parallel circuit of reed switch 2 and resistor R.

As described above, according to this invention, the CTR is located below the detection body and is constantly immersed in engine oil, thereby reliably preventing malfunctions at low temperatures. In addition, since the device has a CTR placed inside the chamber of the support body, which has a chamber whose bottom surface is open, installation is stable and there is no risk of damage caused by engine vibrations, etc. during installation or inspection of the device. There is no danger of

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of an embodiment of this invention, FIG. 2 is a circuit diagram of the same embodiment, and FIG. 3 is a circuit diagram of another embodiment of this invention. 1...Oil pan, 2...Reed switch, 3
...Support, 4...Float, 5...Magnet, 6...CTR (Critical Temperature Register), 7...Lead wire, B...Power supply, A...
...Warning lamp, R...Resistor, TR ₁ ...PNP type transistor, Tr ₂ ...NPN type transistor.

Claims (1)

[Scope of utility model registration request] A mounting part, a support body extending laterally from the mounting part and having a reverse concave cross section and having a chamber whose bottom surface is open inside, a cylindrical chamber erected at the tip of the support body, and a lead inside the cylindrical chamber. In addition to housing the switch, a float with a magnet is inserted around the outer periphery of the cylindrical chamber, a critical temperature register is placed in the chamber of the support body, and one end of one lead wire is connected to one end of the reed switch, and the other end is connected to the reed switch. An engine oil level warning device consisting of one end of a lead wire connected to the other end of a reed switch via a critical temperate register.