JPS60331A - Alarming device of residue of liquid - Google Patents

Abstract

PURPOSE:To remove malfunction due to the vibration of a liquid surface by connecting a malfunction preventing electric circuit consisting of a charging/discharging circuit of a capacitor and a switching means between a float switch and an alarm device. CONSTITUTION:The malfunction preventing electric circuit 5 is connected between the float switch 2 and the alarm lamp 4. Even if the float switch 2 is turned on for a slight period by the vibration of the liquid surface of fuel, the voltage charged to the capacitor 11 does not reach a threshold value or more necessary for turning on a transistor (TR) 9, so that the alarm lamp 4 is not turned on. When the fuel in a fuel tank is reduced and the float switch 2 is turned on, the charging voltage of a capacitor 10 exceeds the threshold value and the alarm lamp 4 is turned on.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid contained so as to cause vibrations on the liquid surface;
For example, the present invention relates to a liquid remaining amount alarm device that issues an alarm when the remaining amount of liquid such as fuel oil, cooling water, lubricating oil, hydraulic oil, etc. in a vehicle reaches a predetermined amount.

Figures 1 and 2 are examples of conventional warning devices for the remaining amount of liquid. The figure is a sectional view showing the float switch portion, and FIG. 2 is an explanatory diagram illustrating the electrical system.

In Figure 1, 1 is a fuel tank mounted on a hydraulic excavator, and this fuel tank 1 contains liquid, that is, engine fuel.
a is accommodated. 2 is a float switch that detects the remaining amount of this fuel 1a, and is made up of a flow (2a) floating on the liquid surface of the fuel 1a, and a hollow float shaft 2b to which this flow (2a) is guided. Flow 2a moves up and down as the liquid level position changes. A permanent magnet (not shown) is built into the float shaft 2a, while a reed switch (
(not shown) is built-in. Therefore, as the fuel 1a is consumed and its liquid level falls, the flow ) 2a also decreases along the float axis 2b, and when the remaining amount of the fuel 1'a reaches a predetermined amount, the flow ) 2a becomes permanent. The magnet activates the reed switch, turning it from off to on. Also 2
C is the lead wire of the reed switch, and this lead wire 2C is the lead wire shown in FIG.
It is connected to the.

By the way, in a machine such as a hydraulic excavator that is equipped with such a warning device and whose vehicle body shakes violently, the liquid level of the fuel 1a shakes violently with the shaking of the hydraulic excavator, so that the flow 2a also moves to the float shaft 2b. It moves up and down a lot along the line.

However, in the conventional warning device described above, even if the remaining amount of fuel has not yet decreased to a predetermined amount.

Especially when the fuel 1a in the fuel tank 1 is low, the series reed switch
In other words, the float switch 2 is easy to repeatedly connect and disconnect,
As a result, the warning lamp 4 tends to blink, which is troublesome for the oiler. Also, alarm lamp 4
The blinking of the warning lamp 4 increases the amount of stain power consumed and has the disadvantage that the life of the warning lamp 4 is shortened.

FIG. 3 is a sectional view showing the configuration of the main parts of another conventional alarm device proposed to eliminate such drawbacks.

In this conventional example, the structure of the 70-tooth switch 2 provided in the fuel tank 1 and the electrical connection state between the float switch 2 and the alarm lamp 4 are the same as those shown in the above-mentioned 1% 1 switch and FIG. The switch 2 is covered with a float outer cylinder 3, and there are two places on the float outer cylinder 3 to prevent changes in the liquid level inside the float outer cylinder 3 in response to sudden changes in the liquid level outside the float outer cylinder 3. Small communication holes 3a and 3b are provided to slow down the response.

By covering the float switch 2 with such a float outer cylinder 3, the vertical fluctuation of the 70-tooth 2a inside the float outer cylinder 3 is small, and as a result, the float switch 2 is less likely to malfunction.

However, in the conventional example shown in FIG. 3, it is necessary to force the float outer cylinder 3 into the fuel tank 1.
It is not easy to install the float outer cylinder 3, and it is uneconomical to change to a float outer cylinder with a different size every time the size of the fuel tank changes.

An object of the present invention is to eliminate the drawbacks of the prior art, prevent an alarm from being activated even if the float switch malfunctions due to fluctuations in the liquid level, and, moreover, provide an appropriate method without requiring a float outer cylinder. An object of the present invention is to provide a liquid remaining amount alarm device that can issue a warning.

In order to achieve this object, the present invention includes a float switch that detects the remaining amount of liquid and an alarm connected to this 70-toswitch 1c, and issues an alarm when the remaining amount of liquid reaches a predetermined amount. In the liquid remaining amount alarm device, an electric circuit for preventing malfunction of the alarm is provided between the float switch and the alarm, the electric circuit for preventing malfunction of the alarm,
a charging/discharging circuit including a capacitor that is charged and discharged by opening and closing of the float switch; a first switching means that applies a charging voltage to the capacitor in accordance with the opening and closing operations of the float switch; and a second switching means for activating the alarm when a predetermined value is reached.

Hereinafter, a description will be given of the liquid remaining amount ledger device of the present invention.

FIG. 4 is an explanatory diagram showing an embodiment of the remaining liquid amount alarm device of the present invention. Similarly, this embodiment is arranged, for example, to detect the remaining amount of engine fuel in the fuel tank of the above-mentioned hydraulic excavator.

In FIG. 4, numerals 2 and 4 are the same float switches and alarm lamps as described above. Reference numeral 5 denotes a malfunction prevention electric circuit for preventing malfunction of the alarm device, that is, the alarm lamp 4, and is provided between the float switch 2 and the reward/g 4. These five electric circuits for preventing malfunction consist of a charging/discharging circuit, a first switching means, and a second switching means, as described below.

In other words, 6 is the first terminal connected to the float switch 2 side.
switching means, for example a transistor, the pace of this transistor 6 is connected via a terminal A to one contact of the float switch 2, and the pace is further connected to a resistor 7.
Terminal B to which a voltage higher than the threshold is applied throughout
), and the collector of this transistor 6 is connected to terminal B via a resistor 8 .

Further, reference numeral 9 denotes a second switching means, for example a transistor, and a voltage sufficient to light up the alarm lamp 4, which is connected to the collector of the transistor 9 via the terminal C, is applied between the collector and emitter of the transistor 9. , the emitter side is grounded. Furthermore, a capacitor 10 is inserted between the transistor 90 pace and the emitter,
One electrode terminal of this capacitor 10 is connected to the collector of the transistor 6 via a resistor 11, and the other electrode terminal of the capacitor 10 is connected to the emitter of the transistor 6. Further, the other contact side of the float switch 2 is grounded.

Then, from the B terminal, resistor 8, l"1 and capacitor 10
A charging path is passed through the capacitor 10 to ground, and from the electrode terminal 1'Δ terminal connected to the base side of the transistor 9 of the capacitor 10, through the resistor 11, through the collector and emitter of the transistor 6, to the transistor 1 of the capacitor 10. The charging/discharging circuit is formed by a discharge path leading to an electrode terminal to which the emitter side of No. 9 is connected.

In one embodiment configured in this way, when there is sufficient fuel in the fuel tank, the 70-tooth switch 2 is turned off).
At that time, a voltage higher than the threshold value is applied from terminal B to the base of transistor 60, so transistor 6 is turned on, and the pace of transistor 9 becomes 0 voltage, so transistor 9 is turned off and an alarm/prompt is generated. 4 is not lit (＼.

In addition, when the fuel in the fuel tank becomes low and the remaining amount reaches a predetermined amount, the float switch 2 is turned on and the Naruto transistor 60 pace is grounded via the float switch 2, so that the voltage reaches the threshold level. When the voltage becomes lower than the value, the transistor 6 is turned off. When the transistor 6 is turned off, the voltage applied to the B terminal causes p1 to turn off.
A capacitor is connected to the charging/discharging path of the charging/discharging circuit, that is, between the B terminal and the ground via a resistor 8.11. When a voltage is applied to charge the capacitor 10 and the charging voltage of the capacitor 10 reaches the threshold value of the transistor 9 or more, the transistor 9 is turned on and current flows to the alarm lamp 4, causing this alarm lamp to 4 lights up. Even if the amount of gas or ζχ fuel in the fuel tank has not reached the level required to issue the 1st alarm, the float switch 2 will be turned on for a short period of time due to fluctuations in the fuel level. It is also conceivable that the operation of switching off and then immediately turning off is repeated. But in this case,
Even if the capacitor IO has a large capacity, and the time constant is determined by the combined resistance value of resistors 8 and 11 and the capacitance value of the capacitor IO, even if the p1 float switch 2 is turned on for only a short time, the charging/discharging circuit is Capacitor 1 depending on the charging path
The voltage charged to 1 never reaches the threshold required to turn on transistor 9, and once float switch 2 is turned off, conduction occurs between the collector and emitter of transistor 6. The discharge path of the charging/discharging circuit is formed, and the capacitor 10 is connected to the float switch in front.
The voltage stored when the switch 2 is turned on for a very short time is completely discharged through the discharge path.

Therefore, even if the float switch 2 malfunctions by repeatedly turning on and off due to fluctuations in the liquid level in the fuel tank, the alarm lamp 4 will not light up, and an appropriate alarm, that is, lighting operation will always be performed. .

Further, in this embodiment, since the alarm lamp 4 does not blink unnecessarily, power consumption can be suppressed and the life of the alarm lamp 4 can be maintained for a long time.

fllll, the first switching means, the second nine switching stages, and the charging/discharging circuit are not limited to those shown in the Honto example, and may have other appropriate circuit configurations.

Also, in the above embodiment, the alarm device is an alarm device, but this alarm device is a device that emits an alarm sound. It may be replaced with lI''-1 or others.

Since the present invention has the above-described structure, even if the float switch malfunctions due to fluctuations in the liquid level, the alarm will not issue an alarm by mistake, and the operator will be freed from the hassle. It has the effect of Furthermore, since the alarm does not operate unnecessarily, power consumption can be suppressed and the longevity of the alarm can be improved.

Furthermore, since there is no need to provide a float outer cylinder as in the conventional case, there is also the effect that installation and drinking becomes easier.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing a conventional liquid 'lAm0 notification device, FIG. 1 is a sectional view showing a float switch portion, FIG. 2 is an explanatory diagram illustrating an electrical system, and FIG. The figure is a cross-sectional view showing the configuration of the main parts of another conventional snack alarm box, and FIG. 4 is an explanatory view showing an embodiment of the liquid remaining amount alarm device of the present invention [ψ]. 2...Float switch, 4...Alarm lamp, 5.
...Electric circuit for preventing malfunction of alarm, 6...Transistor (first switching means), 9...Transistor (second switching means), 10...Capacitor. 1st @ Yao 2 fig. 883 fig. 1974 fig.

Claims (1)

[Claims] In a liquid remaining amount alarm device that includes a float switch that detects the remaining amount of liquid and an alarm connected to the throat switch, and that issues an alarm when the remaining amount of liquid reaches a predetermined amount, the float switch and the An electric circuit for preventing malfunction of the alarm is provided between the alarm and the electric circuit for preventing malfunction of the alarm, and the electric circuit for preventing malfunction is charged and discharged by opening and closing of the float switch. The capacitor is charged according to the opening/closing operation! A liquid remaining amount alarm comprising a first switching means for applying a voltage and a second switching means for activating the alarm when the voltage charged in the capacitor reaches a predetermined value. Device.