JP3022691B2 - Roller sensor circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor circuit for detecting the state of a lorry for transporting fuel oil to a refueling facility, and more particularly for a lorry capable of monitoring the state of a line connecting a sensor and control means. It relates to a sensor circuit.

[0002]

2. Description of the Related Art Rori divides its tank into a plurality of chambers, and provides a hatch lid discharge bottom valve for injecting fuel oil and a liquid level gauge for detecting a liquid amount in each room for each tank. Each room contains different types of fuel oil,
Further, a sensor is provided at each hatch lid bottom valve or the like, and the state of each room is monitored by a microcomputer or the like. For this reason, a large number of sensors are installed in one lorry, and operation errors and the like are checked based on signals from these sensors, thereby preventing accidents. In order for such a system to operate properly, it is assumed that the sensors and the lines connecting them are not short-circuited or disconnected. For this reason, although sensors and lines are checked by starting inspections and the like, there are problems such as requiring human labor and occurrence of human error.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and a purpose thereof is to automatically monitor the state of a sensor or a connection line without manual operation. To provide a novel sensor circuit for lorries.

[0004]

In order to solve such a problem, according to the present invention, a plurality of resistance elements are connected in series, and one of the resistance elements is turned on or off in accordance with a detected state. A sensor body in which switching means for turning off are connected in parallel; a constant current supply means for supplying a constant current to the sensor body via a power supply line; and a voltage detection receiving a terminal voltage of the sensor body via a data line. Means and a reference voltage for detecting a voltage generated by short-circuiting and disconnection of the power supply line and operation of the switching means.
Reference voltage generating means for supplying to the voltage detecting means,
And a display which operates in response to a signal from the voltage detecting means .

[0005]

[Function] A connection line such as a data line or a power line is short-circuited,
Or, when the power supply is disconnected, the voltage becomes abnormally low or abnormally high as compared with the normal state, and the abnormal state can be automatically detected by detecting the abnormal state by the voltage detecting means.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. FIG. 4 shows an embodiment of a lorry to which the present invention is applied. In the drawing, reference numeral 1 denotes a tank, which is divided into a plurality of rooms 3, 3, 3 by partition plates 2, 2, In each room, liquid level gauges 4, 4, 4 for measuring the amount of fuel oil contained, hatch lids 5, 5, 5 opened when refueling the tank, bottom opened when fuel is discharged. Valves 6, 6, 6, and a discharge port valve 8 connected to each bottom valve 6 via a pipe 7 are provided. Each of the hatch lids 5, 5, 5 has a hatch lid open / close detection sensor 9, 9, 9 for detecting that it has been opened, and a bottom valve open / close detection sensor 10, for detecting that the bottom valve 6 has been opened. 1
0 and 10 are provided, and the discharge port valve 8 is provided with an oil type sensor 11 for determining the oil type. These sensors 9, 10, 11 are connected to the driver's seat 1 via a lead wire L.
2 is connected to a control panel 13 provided in the control panel 2. The control panel 13 controls the liquid amount of the fuel oil injected into each of the rooms 3, 3, 3 based on signals from the liquid level gauges 4, 4, 4,
It is configured such that the types of fuel oils 3 and 3 can be registered.

FIG. 1 shows an embodiment in which the hatch lid opening / closing detection sensor section is constituted by an intrinsically safe explosion-proof circuit. In the figure, reference numeral 20 denotes a constant current circuit for driving the sensor 9 and a photocurrent circuit. Switching means 21 such as a coupler
To the power line P1 and then to the sensor 9 via the Zener barrier T and the lead line L1 to supply a drive current.

Reference numeral 9 denotes the above-mentioned hatch lid open / close detection sensor, in which a plurality of resistance elements RS1, RS2 # are connected in series to the terminals 22, 22, and a switch operable externally to one resistance element RS2, for example, a microcontroller. The switch S is connected. This switch S is connected to each hatch lid 5 via an operating rod so as to be turned on when the hatch lid 5 is opened, and is fixed from the constant current circuit 20 via the Zener barrier T, for example, 5 mmA. A current is supplied to the extent that the vapor is not ignited even when the short circuit occurs. A plurality of comparison circuits C1, C2, and C3 having different inversion potentials are connected to a connection point between the zener barrier T and the power supply line P1 via a data line D1.

Reference numeral 23 denotes a reference voltage generating circuit which connects a plurality of reference resistors RS, RS, RS ‥‥ and a resistor R for voltage adjustment in series to form switching means 24 such as a photocoupler.
Is supplied from the constant current circuit 25 via the constant current circuit 25 to generate a voltage VO generated when the line is opened, a voltage VS generated when the sensor is activated, and a voltage VC generated when the lead wire is short-circuited. The voltage signals VO, VS, and VC are output to the non-inverting terminal of the first comparing circuit C1, to the inverting terminal of the second comparing circuit C2, and to the inverting terminal of the third comparing circuit C3, respectively. These comparison circuits C1
The output terminals of .about.C3 are the display units 30, 31, and 32, respectively.
Is connected.

The switching means 21 and 24 are
It is configured to receive an input of a signal from the scanning unit 26, turn on and off at a constant cycle, and operate the sensor 9 and the reference voltage generation circuit 23. The symbol DZ in the figure indicates a Zener diode.

FIG. 2 shows the bottom valve open / close detection sensor 10 described above.
Is a non-explosion-proof circuit, in which a plurality of resistance elements RS1 and RS2 are connected in series to terminals 42 and 42 and a switch operable from outside to one resistance element RS2, for example, a microswitch S are connected. The switches S are connected to the respective bottom valves 6 via operating rods so as to be turned on when the bottom valves 6 are opened, and are connected from the constant current circuit 40 via switching means 41 such as a photocoupler and the power line P2. Then, a predetermined current, for example, a current of about 5 mA is supplied. A plurality of comparison circuits C4, C5 and C6 are connected to a connection point with the power supply line P2 via a data line D2.

Reference numeral 43 denotes a reference voltage generation circuit which connects a plurality of reference resistors RS, RS, RS ‥‥ and a resistor R for voltage adjustment in series, and provides switching means 44 such as a photocoupler.
And a constant current supply 45 from the constant current circuit 45 to generate a voltage VO generated when the line is opened, a voltage VS generated when the sensor is activated, and a voltage VC generated when the lead wire L2 is short-circuited. The voltage signals VO, VS, and VC are output to the non-inverting terminal of the first comparing circuit C4, to the inverting terminal of the second comparing circuit C5, and to the inverting terminal of the third comparing circuit C6, respectively. Output terminals of these comparison circuits C4 to C6 are respectively provided with indicators 50, 51, and 50.
52 are connected.

Each of the switching means 41 and 44 includes:
It is configured to receive a signal input from the scanning unit 46, turn on / off at a constant cycle, and operate the sensor 10 and the reference voltage generation circuit 43.

FIG. 3 shows an embodiment in which the oil type sensor 11 is constructed as a non-explosion proof structure. The reference resistance elements RS 'and RS correspond to the number of oil types to be determined.
, RS`} are connected in series, switching means Sm, Sm, Sm ‥‥ such as a Hall element are connected to each connection point, and a route near each switching means Sm, Sm, Sm ‥‥ is defined as a path. In this embodiment, a permanent magnet is disposed, and one specific switching means Sm, Sm, Sm # is turned on by an oil type selection operation from the outside. Each reference resistance element R
S`, RS`, and RS` ‥‥ are connected to a scanning switching means 70 such as a photocoupler by connecting the series connection end with a lead wire L3.
, And is configured to receive supply of current from the constant current circuit 71 when the switching means 70 is turned on.

Reference numeral 72 denotes a reference voltage generation circuit which is connected to a plurality of reference resistors in series, receives a current from a constant current circuit 73, and generates reference voltages V1 to V1 corresponding to voltages generated according to the position of the switch driving means M. It is configured to output V7. Each of the comparison circuits C7 to C13 has a non-inverting terminal receiving a signal from the sensor 11 via the data line D3, and an inverting terminal receiving each reference voltage signal V from the reference voltage generating circuit 72.
1 to V7 are input, and an output terminal is connected to a display 77 for displaying the oil type.

The sensor 11 is also connected to first and second comparison circuits C14 and C15 via a data line D3 and switching means 74 such as a photocoupler. The inversion terminals of these comparison circuits C14 and C15 are supplied with a reference voltage from the reference voltage generation circuit 75 for detecting a short circuit or disconnection of the lead wire and the data lines D3 and D4. 80 and 81 are connected. Reference numerals 83 and 84 in the figure denote scanning switching means, reference numeral 85 denotes a constant current circuit, and reference numeral 86 denotes a scanning means for outputting a scanning signal.

Next, the operation of the device configured as described above will be described. When a power switch is turned on to activate the sensors 9, 10, and 11, each of the scanning means 26, 46,
86 outputs a channel selection signal. As a result,
Switching means 21, 26, 41, 44, 70, 7
4,83,84 are turned on, and each sensor 9,10,
11, a current for driving the sensor is supplied from constant current circuits 20, 40, 71, and constant current circuits 25, 45, 73,
A constant current for generating a reference voltage is supplied from 85 to the reference voltage generating circuits 23, 43, 72, 75.

In this case, since the hatch lid 5 is closed and the switch S constituting the sensor 9 is off, current flows only through the resistor RS2. As a result, a signal having a voltage higher than the voltage VS and lower than the voltage VO is output from the sensor 9, so that any of the comparison circuits C1 to
No signal for driving the displays 30 to 32 is output from C3.

On the other hand, when the hatch lid is opened in order to supply fuel oil to the tank 1, the switch S constituting the sensor 9 is turned on in conjunction with the opening. As a result, only the resistor RS1 is connected to the constant current circuit 20, and the load voltage of the sensor 9 drops, and a signal of the voltage VS is output.
This voltage VS causes the comparison circuit C2 to output a signal for driving the display 31 and activates the display 31 to switch the hatch cover 5
Indicates that is open. When the supply of fuel oil is completed and the hatch lid 5 is closed, the switch S of the sensor 9 is turned off and the output voltage of the sensor increases, so that the drive signal from the comparison circuit C2 disappears and the hatch lid 5 is closed. You will be notified that it has been closed.

If the tank 1 is provided with a plurality of hatch lid opening / closing detection sensors 9, 9, 9, the sensors 9, 9, 9
9 are sequentially activated, and the opening and closing of the hatch lids 5, 5, 5 can be monitored by the above-described steps. In this way, when the necessary fuel oil has been loaded, each room 3,
The oil level is detected by the output from the liquid level gauges 4, 4, and 4 provided at the 3, 3 mm, and at the same time, the oil type is
3 is registered. When all the hatch lids 5, 5, 5 ‥‥ are confirmed to be closed, shipment becomes possible.

By the way, the lead line L1 and the data line D1,
Further, when the power supply line P1 is disconnected or short-circuited, the sensor 9
When the drive current is no longer supplied to the circuit or the signal from the sensor 9 is no longer input, the voltage input to the comparison circuits C1 to C3 becomes larger than VO or becomes smaller than VC. A display driving signal is output from one of C1 and C3, and one of the displays 30 and 32 for notifying an abnormal state is activated, and the sensor 9, the data line D1, the power line P1, and the lead line L1 are activated. Encourage inspections such as.

On the other hand, in order to supply fuel oil to an oil storage tank such as a gas station, a supply hose is connected to the discharge port, and a target oil type is selected by the oil type sensor 11. M moves to turn on the switching means Sm at the position corresponding to the oil type. The voltage corresponding to the oil type selected from the oil type sensor 11 is a comparison circuit C
Input to 7 to C13. This voltage is compared with reference voltages V1 to V7 determined for each oil type in a comparison circuit. As a result, a display device drive signal is output from the comparison circuit whose oil type matches, and the oil type is displayed on the display 77.

When the matching of the oil type is confirmed, when the bottom valve 6 of the room 3 containing the target oil type is opened, the switch S constituting the bottom valve open / close detection sensor 10 is turned on. . As a result, the load voltage of the sensor 10 decreases, and therefore, a display driving signal is output from the comparison circuit C5 to operate the valve open indicator 51 to indicate that the bottom valve 6 has been opened.

When the bottom valve open / close detection sensor 10 is provided for each of the plurality of bottom valves 6, 6, 6 #,
As in the case of the hatch lid opening / closing detection sensor, the scanning means 4
6, each sensor 10, 10,.
10 may be sequentially operated to monitor the opening and closing of the plurality of bottom valves 6, 6, 6 in the above-described steps. Also,
When the lead line L2, power supply line P2 and data line D2 of the bottom valve open / close detection sensor are short-circuited or disconnected, the comparison circuits C4 to C6
Is extremely low or high, a signal is output from the comparison circuits C4 and C6, and one of the indicators 50 and 52 for displaying an abnormal state is activated. You can know.

On the other hand, when the lead line L3, the power supply line P3, and the data lines D3 and D4 connected to the oil type sensor 11 are short-circuited or cut off, the voltage of the signal input to the comparison circuits C14 and C15 is similarly reduced. Since the size becomes extremely small or large, a driving signal is output from one of the comparison circuits C14 and C15, and the indicators 80 and 81 for displaying an abnormal state are operated.

In this embodiment, the comparison circuit is provided for each state to be detected. However, the load voltage of the sensor is converted into data by an analog-to-digital conversion circuit, and the data is determined by a microcomputer or the like. Obviously, the same effect is obtained even if it does so.

Further, in the above-described embodiment, an example has been described in which each sensor is scanned at a constant period.
Obviously, the same effect can be obtained even when the operation is always performed and the scanning is performed at the time of capturing the signal.

[0028]

As described above, in the present invention,
A plurality of resistive elements are connected in series, and one of the resistive elements is connected in parallel with switching means for turning on and off in response to a detected state. a constant current supply means for supplying a current, a voltage detection means for receiving the terminal voltage of the sensor body through the data lines, short circuit of the power supply line, cutting, and reference potential to detect a voltage generated by the operation of the switching means
A reference voltage generating means for supplying a voltage to the voltage detecting means, and a voltage
An indicator that operates in response to a signal from the detection means is provided to monitor for breaks or shorts in the lead wires connected to the sensor body.
Can be viewed and detected by the sensor body
State can be detected with high reliability .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a sensor circuit for detecting opening and closing of a hatch lid in a sensor circuit according to the present invention.

FIG. 2 is a configuration diagram showing one embodiment of a sensor circuit for detecting opening and closing of a bottom valve in the sensor circuit according to the present invention.

FIG. 3 is a configuration diagram showing one embodiment of a sensor circuit for detecting an oil type in the sensor circuit according to the present invention.

FIG. 4 is a diagram showing an embodiment of a lorry to which the present invention is applied.

[Explanation of symbols]

 Reference Signs List 1 tank 3 room 4 level gauge 5 hatch lid 6 bottom valve 8 discharge port valve 10 bottom valve open / close detection sensor 11 oil type sensor 13 control panel 23, 43, 72, 75 reference voltage generation circuit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B67D 5/32

Claims (1)

(57) [Claims] A plurality of resistance elements are connected in series, and one of said resistance elements is turned on / off according to a detected state.
A sensor body in which switching means for turning off are connected in parallel; a constant current supply means for supplying a constant current to the sensor body via a power supply line; and a voltage detection receiving a terminal voltage of the sensor body via a data line. Means , short-circuiting and disconnection of the power supply line, and
The reference voltage for detecting the voltage generated by the operation is
A lorry sensor circuit comprising: a reference voltage generating means for supplying to a voltage detecting means; and a display which operates upon receiving a signal from the voltage detecting means .