JP2005247322A - Refueling machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an refueling machine capable of detecting a disconnection in a grounding conductor without fail. <P>SOLUTION: According to the refueling machine, a fuel nozzle 2 for delivering fuel is connected to a fuel passage 5 via a fuel hose 20, and the grounding conductor L<SB>1</SB>is arranged along the fuel hose 20. The refueling machine also includes electrodes 40 for detection which are arranged to be in series with the grounding conductor L<SB>1</SB>and not in contact with the fuel nozzle 2 so that a given capacitance Cs is formed between the electrode 40 and the nozzle 2. The refueling machine is further provided with a frequency counter (detecting means) 31 which detects a frequency (physical quantity) that changes in response to a change in a combined capacity of a capacitance Cg, which is generated on a disconnection part 43 when the grounding conductor L<SB>1</SB>is disconnected, and the capacitance Cs, and with a measuring control section (judging means) 3 which judges to determine if the grounding conductor L<SB>1</SB>is disconnected or not on the basis of the frequency detected by the frequency counter 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fueling device that detects a disconnection of a ground wire.

In general, a fuel nozzle of a fueling device is grounded to prevent a fire due to electrostatic discharge. The grounding wire for this purpose is usually wired along the oil supply hose, but there is a risk of disconnection due to the bending of the hose, or a contact failure at the connecting portion with the oil supply body or the oil supply nozzle. The following document exists as one for detecting the disconnection or contact failure of the ground wire (see Patent Document 1).
JP 58-203899 (FIG. 1, page 2)

In Patent Document 1, a contact electrode is provided in a nozzle boot, and the contact electrode and a nozzle pipe of an oil supply nozzle are brought into contact with each other to check conduction, thereby detecting a disconnection of a ground wire.
However, the disconnection of the ground wire may not be detected due to poor contact between the contact electrode and the nozzle pipe, which is unreliable.

  Therefore, an object of the present invention is to provide an oil supply device that can reliably detect disconnection of a ground wire.

  To achieve the above object, the present invention provides an oil supply apparatus in which an oil supply nozzle that discharges fuel oil is connected to a flow path of the fuel oil via an oil supply hose, and a ground line is wired along the oil supply hose. An electrode for detection, which is provided in a non-contact state with the oil supply nozzle and has a predetermined capacitance Cs between the oil supply nozzle, is provided in series with the ground wire, and the electrostatic potential when the ground wire is disconnected. There is a possibility that a detection unit that detects a physical quantity that changes in accordance with a change in the combined capacitance of the capacitance Cg and the capacitance Cs is provided, and the ground line may be disconnected based on the physical quantity detected by the detection unit. It is characterized in that a discrimination means for discriminating whether or not is provided.

  In the present invention, the detection electrode is provided in a non-contact state with the oil supply nozzle and in series with the grounding wire, and the change in the electrostatic capacity (synthetic capacity) when the grounding wire is disconnected is detected by the detecting means. Therefore, it is possible to detect the disconnection of the grounding wire without any fear of contact failure.

In one specific aspect of the present invention, an oscillation circuit that charges and discharges a capacitor having a capacitance Cs composed of the fueling nozzle and the electrode via the grounding wire wired along the fueling hose. And a frequency counter for detecting the frequency of the oscillation circuit is provided, and it is determined whether or not the ground wire is likely to be disconnected based on the frequency detected by the frequency counter.
This facilitates a configuration for detecting a change in capacitance.

  In this case, when the frequency detected by the frequency counter is smaller than a predetermined threshold value, it is determined that the ground line is not broken. On the other hand, when the frequency is larger than the threshold value, the ground line is broken. It was determined that there is a possibility of being.

In the present invention, it is preferable that the detection electrode is provided on a nozzle boot on which the oil supply nozzle is placed.
If it does in this way, when installing the electrode for a detection, since it is not necessary to newly wire along an oil supply hose, it is not necessary to change the structure of the existing oil supply nozzle and the oil supply hose.

In a preferred aspect of the present invention, a second capacitor having another capacitance C ₁ is inserted in parallel with a first capacitor having a capacitance Cs constituted by the fuel nozzle and an electrode, and the fuel nozzle It is now possible to determine whether or not is hung on the nozzle boot.
According to this aspect, the nozzle switch conventionally provided in the nozzle boot can be dispensed with, and the cost can be reduced.

In the present invention, when it is determined by the determining means that the grounding wire is likely to be disconnected, the fuel oil to the fuel nozzle is irrelevant regardless of whether the fuel nozzle is placed on the nozzle boot. The supply may be prohibited.
If it carries out like this, when there exists a possibility that the grounding wire may be disconnected, it can prevent oil supply.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a fueling apparatus according to the first embodiment. The fueling apparatus includes a fueling machine main body 1 and a fueling nozzle 2. The oil supply nozzle 2 discharges fuel oil, and is connected to an oil supply pipe 5 (fuel oil flow path) in the main body 1 via an oil supply hose 20.

  The oil supply pipe 5 is provided with an oil supply pump 12, a solenoid valve 14, and a flow meter F / M. The fuel pump 12 supplies fuel oil pumped up from an unshown underground tank to the fuel nozzle 2 through the oil feed pipe 5 and the fuel hose 20. The amount of fuel oil discharged from the fuel nozzle 2 is measured by the flow meter F / M and transmitted to the metering control unit 3 by the flow rate transmitter 16 connected to the flow meter F / M. The metering control unit 3 displays the amount of oil supply on the display 32 based on the signal from the flow rate transmitter 16.

As shown in FIG. 1, a ground wire L ₁ is connected to the fuel supply nozzle 2. The ground line L ₁ is embedded and wired along the oil supply hose 20, and after being led to the oil supply body 1, it is connected to the electric wire L ₂ in the oil supply body 1. The electric wire L ₂ is connected to an IC 46 provided in the fuel dispenser body 1 and is connected to an electric wire L ₃ connected to the ground G. Therefore, the fueling nozzle 2 is grounded via the ground wire L ₁ and the electric wires L ₂ and L ₃ .

The fuel filler body 1 is provided with a nozzle boot 10 for hanging the fuel nozzle 2. The nozzle boot 10 is provided with a detection electrode 40 in a non-contact state with the fuel supply nozzle 2. The electrode 40 includes two conductor plates that are installed so as to face each other with a space in the nozzle boot 10 in which the oil supply nozzle 2 is accommodated, and that are connected to the IC 46. Accordingly, as shown in the schematic diagram of FIG. 2 (a), the pair of electrodes 40, the provided ground line L ₁ in series, in a non-lubrication state fueling nozzle 2 is placed over the nozzle boot 10, A first capacitor 41 having a predetermined capacitance Cs is formed between the fuel supply nozzle 2 and the first nozzle 41.

A second capacitor 42 having a different capacitance C ₁ is inserted in parallel to the first capacitor 41 having a capacitance Cs formed by the oil supply nozzle 2 and the electrode 40 and connected to the IC 46. . As will be described later, the second capacitor 42 is provided to stabilize the oscillation of the oscillation circuit 30 and to determine whether or not the oil supply nozzle 2 is hung on the nozzle boot 10. ing.

  The IC 46 is a general CR oscillation integrated circuit (controller) that oscillates by connecting an external resistor and an external capacitor to the IC 46. In the present embodiment, the first and second capacitors 41 and 42 are connected as external capacitors to the IC 46, and the resistor 44 in FIG. 1 is connected as an external resistor. That is, one oscillation circuit 30 is formed by the IC 46, the first and second capacitors 41 and 42, and the resistor 44.

The frequency f of the oscillation circuit 30 is obtained by the following equation (1).
f = K / (C × R) (1)
K: Constant determined by circuit configuration C: Capacitance of external capacitor (synthetic capacity)
R: Resistance value of external resistance

As can be seen from the equation (1), the frequency f of the oscillation circuit 30 is equal to the capacitance C of the external capacitor, that is, the capacitance Cs of the first capacitor 41 when the resistance value of the resistor 44 is constant. And the combined capacitance of the second capacitor 42 and the capacitance C ₁ . As will be described in detail later, when the ground line L ₁ wired along the oil supply hose 20 is disconnected, the capacitance Cg generated in the disconnected portion 43 is compared with the capacitance Cs of the first capacitor 41. Since the capacitance C of the external capacitor is reduced in series, the frequency f of the oscillation circuit 30 is increased. Therefore, by detecting the change in the frequency f of the oscillation circuit 30, it is possible to detect the presence or absence of disconnection of the ground line L _1.

The frequency f of the oscillating circuit 30 is detected by a frequency counter 31 (an example of detecting means) in FIG. The frequency counter 31 is connected to the measurement control unit 3 (an example of a determination unit), and outputs the detected frequency f of the oscillation circuit 30 to the measurement control unit 3. The measurement control unit 3 determines whether or not the ground L ₁ is likely to be disconnected based on the frequency f. That is, the measurement control unit 3 determines that the ground line L ₁ is not disconnected when the frequency f of the oscillation circuit 30 detected by the frequency counter 31 is smaller than a predetermined threshold, while the frequency f ground lines L ₁ determines that there is a possibility that disconnection is larger than the threshold value.

Next, detection of disconnection of the ground line L ₁ will be described in detail.
FIG. 2 is a schematic diagram showing the configuration of the oscillation circuit 30 according to the state of the oil supply nozzle 2 and the ground line L ₁ .

FIG. 2A shows a configuration of the oscillation circuit 30 in a state where the ground line L ₁ is in a normal state (a state where there is no disconnection or contact failure) and the oil supply nozzle 2 is placed on the nozzle boot 10. . In this case, the combined capacitance C of the external capacitor for IC46, each capacitance Cs of the first and second capacitors 41 and 42, the sum of the C _1, that is, represented by the following equation (2).
C = C ₁ + Cs (2)

Therefore, the oscillation circuit 30 is smaller than a predetermined threshold value by charging and discharging the first and second capacitors 41 and 42 via the ground line L ₁ wired along the oil supply hose 20. Since it oscillates at the frequency f, the measurement control unit 3 determines that the ground line L ₁ is not broken.

On the other hand, as shown in FIG. 2B, in the state where the ground line L ₁ is disconnected and the oil supply nozzle 2 is hung on the nozzle boot 10, the disconnected portion 43 of the ground line L _1. A small capacitance Cg is generated. Since the capacitance Cg of the disconnected portion 43 is combined in series with the capacitance Cs, the combined capacitance C of the external capacitor is expressed by the following equation (3).
C = C ₁ + ((Cs × Cg) / (Cs + Cg)) (3)

Since the value of the capacitance Cg is small, the value of the combined capacitance C expressed by the equation (3) is very small compared to the equation (2). Therefore, since the oscillation circuit 30 oscillates at a frequency f greater than the threshold value, the measurement control unit 3 determines that there is a possibility that the ground line L ₁ is broken.

FIG. 2 (c), the (d), the case where the fuel supply nozzle 2 is removed from the nozzle boot 10, whether or not a ground line L ₁ is disconnected, the pair of electrodes 40, 40 spaces are opened. Since the capacitance between the electrodes 40 is negligibly small, the combined capacitance C of the external capacitor is almost equal to the capacitance C ₁ of the second capacitor 42. That is, as shown in FIGS. 2A and 2B, compared with the case where the oil supply nozzle 2 is placed on the nozzle boot 10, the combined capacity C is extremely small, so the frequency f of the oscillation circuit 30 is extremely large. . Therefore, when the second threshold value different from the threshold value for determining the disconnection of the ground line L ₁ is provided and the frequency f becomes larger than the second threshold value, the fuel supply nozzle 2 is moved from the nozzle boot 10. If it is determined that the nozzle has been picked up, the nozzle switch conventionally provided in the nozzle boot 10 can be made unnecessary.

  In this way, by inserting the second capacitor 42 in parallel with the first capacitor 41, it is possible to determine whether or not the fuel supply nozzle 2 is placed on the nozzle boot 10. When the second capacitor 42 is not provided, the oscillation circuit 30 oscillates even when the refueling nozzle 2 is detached from the nozzle boot 10 and the extremely small capacitance generated between the electrodes 40 oscillates. There is a risk of becoming. Therefore, it is preferable to provide the second capacitor 42 regardless of the presence or absence of the nozzle switch.

Next, the refueling operation based on the above-described disconnection detection will be described.
The metering control unit 3 in FIG. 1 detects the disconnection of the ground line L ₁ as described above in a state where the oil supply nozzle 2 is placed on the nozzle boot 10. In this disconnection detecting, when the ground line L ₁ is determined that there is a risk that is disconnected, the metering control unit 3, as well as warning to that effect on the display unit 32 to stop the fuel supply pump 12 In this state, the electromagnetic valve 14 is kept closed, and the supply of fuel oil to the fuel supply nozzle 2 is prohibited. Thereafter, the metering control unit 3 maintains a state in which the supply of fuel oil to the fuel nozzle 2 is prohibited regardless of whether the fuel nozzle 2 is placed on the nozzle boot 10 or not. As a result, it is possible to prohibit refueling in a state where the ground line L ₁ is disconnected.

On the other hand, in the disconnection detection, when it is determined that the ground line L ₁ is not disconnected, the metering control unit 3 determines that the oil supply nozzle 2 is based on the change in the frequency f of the oscillation circuit 30 as described above. It is determined whether or not it has been picked up from the nozzle boot 10. When the metering control unit 3 determines that the fueling nozzle 2 has been picked up from the nozzle boot 10, the metering control unit 3 resets the display 32 to zero and drives the fueling pump 12 or opens the solenoid valve 14 to provide fueling. The supply of fuel oil to the nozzle 2 is allowed. Thereby, the oil supply nozzle 2 will be in the state which can be supplied with oil by operating an oil supply lever (not shown).

FIG. 3 shows a second embodiment.
The detection electrode 40 in FIG. 3 is provided on the fuel nozzle 2 itself in a non-contact state with respect to the fuel nozzle 2. The electrode 40 is electrically connected to another wire L ₄ by IC46 is a ground line L ₁ that is wired along the same refueling hose 20 and the ground line L _1.

In such a configuration, when the ground line L ₁ wired along the oil supply hose 20 is not disconnected, the oscillation circuit 30 does not depend on whether the oil supply nozzle 2 is placed on the nozzle boot 10 or not. The configuration is the same as that shown in FIG. On the other hand, when the ground line L ₁ is disconnected, the oscillation circuit 30 is connected to the nozzle circuit 10 shown in FIG. It becomes the same composition as.

As described above, in the second embodiment, since the detection electrode 40 is provided on the fuel supply nozzle 2 itself, it cannot be determined whether or not the fuel supply nozzle 2 is placed on the nozzle boot 10. Whether or not the grounding line L ₁ is disconnected can be detected not only in a state where 2 is placed on the nozzle boot 10 but also in a state where the oil supply nozzle 2 is taken up from the nozzle boot 10.

  Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same portions or corresponding portions, and detailed description and illustration thereof are omitted.

By the way, in each of the above-described embodiments, the frequency f when the ground line L ₁ is in a normal state without setting a threshold value serving as a reference for determining whether the ground line L ₁ is broken or not is a constant value. It may be stored as a normal value, and when the frequency shift with respect to the normal value exceeds a predetermined reference value, it may be determined that there is a possibility that the ground line L ₁ is disconnected.

  Further, as a detection method for detecting a change in capacitance, in addition to the method of measuring the frequency f described above, a method of detecting other physical quantities may be employed. Other detection methods include, for example, a method of measuring the period (time) of the oscillation pulse by counting another reference pulse during one period of the oscillation pulse oscillated by the oscillation circuit 30, Start counting the reference clock at the same time as the voltage is applied, and stop counting when the voltage reaches the specified voltage.This method measures the charging time of the capacitor. Various detection methods such as a method of measuring with an A / D converter and a method of measuring the impedance of a capacitor from a flowing current value by applying a high-frequency current to the capacitor can be employed.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification.
For example, the oscillation circuit is not limited to the RC oscillation circuit, and an LC oscillation circuit using resonance between a coil and a capacitor may be employed.
Further, an intrinsic safety barrier may be provided for controlling so that electric power equal to or higher than the ignition energy of the fuel oil is not supplied to the oscillation circuit.
The present invention can also be applied to a fueling device of a type provided with a plurality of fueling nozzles and a suspension type fueling device in which the fueling nozzle and the fueling hose are held in a state of being suspended from the ceiling.
Accordingly, such changes and modifications are to be construed as within the scope of the present invention as defined by the claims.

  The present invention can be used for an oil supply apparatus including a ground wire for grounding an oil supply nozzle.

It is a schematic block diagram which shows the oil supply apparatus concerning Example 1 of this invention. It is a schematic diagram which shows the structure of an oscillation circuit classified into cases. It is a schematic block diagram which shows the oil supply apparatus concerning Example 2 of this invention.

Explanation of symbols

1: Refueling machine body 10: Nozzle boot 2: Refueling nozzle 20: Refueling hose 3: Discriminating means (measuring control unit)
30: Oscillator 31: Detection means (frequency counter)
40: Electrode 41, 42: Capacitor 43: Disconnected portion 5: Flow path of fuel oil (oil feed pipe)
Cs, Cg, C ₁ : Capacitance L ₁ : Ground wire

Claims (6)

In a fueling device in which a fueling nozzle that discharges fuel oil is connected to a flow path of fuel oil via a fueling hose, and a grounding wire is wired along the fueling hose,
Provided in a non-contact state with the fueling nozzle, a detection electrode having a predetermined capacitance Cs between the fueling nozzle and the grounding line is provided in series.
Detecting means for detecting a physical quantity that changes in accordance with a change in a combined capacitance of the electrostatic capacitance Cg and the electrostatic capacitance Cs generated in the disconnection portion when the ground wire is disconnected;
An oil supply apparatus comprising: a determination unit configured to determine whether or not the ground wire is likely to be disconnected based on a physical quantity detected by the detection unit. In a fueling device in which a fueling nozzle that discharges fuel oil is connected to a flow path of fuel oil via a fueling hose, and a grounding wire is wired along the fueling hose,
Provided in a non-contact state with the fueling nozzle, a detection electrode having a predetermined capacitance Cs between the fueling nozzle and the grounding line is provided in series.
Forming an oscillation circuit that charges and discharges a capacitor having a capacitance Cs composed of the fueling nozzle and the electrode via the grounding wire wired along the fueling hose,
A frequency counter for detecting the frequency of the oscillation circuit is provided;
An oil supply apparatus comprising: a determination unit configured to determine whether or not the ground wire is likely to be disconnected based on a frequency detected by the frequency counter. In claim 2, when the frequency detected by the frequency counter is smaller than a predetermined threshold, it is determined that the ground wire is not disconnected,
On the other hand, a fueling device that determines that the ground wire may be disconnected when the frequency is greater than the threshold value.   4. The oil supply device according to claim 1, wherein the detection electrode is provided on a nozzle boot on which the oil supply nozzle is placed. According to claim 4, for the first capacitor of the capacitance Cs formed between the fuel supply nozzle and the electrode, a second capacitor having a different capacitance C ₁ is inserted in parallel,
An oil supply apparatus that can determine whether or not the oil supply nozzle is hung on a nozzle boot.   6. In any one of Claims 1 thru | or 5, when it is discriminate | determined that there exists a possibility that the said grounding wire may be disconnected by the said discrimination means, irrespective of whether the said oil supply nozzle is hung on a nozzle boot A fueling device that prohibits the supply of fuel oil to the fueling nozzle.

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