JPS61247924A - Safety device for fuel flowmeter for vehicle - Google Patents

Abstract

PURPOSE:To prevent inconvenience such as the sudden stopping of the fuel supply by flowing the fuel automatically via a bypass in case a flowmeter get clogged with an impurity such as dust and a non-flow state is detected. CONSTITUTION:While a fuel pump 4 is operated, in case revolutions of bodies 5 and 6 of revolution are stopped by the impurity intermingled in the fuel, a control part 12 receives a detection signal that the bodies 5 and 6 of revolution are in nonrevolving states from a revolving speed detecting mechanism 7 and an operation signal from the fuel pump 4. In this case, the control part 12 decided this to be abnormal and outputs for an opening and shutting value mechanism 11 and changes over it to an open state. Hereby, the fuel passes via the bypass 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a safety device for a vehicle fuel flow meter that measures the flow rate of fuel supplied to the engine of a vehicle such as an automobile.

[Problems to be solved by the prior art and the invention today]
There is a system that measures the flow rate of fuel supplied to the engine of a vehicle such as an automobile, calculates fuel consumption, etc., and displays this. In this way, in order to measure the flow rate of fuel, it is necessary to install a flow meter in the fuel flow path. In the case of so-called positive displacement flowmeters, which measure the fuel flow rate by counting the number of revolutions of a rotating body that rotates in accordance with the amount of fuel passing through, contaminants such as dust contained in the fuel are detected. If the rotating body is locked and stops rotating due to objects flowing into it, etc.
The disadvantage is that the flow resistance at the flowmeter becomes large and almost no fuel flows, which prevents the smooth supply of fuel.In this case, the engine may suddenly stop, which is extremely dangerous. This is dangerous and it is necessary to take some kind of countermeasure against this, but until now nothing was known about such countermeasures.

[Means for Solving the Problem] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a safety device for a fuel flow meter for a vehicle that can eliminate these drawbacks. A flow meter for measuring the fuel flow rate and a detour having an on-off valve mechanism that bypasses the measuring part of the flow meter are provided in the flow path of fuel supplied to the engine side by the operation of the pump, and this opening/closing valve mechanism is provided. The opening/closing control of the valve mechanism is performed based on the detection signal from the flow meter and whether the fuel pump is operating or not, or whether fuel is being supplied or not based on the operation or non-operation of the fuel supply side such as the engine receiving the fuel supply. When the fuel is being supplied but the flowmeter is not flowing, the control means determines this as an abnormality and outputs an output signal to the opening/closing valve mechanism to open the valve. It is characterized by what it does.

With this configuration, when the flowmeter is clogged with foreign matter such as dust and a no-flow state is detected, the fuel automatically flows through the detour, thereby supplying the fuel. This is to eliminate problems such as unexpected stoppage.

[Example] Next, in 6 drawings for explaining an example of the present invention based on the drawings, 1 is a casing of a positive displacement fuel flow meter, and the casing 1 includes an inflow pipe into which fuel flows. 2,
In addition, a discharge pipe 3 for discharging the fuel is fixed, and the fuel that is supplied to a supplied part such as an engine (not shown) by the operation of the fuel pump 4 passes through the inflow pipe 2, the casing 1, and the discharge pipe 3. A flow path is formed. A rotating body (rotor) 5.6, which has an elliptical shape and has tooth bodies formed on its circumference that mesh with each other, is rotatably supported on this casing 1 and constitutes a measuring section. but,
In this embodiment, the rotating body 5.6 is made of carbon which has excellent chemical resistance and good self-sliding properties.

The rotating bodies 5, 6 are rotated in accordance with the amount of fuel passing through, and by counting the number of rotations of either of the rotating bodies 5, 6 by the rotational speed detection mechanism 7, the volume of fuel passing through is determined. It is supposed to be weighed.

Further, communication ports 8.9 are provided in the casing 1 at the front and rear sides of the measuring portion consisting of the rotary body 5.6.
A detour 10 (relief passage) is formed to detour around the measuring section, and this detour 10 is provided with an electromagnetic on-off valve mechanism 11 that switches between two positions.

Next, the control means for this on-off valve mechanism 11 will be explained. This control means inputs a detection signal from the rotation speed detection mechanism 7 and an operation signal from the fuel pump 4 and makes a judgment, and based on this judgment, a control section 12 outputs a control signal to be described later. It has become. That is, the control section 12
Here, the rotating body 5.6 is rotating due to the passage of fuel, and the fuel pump 4 is also operating normally, and both the detection signal from the rotation speed detection mechanism 7 and the operating signal from the fuel pump 4 are in a normal state. If it is inputted in , it is determined to be normal, and no output is made to the on-off valve mechanism 11, so that the on-off valve mechanism 11 is in the closed state. Further, when the rotation of the rotors 5 and 6 is stopped due to foreign matter mixed in the fuel while the fuel pump 4 is in operation, the control unit 12 detects the rotation of the rotors 5 and 6 from the rotation speed detection mechanism 7. It receives a detection signal indicating that it is in a non-rotating state and an activation signal from the fuel pump 4. In this case, the control unit 12 determines this to be abnormal and outputs an output to the on-off valve mechanism 11 to switch it to the open state, thereby allowing the fuel to pass through the detour 10. On the other hand, even when there is no fuel supply due to reasons such as the fuel pump 4 being stopped, the rotation speed detection mechanism 7 outputs a detection signal indicating that there is no flow rate. , a stop signal is input from the fuel pump 4 indicating that the operation is stopped, and therefore, the control unit 12 determines that this is normal and the input signal from the 1 rotation speed detection mechanism 7 is in a no-flow state. However, there is no output to the on-off valve mechanism 11, so the detour 1
0 is designed to close, and their control methods are shown in Table 1.

In the figure, reference numeral 13 denotes an operation monitor of the on-off valve mechanism 11, and the operation monitor 13 is connected to the control section 12 as described above.
It is possible to monitor whether the opening/closing valve mechanism 11 is in the open state in response to a command from the controller by appropriate notification means such as lighting a lamp or sounding a buzzer.

In the embodiment of the present invention configured as described above, fuel flows into the casing 1 via the inflow pipe 2 by the operation of the fuel pump 4, and the rotating bodies 5 and 6 are rotated in accordance with the amount of inflow. After that, the fuel is discharged from the exhaust pipe 3 and flows to the engine side. In the flowmeter, the rotational speed of the rotating body 5.6 is counted and detected by the rotational speed detection mechanism 7, and thereby the volumetric measurement of the fuel flow rate is performed.

In such a fuel flow meter, when foreign matter such as dust flows into the casing 1 and the rotation of the rotating bodies 5 and 6 is stopped, the rotation speed detection mechanism 7 outputs a detection signal indicating a no-flow state. This will be input to the control section 12. The control unit 12 to which this non-rotation state detection signal is input
In this case, whether or not fuel is being supplied is determined by the presence or absence of an operating signal from the fuel pump 4, and if there is no flow rate even though the fuel pump 4 is operating, this is determined to be an abnormality. Then, as described above, an output signal is issued to open the on-off valve mechanism 11, and the fuel is sent to the engine via the detour 10. On the other hand, even when the fuel pump 4 is stopped and there is no fuel flow, the rotation speed detection mechanism 7 outputs a detection signal indicating a no-flow state. Since the signal is in a stopped state, it is determined that this is a normal state, and the control unit 12
There is no output to the on-off valve mechanism 11 from the detour 10.
In this way, in the present invention, when the rotating body 5.6 is stopped due to foreign matter such as dust, the on-off valve mechanism 11 is automatically opened.
is opened, and the fuel passes through via the detour 10. As a result, it is possible to completely eliminate the conventional problem of stopping the fuel supply when the flow meter fails.

Moreover, in the present invention, the opening of the on-off valve mechanism 11 is not sufficient simply by the output of a detection signal indicating that there is no flow rate from the rotation speed detection mechanism 7, but by the fact that the fuel pump 4 is operating.
It is determined whether the flow is normal or abnormal, including whether or not the fuel is being supplied, and the detour 10 is used only when the metering section of the flowmeter that truly requires a detour breaks down, and in all other cases. This allows accurate flow rate detection using a flow meter.

Furthermore, in this embodiment, since it is possible to very easily determine whether the detour 10 is being used or not using the operation monitor 13, there is no possibility that the flowmeter will be left in a malfunctioning state.

Such a fuel flow meter safety device can be used for anything that needs to detect fuel flow, but if it is used in the fuel system of a car, a malfunction of the flow meter could result in the fuel supply to the engine being cut off. The trouble of stopping can be completely avoided, and therefore the system can be extremely safe. And in this case, detour 10
It takes some time to switch to the carburetor, so the fuel supply to the engine side is stopped, albeit slightly, but the engine continues to operate sufficiently with the fuel remaining in a portion of the carburetor, so there is no problem. Furthermore, the fuel supply is stopped not only when the fuel pump 4 is stopped as described above, but also when the engine is stopped or when driving at high speed, in which case the fuel cut relay is activated to limit the fuel sent to the carburetor. At this time, if the on-off valve mechanism 11 is opened and the detour 10 is used each time it is determined that there is no flow rate, accurate flow rate detection will not be possible. In this case, the detour 10 is not used, so that accurate flow rate detection can be performed at all times.

Furthermore, in the example, since the rotating body 5.6 is made of carbon, the weight of the single rotating body 5.6 can be significantly reduced, and it also has excellent self-sliding characteristics, and has excellent characteristics from low speeds to high speeds. There is almost no change, and it has excellent chemical resistance and heat resistance. Therefore, the rotating body 5.6 can be made lightweight and have low inertia, and it can be made extremely high-performance without wear. convenient. When the weight is reduced in this way, it is common for the rotating bodies 5 and 6 to stop even due to extremely small foreign objects, but by implementing the present invention, troubles caused by stopping the rotating bodies 5 and 6 can be avoided. This means that it can be prevented.

It should be noted that the present invention is of course not limited to the above embodiments, and the flowmeter does not necessarily have to be of a positive displacement type, but in the case of a positive displacement type, the rotating body is There is no limitation, and any suitable member such as a conventionally known resin material can be used. Furthermore, although it is preferable to provide the detour in the casing from the viewpoint of simplifying the structure, it is not necessary to do so, and any means may be used as long as it detours around the measuring section. In addition, if the control means determines that there is an abnormality when the flow meter indicates no flow rate even though there is fuel supply, and controls the on-off valve mechanism to open, the input signal and output The form of the signal does not matter.

[Operations and Effects] In summary, since the present invention is constructed as described above, foreign matter such as dust may enter the flow meter installed in the fuel flow path, causing the flow meter to malfunction, resulting in an interruption in the flow of fuel. When the on-off valve mechanism is obstructed, the on-off valve mechanism is automatically opened under the control of the control means, and the fuel flows through the open detour of the on-off valve mechanism. There is no possibility that the flow will suddenly stop. Moreover, the opening control of the on-off valve mechanism by this control means is performed only when the flow meter becomes a no-flow state even though the fuel supply state is in progress. It is used only when it is truly necessary, such as when passage is obstructed, so that accurate and reliable flow rate detection can be performed in other normal cases.

[Brief explanation of drawings]

The drawings show an embodiment of the safety device for a vehicle fuel flow meter according to the present invention, in which FIG. 1 is a horizontal sectional view of the fuel flow meter, FIG. 2 is a vertical sectional view of the same, and FIG. Figure 3 is a control circuit diagram of the fuel flow meter. In the figure, 1 is a casing, 4 is a fuel pump, 5.6 is a rotating body, 10 is a detour, 11 is an on-off valve mechanism, and 12 is a control section.

Claims (1)

[Claims] 1) A flow meter that measures the fuel flow rate in the flow path of fuel supplied to the engine side by the operation of the fuel pump, and an on-off valve mechanism that bypasses the measuring section of the flow meter. The opening/closing control of this on-off valve mechanism is performed based on the detection signal from the flow meter and whether or not the fuel pump is operating, or whether or not the fuel pump is operating on the fuel receiving side such as the engine receiving the fuel supply. If the fuel is being supplied but the flow meter shows no flow rate, this is determined to be an abnormality and the on-off valve mechanism is activated. 1. A safety device for a fuel flow meter for a vehicle, characterized in that the safety device is operated by a control means that outputs an output signal to open the fuel flow meter. 2) The flow meter uses a pair of rotating bodies arranged oppositely in the casing as a measuring part, and measures the fuel flow rate by counting the number of rotations of the rotating bodies corresponding to the amount of fuel passing through with a rotation speed detection means. The safety device for a fuel flow meter for a vehicle according to claim 1, which is a positive displacement flow meter for measuring the amount of water, and the rotating body is made of carbon. 3) The safety device for a fuel flow meter for a vehicle according to claim 1, wherein the control means has a monitor that indicates the control status.