JPS58107817A - Apparatus for monitoring fuel and controlling engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is coupled to an electric fuel gauge in a vehicle to provide an alarm signal when the level of fuel in the tank is low and the fuel level reaches a predetermined low level before the tank is empty. This invention relates to an electronic fuel level monitoring and engine control system that shuts down the ignition and starter system of a vehicle or boiler.

Devices for warning of low fuel levels in fuel tanks are well known in the art. Typically they are coupled to a fuel gauge and
It has been used in automobiles, aircraft, and boats, and is often used in boilers and heating equipment5). Many of these devices include visual or audible alarm signals or both to indicate low fuel levels. However, in these prior art devices, if the operator does not refuel, the engine continues to run until the tank is empty. Leaving the fuel tank empty would obviously be inconvenient, and damage to the equipment could occur.

The problem of fuel-using equipment being shut down due to empty fuel tanks is particularly acute when it involves non-road equipment or construction vehicles. Not only do you have to refill the tank, you also have to priming the engine (especially diesel powered engines), refilling the fuel filter and cranking the engine.
King). A restart procedure must also be taken.

This often requires a mechanic to be called to the site.

The extensive cranking required for restart also drains battery power and thus shortens battery life by depleting its charge (6). Premature starter motor failure may also occur. Restart problems are particularly exacerbated when environmental temperatures are extreme.

Also, if the device stops working due to an empty fuel tank and the ignition switch is turned on, the ignition coil may overheat, burn out the point, and the battery may eventually become completely discharged. There is.

Additionally, safety issues may also exist. If the equipment runs out of fuel while operating on a steep slope or near a cliff, or unloading a load, the power steering and power brakes will no longer function and the operator may lose control. Become. Accidents can and do occur under these conditions.

Furthermore, there is a great deal of expense incurred due to equipment being shut down due to empty fuel tanks. Driving time is lost and driving effort is idle. As previously mentioned, a mechanic would have to be called in to restart the equipment. Mechanics are especially difficult to find in off-road construction and remote locations. Therefore, the outage time can be quite long.

Accordingly, it is a primary object of the present invention to provide a device that eliminates the safety problems inherent in engine shutdowns due to empty fuel tanks.

Another object of the invention is to minimize the loss of operating time to equipment and labor, thus reducing the cost of the job to the contractor and customer.

Yet another object of the invention is to provide a device that is generally applicable to virtually all fuel-powered devices.

Still another object of the present invention is to provide a device that eliminates problems between devices caused by running out of fuel.

To achieve these and other objects, which will become further apparent from the following description and accompanying drawings.

An electronic fuel level monitoring and engine control system is disclosed that disables the ignition and starter system of a liquid or gaseous fuel powered vehicle or boiler when the fuel in the tank reaches a predetermined low level. After the unit has been refueled above the predetermined upper level, the ignition system is reactivated and the unit is ready for operation. It can work with any fuel powered device regardless of the type of fuel used such as gasoline, oil, diesel, propane, etc. When the fuel level gets low it gives a visual or audible or both alarm signal.

When the alarm signal is activated, after a predetermined time delay, the apparatus of the present invention deactivates the ignition system of the unit. This time delay allows the operator to properly deploy, eg refuel, the unit for any reason. Allows time for evacuation of unit equipment or cargo to a safe level, evacuation of steep slopes or roads, etc.

The delay run time can be fixed or variable depending on equipment requirements and application (9). The use of fixed delay times can eliminate unnecessary equipment interference.

Additionally, the fuel level monitoring and engine control system of the present invention prevents reactivation of the ignition system until the tank is filled above a predetermined upper level, minimizing repetitive refueling operations during daily operation of the unit. Includes a lockout mechanism to limit

More specifically, the fuel level monitoring and engine control system of the present invention includes a monitoring circuit that senses the voltage at the junction of the fuel gauge and tank unit and feeds this voltage to a voltage level sensing circuit. This voltage monitoring and voltage level sensing circuit includes two separate circuitry, both of which can be coupled into a circuit to accommodate commercially known fuel gauge tank unit architecture.

As mentioned above, the monitoring circuit is circuit coupled to the voltage level sensor. When the fuel in the tank reaches a predetermined safe low level, the voltage sensed by the monitoring circuit and delivered to the level sensor causes the latter state (lO) to foreshock. This transient gates the operation of an oscillator whose frequency is typically 2 cycles per second (2 cps).

The output of the oscillator is coupled through a drive circuit to the alarm device to cause the latter to pulse at the oscillator rate.

The output of the voltage level sensor is also coupled to a timing circuit.

This provides a fixed or variable time delay, for example 5 minutes. After a predetermined period of time, the output of the timing circuit changes state and deactivates the vehicle's ignition and/or starter system through the relay drive circuit. Additionally, the output of the timer circuit is coupled to the output of the oscillator circuit, clamping the output of the oscillator circuit to a fixed voltage level when the former changes state. This produces a constant alarm signal that does not pulsate.

Self-tests (self-tests) which permit an instantaneous check of the operability of the equipment and include a mechanism for preventing reactivation of ignition and starter systems etc. until a second, predetermined upper level of fuel is present in the tank. self-test) and lockout circuitry.

Once the fuel has been refueled to a predetermined upper level, the timing and oscillator circuits are deactivated and the unit can be restarted.

Next, preferred embodiments of the present invention will be described with reference to accompanying drawings.

Before discussing the preferred embodiment, it may be helpful to understand standard fuel gauge systems. The fuel level system of the present invention (
The device is responsive to voltage signals from the vehicle's electric fuel gauge system. The former consists of a tank-mounted, dial-type gauge connected in series with a float control potentiometer. Power is supplied from the vehicle's battery via the ignition switch. Generally, the ground resistance of the potentiometer is varied by a movable brush connected to the float arm of the tank unit. Of course, it depends on the level of fuel in the float tank.

There are basically two fuel gauge systems currently in use. A representative strain of one strain is Genera1MOtOrS
Company A, C, 3park Plug Divi, 5i
Manufactured on. In this system, as the fuel drops, and therefore the float drops, the ground resistance of the potentiometer decreases. This reduces the voltage reading at the junction of the gauge and potentiometer. This will hereinafter be referred to as the rNor J strain.

An example of the other system is that of the Steward & Warner company. In this case, a drop in fuel level (again, accompanied by a drop in the float) increases the ground resistance of the potentiometer. As a result, the voltage at the junction of the gauge and potentiometer increases. This will be referred to as rRe
Let's call them v and J. The fuel level engine control system described below is designed to work with both fuel gauge systems.

Referring now to the drawings, a preferred embodiment of the fuel level monitoring and engine control system of the present invention is generally designated by the reference numeral 10 in FIG.

The device 10 is a fuel gauge-tank sender unit (1) of a vehicle.
) from which the fuel level signal is routed either directly through switch 119 for the fuel gauge system (Nor, ) which reads low fuel level at low voltage or at high voltage to read low fuel level. Read the fuel gauge system (Rev
, ) and a voltage level shifter, such as a Zener diode, to the voltage sensor 54. R6 and 09 provide a low pass filter that removes transient effects due to fuel perturbations in the tank. The device 10 allows a single voltage level sensor 511 with a fixed trip point to be compatible with all known fuel gauge systems. The voltage level sensor 511 is typically a Schmitt trigger, the limit voltage of which is matched to the voltage expected at the fuel-sender unit for the predetermined upper and lower levels of fuel at which the control device is to function. .

The Motorola Sem1 conductor company's MC1115811BCP includes 1. C.

It is a device. The rest of the circuit is time Ii! It will be used throughout the 8 mechanisms and will be identified as appropriate.

(ill) The output signal of the voltage level sensor 54 is sent directly to the time delay circuit 56 and the gate oscillator 68 through the switching inverter ll11 and the switch 57, directly through the switch 57. The inverter 55, delay circuit 56, and oscillator circuit 6g portions may include corresponding ones of the six Schmint trigger circuits included in the device 1, C, described above.

When the output signal of voltage level sensor 511 changes state to indicate a low fuel condition, time delay circuit 56 is activated to begin its timing function.

At the same time, gate oscillator 68 is enabled and provides a pulse signal through inverters 6 to audible alarm driver 71 and visual alarm driver 70 with audible alarm 7'5 and/or visual indicator 72.

The output of the time delay circuit is coupled to a beam ray drive circuit 58;
Circuit 58 activates relay 59.

The latter is energized under normal fuel conditions. As a result, the starter and ignition circuits function by following the relay contacts 61 and 62. The latter is energized under normal fuel conditions, ie, when relay 59 is energized, as shown in FIG.

When time delay circuit 56 reaches its predetermined delay time (typically 5 minutes), its output signal changes to shut off relay driver 58 and then deenergize output relay 59. After sniffing, the starter and ignition circuit will stop working.

Also, at the end of the predetermined time delay, the change in the output of the delay circuit, through diode CRII, clamps the oscillator output and changes the pulsation alarm to a constant indication.

Relay drive circuit 58 and lamp and phone circuits 70 and 71 are typically bipolar Darlington drivers. These depression circuits are the second one. C, circuit, i.e. Fairch containing 7 such circuits.
ild Sem1conductor company part number 9
Available as part of 6611fPC.

The engine is currently disabled and cannot be restarted by any combination or manipulation of the ignition or starter switch. Any attempt to restart the engine will always result in a steady alarm condition of visual and audible alarms 72,75.

The circuit that prevents the engine from restarting in low fuel conditions is
Self-Test Lockout Circuit 6. This is coupled to time delay circuit 56 via diode CR2. The interaction of these two circuits is best understood from the design of FIG.

Assuming a low fuel condition, regardless of the type of fuel used, the voltage at the CRI cand (pole of switch 57) will be at a positive voltage level indicating the change state of sensor 511. schmitt trigger 8
Before 0 can undergo a state (indicating low fuel) transformation,
The voltage on its input lead 82 must reach the limits of the device.

The normal time delay (5 minutes) associated with the time delay circuit is controlled (17) by the RC circuit formed by R2 and 01. Typical values are 16 megohms and 39 microfarads. Therefore, at turn-on, the vehicle may be restarted and run for five minutes (or other delay time) before being restarted, unless some means are available to bypass this time delay. Circuit 6 overcomes this. On starting, the input glI of the Schmitt trigger g6 is initially at ground potential since c2 is immediately shorted to ground. As a result, output lead 88 is at a high level, which is applied to input lead 82 of Schmitt trigger 80, charging capacitor C1 across resistor R (typically 1000 ohms).

Capacitor C2 (typically 1 microfarad) charges through resistor R11 (70 kilohms) to the limit level of Schmitt trigger 86. This takes approximately 1 second. At this point, output 8g is at a low voltage level. However, the voltage at 82 is maintained at a high level because capacitor c1 is charged (
18) Ru. This creates a sustained low voltage level on lead 90 (the output of the time delay circuit), which causes wire 59 to be connected to driver 5.
8 is reversed to maintain the deenergized state.

Vehicle cannot be restarted.

After a short (typically 1 second) self-test mode provided by one circuit 6 when a sufficient amount of fuel has been added, the engine may be restarted. This happens as follows. Namely.

The voltage level at the CRI cathode is currently low.

Output 88 of trigger 86 is also initially at a high level;
Input lead 82 is supplied to cause trigger 80 to have a low output state.

Relay 59 cannot be energized. After C2 charges to the critical level of 86, the input level at 8g becomes low again, but this time C1 discharges through R1 (typically 1000 ohms) because the cathode of CRI is at a low voltage level. Thus, the high level at input 82 cannot be maintained and the relay is energized rapidly (1 second) allowing the engine to restart.

However, during this one second period, the alarm system will function as if a low fuel condition existed. Alarm 72.
73 activity gives the driver a positive indication that the monitoring device is functioning.

At the same time, when fuel is sufficient, gate oscillator 68 is disabled (low voltage at CR3 cathode), which causes low fuel alarm 72.75, except in 1 second test mode.
stop operating.

The entire operating power of the device 10 is derived from the engine starting battery through the ignition switch lIO, and the internal supply voltage for the electronics is regulated with a voltage regulator 65 to provide an operating voltage v, R, separate from the actual battery voltage. i give moreover,
A polarity and transient protection circuit 61I of known design is provided.

Referring to Figure 1, this circuit shows how device 10 is coupled to a facility's electrical system 50. Terminals 1-8 correspond to the same numbers in FIG. Terminal 1 is ignition switch I
Connected to the run side (runSlde) of IO. This supplies current to the device 10 with the ignition switch IIO closed. Terminal 2 is connected to alarm lamp 72, and the other side returns to the run side of ignition switch IIO. The terminal socket is connected to the ignition coil or fuel solenoid depending on whether it is a gasoline or diesel fueled engine. Terminal 4 is connected to the start terminal of ignition switch lIO. Terminal 5 is connected to starter solenoid 54. Terminal 6 is connected to the junction of the fuel gauge and tank center unit.

Terminal 8 is connected to circuit ground and permanently grounded to vehicle ground.

The foregoing is merely a description of preferred embodiments of the apparatus of the present invention.

Of course, it is to be understood that this does not limit the scope of the invention as defined by the claims.

Modifications may be made to the preferred embodiments of the invention described above that are within the scope of the claims. For example, the means for measuring time delay may be achieved by a counter that counts the elapsed cycles of the oscillator. proportional to the desired delay. When a predetermined count is reached (21), the cutout mechanism can be activated as described above.

It is also possible to use an additional alarm device connected in series with the relay contacts that are permanently closed on the striker pole when the relay is de-energized. This is also activated at the end of the delay to further indicate a low fuel condition.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the electrical circuit of the fuel level monitoring and engine control system of the present invention. FIG. 2 is a schematic diagram of the timer, self-test and lockout portions of the block diagram of FIG. FIG. 3 is a wiring diagram of the connection between the circuit of FIG. 1 and the vehicle electric circuit. 10--Fuel level monitoring/engine control device, 11--
1 sender unit, 12--fuel m53--voltage level shifter, 51+--voltage sensor. 55--inverter, 56-1 time delay circuit. (22) 5g--Relay drive circuit, 59--Relay, U4--Starter, 56-1 Ignition system, 68-1 Gate oscillator, 6
m-inverter, 70-1 visual alarm driver, 71-1 audible alarm driver, 72-1 visual indicator. 75--one audible alarm, 40--one ignition switch, 64--unipolar/transient protection circuit, 65--one voltage regulator. (2) Procedural amendment (formula) January 28, 1980 Commissioner of the Patent Office Kazuo Wakasugi L. Indication of the case 1982 Patent Application No. 161091a Invention ← Device → Name 1 Category of driving products: Fuel level monitoring and engine control device (Relationship with the case of the person making the amendment) Patent applicant (name) Warren H. Pagan 4, agent 5, date of amendment order January 25, 1982
Pronunciation 6, number of inventions increased due to correction 60
Invention L Subject of amendment Power of attorney/drawings

Claims (1)

[Claims] 1. An electric ignition system including an electric ignition switch and a power source, a starter system, a fuel supply tank, a fuel delivery unit and a fuel gauge electrically connected to each other and to a power source. , an electrically operated fuel gauge system, wherein a first signal voltage is generated to indicate the amount of fuel in the fuel tank, the fuel supply in the tank is A fuel level monitoring and engine control system comprising a fuel delivery unit of said electrically operated fuel gage system and a fuel gage system operative to shut down engine operation when a predetermined low level is reached before exhaustion. a voltage sensing mechanism coupled to the junction, the voltage sensing mechanism changing state when the first signal voltage reaches a predetermined value indicative of a predetermined low level of fuel in the supply tank; : a mechanism electrically connected to the output of the voltage sensing mechanism for timing the elapsed time from when the voltage sensing mechanism changes state at the predetermined low level of fuel to when a predetermined elapsed time period expires; a mechanism electrically connected between the timing mechanism and the electrical ignition and/or starter system, such that the electrical ignition and/or starter system is rendered inactive at the end of the predetermined elapsed time; What was done: The fuel level monitoring and engine control device, characterized in that it consists of: 2 a pulsating alarm mechanism electrically connected to the output of the voltage sensing mechanism, wherein the alarm mechanism is enabled when the voltage sensing mechanism converts to a state indicating a low fuel level; 2. The apparatus of claim 1, wherein the apparatus is adapted to provide an intermittent alarm signal when the system is activated. Claim: wherein the pulsation alarm mechanism includes an oscillator electrically connected to the voltage sensing mechanism, the oscillator gate being opened when the voltage sensing mechanism converts to a condition indicating a low fuel level. The device according to paragraph 2.ヰ The device according to claim 2 or 5, further comprising a mechanism for electrically connecting the time measurement mechanism to the alarm mechanism, so that the alarm signal is made continuous at the end of the predetermined elapsed time. Device. 5 a lockout circuit mechanism electrically connected to the timing mechanism, wherein the timing mechanism is configured such that when the electrical ignition switch is closed for a fuel condition below the predetermined low level that exists while the engine is shut down; Apparatus according to claim 1Ii, wherein the mechanism is electrically responsive to cause the electric ignition and/or starter system to be deactivated before the predetermined elapsed time. 6: the voltage sensing mechanism converts to a second state when the first signal voltage reaches a second predetermined value that is proportional to a second predetermined level of fuel higher than the predetermined lower level of fuel;
6. The apparatus of claim 5, wherein the lockout mechanism and the timekeeping mechanism are inactivated when the voltage sensing mechanism is in the second state. 7. said lockout circuitry being circuited to enable said warning signal for a short predetermined period of time upon engine start when the fuel level is at or above said second predetermined level; 7. The apparatus of claim 6, wherein said alarm signal is determined to be activated. 8. The apparatus of claim 7, wherein said voltage sensing mechanism includes circuitry to minimize the possibility that agitated fuel in said fuel tank will cause the voltage sensing mechanism to change state. 9. Adapting the device to a fuel gauge system where the voltage sensing mechanism is such that an increasing voltage indicates a decreasing fuel level. 5. The apparatus of claim 4, including additional circuitry.