AU7730598A - Simulation device for disconnecting injectors in motor vehicles - Google Patents

Description

V.

9i I S F Ref: 426073

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIRCATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: A.E.B. S.r.1.

Via dell'Industria, Zona Ind. Corte Tegge 42025 Cavriago (RE)

ITALY

Ivan Paterlini and Vincenzo Baroni Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Simulation Device for Disconnecting Injectors in Motor Vehicles Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me/us:- SIMULATION DEVICE FOR DISCONNECTING INJECTORS IN MOTOR

VEHICLES

DESCRIPTION

The present invention~ relates to a simulation device for disconnecting injectors in motor vehicles.

The invcntion is used in vehicles with an internal combustion enine havingi an inJectio)n system fed by two different sources (for example petrol and gas). One of the )ro eins% which arises when changing over from a petrol tleed sysrtemn t0 a feed Syi,'IC usim methane gus oir LPG (or other fuels) is'that. \vhiSn thie petrol injectors are disconne'cd and the petrol flow interrupted, the electronic injection control unit dletects incorrect operation of the injectors or detects that they, ar aio ctive, signalfing mialfutionin rthc e Lli I1 the inectors; are disconnected intentionally.' The known -art, in order to solve this problem, has developed simulation devirces, namneiv devices -which sirimulate the active presenc%-; of the i nJecto rs even- wheni they -ar(.

deactivated.,,-- Said simulation devices proviik;C. for example, or each injector, a voltaa %Vhich is the same as tha -Which the control unit detected during correct operation of the injector itself.

One drawback ofihese dev.'ces lies in the fac~that it is ncesa od~mm h orc poarity (posPiive pole and negative pole).upon instillation anid it is necvssar t,'o have in stocktwo types of simulators, called a ri ht-h~nd and lefi-hand simulator depending on; 2.the position 6f the positivCpoe. so that they canpbe mounted on all'typesof injection v'ehicl& A futher diam~ack consists, in the fact that wnt hi ei~te eur utn'O the original wiringxwith a consequent potential invalidaitkn of the guarantee covering the origil feed sc~ oftevhcle, if it is,a new "ehicle wvhich is still under guantee.

2 In order to overcome these drawbacks, recently simulation devices have been developed, said devices consisting essentially of a resistor which is arranged between the injector and the injection control unit and has the function of reducing the current flow so as to ensure that the injector is kept at the operating voltage, but is supplied by a current which is insufficient to cause it operate.

In this way an additional reference voltage source is not required and the problems associated with installation of the device due to possible inversion of polarity are also eliminated.

However, in some control units of the more advanced type, it is necessary to provide a current which is higher, i.e. sufficiently high to deceive the control unit, but at the same time sufficiently low to keep the injector deactivated.

For this reason it is nevertheless required to have in stock various types of simulators which differ from one another in terms of the ohmic value of the resistor contained therein.

15 The object of the present invention is that of eliminating the aforementioned drawbacks S. and providing a device which is universal, namely can be applied to all injection vehicles whatever type of control unit they use, which allows simulation of the injectors during I operation of the vehicle with a gas feed system, by means of simple limitation of the value of the electric current without interrupting the injector circuit and without therefore activating an alternative path in order to simulate its load.

A further object is that of making the device particularly simple and low-cost and easy to 1/ fit without the need for cutting any of the original wiring.

Said objects are fully achieved by the simulation device according to the present invent.ion, which is characterized by the contents of the claims indicated below and in N' 25 particular by the fact that it comprises internally at least one variable-resistance resistor 2. unit, which allow.'different load values to be simulated. The.resisior.unit may consist; for example, of two or more resistors with a different resistance valuewhich can be selected individually, or may consist of two or more resistors which can be connected in Sparallel or in series so as to vary the overall resistance value of the resistor unit, or may..

consist of a simple variable-resistance resistor or rheostat.

Preferably an external actuating device is present, in the form of a niicroswitch with two or more positions, for. varying directly the resistance value of the resistor unit. by Sactivating for example a secondary reistor in parallel with a main resistor or by activating Sselectively individual resistors of varying resistance value.

S 10 These and other characteristic features will emerge more clearly from the following descripton of some preferred embodiments illustrated, purely by way of a non-limiting 7. example in the accompanyifig illustrative plates, in which: Figure 1 shows an electrical block diagram of the device; Figure 2:illustrates schematically applicatioi of the device; ;7 7' Figure 3 shows a variation of embodiment of a circuit part of the device-.

With reference to the figures, 1 denotes in its entirety the present simulation device enclosed in a box-type casing la of the known type.

The device ay'comprse an external trimmer 2 by means of which it is possible to adjust a command unit 2a for'regulating the fuel overlap time (wherenecessary) in order to 20 avoid supply voids which may cause flashback. The tfmner is calibrated diring testingbut may also be used for subsequent adjustment.

The device 1 may be installed in the passenger compartment in the boot space, or outside the vehicle, in the engine compartment or on the drive system and may be installed or contained also inside other more complex devices or equipment, such as for example a carburation and/or gas injection control unit.

A

I' 3 denotes the individual simulation groups, only one of which is shown in greater detail and each of which is connected to a corresponding injector 4: The number of groups 3 Sis nonnally equivalent to the number of injectors, but there may be a single simulation Sgroup connected to a single injector (in the case of single-point injection) or to several injectors (in the.case of multi-point injection).

Each simulation group comprises an activation relay 5 and a resistor unit 6.

When the relay 5 is closed, the resistance circuit of the simulation group is disabled, whereas when the relay is open the present device is activated and consequently the injectors deactivated. This represents a safety condition because, in the event-of S 10 malfunctions, the closed condition of the relay ensures exclusion of the divice.

The relay is activated by the command unit 2a which is operated by the vehicle driver by r means of an actuating member (switch member) of the known type situated inside the i. Il passenger compartment.

3 The relay 5 may bereplaced byan active component such as, for example, a MOSFET.

i 15 The resistor unit 6 comprises a plurality ofresistors 7 arranged in parallel (as shown in Figure 1) orin series; called Ro, but may also comprise a variable resistor or rheostat The resistors in apaallel are configured with a resistor Ro always selected and one or more resistors in parallel R, which can be selected individually or in a group, as in 20 Figure 1, by means of respective selectors 8 called Si, in order to reduce the overall resistance value of the resistor unit, in accordance with Ohm's law. It is obvious that, in the case of resistors in series, the total resistance value will be determined instead by the sum of the individual resistance values.

According to a variation of embodiment illustrated in Figure 3, the resistors Ro, R. may be configured in such a wayhat they can be selected individually by means of ^y a single multiple-position load selector 8.

In this case the resistance value of the resistor unit coincides with the resistance value of the resistor selected.

The selectors 8 are of the type which can be operated manually from the outside upon installation of the device.

This is achieved by designing the selectors 8 as microswitches or movable jumpers which are intended to connect selectively the resistors 7 by means of the connection of selected pins, so as to close the circuit between an injection control unit 9 and the injectors 4.

However, it is possible to envisage automatic selection of the resistors 7: the device detects the self-diagnosis output signal of the control unit 9 which signals an error or malfunction situation, after which it varies the load (or the resistance value) until it detects several malfunction signals of the control unit 9.

The present device is installed between the injection control unit 9 and the injectors 4 and is provided with connectors 10 such that each input connector 1 Oa ofthe device is coupled S" 15 with a corresponding output connector 1 1 of the control unit, while each output connector 10b of the device is coupled with a corresponding input connector 12 of each injector.

In this way the device is inserted between injection control unit 9 and injectors 4 without cutting any of the existing wiring.

The present invention continues to function correctly even after 50,000 simulation cycles, 20 without the need for periodic checks.

At the moment of installation of the device, depending on the load value required by the vehicle control unit, the load needed is correspondingly set in the device by operating the external actuating device (multiple switch, multiple relay or connector with movable jumper).

Selection and setting of the load value to be activated in series with the injector circuit, however. may also be peribrmed automailcally bi. means of detection of suitable sicrl~1S from the control unit. as already described above.

At this stage the device is ready for operatien and dkces no, require furt~her calibrazion, nor periodic calibration, and is uni'.ersal- beine, able to be applied ito all tile commnerclil l available control units, since thc rcsistance valuC in. Y be varied.

The choice Ofthe resistance VaIlue dCe;-nd not on t he t' PC of vehicle. but on thie ype tit con~uol unit mounted on the .ehlicle.

Deactivation a fthe injectors. durine operaition vith gas, is perfoined xithout lhe iiccd to determine the polarity of'said injectors. using a sieedevice ofilhe uni\. crszl ivrc \vlliclt can be easilv installed on, all1 the in1jection control uItS ZmtI Which AriowS aial resistor to be activated such thlat acurrent insultict ito cause activation otf me Injctlors passes into the injector circuit.

This has the purpose iof deactivatingu the petrol injectors and scildinge to the electrorn: injection control unit of the vehicle a signal such that the disabled conditimonf) the injectors is not detected as being~ a malfunction the same control Unit.

Installation of the device Is performed wiithout the: need to identify, the polarity tilih injectors and without cutting any oriiinal winng and therefore wvithout. Invalidating thevehicle gtuarantee.

Claims (6)

1. Simulation device for disconnecting injectors in motor vehicles, of the type mounted between an injection control unit and injectors characterized in that it comprises internally at least one resistor unit with a variable resistance value for simulating ditTerent load values.

2. Device according to Claim I, in which each resistor unit consists of a rheostat. 3 Device according to Claim 1, in which each resistor unit comprises a plurality of resistors which are connected in parallel and one or more selectors for selecting one or more of said resistors so that the resistance value of the resistance unit depends on the resistors selected, in accordance with Ohm's law on the resistors in parallel.

4- Device according to Claim 1, in which each resistor unit comprises a plurality of resistors connected in series or one more selectors for selecting one or more of said resistors so that the resistance value of the resistance unit depends on the resistors selected in accordance with Ohm's law. Device according to Claim 1, in which each resistor unit comprises a plurality of resistors and a selector by means of which the resistor with the desired resistance S- value is selected. S 6. Device according to Claims 3, 4 or 5, in which each selector consists of a movable jumper which closes the circuit between the control unit and the injectors by selecting a resistor

7. Device according to Claim 3 or 4, in which each selector consists of a microswitch. 8_ Device according to Claim 5, in which the selector consists of a multiple-position microswitch.

9. Device according to Claim 3. in which the selectors are activated automatically, with setting of the load value (or resistance value) to be activated in series with the injector 8 circuit being performed by means of detection of self-diagnosis output signals of the control unit Electronic apparatus for motor vehicles, characterized in that it comprises a device according to any one of the preceding claims.

11. Simulation device for disconnecting injectors in motor vehicles, substantially as described herein in relation to any one of the embodiments with reference to the accompanying drawings. o DATED this Second Day of July 1998 A.E.B. S.r.l. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON