ITBR20130004A1 - CONSUMER ECONOMISER FOR MOTOR VEHICLES - Google Patents

Description

Consumption saver for motor vehicles.

Field of application:

The present invention is applied to motor vehicles for civil, industrial, military use, etc. equipped with electronic injection both in the Otto cycle and in the Diesel cycle also powered by alternative fuels.

State of the art:

The electronic injection systems for Otto cycle and Diesel cycle engines are both equipped with a sensor called WTS (Water temperature Sensor).

This sensor is responsible for regulating the injection time according to the temperature of the coolant, determining the â € œcold enrichmentâ € phase with internal algorithms of the injection control unit.

Cold enrichment provides for an increase in the injection time and therefore an increase in the amount of fuel injected. This additive time is called â € œenrichment timeâ €.

From the tests carried out it emerged that for most engines an enrichment lasting 30 to 60 seconds is sufficient, at the end of which the enrichment is almost useless, while in the state of the art the time to enrichment is considerably higher.

In the state of the art, the basic injection time plus the enrichment time is progressively reduced as the temperature of the refrigerant fluid increases.

The enrichment time tends to cancel itself out when the working temperature of the motor known as the â € œthermal speedâ € temperature is reached.

The thermal regime is never reached if you travel short distances, such as a home-office journey lasting a few minutes.

Technical problem.

In the state of the art, failure to reach the thermal regime determines the operation of the engine always in an enrichment regime, resulting in considerable fuel consumption.

The problem that the present invention intends to solve is to interrupt the enrichment time in a phase preceding the heating of the coolant, calculating this time in such a way that enrichment can stop when the engine is ready for optimal operation. , without this time being linked to the temperature of the coolant.

Solution of the technical problem.

The device in question solves the technical problem by sending an “enrichment stop” command to the injection control unit, considerably saving consumption and therefore the pollutants emitted.

That said, a device has been devised that is able to activate automatically when the engine is started, causing an enrichment phase which lasts for the time set in the internal timer of the device. At the end of this period, a signal which indicates to it an engine temperature equal to that of the thermal regime, consequently the control unit excludes enrichment thus saving consumption.

The device, which can also operate manually with the help of a double-exchange diverter, has been automated so as not to ask the driver to stop the enrichment phase, who could also forget to switch.

In the state of the art, the injection control unit controls, in some vehicles, the thermometer of the temperature of the coolant.

The control unit determines the value of this signal by deducting it through an A / D (Analog / Digital) conversion of the voltage value read across the WTS sensor.

The invention in question works by sending a false signal from the WTS sensor in order to stop the enrichment phase first.

In this way the device will give a value of the temperature of the refrigerant fluid that is not real. So that this false information is not reported to the driver, the device is also composed of a device which skips the correction of the economizer for as long as the economizer is running, allowing the real temperature of the fluid to be read. refrigerant.

This last device works by activating a special timer which bypasses the modification of the signal for the necessary time. A mechanical manual version of the same is also foreseen.

Related items.

The switching phase is signaled to the driver by means of an on or off LED diode, two-color LED, two different colored LEDs placed in the passenger compartment in a visible position, which indicate that the enrichment phase has stopped or display ( 29) with the engine conditions written on it.

To avoid the driver being disturbed by excessive brightness of the LED or LEDs in the event that the LED (s) are mounted in the passenger compartment, the luminescence of the same has been made adjustable.

The signaling LED or LEDs can remain confined to the engine compartment or to the installation position of the control unit.

In order to inform the driver of the enrichment condition, a display (29) can also be adopted with additional information such as the real engine temperature and the emulated temperature, their difference, etc.

The display (29) can be a Led matrix, Seven Segment, LCD, LED, etcâ € ¦

The display (29) can be integrated into the passenger compartment in the dashboard of the vehicle or shown on it with metal, plastic, polymeric or natural fiber containers such as wood.

Technical description:

In the state of the art, in the cold enrichment phase, the injection control unit determines the temperature value of the refrigerant fluid by means of an A / D conversion and a WTS sensor.

The WTS sensor is a variable resistance sensor placed in contact with the refrigerant fluid, it can be of two types: NTC (Negative Temperature Coefficient) or PTC (Positive Temperature Coefficient) depending on the manufacturer's choice.

Depending on whether the sensor is of the NTC or PTC type, the device has some variants, merely adaptive to the two types of sensor.

The WTS sensor has different full scale values depending on the manufacturer (Eg. Marelli 1kâ „¦, Lucas 5 kâ„ ¦, etcâ € ¦, some Bosch 10 kâ „¦), it is therefore necessary to provide in the device such a good operation over the whole range of full scale adjustment ranges.

The most commonly used sensor is the NTC sensor (17), for this reason in the description the latter will be taken into consideration and then insert the appropriate variants that allow to use the same device also in cars with PTC sensor ( 18).

NTC (Negative Temperature Coefficient) sensors decrease their resistance as the temperature increases.

The NTC sensor is also referred to as a negative coefficient thermistor.

The device in question is composed of a group of resistors (13) including one or more trimmers (10) (the trimmer is a resistor capable of varying its resistive value). If analog, the trimmer can assume infinite intermediate resistance values between 0 and full scale, if digital (19) it can assume a number of discrete resistance values [eg. if it is 8-bit it can discretize 256 levels including â € œ0â € (always between 0 and full scale)] placed in parallel with each other with an appropriate PCB (Printed Circuit Boardâ † 'Printed Circuit) which will then be soldered by means of an alloy Sn / PB (the tin-lead alloy contrary to the Lead Free alloy bears well the vibrations produced by the vehicles during motion), a track obtained on the PCB to which the resistance terminals are connected and the trimmer acts as a collector node into which they converge the various currents (20).

Connecting the collector terminal (21) to one of the ends of the relay contact (7) and connecting one of the ends of the NTC (17) to the other end of the relay contact (7) through the connector (14) and the track ( 22) the resistors (13) // (10) can be connected and disconnected as a whole (the symbol â € œ // â € indicates that the two elements are in parallel with each other) in parallel at the ends of the NTC sensor (17 ). The resistors available on the market can be carbon or ceramic, in 1/8 W format or in SMD format, the effect produced (the voltage drop) is identical in both cases given the minimum currents involved (a few mA [milli Ampere]).

The combination (see above: explanation of the combination) of the group of resistors (13) // (10) and of the NTC (17) will give rise to a resulting resistance smaller than the smallest of the resistors connected together. A greater voltage drop is therefore caused at the sensor ends according to what is known from Ohm's law (V = RxI where V is the voltage, R the resulting resistance across the circuit and â € œIâ € the intensity of current that crosses the circuit itself).

This lowering of the resistance and therefore of the voltage is read through the connector (15) by the car injection control unit (16) as an increase in temperature and consequent reduction in the injection time (less fuel injected). The device makes use of various (discrete and logical) electronic components used for the assumption of motor data (better explained below) â € œdecidesâ € according to which events to generate an electronic driving command intended for the relay coil (6). previously. The relay coil (6) sees connected to its ends on one side the electronic signal coming from the logic part of the circuit through the track (23) (this signal can come from the chip (3) or from the microcontroller (25)) and from the ™ other the ground terminal (24).

At the ends of the power contacts (7) there is on one side the collector node (21) and on the other one of the ends of the NTC sensor (17).

The electronic signal coming from the logic circuit activates the relay coil (6) by switching the power contacts (7) of the relay.

This reconfiguration of the power contacts (7) is responsible for the interposition of the group of resistors (13) including the trimmer (10) in parallel with the WTS sensor (17) if it is of the NTC type.

The effect thus obtained is to simulate an increase in the temperature of the refrigerant fluid with consequent reduction / cancellation of the enrichment phase.

At the ends of the connector (15) from which the control unit (16) originally evaluated the variation of the voltage proportional to the real temperature of the engine, now in contrast due to the effect of the interposition of the resistance in parallel as explained above by the control unit (16 ) will evaluate a lower voltage sensing a higher temperature of the refrigerant fluid.

The aforementioned interposition takes place through a relay type electromechanical device formed by the assembly (6) (7), the switching of the relay is a very fast variation in the order of mS and can in some cases compromise driving comfort.

The power contacts (7) of the relay change their configuration in infinitesimal times, in the order of a few mS [thousand seconds]. The sudden change in voltage can be interpreted by some control units as a false contact, therefore an electronic capacitor of the capacitor type (11) is interposed on the output circuit which charges when powered at the output voltage of the WTS sensor (17) ( The voltage at low temperatures is higher than the voltage at high temperatures), once the relay has been switched, the capacitor (11) starts the discharge phase as its ends are placed at a lower voltage.

The discharge phase takes place starting from the initial voltage until reaching the new circuit voltage, progressively reducing the value of the electrical signal.

The progressive reduction of the electrical signal thus suggests to the electronic control unit a rapid warm-up of the engine and not a false contact.

This discharge phase follows the mathematical law:

I (t) â ‹… R

V (t) = t

to'

and Ï "

Where V (t) represents the trend of the voltage as a function of time.

Furthermore, a rapid variation of the voltage (after switching the relay), as well as generating errors in the interpretation of the signal, can generate a “torque vacuum”, perceived by the driver as a sudden drop in engine power.

The capacitance (11) placed in parallel extends the switching time (meaning with the term â € œchangeâ € the time to pass from the initial value and final value of the voltage).

In fact, the capacity (11), progressively yielding energy to the system as seen above, improves driving comfort after switching.

Thanks to the capacity (11), the switching does not last for a few mS but can also last for a few seconds depending on its capacitive value, so the driver will not perceive the sudden drop in power during the switching phase.

The resistance of the WTS sensor (17) can have different full scale values according to what the system manufacturer decides, it is therefore necessary that the device is able to adapt to the different values of the sensor (17), otherwise it will lose precision in the adjustment. or in the most serious cases, it is impossible to intervene in regulation.

This variation is obtained by interposing in parallel to the adjustment trimmer (10) a group of fixed value resistors (13) that can be manually selected when installing the device by means of a jumper type contact (26) or switches / deviators also Dip Switck type, the result is indifferent. The enrichment time during which no resistance is interposed in parallel to the sensor WTS (17) (relay (6) (7) not switched) is determined by an electronic or mechanical timer. The timer is a programmable timer device, able to delay the triggering of a given event.

If electronic (proposed solution), the timer at the end of the set time sends an electrical signal to the ends of the coil (6) of the switch relay.

The coil (6) traversed by current is excited generating a magnetic field capable of switching the power contactors (7) of the relay.

The new configuration of the contacts (7) thus obtained allows the trimmer (10) and the group of resistors (13) to be placed in parallel with the WTS (17), reducing the injection time.

If the timer is mechanical, it can itself provide for the switching of the contacts or delegate the switching to another actuator according to what is well known from electromechanics.

In summary, when the start-up request is made, the circuit on which the device is also placed starts a count according to two possible solutions.

A first variant provides for the presence of a relay whose coil (27) receives the starting impulse from the rotary switch (51) the vehicle is already equipped with, the same impulse intended for starting the engine through the coil (52) (Note: The start command can be activated by taking the signal from the starter motor coil, but also from the glow plug heating signal for the Diesel cycle, from a signal derived from the coils for the eight cycle, from the pump signal fuel, etc ...)

When excited, the coil (27) activates the contacts (28) which lead to â € œ0 logicâ € a pin of the control chip (3) starting the count.

If you decide to use a microcontroller (25) instead of a chip (3), in the firmware of the same you will be asked to wait for a signal change on a dedicated input PIN.

The arrival of the start signal generates an â € œInterruptâ €, that is, it forces the interruption of any other activity of the microcontroller, and it is forced to start the timer count.

At the end of the count the Chip (3) (or the Microcontroller (25) depending on the variation) generates an output signal directed to the relay coil (6) generating the events already discussed above.

At the end of the time set in the timer by means of the trimmer (9), the Chip (3) (or the Microcontroller (25) depending on the variation), sends an electronic pulse which activates the switches (7) above by inserting a resistor in parallel to the WTS sensor (17), this resistor (13) // (10) distorts the temperature value of the coolant and consequently reduces the injection time.

From the same impulse destined for the relay coil (6) the Chip (3) through the resistor (4) (or the Microcontroller (25) depending on the variation) an electronic impulse is derived to activate the LED indicators (5) used as monitor driver.

In the microcontroller solution, instead of adopting the LED (5) as the driver monitor, a display (29) is adopted, the system status can be indicated on the same at the same time as other engine parameters such as the real temperature of the coolant.

The correction of the temperature signal can be deactivated / reactivated at any time by the driver who, acting on a button, on a switch (12), or on a diverter, switches off / on the relay coil (6) and forces the circuit to intervene. on correction.

Thanks to the solution found, this intervention does not require a restart of the timer count. The timer count can be restarted by pressing a button (30) specially prepared for it.

A second variant, which is much simpler than the previous one for installation purposes, does not provide for a start impulse, it is set up in such a way as to start the timer count upon receipt of the positive power supply voltage. controlled by the general rotary switch (31) which the vehicle is already equipped with.

The main switch (31) interrupts the positive signal on the vehicle by cutting off the power supply to any device connected to it.

This solution requires that the positive voltage is strictly of the “under key” type, ie absent with the engine off.

The power supply of the PCB on which it is found is obtained by connecting two cables coming from the car battery (32) to the connector (1) which has only two contacts.

Thanks to the adoption of the diode bridge (2), the installer can connect either end of the connector (1) to the keypad signal without having to pay attention to the color of the cables or the pole. of connection, thus avoiding distraction errors which could damage the assembly itself due to a voltage inversion.

In the event that the vehicles are equipped with a WTS sensor of the PTC type (18), the device has some variants.

More specifically, PTC (Positive Temperature Coefficient) sensors increase their resistance as the temperature increases.

The PTC sensor (18) is also referred to as a Positive coefficient thermistor.

By adding a resistance in Series across the PTC sensor with the same methods seen previously (electronic pulses that control the relay), a resulting resistance equal to the sum of the resistances connected to each other will be created. A greater voltage drop is therefore determined at the sensor ends according to what is known from Ohm's law (V = RxI where V is the voltage, R the resulting resistance across the circuit and â € œIâ € the intensity of current that crosses the circuit itself).

This increase in resistance and therefore in voltage is perceived by the car control unit (16) as an increase in temperature and consequent reduction in injection time (less fuel injected).

Unlike the systems seen for the NTC sensor, in this case the device under examination is composed of a group of resistors (13) // (10) in turn in parallel with the NTC sensor (33), interposed in series with the WTS sensor.

The resulting resistance simulates an increase in the temperature of the refrigerant fluid with a consequent reduction / cancellation of the enrichment phase.

The voltage variation by interposition of resistance in series takes place with the aid of an electromechanical component of the relay type, which differs from the previous one and has three contacts instead of two.

The two contacts are (35) and (37) generate the switch configuration with the common in the contact (36).

The additional contact is necessary to generate the â € œtransparentâ € configuration at rest. That is to say that even with the circuit powered and until the timer expires there is no change to the signal, and the assembly behaves as if it were a cable.

At the end of the time set in the timer by means of the timer trimmer (9), the command pulse destined for the coil (6) excites it and changes the configuration of the contacts.

In this new configuration the contact (36) is disconnected from (37) and connected to (35) by placing the complex of resistors (10) // (13) // (33) in series with the WTS sensor (18).

As previously mentioned in the case of the NTC sensor, also for PTC sensors the sensor resistance can have different full scale values according to what is decided by the system manufacturer.

It is therefore necessary for the device to be able to adapt to the different values of the sensor (18), otherwise it will lose accuracy in the adjustment or in the most serious cases it will not be possible to intervene in the adjustment.

This variation is obtained by interposing in parallel to the adjustment trimmer (10) a group of fixed value resistors (13) that can be manually selected when installing the device by means of a jumper type contact (26) or switches / deviators also Dip Switck type, the result is indifferent.

In this variant, however, it is necessary to reduce the intervention of the group of resistors (10) // (13) as the engine temperature increases, as their total value would be added to the value of the WTS (18) to generate as the temperature increases, a data that cannot be tolerated by the control unit (16) with consequent generation of error signals.

A solution to this problem has been found by interposing an NTC sensor (33) in parallel with the trimmer (10) via track (34) and track 21.

The NTC sensor (33) must be placed in contact with the coolant or with engine parts whose temperature is proportional to it.

An optimal point on which to contact NTC (33) is the motor head.

In turn, the group of resistors (13) is also parallel to (10) and (33) through the trace (20) and (21).

As the temperature increases, the NTC sensor (33) as explained above, reduces its resistive value, generating an equivalent resistance whose value is smaller than the smallest resistance present in the evolved branch between the traces (21) and ( 34).

So if the equivalent resistance referred to in branch (21) (34) is placed in series with the WTS sensor.

At â € œhigh temperaturesâ € the parallel (10) // (13) // (33) produces an almost zero effect and prevents the generation of errors due to signal inconsistency.

In this configuration it is not possible to make the switching progressive with the help of a capacitor.

The enrichment time during which no resistance is interposed to the WTS sensor (18) is determined by an electronic or mechanical timer (timer). The electronic timer (proposed solution) sends a pulse to the relay coil (6).

The coil reconfigures the relay contacts so that the central contact (36) communicates with the contact (35), in this way the group of resistors (10) // (13) are placed in series with the WTS sensor (18) // (33) and a high temperature of the refrigerant fluid is emulated by reducing the injection time.

In summary, when the start request is made, the circuit receives a `` timer start '' command, at the end of the time set in the timer the system activates the above switches by inserting an equivalent resistance in series with the WTS sensor, reducing the injection time and changing the status of the driver monitor, whether it has one or more LEDs or a display (29).

The correction of the temperature signal can be deactivated / reactivated at any time by the driver who, acting on a button, on a switch (12), or on a diverter, forces the device to intervene on the correction.

This intervention does not require a restart of the timer count to report the correction. By adding to the set of components already seen a special circuit whose heart is formed by an operational amplifier (8) such as an LM358, by an NTC type sensor (11) and by a series of resistors (38) ( 40) (41) (42) both fixed value and trimmer type (39).

The operational amplifier is able to evaluate the motor temperature by comparing the voltage present on the non-inverting branch (44) with the voltage present on the inverting branch (45).

The branch (44) is subjected to the voltage of the voltage divider formed by the resistors (38) (40) and the trimmer (39).

The trimmer (39) is necessary to regulate the voltage to be imposed on the branch (44).

The branch (45) sees its voltage vary due to the variation of the voltage divider formed by the resistor (41) and by the heating NTC (11).

When the branch (45) and the branch (44) reach the same voltage, they trigger the saturation of the operational amplifier which in turn sends a positive voltage signal to the branch (43) through the limiting resistor (42).

This positive signal reaches the relay coil (6) by switching the contacts and to the LED diode (5) by changing the status of the driver monitor.

This event occurs regardless of the condition of the timer signal.

The trimmer (39) adjusts the voltage of the voltage divider, they actually allow you to set the switching temperature above which the timing phase is not performed or rather, even if the timer starts when the time expires, it will already find the relay active, making the his signal is irrelevant.

The advantage of this operation is to optimize consumption by also canceling the cold regulating phase if the engine is â € œhotâ €.

The same effect can be achieved with greater circuit simplicity by adding a Firmware function in the microcontroller variant (25).

Specifically, the microcontroller (25) evaluating the voltage of the NTC sensor (47) by means of an on-board (or external) A / D converter activates the relay coil (6) once the desired temperature has been reached, avoiding running the routine. firmware related to the Timer.

Thanks to this function it is possible to avoid or reduce the cold regulation phase in the case of refrigerant temperatures above a certain threshold.

Assuming that a vehicle on which the circuit object of the discovery is installed has traveled a short distance â € œheatingâ € the refrigerant fluid.

Let's suppose that during this short journey the temperature reached by the refrigerant fluid is equal to or greater than 50 ° C, the circuit evaluating through the NTC (11) a temperature higher than the threshold can directly emulate the maximum temperature without waiting for the set time to expire. in the timer, effectively reducing the enrichment phase by a time equal to the time set in the timer itself.

The enrichment phase is then reduced or completely bypassed / ignored.

If the timer count is reduced only, the cold enrichment phase is reduced without completely canceling it, thus requiring the timer to reduce the intervention time by half, for example. This function is useful to facilitate starting without difficulty of any kind, in fact some engines in Diesel Cycle detecting high temperatures [â ‰ ¥ 90 ° C] do not turn on the preheating glow plugs in order to save electricity which, in order to be when restored, it will require energy from the engine and therefore consumption. By starting the engine without correcting the signal, I place myself in the â € œoriginalâ € conditions imposed by the vehicle manufacturer, allowing it to start well.

Therefore in this variant the user can ask the device not to wait for the timer count at every start before emulating the operating temperature.

This choice is left to the user because on some thermal units in the Diesel cycle, the injection control unit, detecting the operating temperature, does not activate the preheating glow plugs, thus jeopardizing the engine start-up in some cases. To deactivate the function, the user acts on the switch (49) which cuts off the power supply to the operational amplifier, the same effect is obtained by interrupting the track (43) (6) with a switch

The correction of the temperature signal can be deactivated / reactivated at any time by the driver who, acting on a button, on a switch (12), or on a diverter, forces the device to intervene on the correction.

This intervention does not require the restart of the timer count.

The devices referred to in variant 1 and 2 if equipped with a digital trimmer (46) become much more versatile and efficient.

A digital trimmer (46) is an electronic component capable of varying its existing resistance at the ends of an internal trimmer as a result of an appropriate command sent by a microcontroller via the 232 standard or the I2C standard.

Such complex signals can only be generated with the help of a microcontroller or through a computer.

The digital trimmer (46) is able to replace the group of resistors (10) // (13) for the NTC variant and (10) // (13) // (10) // (33) for the variant PTC

The microcontroller (25) is an electronic component containing a microprocessor, volatile and non-volatile memories, one or more timers, A / D converters, communication devices, input and output devices, etc ...).

It is to be understood as a micro-computer which, if properly instructed through firmware instructions, is able to repeat endlessly a series of operations, perform calculations, evaluate the conditions of the environment through dedicated sensors. It is subject, it can communicate with a PC (54), and it is also able to choose the best among several options.

An NTC sensor (47) is a negative coefficient thermistor, available on the market in several variations of shape (Eg. Threaded, eyelet, droplet, etc ...) and in different resistive values (1Kâ „¦, 2.2Kâ„ ¦, 5kâ „¦, 10kâ„ ¦, etc ...).

Withstands temperatures from -40 to 150 ° C, it can be placed in direct contact with the fluids whose temperature you want to evaluate or with a part of the engine whose temperature is proportional to the temperature of the fluid itself.

Different from that equipping the vehicles referred to in variant 1) it allows to evaluate the temperature value of the engine to which the device is connected.

The microcontroller (25) is programmed in such a way as to start, as soon as the supply voltage is received, an evaluation of the voltage signal present on the pin to which the NTC sensor (47) is connected.

The microcontroller is also programmed to evaluate this voltage and consequently to understand if the motor is â € œhotâ € or if it is â € œcoolâ €.

If it is cold, it reads the value to be assigned to the Timer register in a dedicated non-volatile memory cell.

The Timer can be incremented or decremented and works by reading the value from the Timer register.

If it is decremented, when the value of the Timer register is equal to â € œ0â € it generates an interrupt directed to the core of the microcontroller (25), if it is incremented it generates the interrupt when the value is maximum.

At the next step of the firmware, the microcontroller (25) activates the timer and waits for the time to expire.

Once the time set in the internal timer has elapsed, the microcontroller (25) is instructed in such a way as to evaluate the real temperature of the motor through the NTC sensor (47).

Once the latter has been evaluated, the microcontroller (25) points to a memory cell whose number is equal to the value converted by the analog to digital converter.

Let's try to clarify the concept better: the analog to digital converter is a solid system able to discretize (divide) a voltage usually included between VSS (â € œ0â € logic) and the supply voltage VDD (â € œ1â € logic), on several levels.

For example, an 8-bit analog to digital converter is able to discretize a signal between 0 and 5V on several levels for a total of between 0 and 256.

Therefore it will be able to evaluate jump voltages of about 20mV, as defined here.

VA </> D = <Vdd> ∠’<Vss> 5 − 0

= = 0.01953125V â ‰ ˆ 20mV

2 <8> 256

If the microcontroller (25) asks the analog digital converter to evaluate the temperature of a motor whose temperature extremes vary between -40 and 130 ° C through an NTC sensor (47), the same will be able to discretize the signal to evaluate the temperature with steps lower than 1 ° C and to be precise:

T 0 170

Tval = min T max âˆ'40 13

= = 0.6640625 ° C

2 <8> =

256 256

At 50 ° C for example we will have a voltage value equal to:

50V NTC = <T> â ‹… VA / D = â‹… <0.01953125> = <1.47> V

T val0.66

This voltage discretized by the A / D converter (analog to digital) will return the value:

ï £ «ï £ ¶

Val NTC <1.47>

<A> / <D> = intï £ ¬ï £ ¬ <V> ï £ «ï £ ¶

= int ï £ ¬ ï £ · = 75

ï £ VA / Dï £ ï £

ï £ ̧ ï £ 0.01953125ï £ ̧

A special Routine of the firmware of the microcontroller (25) reads the value to be assigned to the digital trimmer (46) in cell 75 of the non-volatile memory.

At the next step, the microcontroller (25) translates the value read in the â € œ75â € cell into a signal that can be understood by the digital trimmer (46), and sends it to the same in ways to emulate the desired temperature.

In this way, an emulation of the temperature (for example 90 ° C) and not the real temperature will be sent to the injection control unit (16), all to the advantage of fuel consumption.

At each variation of Tval this value is updated, guaranteeing maximum savings in any temperature condition.

By appropriately programming the microcontroller (25), the electronic capacity (11) placed on the output signal channel can be made superfluous.

The microcontroller (25) has been programmed in such a way as to perform what we have defined as a â € œprogressive changeoverâ €.

I clarify the concept better; when the timer expires, therefore, with the engine cold, an almost instantaneous switching of the relay is expected with consequent emulation of the temperature set in the memory.

In order not to produce torque gaps in the motor, the microcontroller (25) has been instructed in such a way as to make intervention on the temperature correction almost zero.

In particular, the digital trimmer (46) is set to its maximum value in the case of connecting the parallel to an NTC sensor, or to a value close to â € œ0â € in the case of a PTC sensor and relative connection in series, followed by switching the relay .

This strategy allows to obtain a minimal influence on the original signal at the output. The instructions of the microcontroller then provide for the evaluation of the real temperature value by means of the A / D converter and the NTC (47), then reading the corrective value from the appropriate memory cell as seen previously.

The read value is not immediately output on the digital trimmer but in steps of 1 until the necessary value is reached (Es We have a motor equipped with NTC sensor (47), we are at 50 ° C and we want to emulate 90 ° C deriving the signal progressively, we start from the maximum value that can be assigned to the digital trimmer then â € œ255â € and then progressively reduce it for example to â € œ5â € (value corresponding to the corrective for 90 °).

Each step is assigned a â € œswitching delayâ € which is necessary for the ECU to have time to adapt to the new driving conditions emulated (about 1 Sec). The switching delay value is loaded into the non-volatile memory when programming the microcontroller (25).

If the microcontroller (25) is asked to perform this function, it reads from the non-volatile memory a value to be assigned to the timer register and then starts the count.

At the end of the count, the timer, through a dedicated interrupt, warns the microcontroller (25) that the count has ended.

At this point the microcontroller subtracts a unit from the last value sent to the digital trimmer (46) and sends the updated result to the trimmer itself so that it emulates the new condition.

At this point the microcontroller (25) evaluates the difference between the emulated value and the desired value, if the error is greater than â € œ0â € it recycles the last step, that is: it reads the value of the switching delay and puts it in the timer register, waits for the timer to expire, resets the value in the digital trimmer (46) and so on until the desired value is reached.

During the `` tracking '' of the desired value, the microcontroller (25) continuously evaluates the real temperature conditions through the NTC (47) and the A / D converter, then updates the target value (final value of the progressive switching) .

The microcontroller that equips the device in this variant has been instructed to communicate with a personal computer, in order to transfer / update the internal data to the non-volatile memory and in order to facilitate the task of the installer called to find the € ™ excellent calibration on a large number of vehicles.

In particular, said `` mapping '' the overall content of the non-volatile memory present in the microcontroller and used to activate the timer and digital trimmer (46), it has been made so that the device found in the microcontroller variant is able to self-map the memory .

That is, the microcontroller communicating continuously with the PC (54) through the classic channels (USB, RS232, wireless, etc.), is able to update all the values in the memory, looking for the optimum consumption.

In particular, the user imposes through the PC (54) the target values (to be reached) for the device, such as the maximum temperature to be emulated, the warm up time (time in which the engine is allowed to warm up and the timer), the progressive switching time, as well as the threshold temperature beyond which the warm up should not be activated.

In order to comply with the self-mapping task of the emulated temperatures, the PC (54) needs to communicate simultaneously with the ECU (16) of the car and with the microcontroller (25) equipping the device.

Communication with the ECU is achieved through the standard OBD / OBDII communication interface (53).

Through it it is possible to read various values relating to the engine parameters, including the temperature detected by the ECU (16).

So when the programmer user connects the device and an OBD / OBDII interface (53) to a PC (54), he launches the relative program and asks for the self-mapping procedures to be started:

1. The PC (54) connects to the ECU (16) and queries it via the OBD / OBDII interface (53) for the detected temperature

2. Evaluate the difference between the temperature detected by the ECU (16) and the temperature detected by the device via NTC (47).

3. If this difference is greater than â € œ0â € ask the microcontroller (25) to vary the value of the digital trimmer (46) by one unit.

4. It restarts from point â € œ1â € until the goal is reached.

5. Once the number of units necessary for the device to emulate the target value has been found, it forces the microcontroller (25) to store this number in the non-volatile memory cell in the position resulting from the A / D conversion.

6. Then ask the device about the temperature variation detected, if there has been a change, repeat the operations starting from point 1. This occurs for temperatures between the ambient temperature and the engine operating temperature. The range not included, i.e. temperatures lower and higher than the limits just dictated, can be modified manually by the installer using appropriate Software functions, or it will be the PC (54) itself that determines a law of trend of the corrections and then imposes it on the rest of the memory. including.

7. Finally, the PC (54) transfers the data just detected into the memory of the microcontroller.

It is possible to ask the microcontroller (25) through the PC (54) to reduce the temperature range between two limits set by the installer in order to make the discretization more fine to the advantage of the calculation accuracy.

For example, we think of particularly cold temperatures or much higher than the temperature at which the forced cooling fan starts (between 95 and 105 ° C).

The interposition of this â € œdigital resistor (46) â € can always take place through the electromechanical switches, or by varying the value of the resistance so that the resulting value is irrelevant in the heating phase.

The reference NTC (47) must be placed in contact with the refrigerant fluid or with a component whose temperature is proportional to the temperature of the aforesaid fluid. The microcontroller (25) through the on-board A / D converter (or with the help of an external A / D converter) translates the voltage of the reference NTC (47) into the temperature value of the refrigerant fluid.

The translated temperature value will be used by the microcontroller (25) to decide which resistance to put in output from the device in order to emulate the desired temperature in order to reduce fuel consumption.

The corrective values are loaded into the memory by the manufacturer of the device and adapted to the vehicle by the installer at the time of installation on the car with a special software provided by the manufacturer.

The voltage / temperature characteristic of the reference NTC is loaded into an on-board memory of the microcontroller (25) or into an external memory.

Note the characteristic of the reference sensor (47), it is possible to emulate a high temperature already starting from very low real temperatures of the coolant, or it is possible to emulate a temperature such as to guarantee a certain driving comfort for the driver.

The customization also allows you to decide the time of variation of the emulated temperature, which is instead of a few mS in the case of variant 1 and 2, this allows to avoid the capacity present in variant 1, allows to improve driving comfort, finally allows to further reduce consumption as the output voltage is no longer linked to the vehicle's WTS sensor but can always be emulated at a value (eg: 95 ° C) as soon as the timer expires.

This version also makes it possible to avoid or reduce the cold regulation phase in the case of refrigerant temperatures above a certain threshold.

That is to say, if the refrigerant fluid is for example at a temperature above 50 ° C, the microcontroller (25) can directly emulate the maximum temperature without waiting for the time set in the timer to expire, effectively reducing the enrichment phase of a time equal to the time set in the timer itself.

It can also reduce the timer count by reducing the cold enrichment phase.

Therefore in this variant the user can ask the device not to wait for the timer count at every start before emulating the operating temperature.

This choice is left to the user because on some thermal units in the Diesel cycle, the injection control unit, detecting the operating temperature, does not activate the preheating glow plugs, thus jeopardizing the engine start-up in some cases. Since there is a microcontroller on board, this variant is equipped with a communication interface with a PC (54), on which the installer can view the real values emulated by the device, set the different values to be emulated, set the time of the timer, the threshold temperature above which to directly start the operating temperature without waiting for the timer, etc ...

The device in this variant can work by itself also by disconnecting the WTS sensor (be it NTC (17) or PTC (18)) but in this case the driver would be forced to continuously intervene in the manual correction of the signal, in fact some electronics translate the failure to change the WTS signal in an engine failure by starting so-called â € œRecoveryâ € strategies.

On the other hand, by connecting the WTS sensor (be it NTC (17) or PTC (18)), the electronic injection control unit is allowed to evaluate values gradually varying with the temperature of the refrigerant fluid, which do not allow the control unit to generate any error or recovery strategies.

In this variant there is no timer but it is the user who decides according to his perceptions to activate / deactivate the correction by means of a manual command obtained with diverter (50), while the correction of the injection time takes place manually on the trimmer (10).

The ECUs (16) fitted to vehicles with a Diesel cycle engine also evaluate the fuel temperature, which by its nature significantly reduces viscosity as the temperature increases.

This reduction in viscosity translates into a higher dosage of fuel for the same injection time.

Due to this characteristic of Diesel cycle engines, manufacturers are forced to evaluate the fuel temperature and adapt the injection time, reducing it in the case of â € œhighâ € temperatures.

The high temperatures of the fuel occur as a consequence of the continuous compressions of the fluid and of the heat exchange with the â € œhotâ € parts of the engine, they occur on medium / long journeys or in the case of low fuel in the tank.

The sensors adopted to achieve this objective are always of the NTC or PTC type, therefore they allow the device to be used in all its variants to emulate a high fuel temperature and consequently reduce its consumption on short journeys or in the presence of low temperatures.

The device can be calibrated in such a way as not to compromise the performance of the vehicle in emulation conditions.

This variant can work in parallel to the previous variants as it intervenes on different signals.

The ECUs equipping all vehicles also evaluate the temperature of the combustion agent (air), which, being of a gaseous nature, significantly reduces its density as the temperature increases.

Because of this characteristic, manufacturers are forced to evaluate the combustion agent temperature and adapt the injection time, reducing it in the case of â € œhighâ € temperatures.

The sensors adopted to achieve this objective are always of the NTC or PTC type, therefore they allow the device to be used in all its variants to emulate a high combustion agent temperature and consequently reduce fuel consumption both on short and long journeys. journeys and even in the presence of low temperatures.

The device can be calibrated in such a way as not to compromise the performance of the vehicle in emulation conditions.

This variant can work in parallel to the previous variants as it intervenes on different signals.

In the case of industrial vehicles or vehicles powered with electrical voltages higher than 12V, the inventor has equipped the device with a voltage reducer designed to safeguard the device and adapt the power supply of the vehicle to the requirements of the internal components.

Claims (6)

CLAIMS. 1. Consumption saver for cars, interposable, after a certain time, between the NTP (Negative Temperature Coefficent) type WTC (Wather Temperature System) sensor (17) and the injection control unit (16), characterized by the fact that a group of resistors (13), connected through a jumper type contact (26) to one or more Trimmers (10), placed in parallel with each other with a Printed Circuit Board, which supports the electrical track (20), to which the the ends of the said resistors (13), through the collector node (21), flow into the relay contact (7), which connects the said circuit to the original circuit, passing through an electronic capacitor of the capacitor type (11). 2. Consumption economizer as per the preceding claim, which can be interposed between the PTC (Positive Temperature Coefficient) type WTC sensor (18) and the injection control unit (16), characterized by the fact that the group of resistors (13) and (10 ) referred to in claim no. 1, are placed in parallel to an NTC type sensor (33), by means of two electrical traces (21) and (34) and placed in series with the WTC sensor (18), through the relay type component, consisting of two contacts (35) and (37). 3. Consumption economizer, as per the preceding claims, characterized in that the relay-type component and the coil (6) are connected with electric wires (23) to the programmable timer device (3) operated by an electric contact (28 ), by means of a coil (27) that receives the starting impulse and by means of a trimmer (9). 4. Economizer as per claims 1 and 2, characterized in that the relay coil (6) is connected, via an electrical branch (43) and a limiting resistor (42), to an operational amplifier (8), connected to a non-inverting branch (44), subjected to a voltage divider composed of two fixed resistors (38) (40) and to a trimmer resistor (39) and to an inverting branch (45) subjected to a voltage divider consisting of a fixed resistor (41) and an NTC type amplifier (11) located in the electrical circuit of the injection control unit (16). 5. Economizer as per claims no. 1 and 2, characterized by the fact that the relay-type component and the coil (6) are connected, with electric wires (23), to a digital trimmer (26) in turn connected to a microcontroller (25), which contains the timer, a microprocessor and volatile and non-volatile memories, connected to a negative coefficient thermistor (47), from which it detects the real temperature of the motor, processes it and transmits it to the digital trimmer (46) capable of varying the resistance as a result of the commands of the microcontroller (25), a command corresponding to the emulated temperature. 6. Consumption saver as per claims 1 and 2, characterized in that the relay-type contact is operated manually by a diverter (50).