US3862625A

US3862625A - Ignition device for explosion engines

Info

Publication number: US3862625A
Application number: US293741A
Authority: US
Inventors: Vincenzo Fazzo
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-09-29
Filing date: 1972-09-29
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

An electrical ignition device for explosion engines of the type with a low ohmic resistance of the primary winding and a resistor in series with this winding. A discharge condenser acts on opening of the primary circuit in which the condenser is connected, directly or indirectly, between earth and an intermediate point in the circuit formed by the resistor and primary winding, thereby excluding the resistor from the circuit during the discharge stage.

Description

United States Patent Jan. 28,1975

Fazzo l5 l lGNlTlON DEVICE FOR EXPLOSION 3.581,?25 6/l97l Hemphill .1 l23/l48 E ENGINES [76] Inventor: Vincenzo Fazzo, Via Albani 7, 'f 'f 'l l Myhre Milan Italy 20149 Avm'la/zr [:xummefi-Ronbld B. Cox

Attorney Agent, or Firm-Guido Modiano; Albert [22] Filed: Sept. 29, I972 .losii [21] Appl. No.: 293,741

1 [57] ABSTRACT [52] [1,5, (,l, H 123/148 [)(j, 123/148 3 An electrical ignition device for explosion engines of 1511 1111.01. F02p 1/00 the yp with a low Ohmic resistance of the p y 15g i ,1 S 123/143 g 141; AC, 43 DC winding and a resistor in series with this winding.

l B A discharge condenser acts on opening of the primary circuit in which the condenser is connected directly Reference-S Cited or indirectly, between earth and an intermediate point UNITED STATES PATENTS in the circuit formed by the resistor and primary 3 1125 4311 3/1962 Leppala... l23/l48 E Winding thereby excluding the resistor fmm 3.217.216 ll/l965 D0110 123/148 E Circuit during the discharge Stage- 3.34().86l 9/1967 Schiff l23/l48 E 3.550.573 12/1970 Kowalski 123/]48 E 3 l Drawmg 1 IGNITION DEVICE FOR EXPLOSION ENGINES BACKGROUND OF THE INVENTION The present invention relates to an electrical ignition device for explosion engines, of thecoil ignition type.

Ignition devices of the coil ignition type commonly used in explosionengines comprise the use of a primary winding with a few turns'which is magnetically linked with a secondary winding with a much larger number of turns. The primary winding is connected at one end to the source of energy (for example the battery) and at the other end it is connected to earthby way of a switch or contact breaker which is cyclically controlled so that it opens and closes in phase with the engine cycle. In addition, a condenser is connected in parallel with this switch. In its turn the secondary of the coil is connected at one end directly or indirectly to the I sparking plugs'of the engine, and at the other end is fed by the battery.

The operation of these devices is well known in the art and does not require illustration. It is sufficientto note that during each cycle, when the switch or circuit breaker connecting the primary to earth is closed, the current flows in theprimary without concerning the condenser. i

However, when the primary circuit is opened at the switch, the condenser charges and then discharges through the primary, to create the known electromagnetic phenomena which lead to the formation of the spark at the sparking plugs.

As the current in the primary winding, subjected to the constant available voltage, could reach excessive values when the engine is at rest with the key inserted, or when it rotates slowly (in that the time available for the establishment of the current is in this case greater) it isnecessary for the ohmic resistance of the primary circuit to be suitably sized, both to avoid excessive heating of the coil and so as not to overload the switch contacts.

This is the reason that in those coils at present available which have a low ohmic resistance (and give better performance) there is a resistor connected in series, which constitutes a barrier against excessive increase in the charging current.

This separation of function hence enables the resistor to be mounted external to the coil casing, so favouring dissipation of heat. Devices constructed up to the pres- SUMMARY OF THE INVENTION The present invention proposes to obviate these disadvantages by providing an electrical ignition device of a new type, which because of its improved solution to the problem gives aconsiderable reduction in losses at the resistor, specifically during the discharge cycles, thus leading to an increase in the efficiency of the device with respect to traditional devices.

A further object of the invention is that said improved device facilitates and renders more convenient the use of resistors of a particular type, so as to give spark characteristics which are more satisfactory and substantially constant over a wide range of engine speeds.

A further object of the invention is that the device according to the invention gives unexceptionable operation for any engine speed, i.e., both at low and high engine speed, and does not require mechanical or electro mechanical intervention members for adaptation to the engine speed.

These and further objects are attained by an electrical ignition device for explosion engines, of the type with a low ohmic resistance of the primary winding and a resistor in series with this winding, and with a discharge condenser acting on opening of the primary circuit, in which said condenser is connected, directly or indirectly, between earth and an intermediate point in the circuit formed by the resistor and primary winding, so as to exclude said resistor from the circuit during the discharge stage.

BRIEF DESCRIPTION OF THE DRAWING Further characteristics and advantages will be more evident from the description of an ignition device according to the invention, a preferred but not exclusive embodiment of the electrical schematic diagram of which is shown in the single FIGURE in the accompanying drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT In this drawing the primary winding (with a few turns) and secondary winding (with a large number of turns) of the ignition coil are indicated by the reference numerals 1 and 2. Both theprimary and secondary are connected, in known manner by way of the conductor 3, to the battery 4. The secondary is connected in known manner by way of the conductor 5 to the single sparking plug or to the sparking plug ignition distributor 6, connected to earth at 7. As the primary winding 1 is of low ohmic resistance, it is connected in series with a resistor 8, preferably non-inductive, having an ohmic resistance of such a value as to limit the intensity of the charging current which traverses the primary 1 when it is fed by the battery (switch closed) to the required value. The switch of this circuit is indicated diagrammatically by the reference numeral 9, and connects the resistor 8 to earth 7.

The circuit is new in that it comprises the connection of a discharge condenser 10 between the earth 7 and an intermediate point 1 1 between the resistor 8 and primary 1.

The connection of the discharge condenser 10 in this position leads to really surprising and notable results. Whereas, as is usual, the condenser 10 is practically inert when the primary 1 is fed by the battery, because the circuit is closed by the circuit breaker 9, it however acts when the circuit is broken at 9. charging and successively discharging through the winding 1, without the alternating current traversing the resistor 8. It follows that during discharge the primary circuit has a lower resistance (caused by the exclusion of the resistor from the circuit during this stage), because of which a superior and better utilisation of the energy stored by this circuit during charging is obtained. The resistance losses due to the element 8 are in fact eliminated. This different degree of conductivity of the circuit between the charging and discharging stages exists for any engine speed and is produced not by mechanical means (such as switches which connect or disconnect resistare used, because this requires larger supplementary resistors (for the already stated requirement of limiting the charging current), Moreover, the fact of having separated the resistor 8 from the discharge currents facilitates and renders more convenient the use of resistors having particular characteristics (for example, resistors with positive temperature coefficients to ensure the constancy of the discharge tension as the motor speed varies).

I Evidently the invention so conceived is susceptible to numerous modifications all of which fall within the scope of the inventive idea. Thus, it is possible within the inventive idea to connect a resistor of suitablevalue in parallel with the contacts of the circuit breaker 9 for reducing the voltage across the contacts during their opening. A condenser'may beseries connected to the resistor, this assembly thus defining a means for reducing overtension upon opening of the circuit breaker 9. lclaim:

1. An electrical ignitiondevice for explosion engines comprising an ignition coil including a primary and a secondary winding circuits, a sourceof electrical current connected toat least one of said winding circuits,

a sparking plug branch connected with said secondary circuit, circuit breaker means -in series with said primary winding circuit, a resistor in series with said primary winding circuit and a condenser directly connected between the point of connection of said primary winding circuit with said resistor and the ground, said the source of electrical current has one pole thereof V breaker means.

grounded, said condenser has i one plate thereof grounded and said circuit breaker has one end thereof groundedr V 3. An electrical ignition device for explosion engines as claimed in claim vl, further comprising in parallel with said circuit breaker means a further resistor in 'se ties with a further condenser for reducing overtension occurring upon opening of the contacts of said circuit with said primary winding

Claims

1. An electrical ignition device for explosion engines comprising an ignition coil including a primary and a secondary winding circuits, a source of electrical current connected to at least one of said winding circuits, a sparking plug branch connected with said secondary circuit, circuit breaker means in series with said primary winding circuit, a resistor in series with said primary winding circuit and a condenser directly connected between the point of connection of said primary winding circuit with said resistor and the ground, said primary winding circuit being of the type in which the primary winding circuit has a low ohmic resistance, and wherein, according to the improvement, said resistor is arranged in series with said primary winding circuit between said circuit breaker means and the point of connection of said condenser with said primary winding circuit.

2. An ignition device according to claim 1, wherein the source of electrical current has one pole thereof grounded, said condenser has one plate thereof grounded and said circuit breaker has one end thereof grounded.

3. An electrical ignition device for explosion engines as claimed in claim 1, further comprising in parallel with said circuit breaker means a further resistor in series with a further condenser for reducing overtension occurring upon opening of the contacts of said circuit breaker means.