breaker is an important part of the ignition system of the battery, breaker contacts open, closed, the ignition coil primary circuit is turned on or off, the secondary electromagnetic induction coil induces a high voltage ignition. Breaker is periodic action through the ignition coil primary circuit, generally consisting of a cam and off by the shock. Sub breaker contacts made of a tungsten alloy, a fixed contact of the contact, the other contact of the movable contact. Ground fixed contacts is achieved by a fastening screw on the fixing base is fixed to the base plate and a lower activity, may be adjusted by rotating eccentric screw contact gap.
1. Breaker Introduction
breaker is an important part of the ignition system of the battery, breaker contacts open, closed, the ignition coil primary circuit is turned on or off, since the electric the secondary magnetic induction coil induces a high voltage ignition. The secondary high voltage by the distributor allocated to each of the engine cylinders to ignite the gas mixture. Ignition system of direct impact on the technical performance of the car, and breaker status and affect the entire ignition system. Repeatedly opening and closing off the appliance, spark ablated contact therebetween. Poor working conditions, making it a battery ignition system and the engine failureThe multiple sites.
2. Breaker Ignition System Property Analysis
based battery ignition by the ignition coil, spark plugs, breakers, distributor, ignition switches, wires and other components, inductive energy storage type belongs. Its characteristics are summarized as follows:
(1) the energy stored in the ignition coil, the primary current in the case where the same, the larger the primary inductance, the more the ignition energy storage.
(2) When the contacts are closed, due to the back EMF of the primary current to a certain value does not increase immediately, but scratch, with the closing time of growth, the primary current is gradually increased to a certain extreme value. Closing the length of time, depending on the closure and the contact angle of the engine rotation speed. In the case where the dwell angle unchanged, the closing time is inversely proportional to engine speed. Therefore, the higher the engine speed, the smaller the primary current, the contact is also less energy.
(3) Since the inductance of the ignition coil at the instant the contacts open will be the back EMF induced secondary, while the back EMF induced in the primary, so that the contacts between the contact erosion sparks.
(4) reduces the back EMF of the cutting rate of the primary current, the secondary potential rise rate decreases. Battery ignition system to spark plug fouling also very sensitive to the root of this. Battery ignition system for the analysis of the characteristics, taken a number of measures to overcome its shortcomings, including the breaker.
3. Breaker Breaker Structure
breaker by the cam, the sub-contacts, a capacitor, a spark advance devices and other components. Cam control of the switching contact during rotation, the primary current switching. A capacitor connected in parallel to the contact, whose role is to form a primary inductive loop back EMF to reduce erosion of the contacts, to accelerate the rate of the primary current switching.
Since the ignition system operating conditions not only affected by pitting, and advance the ignition device, capacitor and related technical condition of the cam. Therefore, the analysis of the ignition system status, should consider these sites and their related parts and components. .
4 breaker contacts using analytical techniques
For the sub-contacts, its technical condition only include: size of the gap, the surface quality of the contact, the spring tension.
(1) the size of the contact gap, affecting both dwell angle, the primary current and the secondary pressure, and affects the ignition timing. So when adjusting ignition timing, you must adjust the contact gap. The standard value is generally 0. 35-0. 45mm.
the contact surface (2) contacts the contact resistance,Primary current and the secondary high pressure. We must ensure a contact surface parallel to the contact, and more than 90 percentage bound surface. Direct factor
(3) the influence of the spring tension of the thermal effects of the primary current. When the high voltage generator; primary current is too large; long time at low speed of the engine; additional resistance shorted secondary short-circuit and the ignition coil, the spring will cause annealing, reduced tension.