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50-FIRING ORDER 1-3-4-2.
60-FIRING ORDER 1-5-3-6-2-4. Magneto Setting-Points break with lever fully retarded and piston on dead centre.
35-FIRING ORDER 1-2-4-3. Magneto Setting-Piston top dead centre. Maximum advance of magneto .5 inch on piston travel.
6–48 AND WEIDELY-FIRING ORDER 1-4-2-6-3-5. Magneto Setting-Piston dead centre, lever fully retarded.
C, T, N AND NC-FIRING ORDER 1-2-4-3.
FIFTH-FIRING ORDER 1-3-4-2. Remy System—Piston top dead centre when indexing button on distri. butor engages.
A-FIRING ORDER 1-3-4-2.
38 AND 50-FIRING ORDER 1-3-4-2. Magneto Setting—Piston .015625 inch before top dead centre.
75-FIRING ORDER 1-3_4-2. Magneto Setting-Piston dead centre or slightly after.
H-FIRING ORDER 1_5-3-6-2_4.
ROTARY-FIRING ORDER 1-5–3–6–2–4. Magneto Setting-One-sixteenth inch after top dead centre, lever fully retarded.
FOUR-FIRING ORDER 1-2_4_3.
Six-FIRING ORDER 1-5-3-6-2_4. Magneto Setting-Piston top dead centre, points breaking.
C6-FIRING ORDER 1-4-2-6-3-5. Magneto Setting-Figure 1 showing in timing window, 25 degrees before top dead centre (flywheel).
FOUR-FIRING ORDER 1-3-4-2.
Six-FIRING ORDER 1-5-3-6-2_4.
AND 9-FIRING ORDER 1-3-4-2.
10-FIRING ORDER 1-5-3-6-2_4. Magneto Setting-Piston top dead centre.
Six-FIRING ORDER 1–5–3–6–2–4. Magneto Setting-Piston .125 inch after top dead centre, lever fully retarded and points breaking.
ELEMENTARY ELECTRIC STARTER PRINCIPLES
Types of Self-Starters Defined-One Unit Systems—Two Unit Systems,
Three Unit Systems—Parts of Systems and Functions—Generator Types—Current Regulating Means—Methods of Cranking EngineStarting Switches—Indicators—Roller Clutches—Miscellaneous Devices.
ELECTRIC lighting, cranking and ignition systems for motor cars are of such recent development that it is not possible to describe all systems used for this purpose. Not only do the individual systems vary in detail, but the components of the same system are often of different construction when used on cars of different makes. The standard equipment must include three important functions, namely, the generator which is driven by the engine end which produces electric current to keep a storage battery charged, and the starting motor which is in mechanical connection with the engine and in electrical connection with the storage battery when it is desired to turn the engine over for starting. If the motor and generator are combined in one instrument the starting system is known as a one unit type. If the motor is one appliance and the generator another, the system is said to be a two unit system. Each of these has advantages, and both forms have demonstrated that they are thoroughly practical. In addition to the three main items enumerated, various accessories, such as switches, ammeters, connectors, wiring, protective circuit breakers, automatic current regulators, etc., are necessary for the convenient distribution and control of the electric current. The arrangement of the parts of a typical one unit system in which the motor-generator is used only for starting and lighting is shown at Fig. 139. This shows the location of the various parts in their relation to the other components of the motor car. The motor generator is mounted at the side of the engine, and is driven by the magneto drive shaft as at A, Fig. 140, when used as a generator, and serves to drive the engine through this means when it is used as a motor. The ignition current is supplied from an independent source, a high tension magneto. The starting switch and that controlling the lighting system are placed on the dash, while the storage battery is carried under the floor of the tonneau. This system, which is known as the Entz, will be described more in detail in following chapter. Latest practice is to use the direct silent chain drive as at Fig. 140, B.
The elements of a one unit system are shown in diagram form at the left of Fig. 141. It will be observed that the armature car
ries two commutators, one of which is used when the armature is driven by the engine and when the device serves as a current generator, the other being employed when the operating conditions are reversed and the electrical machine is acting as a motor to turn over the engine crankshaft. When the device is driven as a generator the small sliding pinion on the short end of the shaft is out of engagement with the spur gear cut on the flywheel exterior. When it is desired to start the engine the spur gear is meshed with the member cut on the flywheel and the current from the storage battery is directed to the windings of the electric machine which becomes a motor and which turns over the engine