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(11) | EP 0 215 750 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Device for controlling polluting emissions from internal combustion engines |
| (57) First (3) and second (9) inlet ducts are provided in the carburettor (C) of the engine
and are located downstream and upstream respectively of the throttle valve (V) in
the air intake direction. A first pneumatic line (2) puts the first inlet duct (3)
into communication with the barometric control chamber (S) of an actuator (A) which
controls the angle of ignition advance. The same barometric control chamber (S) is
also put into communication with the second inlet duct (9) through a second pneumatic
line (6) including at least one restricted section (l0) and a third pneumatic line
(7). The first (2) and third (7) pneumatic lines have two associated solenoid on-off
valves (4, ll), the operation of which is controlled by a sensor (l3) associated with
the starter (W) and a heat sensor (l4) sensitive to the temperature of the engine
lubricant. When the starter (W) is active, the low pressure downstream of the throttle
valve (V) is transferred to the barometric control chamber (S) of the advance angle
control actuator (A). When the starter (W) is returned to the rest position, the low
pressure upstream of the throttle valve (V) is transferred to the barometric chamber
(S) through the second pneumatic line (6) The restricted section (l0) of which delays
the propagation of the pressure gradients towards the barometric control chamber
(S) of the actuator (A). This operating condition exists until the temperature of
the engine lubricant reaches a threshold level of the order of 45-85° C. When this
treshold level is reached the third pneumatic line (7) is opened to put the second
inlet duct (9) directly into communication with the barometric control chamber (S)
of the actuator (A) for controlling the angle of advance and the ignition. |