Internal-combustion engines – Cooling – With jacketed head and/or cylinder
Reexamination Certificate
2000-08-03
2002-06-18
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Cooling
With jacketed head and/or cylinder
Reexamination Certificate
active
06405687
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention pertains to a control system for a two cycle internal combustion engine adapted to control a rotational direction of the engine in a reverse direction.
BACKGROUND OF THE INVENTION
There have been used many two cycle gasoline engine (referred to as a two cycle internal combustion engine later) which can easily start by wire-recoiling, kicking or the like and can be provided in an small-sized and inexpensive manner as a primer for a traveling machine such as a scooter or a snowmobile which is required to be easily operated.
Since such a traveling machine comprises a transmission having no backup gear provided therein, the entire machine has been brought up and turned so that a front side thereof is directed in a back side in order to reverse a travelling direction thereof when it should be reversed in a narrow place etc., which causes the traveling machine to have a poor operation ability.
Of late, it has been considered that the traveling machine is adapted to have a backward traveling function by switching the two cycle internal combustion engine from the forward direction to the reverse direction in view of the characteristic of the two cycle internal combustion engine being able to normally operated in either of the forward and reverse directions.
It is required for driving the traveling machine in a forward or backward direction to arbitrarily switch the rotational direction of the two cycle internal combustion engine in accordance with a driver's instruction.
Such control devices as control to switch the rotational direction of the internal combustion engine are disclosed in U.S. Pat. No. 3,036,802, JP11-93719, JP11-82270 and JP9-252378.
These control devices serve to fully lower the revolution of the internal combustion engine for restraining the inertia of the engine as much as possible when the reversion instruction is provided by the driver. When the revolution of the engine is fully lowered, the ignition of the engine is made at an overadvanced position (a position where the ignition position is further more advanced than the most advanced position suitable for the usual operation) whereby a piston of the engine is forced back so as to rotate the internal combustion engine in a reverse direction. When it is confirmed that the engine is rotated in the reverse direction, the engine is ignited at the ignition position suitable for maintaining the rotation of the engine in the reverse direction so that the engine is operated while the rotational direction of the engine is kept reversed.
Various methods have been proposed which lower the revolution of the engine when the reversion instruction is provided. In these methods, the engine fails to be ignited as disclosed in U.S. Pat. No. 3,036,802, an injection of fuel from an injector which supplies the fuel into the engine is stopped as disclosed in JP11-93719, the ignition position is gradually advanced as disclosed in JP11-82270 and the ignition position is gradually delayed as disclosed in JP9-252378.
These control devices is provided with induction type signal generator means comprising a rotor having reluctors mounted on a crank shaft of the engine and a pulser (signal generator) to detect the rotor type reluctors to generate a pulse signal. The information about the revolution of the engine and the rotary angle position of the crank shaft are read from the pulses generated by the signal generator means and the ignition position of the engine and the injection time of the fuel are controlled by using the information.
The control devices to control to rotate the engine in the reverse direction are adapted to ignite the engine at a position suitable for maintaining the rotation of the engine in the reverse direction after the rotational direction of the engine in the reverse direction which is accomplished by the igniting the engine at the overadvanced position is confirmed. Thus, it will be noted that the control devices are required to comprise means to detect the rotational direction of the engine.
The proposed control devices comprise signal generator means including reluctors of particular figure to detect the rotational direction of the engine. The rotational direction of the engine is detected from the phase relation of the pulses obtained by the signal generator means after the engine is ignited at the overadvanced position and thereafter the engine is ignited at the position suitable for rotating the engine in the detected rotational direction.
Since the revolution of the engine cannot be arithmetically operated in a precise manner when the engine starts and therefore the ignition position of the engine cannot be decided by the arithmetical operation, the signal generator means is so constructed as to generate pulses of positive polarity at a position slightly advanced relative to a top dead center of respective cylinders (a position of 12° before the top dead center, for example) when the engine rotates in the forward direction. An ignition timing signal is applied to an ignition system whenever the pulses of positive polarity are generated when the engine starts whereby the ignition of the respective cylinders are made.
When the ignition of the engine is made at the overadvanced position for reversing the rotational direction of the engine, the explosion power generated by the ignition is applied against the inertia of the engine which tries to maintain the present rotation of the engine and the engine is successfully rotated in the reverse direction when the explosion power overcomes the inertia. If the explosion power is defeated by the inertia, then the engine fails to be rotated in the reverse direction. If the explosion power is equal to the inertia, then the engine stops.
In any cases, since the engine is in the condition of being rotated by a slight difference between the explosion power and the inertia after the engine is ignited at the overadvanced position and before the rotational direction of the engine is confirmed, the engine tends to easily stop. In order to maintain the rotation of the engine in this condition, the engine desirably continues to be ignited. However, in the prior art control devices, since the engine cannot continue to be ignited during the period after the ignition of the engine is made at the overadvanced position and before the rotational direction of the engine is detected, the engine tends to be undesirably stalled during the period.
It is considered that the engine is ignited by applying to the ignition system the pulses generated by the signal generator means as the ignition timing signal during the transient period after the engine is ignited at the overadvanced position and before the rotational direction of the engine is detected. However, the pulses which can be used as the ignition timing signal when the engine rotates at low speed are only the ones of positive polarity among the pulses generated by the conventional signal generator means. Since the pulses generated by the signal generator means when the engine rotates in the reverse direction is generated at the position not suitable for any ignition position, the pulses generated by the signal generator means during the transient period after the engine is ignited at the overadvanced position and until the reversion of the engine is confirmed cannot be used as the ignition timing signal.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the invention to provide a control system for a two cycle internal combustion engine so constructed for the engine to never fail to stall during the period after the engine is ignited at the overadvanced position for operating the engine in the reverse direction until it is confirmed that the rotational direction of the engine is reversed.
The present invention relates to a control system for a two cycle internal combustion engine comprising reversion instruction generator means to generate a reversion instruction to instruct a rotational direction of the internal combustion engine to be reversed and a control unit t
Arakawa Yoshinobu
Sasaki Kouji
Tsukada Yoshikazu
Benton Jason
Kokusan Denki Co. Ltd.
Pearne & Gordon LLP
Wolfe Willis R.
LandOfFree
Control system for two cycle internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control system for two cycle internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control system for two cycle internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2976532