SE461237B - DEVICE FOR MANUALLY REPLACING THE LIGHTING SPECIFICALLY IN CONNECTION WITH COMBUSTION ENGINE DRIVING MACHINES SUCH AS MOTOR SAW AND DIFFERENT - Google Patents

Description

461 237 coupling, which saw is provided with control handles in the form of throttle controls and the like, wherein according to the invention manual switching of the ignition angle takes place by means of a switch.

The object of the invention is thus to be able to increase the ignition process in order to avoid backlash at start-up, to obtain a smooth idling and a good acceleration from idling to working speed.

The characteristics of the invention appear from the following claims.

An embodiment of the invention is described below with reference to the accompanying drawing, which shows a diagram of a device according to the invention.

The device shown consists of a three-legged magnetic core 1 for co-operation with a magnetic flywheel 8 comprising a north and a magnetic pole. The flywheel is assumed to rotate in the direction of the arrow 3, the core leg H located first in the direction of rotation carrying a first trigger winding ¶ ', the second core leg 5 carrying a second trigger winding S' and the third core leg B carrying a charge winding E '. The charge winding is connected via a rectifier 7 in series with a charging capacitor 8 and with the primary winding in an ignition transformer S, the secondary winding of which is connected to a spark plug gap 10. The second spirit of the primary winding is connected to a common chassis conductor 11. A trigger point 1E, triac or the like is connected between an outlet point, located between the rectifier 7 and the capacitor B, and the chassis conductor 11.

The first trigger winding ä 'is connected, via a switch 13 which is located outside the ignition system, for example in a throttle handle, and a more rectified bearing, to the riser 18 of the riser 18. The second trigger winding 5' is also connected to the riser. 18 riser 16, via a rectifier 153 The system works in the following way. The charging capacitor B is charged in the usual way by the charging winding 6 'on the core leg 5 emitting a charging voltage applied to the rectifier 7, which in this case emits a direct current pulse which charges the capacitor 8 in the usual manner. Uid team- lap ie. starting lap, the switch 13 is open. The pulse which arises when the magnets pass the first core bone Q with the first trigger winding Ä 'is thus not passed on. The pulse Eran the second trigger coil 5 'is led via the rectifier 15 to the riser input 25 of the timer 12.

In this case, the current path of the charged capacitor 8 is closed, whereby this is discharged through the primary coil of the ignition transformer 5, resulting in a spark flux in the ignition pin.

By closing the switch 13, a trigger pulse is produced from the trigger winding ä 'of the first core bone, which is conducted via the switch 13 and the rectifier lies to the riser 16 of the riser. the ignition occurs earlier than when the trigger pulse Eran winding 5 'is used.

The combustion engine-powered saw is of the usual type, with an electronically controlled ignition system and equipped with a throttle control.

When the engine is started, ie. with the lowest occurring speed, the ignition occurs at a time that is adapted to this speed.

If the speed increases, the ignition time must be shifted to a previous ignition position. This is achieved with the switch 13, which according to the invention e.g. can be arranged in the throttle handle or in a so-called "dead man's grip". The switch is thus arranged outside the ignition system and can be mechanical, electromechanical or electronic.

In the preferred embodiment, an electrical switch, e.g. in the form of a contact affected by the movement of the throttle or by the "dead man's grip".

The invention can of course be carried out in various ways, the essential thing is that through a switch, switch etc. 461 237 can affect the timing of the ignition process. According to the invention, such an embodiment is also conceivable, in which more cores with trigger windings are arranged for stepwise connection after start-up for achieving things acceleration to operating speed. The embodiment according to the figure is thus only to be considered as an example.

Claims (2)

461 237 PATENT REQUIREMENTS Device for manual adjustment of the ignition position, especially in connection with internal combustion engine-driven hand tools such as chainsaws and the like to prevent kickback at start-up and achieve good acceleration from idle to operating condition, which hand tools are provided with control handles in the form of throttle controls or the like, characterized by in the event of actuation of the throttle control or the like and / or a so-called dead man's grip in a direction intended for obtaining an operating condition, a switch-on and disconnection (13) of one or more circuits (14, 16, 12) for higher and lower spark plugs, respectively. The setting is made so that the engine is put on standby for initiating an operating condition or transitioning to an operating condition. Device according to claim 1, in which an igniter comprises a capacitor ignition system (7-12) with charge winding (6 ') and trigger winding (5') on a multi-legged core (1), which cooperates with a magnetic system (2) for voltage pulse generation in the windings, characterized in that on a core leg (4), which lies before the core legs (6, 5) which support the charge winding (6 ') and the trigger winding (5') in the relative direction of movement (3) between magnets and a core is provided with a further trigger winding (4 '), which can be connected to the trigger circuit (16, 12) by means of a switch (13) to advance the ignition setting.