JPS6362996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition pulse generator for an engine.

In general, the above-mentioned ignition pulse generator includes a signal rotor that is equipped with a signal protrusion on its outer periphery and rotates in conjunction with the crankshaft of the engine, and a signal rotor that is fixed at a suitable position on the engine body and ignites when the front side is crossed by the signal protrusion. However, if such a device is installed inside the engine, if magnetic noise generated from the generator or other electrical equipment inside the engine acts on the signal rotor,
The magnetic flux change in the pickup coil that should be caused by the signal protrusion of the signal rotor may become abnormal and the coil may not accurately generate the ignition pulse signal. Therefore, it is necessary to block the magnetic noise from the signal rotor. There is.

The present invention provides a signal rotor for the ignition pulse generator by simply forming a signal protrusion on the steel plate cover that covers the clutch outer of the starting overrunning clutch disposed at one end of the crankshaft of the engine. This clutch has a simple structure that allows it to be used both as a means for magnetic shielding against magnetic noise generated from the generator and other electrical equipment inside the engine. , an object of the present invention is to provide a pulse generator for ignition in an engine.

To achieve this object, the present invention provides a clutch inner rotatably supported on one end of the crankshaft, a clutch outer surrounding the clutch inner and fixed to the crankshaft, and a clutch outer interposed between the clutch inner and the clutch outer. A clutch roller constitutes an overrunning clutch, and in an engine in which a starter motor is linked to the clutch inner so that the crankshaft is driven by the starter motor via the overrunning clutch, the clutch outer is covered with a steel plate. The cover is fixed to form a signal rotor, and a signal protrusion is formed on the outer circumference of the cover to face a pick-up coil fixed to the engine body.The signal protrusion is formed to have approximately the same diameter as the clutch outer and is linked to the starting motor. The starting gear to
The present invention is characterized in that one side of the gear is integrally connected to the clutch inner so that one side of the gear closely opposes the side of the cover on the inside of the engine.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a crankshaft supported by a crankcase 2 of an engine, and its output torque is transmitted via primary reduction gears 3 and 4 to a speed change input shaft (not shown). The transmission is transmitted to the input member of the clutch 5, which is connected to the cylindrical shaft 6 adjacent to the outside of the gear 3.
is spline-fitted to the end of the crankshaft 1 and secured by bolts 7, and a flange 8 is integrally provided at the outer end of the cylinder shaft 6.

A clutch inner 9 is rotatably supported on the outer periphery of the cylinder shaft 6 via a needle bearing 10, and a starting gear 11 including a gear and sprocket driven by a starting motor (not shown) is integrally attached to the inner end of the clutch inner 9. It is formed.

Further, a clutch outer 12 having an inner diameter slightly larger than the outer diameter of the clutch inner 9 is fitted on the outer periphery of the clutch inner 9 between the flange 8 and the starting gear 11 . The starting gear 11 is formed to have approximately the same diameter as the clutch outer 12, and faces a side surface of the clutch outer 12 on the engine inner side of a steel plate cover 19, which will be described later.

A wedge groove 13 is formed on the inner circumferential surface of the clutch outer 12 as usual in the past, and a clutch roller 14 and a spring 15 for pressing the roller 14 toward the shallow side of the wedge groove 13 are accommodated in the wedge groove 13. be done. The clutch outer 12, clutch roller 14, clutch inner 9, etc. constitute an overrunning clutch C that transmits only the rotational torque of the starting gear 11 rotated by the starting motor to the crankshaft 1.

A circular centering recess 16 is provided on the outer surface of the clutch outer 12 , and the flange 8 fits into this recess 16 to hold the clutch outer 12 in a concentric position with the clutch inner 9 . , 12 is provided with a specified gap 17 to avoid direct contact between them. Then, flange 8 and clutch outer 1
2 and 2 are integrally connected to each other by bolts 18.

Further, the outer peripheral surface and inner surface of the clutch outer 12 are covered with a cover 19 made of a steel plate, and this cover 19 is fixed to the clutch outer 12 by caulking its outer end 19a. This cover 19 and the flange 8 close the openings at both ends of the wedge groove 13 and prevent the clutch roller 14 from coming off from the wedge groove 13.

The cover 19 is attached to the outer peripheral surface of the steel plate cover 19 fixed to the clutch outer 12 by press working.
A signal protrusion 20 having a trapezoidal cross section is formed by punching out a part of the signal protrusion 2 from the inside.
Starting end surface 20a and terminal end surface 20b in the turning direction of 0
are sheared surfaces separated from the cover 19, respectively. On the other hand, since the hem portions 20c, 20c of the signal protrusion 20 sandwiched between these end faces 20a, 20b are integrally connected to the cover 19, the rigidity of the signal protrusion 20 is extremely high. Therefore, the dimensional accuracy given during molding can be maintained for a long time without deformation. In this way, the signal rotor 2 of the ignition pulse generator 22 is controlled by the clutch outer 12 and the cover 19.
6 is composed.

The pick-up coil 21 of the ignition pulse generator 22 is mounted on its mounting base 21a at a predetermined location on the crankcase 2 so as to face the turning path of the signal protrusion 20 with a certain gap (for example, 0.3 to 0.7 mm). It is fixed with bolts 27. This pick-up coil 21 operates based on the change in magnetic flux within the pick-up coil 21 caused by the signal protrusion 20 when the signal protrusion 20 crosses the front surface of the pick-up coil 21.
A pulse signal can be generated to drive an ignition circuit (not shown).

In order to define the pulse signal generation timing of the pick-up coil 21, that is, the ignition timing, the flange 8 and the clutch outer 12 are provided with their positioning holes 2.
The relative positions in the circumferential direction of the clutch outer 12 and the cover 19 are determined by fitting the positioning pins 25 into the bolt holes 28 of the clutch outer 12.
By caulking, the relative position in the circumferential direction is determined.

A side surface of the cover 19 on the inside of the engine closely faces one side of the starting gear 11, which has approximately the same diameter as the clutch outer 12. Therefore, the magnetic shielding effect of the starting gear 11, which is generally made of iron-based material, prevents magnetic noise generated by a generator or other electrical equipment (not shown) inside the engine from acting on the signal protrusion 20 of the steel plate cover 19. can be effectively prevented.

Next, the operation of the above embodiment will be explained. In order to start the engine, when the starting motor (not shown) is activated to rotate the starting gear 11 in the normal rotational direction of the crankshaft 1, the clutch inner 9 guides the clutch roller 14 to the shallow side of the wedge groove 13 and starts the engine. As a result, the clutch roller 14 exerts a wedge action to connect the clutch inner and outer clutches 9 and 12. Therefore, the rotational torque of the starting gear 11 is transmitted to the flange 8 and the crankshaft 1 via the clutch inner and outer clutches 9 and 12, and the engine can be cranked and started.

After starting, the clutch outer 12 that rotates together with the crankshaft 1 moves the clutch roller 14 into the wedge groove 13.
Since the wedge action of the clutch roller 14 is released by guiding the clutch roller 14 to the deeper side, the connection between the clutch inner and outer clutches 9 and 12 is severed. Therefore, the clutch inner 9 can be stopped simultaneously with the stopping of the starting motor.

Further, when the ignition timing arrives as the crankshaft 1 rotates, the signal protrusion 20, which rotates simultaneously with the rotation of the crankshaft 1, crosses the front surface of the pickup coil 21, causing the pickup coil 21 to generate a pulse signal. In this case, signal protrusion 2
The starting end surface 20a and the terminal end surface 20b of 0 form a sheared surface that stands out from the outer peripheral surface of the cover 19, so when the starting end surface 20a enters the front surface of the pick-up coil 21, and the terminal end surface 20b When leaving the room, pick up coil 2.
1, the pulse generated by the pickup coil 21 has a steep waveform that is effective as an ignition signal. The ignition circuit is driven by this pulse signal, and ignition is performed in the combustion chamber of the engine.

As described above, according to the present invention, there is a clutch inner rotatably supported on one end of the crankshaft, a clutch outer surrounding the clutch inner and fixed to the crankshaft, and a clutch interposed between the clutch inner and the clutch outer. The overrunning clutch is made up of rollers,
In order to drive the crankshaft by the starter motor through the overrunning clutch, in an engine in which the starter motor is linked to the clutch inner, a signal rotor is configured by fixing a steel plate cover to the clutch outer to cover the surface thereof;
The outer periphery of the cover is formed with a raised signal protrusion that can face the pick-up coil fixed to the engine body, and the starting gear, which is formed to have approximately the same diameter as the clutch outer and is interlocked with the starting motor, is formed on one side of the gear. Since the cover is integrally connected to the clutch inner so as to closely face the inner side surface of the engine, the signal protrusion can be easily formed by press processing on the outer circumferential surface of the steel plate cover that covers the clutch outer of the overrunning clutch, and with a high yield. This can contribute to cost reduction of the ignition pulse generator. Moreover, in order to prevent magnetic noise generated from the generator and other electrical equipment inside the engine from acting on the steel plate cover with the signal protrusion, the cover is formed to have approximately the same diameter as the clutch outer and is located opposite to and close to the side surface of the cover on the inside of the engine. The magnetic noise can be effectively prevented by the magnetic shielding effect of the gear (usually formed from a magnetic iron-based material), and therefore, the overrunning clutch itself inside the steel plate cover originally generates magnetic noise. Coupled with the fact that it is not a source of magnetic noise, it is effective in preventing malfunctions due to magnetic noise in the pickup coil, and since the starting gear can also be used as a member for the magnetic shielding, it can contribute to simplifying the structure. . Furthermore, the starting gear is stationary under normal operating conditions after the engine has started and does not move relative to the pick-up coil. There is no risk that the starting gear will have an adverse effect on the change in magnetic flux.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of the main part of an engine equipped with an ignition pulse generator according to an embodiment of the present invention, and FIG.
The figure is a perspective view of essential parts of the above device. 1...Crankshaft, 9...Clutch inner, 1
1... Starting gear, 12... Clutch outer, 14
...Clutch roller, 19...Steel plate cover, 2
0...Signal protrusion, 21...Pickup coil, 22...Ignition pulse generator in the engine, 26...Signal rotor, C...Overrunning clutch.

Claims (1)

[Claims] 1 A clutch inner 9 rotatably supported on one end of the crankshaft 1, a clutch outer 12 surrounding the clutch inner 9 and fixed to the crankshaft 1, and a clutch roller 14 interposed between the clutch inner 9 and the clutch outer 12. An overrunning clutch C is constructed from the above, and in order to drive the crankshaft 1 by the starter motor through the overrunning clutch C, the clutch outer 12 is coated on the surface of the engine in which the clutch inner 9 is interlocked with the starter motor. The signal rotor 26 is constructed by fixing a steel plate cover 19, and the outer periphery of the cover 19 includes
Pickup coil 21 fixed to the engine body
A starting gear 11 is provided with a raised signal protrusion 20 that can face the clutch outer 12 and is formed to have approximately the same diameter as the clutch outer 12 and is interlocked with the starting motor. An ignition pulse generator for an engine, characterized in that it is integrally connected to a clutch inner 9 so as to do so.