JPH0211865A - Starter device for small two-cycle engine - Google Patents

Abstract

PURPOSE:To enable the smoothness to be attained in starting of an engine and eliminate its starting in a non-lubricated condition by performing a dis charge of spark plug after the predetermined time, after a crankshaft is driven rotating by a self-starting. CONSTITUTION:A flange 25A of a stop control switch rod 25 is pressed in by a flange piece 16B of a control knob, and a movable contact 23 is brought into contact with a fixed control 21, closing a short-circuit switch. Hence, a generated current in the primary side of a magneto is connected to the earth, performing no ignition, but mixed oil is sucked into an engine by rotating a crankshaft, lubricating a friction part. Next returning the knob by a spring 14, the contact 23, after starting of the motor, is detached from the contact 21 with a delay of about 1 second by a damper function in a cylinder 24, that is, a delay means operates opening the short-circuit switch, then a spark for the first time is generated in a spark plug being ignited. Accordingly, an engine speed increases to about 1,000rpm, when it is stabilized by inertia of rotation also with a mixture stably supplied, the spark plug 30 is ignited so that the engine is surely started.

Description

[Detailed description of the invention]

r Industrial Application Field] This invention relates to a starting device for a small two-stroke engine,
More specifically, the present invention relates to making it easier to start a small two-stroke engine used in a portable working machine such as a brush cutter or a power sprayer, and to improving a starting device that improves lubricity during starting.

[Conventional technology]

It is well known that most of the small engines used as the power source for portable working machines such as brush cutters and power sprayers are two-stroke engines, and a beam coil starter is used as a starting device for these types of engines. However, recently, a starting device using a starter motor has been proposed for the purpose of facilitating the starting operation. This applicant had also previously proposed a starting device using a starter motor (for example, in Japanese Patent Application No. 62-181
No. 997). This type of starting device uses external power to drive the crankshaft, which moves the piston. In particular, many two-cycle engines use a lubrication system that uses mixed oil, so starting is relatively difficult. In addition, in this type of engine, when the engine is not rotating, there is not enough lubricating oil in the cylinder, so when starting the engine after it has been in a dormant state for a long time, The piston is supposed to rotate under non-lubricated conditions. Although it is not intended to improve engine lubrication, it controls the supply of fuel at startup so that the air-fuel mixture is supplied and ignited only after the engine speed reaches a predetermined number of revolutions. A starting device (Japanese Patent Publication No. 50-2776) is known that facilitates this, but this is designed to improve lubricity by preventing raw scum from being released when starting the Kallin engine. isn't it.

[Problem to be solved by the invention]

It is relatively difficult to start the small two-stroke engine starting device as mentioned above, and driving the piston before fuel is supplied with the mixed oil increases the starting load, making it difficult to use a starter motor with a large output. This resulted in the problem of making the small two-cycle engine itself larger and heavier. Therefore, this invention makes it easier to start the engine by igniting the spark plug after the engine rotation has stabilized after a predetermined period of time, and also supplies lubricating oil between the piston and cylinder and further to the crankshaft. The aim is to provide a starting device that ignites and increases the rotational speed after the engine is activated.

[Means to solve the problem] In order to achieve the above-mentioned objects, the present invention comprises means for turning on a starting switch of a starter motor, a short-circuiting means that is turned on in conjunction with the starting switch and grounding the discharge current of the spark plug, and this short-circuiting means. The present invention is characterized in that it includes a delay means that turns off after a predetermined period of time, and is configured such that the ignition voltage of the ignition plug is applied to the ignition plug with a delay after the engine is driven by the starter motor. [For production]

For a while after operating the starter motor switch, the primary ignition current generated in the magneto is grounded and no spark is generated at the ignition plug, but the rotation of the crankshaft increases, e.g.
After the rotation of the engine has stabilized due to the rotational inertia after increasing to around 000 rpm, the ignition current is grounded and ignited.

【Example】

Embodiments of the present invention will be described below with reference to the accompanying drawings. In these figures, numeral 10 indicates a starter motor;
A pinion 12 is attached to the output shaft 11, and the starter motor 0 is pivotally connected to a component of the engine by a pivot 13, and the pinion 12 moves in a partial circle and meshes with a ring gear to be described later. It is now possible to move in and out. One end of a return spring 14 is locked to an operation knob (to be described later) for pushing in the starter motor 0, giving it the ability to rotate in the return direction. One end is working and the cell motor is 0.
When the pinion 12 is pushed past the recursion point, the pinion 12 meshes with the ring gear, and in the region that does not exceed the recursion point, the pinion 12 acts in a direction to separate it from the ring gear. The starter motor 0 has an operation knob 16 as a starting operation means.
is provided via a pivot 13, and this operating knob 16 is seen through a window hole 17A of a cover 17 that appropriately covers the engine body, and the operating knob 16 has a flange piece 16B that extends from this. It is designed to work in conjunction with an engine stop switch, which will be described later. Electric contacts 18A and 18B are provided on the circumferential surface of the starter motor 0, and both contacts 1 are provided on a contactor 16X provided on the inner surface of the operating arm 16C provided integrally with the operating knob 16.
Power is supplied when 8A and 18B touch. The pinion 12 can be engaged with or disengaged from a ring gear 19 provided at the end of the crankshaft 19A, and is engaged only when the engine is running, and is disengaged after starting or when stopped. An engine stop operation switch 20 is disposed adjacent to the operation knob 16 for starting the engine, and the power supply circuit 31 of the ignition plug 30 is closed by closing the contact of the switch.
A movable contact 23 is placed at an appropriate distance from the fixed contact 21 to act as a buffer via a spring 22. The end of the spring 22 is fixed to a flange 25A formed on the outer end of a rod 25 housed in the chamber 24A of the cylinder 24 provided in the covering 17, and the rod 25 The movable contact 23 is connected to the fixed contact 2 by the spring 26.
A movement habit is given in the direction away from 1. The inner end of the rod 25 is connected to the piston 2 within the chamber 24A of the cylinder 24.
A small communication hole 25T is bored in the screws 1 to 25B to communicate the two chambers partitioned by the screws 1 to 25B. There is a partition wall 24X having a through hole 24T in the center of the cylinder 24, and a piston 27A of the stop operation knob 27 is accommodated in a chamber 24B opposite to the chamber 24A that accommodates the piston 25B. The air damper is configured as a delay means that is given a return behavior and has an interlocking relationship with the activation means. Therefore, when the stop operation knob 27 is pushed against the elasticity of the spring 27B, the air in the chamber 24B is compressed and the through hole 24 is compressed.
It is sent from T to the adjacent chamber 24A, and the screw part 25
B against the spring 26 and move the movable contact 23 to the fixed contact 2.
1 to ground the ignition current. When starting the engine, pushing in the operating knob 1G causes the starter motor 10 to rotate together with the operating arm 16C around the pivot shaft 13 to engage the pinion 12 with the gear 19, and the operating knob 16 is returned by the return spring 14 to start the engine. The starter motor 10 is started by bringing the contacts 18A18B constituting the switch into contact with the contact hole 16X, and the crankshaft is driven via the ring carrier 19. However, since the flange piece 16B of the operation knob 16 pushes and moves the flange 25A provided on the rod 25 of the stop operation switch 20, bringing the movable contact 23 into contact with the fixed contact 21 and closing the short-circuit switch, the primary side of the magnet The ignition current that is generated is grounded and does not ignite the ignition plug, but the rotation of the crankshaft draws mixed oil into the engine and lubricates the friction parts. After the operation knob 16 is returned by the spring 14 and the starter motor 0 is started as described above, the movable contact 23 is fixed after a delay of about 1 second due to the tamper function formed in the silicator 24. Only when the contact 21 is separated, in other words, the delay means is operated and the short circuit switch is opened, does a spark fly to the ignition plug 30, and the spark plug 30 is ignited. Therefore, when the rotation of the engine increases to, for example, around 11,000 rpm, the rotation of the engine becomes stable due to rotational inertia, and the air-fuel mixture is stably supplied, the ignition plug 30 is ignited, thereby ensuring engine startup. . An example of the above-mentioned starting device is the brush cutter 8! shown in FIG.
The shoulder strap is built into the engine 41 of 40, and the shoulder strap is configured to use the battery 43 mounted on the band 42 as a power source to supply power to the pin jack 18C of the starting motor 10 via the connector built into the hanging tool 42A. The engine 41 can be started prior to the mowing work. In addition, in the above embodiment, a mechanical delay means was introduced for opening the short-circuit switch of the ignition hydrant, but as shown in FIG. An electromagnetic coil L1 is built into the time constant circuit of a resistor R1 and a capacitor C1, and a start switch S2 that is linked to 1 is built into the start switch, and when the start switch S2 is turned on, the electromagnetic coil L1 is energized to activate the short circuit switch S1. The electromagnetic coil L1 may be reset and the short-circuit switch may be opened when the capacitor C1 is saturated several seconds after the start switch is turned on and the capacitor C1 is saturated. In this case, a discharge switch S3 is used on the output end side of the capacitor C1.

【Effect of the invention】

As is clear from the above description, the starting device for a small two-stroke engine of the present invention is configured so that discharge occurs at the spark plug only after a predetermined period of time has elapsed after the starter motor drives the crankshaft. When the mixture is stable and the air-fuel mixture is supplied stably, the spark plug ignites, and after sufficient lubricant is supplied into the engine cylinder, it is ignited and the engine rotates at high speed. There is no need to start the engine, and the engine starts smoothly.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the starting device for a small two-stroke engine according to the present invention, Fig. 2 is an explanatory diagram of the same during a starting operation, Fig. 3 is an explanatory diagram of the same during starting, and Fig. 4 is another embodiment. FIG. 5 is a perspective view of a brush cutter equipped with a starting device for a small two-stroke engine according to the present invention, and FIG. 6 is a longitudinal sectional view of FIG. 1. 10... Cell motor 11... Output shaft, 12... Pinion, 13...
・Pivot 14...Spring, 15...Toggle spring, 1
6... Operating knob 16A... Pivot, 16B... Flange piece 16c... Operating arm, 16X... Contactor 17... Covering, 17A... Window hole 18A,
18B...tt=dot, 18C...pin jack 1
9...Ring gear 20...Stop operation switch 21...Fixed contact, 22...Spring, 23...
Movable contact 24... cylinder, 24A, 24B...
・Chamber 24X...Partition wall, 24T...Through hole, 25・
...Rod 25A...Flange, 25B...Piston 25T...Through hole, 26...Spring, 27...
・Stop operation knob 27A...piston, 27B...
Splash 30...Spark plug, 31...Power circuit.

Claims (3)

[Claims] (1) In a small two-stroke engine equipped with a starting device using a starting motor, a means for turning on the starting switch of the starter motor, a short-circuiting means that is turned on in conjunction with the starting switch and grounding the discharge current of the spark plug, and a means for turning on the starting switch of the starter motor; A starting device comprising: a delay means that turns off after a predetermined period of time, and configured such that the ignition voltage of the ignition plug is applied to the ignition plug with a delay after the engine is driven by the starter motor. (2) The delay means for turning off the short-circuiting means is an air damper, and the short-circuiting means is configured to be released after a predetermined period of time has elapsed after the short-circuiting means has been turned on. Starting device for small 2-stroke engines. (3) The starting device for a small two-stroke engine as set forth in claim 1, wherein the delay means for turning off the short-circuiting means interlocked with the means for turning on the starting switch is constituted by a delay circuit.