JPH0649900Y2 - Internal coil decoupling starter pressure reduction device for recoil starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used in various working machines such as a brush cutter and a power spreader having an internal combustion engine as a prime mover, and facilitates the starting operation of the internal combustion engine. The starting decompression device is characterized in that it is interlocked with the operation of a recoil starter of an internal combustion engine with a simple configuration.

The starting decompressor is a device that allows the internal pressure of the cylinder to be released by opening the exhaust valve and allowing the crankshaft to rotate easily when starting the internal combustion engine. Is provided in order to reduce the force required for it and, in the case of a self-starter, to use a small and lightweight object having a small torque as a starting motor.

[Prior Art] Conventionally, as the starting operation means of the internal combustion engine as described above,
Generally, a push button switch of a starter motor that constitutes a recoil starter or a self starter and a push button switch that opens an exhaust valve of the start decompressor are provided separately. In addition, in an engine in which a starting device for starting the engine is also provided in the engine body, and a decompression passage is formed in the cylinder block, an opening / closing valve is provided in the decompression passage, and the opening / closing valve is connected to the starting device. There has also been proposed a device (see Japanese Utility Model Laid-Open No. 63-100608) in which a pressing member that is interlocked and protrudes is provided oppositely via a transmission member.

[Problems to be solved by the invention] Therefore, particularly when starting an internal combustion engine with a recoil starter, the recoil rope must be pulled out with the other hand while pressing the push button switch of the starting pressure reducer with one hand. There was a drawback that it was extremely difficult to operate.

As a countermeasure against this, a device for interlocking a starting pressure reducer with the above-mentioned engine starting device has been proposed, but further reduction of the number of parts and operating space, simplification of structure and weight reduction, and reliability of operation, etc. There was a request left.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a device which has a simple structure and can surely automatically open the exhaust valve of the starting pressure reducer in synchronization with the operation of pulling out the recoil rope.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention forms a tooth profile on the outer peripheral surface of a recoil reel and provides a space between the recoil reel and a starting pressure reducer provided in a cylinder of an internal combustion engine. , A base is provided with a swing lever which is pivotally supported by an axis parallel to the rotation axis of the recoil reel and which repeatedly swings within a predetermined angle range, and the outer periphery of the base of the swing lever is engaged with the tooth profile of the recoil reel. The start decompression is performed by the rotation of the recoil reel when pulling out the recoil rope wound around the recoil reel, at the swing end of the swing lever opposite to the shaft, while forming a tooth shape to be fitted. The configuration is such that an operating portion for opening the exhaust valve of the container is provided.

[Operation] According to the present invention, when the recoil rope 13 is pulled out, the recoil reel 15 is rotated in the clockwise direction as shown in FIG. 3, and the tooth profile 16 provided on the outer peripheral surface of the recoil reel 15 is rotated. By the toothed shape 23 on the pivot side of the rocking lever 20 meshed with the rocking lever 20, the rocking end of the rocking lever 20 is rotated within a predetermined angle range in the direction opposite to the rotation direction of the recoil reel 15. As a result, the operating portion 24 formed at the swing end of the swing lever 20 presses the outer end head portion 11 of the exhaust valve 6 that constitutes the starting pressure reducer 4, the exhaust valve 6 is opened, and the inside of the cylinder 2 becomes
The air is communicated with the outside air through the ventilation groove 5 between the exhaust valve 6 and the exhaust valve support 8 and the narrow communication hole 7 of the exhaust valve support 8.

As a result, the rotation of the crankshaft 18 is facilitated, and the internal combustion engine 1 can be reliably started with a small force.

Further, when the handle 14 of the recoil rope 13 is released, the spiral spring 17 causes the recoil reel 15 to reversely rotate and return, and the recoil rope 13 is rewound,
Since the swing lever 20 is also configured to be repeatedly swung within a predetermined angle range, the swing lever 20 is returned to the initial position, and the exhaust valve 6 constituting the starting pressure reducer 4 is also automatically returned by the coil spring 10 to be closed. The internal combustion engine 1 continues a normal operating state.

As described above, in the present invention, it is possible to synchronize the opening of the exhaust valve that constitutes the starting decompressor with a single operation of pulling the recoil rope, and a separate push button switch or the like for the exhaust valve opening operation is provided. It becomes unnecessary, and even when the pressure reducing device is interlocked with the start of the engine, as in the above-mentioned conventional technology, a driven member, a pressing member including a flyweight, a rod, a transmission member such as a lever is not required, The starting operation of the internal combustion engine can be easily performed only by the rocking lever 20.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 1 is an air-cooled two-cycle internal combustion engine that is a prime mover of various working machines such as a brush cutter and a power spreader, and 2 is a cylinder thereof.

A through hole 3 is provided at an appropriate position on the upper portion of the cylinder 2 that does not hinder the activation, and a starting pressure reducing device 4 is arranged so as to normally block the through hole 3.

In the embodiment shown in the drawings, the starting decompressor 4 is fitted with an exhaust valve 6 having a ventilation groove 5, and the exhaust valve 6 is fitted therein. When the exhaust valve 6 is opened, the cylinder 2 is communicated with the outside air through a narrow communication. It is composed of an exhaust valve support 8 having a hole 7 facing downward, a stopper 9 provided at an outer end of the exhaust valve 6, and a compression coil spring 10 interposed between the stopper 9 and the exhaust valve support 8. Further, the head 11 of the exhaust valve 6 is projected outward from the stopper 9.

Next, the recoil starter 12 will be described. Reference numeral 13 is a recoil rope, and as shown in FIG. 2, a handle 14 having a substantially inverted T-shape 14 so that an operator can easily pull it out to the tip pulled out to the outside. Is provided. 15 is a recoil reel around which the recoil rope 13 is wound, and a tooth profile 16 is formed on the outer peripheral surface of the inner flange thereof. 17 is a spring spring for returning the recoil reel 15, 18 is a crank shaft, 19 is the recoil reel
A centrifugal ratchet claw for transmitting the rotation of 15 to the crankshaft 18.

In the above configuration, hold the handle 14 to recoil the rope.
When 13 is pulled out, the recoil reel 15 is rotated, the crankshaft 18 is rotated via the centrifugal ratchet pawl 19, and the internal combustion engine 1 is started.

After the internal combustion engine 1 is started, the centrifugal ratchet pawl is
The engagement of 19 is automatically disengaged, the space between the recoil reel 15 and the crankshaft 18 becomes free, and if the handle 14 is released, the recoil reel 15 will rotate in the reverse direction by the action of the spring 17, and the recoil rope 13 will be rewound. is there.

Next, the tuning mechanism of the starting pressure reducer 4 when the recoil rope 13 is pulled out will be described.

Reference numeral 20 is a rocking lever, and between the recoil reel 15 and the start-up pressure reducer 4 provided at an appropriate position above the cylinder 2, its base 25 has an axis 21 parallel to the rotation axis of the recoil reel 15. When the recoil starter 12 is not operated, it is in a predetermined position as shown by the solid line in FIG.

Further, on the outer periphery of the base portion 25, there are formed a tooth profile 23 in a sector gear shape, the number of which is meshed with the tooth profile 16 on the outer peripheral surface of the recoil reel 15 and required to rotate the swing lever 20 within a predetermined angle range. The swing end of the upper end provided on the opposite side of the shaft is synchronized with the rotation of the recoil reel 15 when the recoil rope 13 wound around the recoil reel 15 is pulled out, and Operation unit that opens the exhaust valve 6
24 are provided in a fan shape.

That is, when the recoil reel 15 is rotated in the clockwise direction in FIG. 3 by pulling out the recoil rope 13, the tooth profile 16 on the outer peripheral surface of the recoil reel 15 and the lower end of the rocking lever 20 meshed therewith. Due to the tooth profile 23 formed on the base, the upper end of the rocking lever 20 and the operating portion 24 provided there are counterclockwise as shown by the one-dot chain line in FIG.
The operating portion 24 is configured to press the head portion 11 of the exhaust valve 6 by being rotated within a predetermined angle range until the tooth profiles 16 and 23 are disengaged.

Therefore, the exhaust valve 6 is opened as shown in FIG.
Vent groove 5 of exhaust valve 6 and exhaust valve support 8 in cylinder 2
The pressure is released by communicating with the outside air through the communication hole 7 and the crankshaft 18 is easily rotated, so that the internal combustion engine 1 can be started with a small operating force.

After that, when the hand is released from the handle 14 of the recoil rope 13, the recoil reel 15 reversely rotates and returns by the action of the spiral spring 17, and at the same time, the tooth profiles 16 and 23 of the both are meshed again, and the swing lever 20 is also shown in FIG. Also, since it is configured to be repeatedly swung within the predetermined angle range to the predetermined position shown by the solid line in FIG. 3, it returns to the initial position and prepares for the next start.

Further, the pressure on the head portion 11 of the exhaust valve 6 which constitutes the starting pressure reducer 4 is released, and the exhaust valve 6 is closed by the action of the coil spring 10, so that the internal combustion engine 1 continues the normal operating state.

The operation timing and the swing range of the swing lever 20 can be arbitrarily set depending on the number of the tooth profiles 16 and 23, the disposition position of the stopper (not shown), and the like.

According to the present invention, the opening operation of the exhaust valve of the starting decompressor can be synchronized with the single operation of pulling the recoil rope, and the push button provided separately for the opening operation of the exhaust valve. A switch or the like is not necessary, and the starting operation of the internal combustion engine can be achieved with a very simple structure in which only a rocking lever is provided.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an essential part, FIG. 2 is a side view of the same, and FIG. 3 is an explanatory view showing a turning state of a swing lever, and FIG. FIG. 4 is an enlarged sectional view of an essential part showing an opened state of an exhaust valve. 1 ... Internal combustion engine, 2 ... Cylinder, 4 ... Starting pressure reducer,
6 ... Exhaust valve, 9 ... Coil spring, 13 ... Recoil rope, 15 ... Recoil reel, 16 ... Tooth profile, 20 ... Oscillating lever, 21 ... Shaft, 23 ... Tooth profile, 24 ... Operating part , 25 …… Base.

Claims (1)

[Scope of utility model registration request] 1. A tooth profile 16 is formed on an outer peripheral surface of a recoil reel 15, and the recoil reel 15 and a cylinder 2 of an internal combustion engine 1.
A swing lever 20 is provided between the start decompressor 4 and the start decompressor 4, and a base 25 is pivotally supported by a shaft 21 parallel to the rotation axis of the recoil reel 15 to repeatedly swing within a predetermined angle range. A tooth profile 23 that meshes with the tooth profile 16 of the recoil reel 15 is formed on the outer periphery of the base portion 25 of the moving lever 20, and at the swing end of the swing lever 20 opposite to the shaft 21, The internal combustion engine 1 is provided with an operating section 24 for opening the exhaust valve 6 of the starting pressure reducer 4 by rotating the recoil reel 15 when the recoil rope wound around the recoil reel 15 is pulled out. Recoil starter interlocking start decompression device.