JPH0132517Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a braking device for the cutting blade of an internal combustion lawn mower that rotates the cutting blade using an internal combustion engine as the prime mover. This invention relates to a drum brake type braking device that stops a cutting blade rotating after inertia.

In the case of the above-mentioned drum brake system, the space around the flywheel is limited by the cooling air passage or auxiliary equipment such as the air cleaner, muffler, fuel tank, starter motor for starting the engine, etc. In particular, the starter motor and brake shoe are located at approximately the same location. I often have trouble installing the brake shoe.

The purpose of this invention is to solve the above-mentioned problems with the drum brake type braking device for power lawn mowers. The gist is that the starter motor is commonly supported by the pedestal on which the starter motor is mounted, and the starter motor mounting pedestal is fixed to the engine body.

To specifically explain the structure of the embodiment shown in the drawings, FIG. 1 shows an example of a walk-behind power lawn mower to which the braking device of the present invention is applied, in which 1 is a generally disc-shaped cutting blade housing with an open bottom surface; 2 is a grass clipping storage bag connected to the discharge port at the rear of the cutting blade housing 1;
is a vertical internal combustion engine, 4 is a wheel, and 5 is a control handle.

The internal combustion engine 3 is equipped with a starter motor, an engine stop switch, and a drum brake for stopping the cutting blade.
The operation parts for the starter motor, engine stop switch, and drum brake for stopping the cutting blade, that is, the start switch 6, and the operation lever 7 that is used commonly for the engine stop switch and the drum brake, are centrally arranged in the grip part of the handle 5. As long as the lever 7 is held together with the engine stop switch 8 (shown in the third diagram)
When the drum brakes 12, 14 for opening and stopping the cutting blades are kept in the released state and the handle 5 and lever 7 are released, the switch 8 is closed and the ignition circuit of the engine is grounded, and the drum brakes 12, 1 are kept in the released state.
4 is configured to work.

As shown in FIGS. 2 and 3, the starter motor 9 of the internal combustion engine 3 is suspended from the lower surface of a pedestal 11 attached to the upper end of the crankcase 10 so as to extend laterally. A starter pinion 91 of the starter motor 9 protrudes from the upper surface of the base 11 and is removable from a ring gear 121 on the outer periphery of a flywheel 12 that is integrated with the crankshaft.

A brake shoe attachment fulcrum shaft 13 stands on the upper surface of the pedestal 11, and one end of a brake shoe 14 that comes into contact with and separates from the outer peripheral surface of the flywheel 12 is rotatably mounted on the fulcrum shaft 13. A torsion coil spring 15 is provided between the brake shoe 14 and the base 11 to maintain the brake shoe 14 in pressure contact with the flywheel 12.

A brake cam 16 that acts on the free end of the brake shoe 14 is attached to a shaft 1 that stands on the upper surface of the pedestal 11.
7 and is rotatably supported. An arm 161 is integrally formed at the lower end of the brake cam 16, and the arm 161 and the brake lever 7 on the handle 5 are connected with a wire 18. The engine stop switch 8 is placed beside the arm 161, and is opened and closed by the swinging of the arm 161. 19 is the outer tube 18 of the wire 18
1 is a bracket for supporting and fixing the end fitting 182 to the engine body; 20 is a cover that covers the side surfaces of the starting motor 9 and the brake shoe 14; 21 is a fuel cover placed on the side of the flywheel 12 and covered with the top cover 22 of the engine; Tank 23 is a brake wire return spring.

In the figure, the internal combustion engine is stopped, the engine stop switch 8 is pushed by the arm 161 and closed (grounded), and the brake shoe 14 is pressed against the outer peripheral surface of the flywheel 12 by the force of the spring 15. .

When the control handle 5 is squeezed together with the brake lever 7, the brake wire 18 is pulled, the brake arm 161 and the brake cam 16 swing as shown by the chain line, the engine stop switch 8 opens, and the brake shoe 14 moves to the flywheel. away from the outer peripheral surface of 12. When the start switch 6 is closed in this state, the starter motor 9 is activated, the pinion 91 is engaged with the ring gear 121, and the engine is started.

When the user releases the control handle 5 and the brake lever 7, the ignition circuit is automatically grounded by closing the switch 8, and the brake shoe 14 is pressed against the flywheel 12 to immediately stop the inertially rotating cutting blade.

The braking device of the present invention is a drum brake type braking device for cutting blades of a power lawn mower as described above, in which a brake shoe placed around the flywheel 12 is attached to a starter motor for starting the engine, which is also placed beside the flywheel. The starting starter motor and the brake shoe, which must be placed around the flywheel, are commonly supported on a single pedestal, and the starter motor mounting pedestal is fixed to the engine body. As a result, the starter motor and brake shoe are compactly integrated into one assembly, and the brake shoe can be easily installed even if the space around the flywheel is limited by the installation of the starter motor for engine starting. effective.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a power lawn mower to which the braking device of the present invention is applied, FIG. 2 is a front view of the braking device of the present invention, and FIG. 3 is a plan view thereof. 9 is a starter motor, 10 is a crank case, 11
is the pedestal, 12 is the flywheel, 14 is the brake shoe, 16 is the brake cam, and 18 is the brake wire.

Claims (1)

[Scope of utility model registration request] In power lawn mowers, the brake shoe is placed around the flywheel of an internal combustion engine to stop the cutting blade rotating inertia after the engine has stopped by pressing the brake shoe against the outer circumferential surface of the flywheel of the internal combustion engine.
A braking device for a power lawn mower in which a starter motor for starting the engine, which is also placed beside the flywheel, is commonly supported by a pedestal, and the starter motor mounting pedestal is fixed to the engine body.