JPS5854641B2 - Chainsaw braking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is activated by sudden fluctuations detected by the horizontal rod of a sensing lever disposed in front of the front bundle in the event of a kick-pack phenomenon or other accident of the chenosaw, and It is an object of the present invention to provide a simple emergency braking means suitable for rapidly stopping the drive.

FIG. 1 shows a main part of a side view of a chenosaw according to the present invention, and FIG. 2 shows a detailed front view of a braking device according to an embodiment of the present invention.

FIG. 3 shows a side view of FIG. 2.

The chain shown in FIG. 1 is equipped with a rear bundle 3 at the rear of a main body 1 that mainly includes an engine 2, and a front bundle 4 that surrounds one side of the main body 1 from the outside to the upper side. There is.

The engine 2 is supported by the frame of the main body 1 including the bundles 3 and 4 in a vibration-absorbing manner.

On one side of the output shaft 5, the saw chain is positioned around the outer periphery of the guide plate 9 by means of a sprocket (not shown) attached to the clutch drum 6 of the centrifugal clutch device.

Since these parts of the saw chain driving device are exposed on the outside of the main body 1, the outer cover γ is fastened to the main body 1 together with the guide plate 9 by bolts and nuts 8.

The figure discloses an embodiment in which a device is disposed inside this outer lid 1.

The device of the present invention includes a base column 11 in which a braking band 10 made of spring steel or the like is elastically biased in a diameter-reducing direction on the outer periphery of a clutch drum 6 and is embedded in an outer cover 7. a plurality of concentric positioning protrusions 12 provided inside the outer cover 7 along the outer periphery of the clutch drum 6.
It is encircled along the inside of...

In front of the horizontal rod part 4 of the front bundle 4 of the main body 1, there is a horizontal rod body 13' substantially parallel to the horizontal rod part 4, and a sensing lever 13 is provided on the side surface of the main body housing so as to be swingable by a support shaft 14. .

A hook 15 is provided near the shaft portion of the lever 13, and a restoring spring 16 is wound around the shaft 14 to urge the lever 13 to rotate counterclockwise.

A stopper projection 17 is provided on the front edge of the outer cover 7 to limit the tilting of the lever 13.

Next, the expansion/contraction operation link 18 connecting the other end 10b of the band 10 and the sensing bar 13 is connected to the shaft 1 of the sensing lever 13.
4, it is made swingable by a shaft 19.

The operating link 18 is connected to the other end 10b of the band 10 by a pin 20 at one end thereof, and pins 21 and 22 are provided on the opposite side of the shaft 19, and the sensing lever 13 is hooked to the protrusion 1.
5 and can be disconnected from it at will.

Further, a stopper 23 is provided on the outer cover 1 to restrict the operation of the operating link 18.

The solid line layout diagram in FIG. 2 shows the device in a non-braking state, but the operating link 18 is locked to the stopper 23 and the pin 2
Since the other end 10b of the band member 10 is located outside the tangent line 01-02 formed between the center 02 of the shaft 19 of the operating link 18 and the contact point 01 of the band member 10 with the clutch drum 6, it is possible to keep it stationary. can.

At this time, the band 10 is inscribed in and expanded by the protrusions 12 disposed around its outer periphery, while maintaining a concentric state with the clutch drum 6. I am able to do that.

This effect is due to the fact that the band 10, which is elastically biased in the direction of diameter reduction, is forced to expand.

As a result, a constant gap from the clutch drum 6 can be maintained, and the operation of the chain saw will not be hindered.

Next, the braking operation will be explained.

For example, if a chain saw causes a kickback phenomenon, the guide plate 9 is strongly kicked upward and the machine tilts upward for a moment, and the hand and neck that grips the front handle 4 touch the sensing lever horizontal rod 1.
3 will cause the sensing lever 13 to tilt forward.

As a result, the lever 13 is hooked by the protrusion 15 pushing up the pin 21 of the operating link 18 and moving the operating link 18 in the direction of the hour hand.
Rotate.

At this time, the other end 10b of the band 10 that is engaged with the pin 20 is once pushed in the expansion direction, while the pin 20 is moved inside the 01-02 line.

As a result, the actuating link 18 becomes free to rotate, so that the band 10 is automatically tightly attached to the outer diameter of the clutch drum 6 by its own diameter-reducing elastic force.

Furthermore, since the band 10 is wound around the clutch drum 6 in the rotational direction, the tightening action is more effective.

This operating state is shown by the phantom line in FIG.

In this case, the forward tilt of the sensing lever 13 is caused by the stopper protrusion 17
limited by.

Since the above-described operation sufficiently brakes the saw chain, the operator can safely decelerate the throttle or stop the engine.

Next, to restore this operation, if the lever 13 is manually pulled back toward its original position, the back side of the protrusion 15 pushes the pin 22 of the operating link 18 in the counterclockwise direction and rotates the operating link 18. The band member 10 expands its diameter under the expansion force and separates from the outer periphery of the clutch drum 6 to release the braking state, and the pin 20 moves along the tangent line 0. - reaches the outside of 02, operating link 1
8 comes into contact with the stopper 23 and stops, keeping the band 10 in an unbraked state.

This braking interlocking device operates against the elastic biasing force of the band 10 to store braking force.

At this time, the sensing lever 13 is restored in the counterclockwise direction by the spring 16, and the protrusion 15 of the hook comes into contact with the pin 21 and remains stationary, completely returning to the restored state.

Conventional braking devices usually use dedicated springs for each attached interlocking member, such as a braking energizing spring, an operating link, or a trigger device, but this increases the number of parts and complicates the structure. It has the disadvantage of requiring space and volume.

The braking device according to the present invention elastically biases the braking band itself in the diameter-reducing direction to provide the effect of a conventional braking spring, while also exerting a spring action on the operating link etc. due to the drag force of the band. The present invention is characterized in that it can be used in combination as a biasing force for holding the brake release position, and as shown in the drawings, it has a simple structure and is light in weight, making it a great contribution as a brake device for chain saws.

Although this embodiment discloses an example in which the clutch is disposed on the outer cover of the centrifugal clutch device, it is also possible to dispose it on the main body side as well.

[Brief explanation of drawings]

Fig. 1 is a side view of the main parts of a chainsaw in which the present invention is implemented, and Fig. 2 is a front view showing the entire appearance of a braking device according to an embodiment of the present invention. FIG. 3 is a side view of FIG. 2, showing the state of the transverse rod of the sensing lever. 6... Clutch drum, 10... Brake band, 13... Sensing lever 18...
Scaling link.

Claims (1)

[Claims] 1. In a portable power chain saw that drives a saw chain via a centrifugal clutch device disposed on one side of the output shaft 5, the outer periphery of the clutch drum 6 of the clutch device is placed inside a plurality of concentric positioning protrusions 12, 12° 12. The front bundle 4 disposed on the main body 1 is elastically biased in the direction of diameter reduction, and one end 10a is surrounded by a braking band 10 secured to the main body 1 of the chenosaw. A sensing lever 13 is provided on the side surface of the main body 1 with a support shaft 1, which has a horizontal rod body 13' projecting from the side of the upper end, which is located in front of the horizontal rod portion 4' and is approximately parallel to the horizontal rod portion 4'.
4, the lever 13 is pivotably supported by a shaft 19, and a hook 15 is provided near the pivot of the lever 13 to connect the other end 10b of the band 10 to one side end, and the intermediate part is pivotably supported by a shaft 19. It is provided so as to hook and interlock with the other end of the supported expansion/contraction operation link 18, and when not braking, the other end 10b of the band 10 is connected to the center Q2 of the shaft 19.
and the contact point 01 of the belt member 10 with the clutch drum 6.
1-02.