JPH0528604U - Chain saw braking device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a chain saw brake device that can release the automatic brake with one-touch operation in a work environment where malfunctions are likely to occur, thus ensuring work safety and ease. . [Structure] In a chainsaw having an automatic braking device that is actuated by kickback reaction force, an automatic brake releasing means such as a pin, a plate member, a cam mechanism, etc. that blocks the braking force of the automatic brake by a deterrent force stronger than the kickback reaction force Was established.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chain saw braking device that saws trees and timber, and more particularly, to a chain saw braking device that can release the automatic brake according to the sawing work environment to improve work safety and efficiency. ..

[0002]

[Prior Art]

 Chainsaws, which perform sawing work on trees and timber, are equipped with manual brakes to protect the face and hands from kickbacks during work. The manual brake is attached to the front part of the chain saw body, and is configured so that the chain drive is stopped by, for example, tilting the lever of the manual brake forward.

By the way, in recent years, in order to improve the safety of sawing work, an automatic brake has been adopted. The automatic brake described above is configured such that the brake operates by utilizing a reaction of the brake caused by kickback.

[0004]

[Problems to be solved by the device]

 With a chainsaw equipped with an automatic brake as described above, when sawing a branch of a tree that prospered, the automatic brake sometimes worked by hitting another branch. In particular, this type of chain saw often saws the lower branches that have climbed up trees and proliferated, often resulting in a physical accident due to a malfunction and a significant reduction in workability.

The present invention has been made in view of the above points, and in an operating environment where malfunctions are likely to occur, the automatic brake can be released by a one-touch operation, which improves work safety. The purpose is to provide a brake device for a chainsaw that can ensure ease.

[0006]

[Means for Solving the Problems]

 This invention is a chain saw equipped with an automatic braking device that is actuated by kickback reaction force to achieve the above-mentioned object. It is a brake device for a chainsaw characterized by having means.

[0007]

[Action]

 In the embodiment, in the normal use in which the automatic brake releasing means C is not operated, when the safety brake 3 is pushed forward or the safety rake 3 is pushed slightly forward by the kickback reaction force, the safety brake 3 is integrated with the safety brake 3. The lever 6 rotates clockwise about the pin as a fulcrum by the mechanical pin. Then, the tip of the link 7 connected to the tip of the lever 6 with a pin is pulled downward.

At this time, the tip of the link 7 is connected to the link, and the link moves counterclockwise about the pin as a fulcrum as shown in FIG. 3, so that the other end of the link 7 moves forward and the break spring is moved. Will be extended. As a result, the brake band connected to the other end of the brake spring is pulled by the extension force of the brake spring and the clutch drum is tightly tightened, and the braking force acts to stop the rotating cutting chain.

When the pin which is the automatic brake releasing means C is pulled out as shown in FIG. 2, the lever 6 slightly moves counterclockwise about the pin as a fulcrum. Then, the tip of the link 7, which is connected to the tip of the lever 6 by a pin, is pushed up slightly. In this state, the braking transmission means A is strongly urged upward, and even if the kickback reaction force is transmitted to the braking transmission means A, the lever 6 does not move downward and is automatically driven. The brake does not work. If the safety brake 3 is tilted forward by hand, the braking transmission means A operates normally and the cutting chain stops.

[0010]

【Example】

 Hereinafter, an example of implementation of a brake device for a chainsaw according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing a braking device such as a braking link means, a clutch drum, etc. arranged inside a clutch cover. 2 is a front view showing a state in which the automatic brake is released in FIG. 1, and FIG. 3 is a front view showing a braking state in FIG. 4 to 7 are cross-sectional views showing each part of the brake device, and FIG. 8 is a perspective view with a part of the chainsaw omitted.

In FIG. 9, reference numeral 1 denotes a housing molded in a hollow structure made of hard synthetic resin. A top handle 2 molded of the same material is attached to the upper portion of the housing, and a safety brake 3 is attached to the front surface of the housing. A front handle 4 is attached.

A cylinder chamber, a carburetor chamber, a fuel tank chamber, an oil tank chamber and the like (not shown) are formed in the housing 1 having a hollow structure. An air intake port is formed on one side surface and a clutch is provided on the other side surface. It is opened for mounting, etc., and has a cylinder, a cooling fan, a chain sprocket, a clutch, etc. built therein, and the other side surface is closed by a clutch cover 5.

The chain saw brake device according to the present invention is disposed inside the clutch cover 5. As shown in FIGS. 1 to 3, the braking device is composed of a braking transmission means A, a brake band means B and an automatic brake releasing means C, and is arranged in a brake chamber 5a formed inside the clutch cover 5. It

The braking link means A transmits the braking command operation from the safety brake 3 to the brake band means B, and the lever 6 and the link 7 constitute a main member. The braking link means A is strongly urged outward (up and down) on both sides by a brake spring that tries to extend from the right side when the neutral link is removed. The lever 6 has a branch plate 6a extending in a V shape, one end of which is pivotally supported by the clutch cover 5 by a pin 8 and the other end of which is connected to the link 7, and the branch plate 6a is It engages with the pin 3b of the safety brake 3.

The pin 8 that pivotally supports the lever 6 is pivotally supported by the clutch cover 5 and the inner cover 10, as shown in FIG. The inner cover 10 separates each member arranged on the clutch cover 5 side from an internal combustion chamber (not shown) in the housing 1.

The link 7 whose one end is connected to the lever 6 has a stopper 7 a bulging in the lower part, so that the other end is connected to the spring holder 11.

The spring holder 11 is disposed above the inside of the clutch cover 5 and has a built-in brake spring 15. The brake spring 15 has a front end fixed to the holder and a rear end connected to one end of the brake band 16. The brake band 16, one end of which is connected to the brake spring 15, makes one round around the outside of the clutch drum 17 with a small gap g formed, and the other end is fixed to a pin 24 planted in the clutch cover 5.

The clutch drum 17 is rotatably supported by a shaft 18 on the output side of an internal combustion engine (not shown). A sprocket wheel 20 that drives a cutting chain 19 is attached to the shaft 18, and the cutting chain 19 is rotated by an internal combustion engine.

The automatic brake releasing means C is, for example, a pin 21 having a simple structure as shown in FIGS. 1 and 4, and by pulling out the pin 21, only the reaction force P of the kickback, which is not relatively strong. The braking force transmitting means A does not work, but the deterrent force P ₁ works. As described above, the restraining force P ₁ stronger than the kickback reaction force P is exerted by the spring or the like having an upward biasing force as shown in FIG. Further, in the case of manual braking, the force P ₂ which is stronger than the restraining force P ₁ of the braking force transmitting means A is used.

In the embodiment, the insertion type pin 21 is used as the automatic brake releasing means C, but an insertion type plate material, an inversion type plate material, a slide type plate material, or a cam mechanism or the like can be adopted. . Further, it is possible to provide a notch on the side of the brake band means B with which the automatic brake releasing means C is fitted. That is, when the automatic brake for normal use is activated, the braking force transmission means A is positioned at the neutral position so as to be acted upon by the reaction force of the kickback. In addition, when climbing a tree and cutting off a thickened lower branch, the braking force transmission means A is compared by using the depressing force P ₁ of the automatic brake release procedure C in order to avoid a malfunction. Make sure that the braking force does not work with the kickback reaction force P that is weak.

In the above-described embodiment, when the automatic brake releasing means C is not operated, the safety brake 3 is pushed forward or the safety rake 3 is pushed slightly forward by the reaction force of kickback, so that the safety brake 3 is pushed forward. A lever integrated with the brake 3 causes the lever 6 to rotate clockwise about the pin as a fulcrum. Then, the tip of the link 7 connected to the tip of the lever 6 with a pin is pulled downward. At this time, the tip of the link 7 is connected to the link, and the link moves counterclockwise about the pin as a fulcrum as shown in FIG. 3, so that the other end of the link 7 moves forward and the brake spring 15 moves. It will extend to the left in the middle. As a result, the brake band 16 connected to the other end of the brake spring 15 is pulled and the clutch drum is tightly tightened, and the braking force acts to stop the rotating cutting chain.

Further, when the pin which is the automatic brake releasing means C is pulled out as shown in FIG. 2, the lever 6 slightly moves counterclockwise about the pin 8 as a fulcrum. Then, the tip of the link 7, which is connected to the tip of the lever 6 and the pin 12, is pushed up slightly. In this state, the braking transmission means A is strongly urged upward, and even if the reaction force due to kickback is transmitted to the braking transmission means A, the lever 6 does not move downward and the automatic brake is activated. Absent. If the safety brake 3 is tilted forward by hand, the braking transmission means A operates normally and the cutting chain stops.

As described above, the chain saw brake device according to the present invention is provided with the brake device that is actuated by the kickback reaction force, and the braking force of the automatic brake is increased by the deterrent force stronger than the kickback reaction force. It is equipped with an automatic brake release means to prevent it, and its operation can be done with one touch. Therefore, when climbing a tree and cutting through a thickened lower branch, the automatic brake can be released to avoid erroneous operation of the automatic brake, and safe and efficient sawing work can be performed.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which an automatic brake can be operated in an example of implementation of a brake device for a chainsaw according to the present invention.

FIG. 2 is a front view showing a state in which an automatic brake is released according to a work environment.

FIG. 3 is a front view showing a state of a braking link means during braking.

4 is a perspective view of a pin as an example of automatic brake releasing means C. FIG.

5 is a plan sectional view showing a state of being cut along the line EE in FIG.

FIG. 6 is a plan sectional view showing a state of being cut along the line of FIG.

FIG. 7 is a cross-sectional view showing a state of being cut along the line of FIG.

FIG. 8 is a cross-sectional view showing a state of being cut along a line II in FIG.

FIG. 9 is a perspective view of a chainsaw incorporating the chain saw brake device according to the present invention.

[Explanation of symbols]

 1 Housing 3 Safety Brake 5 Clutch Cover 6 Lever 7 Link 8 Pin 9 Coil Spring 10 Inner Cover 11 Spring Holder 13 Pin 15 Brake Spring 16 Brake Band 17 Clutch Drum A Braking Transmission Device B Brake Band Device C Automatic Brake Release Device

Claims (1)

[Scope of utility model registration request] 1. A chain saw provided with an automatic brake device that is actuated by kickback reaction force, wherein automatic brake release means is provided to prevent actuation of the automatic brake by a deterrent force that is stronger than the kickback reaction force. Braking device for chainsaws.