JPH0723501U - Chainsaw - Google Patents

Abstract

(57) [Summary] [Purpose] Prevents dust from adhering to the saw chain from entering the centrifugal clutch near the sprocket and causing malfunction or damage. A dustproof cover 45 fitted between the centrifugal clutch 21 and a sprocket 41 via a dustproof means on a boss portion 33 of a clutch drum 31 is secured to the main body case 1 while covering the centrifugal clutch 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chain saw for cutting tree trunks, branches, roots, etc. by a saw chain that is driven by an engine to rotate an outer periphery of a guide bar protruding forward on one side surface of a main body case.

[0002]

[Prior art]

 Generally, in this type of chain saw, as shown in FIG. 1, a guide bar 3 projects forward from one side of a main body case 1 containing an engine, and is fixed between the side cover 5 and nuts 7, 7. ing. A saw chain 9 is slidably engaged with the outer periphery of the guide bar 3. A rear handle 11 is provided at the rear of the body case 1, and a front handle 13 and a guard plate 15 are provided at the front of the upper surface.

In a conventional chain saw, as shown in FIG. 4, a centrifugal clutch 21 is attached to an end portion of a crank shaft 19 of an engine in a main body case 1. That is, a clutch shoe 27, which is slidable in the radial direction, is biased toward the center of the clutch body 25, which is engaged with the crank shaft 19 via the screw 23, by a bullet 29. The boss portion 33 of the clutch drum 31 near the outer circumference of the clutch shoe 27 is rotatably fitted to the crankshaft 19 via a bearing 35, and is axially locked by a nut 37. A sprocket 41 meshing with the saw chain 9 is engaged with the outer periphery of the boss portion 33 via a spline 39.

[0004]

[Problems to be solved by the device]

 In a conventional chain saw, dust such as chips and dirt that adheres to and enters the saw chain 9 through the opening of the saw chain 9 at the front end of the side cover 5 during the work and the outer periphery of the clutch drum 31 and the main body. The centrifugal clutch 21 and the oil pump and the like entered the inside through the gap with the case 1, causing malfunction or damage.

[0005]

[Means for Solving the Problems]

 As shown in FIG. 2, the present invention is a dust-proof cover which is fitted between the centrifugal clutch 21 and the sprocket 41 on the boss portion 33 of the drum 31 through a dust seal or dust-proof means such as a dust-proof portion by centrifugal force. 45 is fixed to the main body case 1 by covering the centrifugal clutch 21.

[0006]

[Action]

 During the work, dust such as chips and dirt that adheres to the saw chain 9 and enters from the opening at the front end of the side cover 5 is prevented from entering the centrifugal clutch 21 by being blocked by the dust cover 45.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, the same reference numerals as those shown in the conventional example of FIG. 4 represent the same components.

Between the centrifugal clutch 21 and the sprocket 41, the inner diameter of the dustproof cover 45 is fitted to the outer periphery of the boss portion 33 of the clutch drum 31 via the dust seal 43, and the dustproof cover 45 covers the centrifugal clutch 21. The outer peripheral portion is brought into contact with the main body case 1, and is fixed to the main body case 1 with a bolt 47.

When the engine is driven, the clutch body 25 and the clutch shoe 27 rotate together with the crankshaft 19. When the rotational speed is increased, the clutch shoe 27 is pressed against the inner diameter surface of the clutch drum 31 against the bullet 29 by the centrifugal force, and the centrifugal clutch 21 is connected to rotate the clutch drum 31, the sprocket 41, and the saw chain 9. . The operator grips the front handle 13 and the rear handle 11 with both hands and cuts a tree or the like with the rotating saw chain 9. However, the worker attaches to the saw chain 9 and opens the front cover of the side cover 5. The dust-proof cover 45 prevents dust and other dust from entering from the inside so that it does not enter the inside of the eccentric clutch 21.

FIG. 3 shows another embodiment of the present invention, in which a dustproof plate 49, which is close to the outer surface near the inner diameter hole of the dustproof cover 45 fitted to the boss portion 33 at an appropriate interval, has an outer periphery of the boss portion 33. The dust that adheres to the gap and tries to enter this gap is blocked by the centrifugal wind generated by the rotation of the dustproof plate 49, and is prevented from entering. It is what is done.

[0011]

[Effect of device]

 According to the present invention, dust adhering to and entering a saw chain can be prevented, and malfunction or damage of the centrifugal clutch can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of a chain saw.

FIG. 2 is a plan sectional view of an embodiment of the present invention.

FIG. 3 is a plan sectional view of another embodiment of the present invention.

FIG. 4 is a conventional plan sectional view.

[Explanation of symbols]

 1 Body Case 3 Guide Bar 9 Saw Chain 19 Crank Shaft 21 Centrifugal Clutch 31 Clutch Drum 33 Boss 41 Sprockets 45 Dust Cover

Claims (1)

[Scope of utility model registration request] 1. A guide bar 3 protruding forward from one side surface of a main body case 1 containing an engine, and the guide bar 3
And a saw chain 9 which rotates by engaging with the outer periphery of the engine, a boss portion 33 of a clutch drum 31 of a centrifugal clutch 21 is rotatably fitted to one end of a crankshaft 19 of the engine,
In a chain saw in which a sprocket 41 for driving the saw chain 9 is attached to the outer periphery of the boss portion 33, a dustproof means is provided on the boss portion 33 of the clutch drum 31 between the centrifugal clutch 21 and the sprocket 41. A chain saw in which a dustproof cover 45 to be fitted is fixed to the body case 1 so as to cover the centrifugal clutch 21.