JPS633395Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a chain saw lever link mechanism that is suitable for chain saws and other working machines equipped with internal combustion engines. The purpose is to make it easy to remove and disassemble and reassemble.

Conventionally, for example, in a chain saw, as shown in FIG.
b, the horizontal part 1c and the vertical part 1d are continuous in a step-like manner,
The horizontal part 1c fits into the hole 3 of the chiyoke lever 2,
The other end of the horizontal portion 1a passes through the hole 5 of the bracket 4, and a knob 6 is attached to the tip. According to this structure, after separating the carburetor 8 from the handle frame 7, the link 1 cannot be removed from the carburetor 8 unless the carburetor 8 is slightly tilted relative to the link 1, making disassembly and assembly difficult. FIG. 9 shows an example of a removable type, in which one end of the horizontal part 9a of the thick link 9 has a vertical part 9b,
The horizontal portions 9c are continuous, and the horizontal portions 9c are fitted into the holes 3 of the tie yoke lever 2, and are prevented from coming off by split pins 10. According to this structure, the split pin 10
Since it is necessary to use a thick link so that the pin hole can be machined, an increase in weight and cost is unavoidable, and it is not easy to attach and detach the small split pin 10. Related prior art documents include 1987 Utility Model Publication
There is −11235.

This invention allows the link to be removed from the carburetor without removing the carburetor.
A case where the present invention is applied to a chain saw will be explained with reference to FIGS.

Figure 1 is a perspective view showing the appearance of a chain saw.
1 is a guide bar, 12 is a chain cover, 13 is a front handle, 14 is a cylinder cover, 15 is a cab cover, 16 is a switch, and 17 is a rear grip. FIG. 2 is an enlarged view of the exterior of the portion shown in FIG. 1 with the cab cover 15 removed. The carburetor 8 is fixed to the handle frame 7, and an air cleaner 20 is attached to the tip thereof with two mounting bolts 21. horizontally from the side wall of the carburetor 8
2 protrudes, and a chiyoke lever 2 is attached to its tip.
is fixed, and the chain yoke lever 2 is elastically held in an open position shown by a solid line and a closed position shown by a chain line 2' by a spring (not shown) incorporated in a yoke shaft 22. The chain lever 2 extends diagonally downward from the chain yoke shaft 22, and has a hole 3 at its tip parallel to the chain yoke shaft 22, into which the link 2 is inserted.
The upper ends of 3 are fitted. That is, the link 23 extends from one end of the horizontal portion 23a to the vertical portion 23b and the bent portion 23c.
The upper end of the bent portion 23c is fitted into the hole 3, and the other end of the horizontal portion 23a passes through the positioning hole 5 of the bracket 4, and has a chain yoke knob 6 at the tip. The hole 5 has a slightly larger diameter than the link 23, and when the knob 6 is operated in the direction of arrow A from the illustrated fully open position to the fully closed position 6, the horizontal part 2 of the link
3a can be tilted to some extent within a vertical plane orthogonal to the chain yoke axis 22, and when the positioning plate 24, which will be described later, is removed and the link 23 is removed from the chain yoke lever 2, the horizontal part 23a of the link can be tilted to a certain extent in a vertical plane perpendicular to the chain yoke axis 22. It is now possible to move in any direction. The positioning plate 24 is provided with a vertical groove 25 that opens upward, and is fixed to the handle frame 7 by two tightening screws 26 so that the vertical groove 25 supports the middle portion of the horizontal portion 23a. Therefore, the horizontal movement of the link horizontal portion 23a (in the direction of arrow B) is prevented by the vertical groove 25 of the positioning plate 24. The bent portion 23c is smoothly curved in the direction opposite to the carburetor from the upper end of the vertical portion 23b and extends obliquely downward, and the angle α between the bent portion 23c and the vertical line is preferably between 30 and 60 degrees. , within this range, the bent portion 23c can be easily removed from the chain yoke lever 2 by simply removing the positioning plate 24, as will be described later.

To remove the link 23 from the chain lever 2,
First, remove the tightening screw 26, and then remove the positioning plate 24.
(Figure 3). Then the link vertical part 23
At the same time as shifting the lower end of b sideways in the direction of arrow B,
When the bent portion 23c is shifted laterally in the direction of arrow C,
The bent portion 23c is in a substantially horizontal position, and the bent portion 23c is in a substantially horizontal position.
c can be pulled out from hole 3. After inspecting and repairing the carburetor 8 or replacing the carburetor 8, the operation for connecting the link 23 can be performed in the reverse order.

FIG. 4 shows another embodiment, in which a positioning plate 29 having a downwardly opening vertical groove 28 is integrally provided with the air cleaner 20', and the vertical groove 28 is fitted from above into the middle part of the link horizontal part 23a. This prevents the link horizontal portion 23a from moving in the lateral direction. To remove the link 23 from the carburetor 8, remove the two bolts 21 and remove the air cleaner 20' from the carburetor 8, and the positioning plate 29 will automatically release the link 23, so do the same thing as in the case of Fig. 3. The link bent portion 23c can be removed from the chain yoke lever 2.

5 to 7 show the link 23 according to the present invention,
In the three-view diagram, the holes 5 and 3 for the link horizontal part 23a
, the shape and angle of the bent portion 23c, etc. can be understood.

As explained above, in the present invention, the wheel yoke knob 6 is attached to the tip of the horizontal portion 23a of the approximately L-shaped link 23, which is comprised of the horizontal portion 23a and the vertical portion 23b, in a vertical plane perpendicular to the horizontal yoke axis 22 of the carburetor 8. The horizontal portion 23a near the knob 6 is fitted into the positioning hole 5 with a slightly larger diameter than the horizontal portion 23a, and a short bent portion 23c is provided at the upper end of the vertical portion 23b extending diagonally horizontally downward from there toward the side opposite to the carburetor. 22 tip lever 2 in the vertical plane
A hole 3 parallel to the axis 22 is made at the tip of the hole 3, and the upper end of the bent portion 23c is fitted into the hole 3, and the middle portion of the horizontal portion 23a is attached to the removable positioning plate 24, which is vertically opened upward or downward. Since it is fitted into the grooves 25 and 28 so that it can move up and down freely, and the bent part 23c can be removed from the hole 3 of the choke lever 2 only when the positioning plate 24 is removed, the carburetor 8 can be maintained, inspected, replaced, etc. At this time, the link 23 can be removed from the brake lever 2 by simply removing the positioning plate 24 before separating the carburetor 8, making the disassembly and assembly work extremely easy. In particular, in the present invention, since the horizontal portion 23a near the knob 6 is fitted into the positioning hole 5 having a slightly larger diameter than the horizontal portion 23a, the horizontal portion 23a near the knob 6 is fitted into the positioning hole 5 with a slightly larger diameter.
Or, when operating in the reverse A direction, the horizontal portion 23a of the link 23 can move smoothly within the vertical plane,
Even if the hole 3 moves up and down with the rotation of the choke lever 2, no unreasonable force is applied to each part. That is, between the link horizontal part 23a and the positioning hole 5, and the vertical part 23
No kneading occurs between b and hole 3. In addition, the protrusion length from the positioning hole 5 to the tip of the link 23 is reduced, and the link 23 is supported by the holes 3 and 5 at substantially both ends, so that the link 23 is supported by the holes 3 and 5 at approximately both ends, so that the link 23 can be vibration of the parts is minimized. Furthermore, according to the present invention, the intermediate portion of the horizontal portion 23a is formed into an upper opening vertical groove 25 (FIG. 2) of the removable positioning plate 24 or a lower opening vertical groove 29 (FIG. 4) of the positioning plate 29 (FIG. 4). Since the vertical grooves 25 and 28 are fitted into the vertical grooves 28 so that they can move up and down, they not only act as a vibration suppressing member for the intermediate portion of the link 23 during operation, but also completely separate the positioning plates 24 and 29 from the link 23. It can be removed, making it easy to attach and detach the link 23. Also, since there is no need to use split pins, there is no need to make the links thicker or drill holes for split pins in the links, reducing both weight and cost, and work efficiency is significantly greater than when using split pins. improves. Note that the terms "horizontal" and "vertical" in the present invention are used to indicate relative positional relationships in normal conditions, and it is natural that each part is inclined when a chain saw or the like is used.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the appearance of a chain saw to which the present invention is applied, Fig. 2 is an enlarged perspective view showing a state in which the cab cover in Fig. 1 is removed, and Fig. 3 is a perspective view showing a method of removing the link. FIG. 4 is a partial perspective view showing another embodiment, FIG. 5 is a horizontal sectional view showing the planar shape of the link, FIG. 6 is a sectional view taken from FIG. The cross-sectional view, FIGS. 8 and 9 are perspective views showing conventional examples. 2...Chiyoke lever, 3...Hole, 5...Positioning hole, 6...Chiyoke knob, 22...Chiyoke shaft, 23...Link, 23a...Horizontal part, 23
b... Vertical part, 23c... Bent part, 24... Positioning plate, 25... Vertical groove.

Claims (1)

[Scope of utility model registration request] A chiyoke knob is fixed to the tip of the horizontal part of a roughly L-shaped link consisting of a horizontal part and a vertical part in a vertical plane perpendicular to the horizontal chiyoke axis of the carburetor, and a positioning hole with a slightly larger diameter is attached to the horizontal part near the knob. A short bent part is provided at the upper end of the vertical part that extends diagonally laterally and downward from there to the side opposite to the carburetor, and a hole parallel to the chain yoke shaft is made at the tip of the chain yoke lever in the vertical plane at the tip of the chain yoke shaft. Fit the upper end of the bent part into the hole, fit the middle part of the horizontal part into the vertical groove of the removable positioning plate that opens upwards or downwards, so that it can move up and down only, and fold only when the positioning plate is removed. A link mechanism for a chiyoke lever characterized in that a bent portion can be removed from a hole in the chiyoke lever.