JPH088082Y2 - Saw chain tension adjustment device for chainsaw - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a saw chain tension adjusting device for a chain saw used for cutting and cutting timber, and particularly when the saw chain guide bar is attached, the adjusting bolt is bent, It is characterized by being able to perform reliable saw chain tensioning work without breaking and without requiring any trouble.

[Prior Art] When the chain saw as described above is used for a long period of time, the saw chain itself and the saw chain guide bar are worn and loosened, so it is necessary to adjust the tension of the saw chain to an appropriate value in a timely manner. .

Conventionally, an adjusting device for tensioning a saw chain is provided with an adjusting bolt having a threaded portion arranged along a longitudinal direction of the saw chain guide bar in a narrow space between the saw chain guide bar and a machine body, and the adjusting bolt. After being loosened from the nut for fixing the saw chain guide bar to the machine body of the chain saw, one end of the adjusting bolt is attached. Rotate with a screwdriver etc. to move the chain tension metal fitting outward along the axial direction of the adjustment bolt, slide the saw chain guide bar engaged with this to the outside in the longitudinal direction, and span the saw chain. The guide bar is clamped and fixed by the nut when the span between the drive sprocket and the drive sprocket is widened and the tension becomes appropriate.

[Problems to be solved by the device]

The saw chain tension adjusting device in the conventional chain saw is a guide for attaching the saw chain because the chain saw is a portable work machine, and it is desired to reduce its size and weight, and because of structural problems such as the guide bar and the replacement of the saw chain. Since it is difficult to provide it on the outside of the bar, etc., it is provided in a narrow space between the guide bar and the machine body, so that it is extremely difficult to adjust and it requires labor.

Furthermore, since the guide bar cover, which also serves as a retainer for the mounting base of the guide chain, is tightened together with the saw chain guide bar, the tension metal fittings of the saw chain are covered,
When the saw chain tension is not fitted into the engagement hole provided at the predetermined position of the guide bar, tighten the nut that tightens the guide bar when adjusting the saw chain. In that case, the tensioning metal fitting of the saw chain screwed to the adjustment bolt is forcibly pressed toward the machine body side, bending or breaking the adjustment bolt, and adjusting the saw chain tension thereafter. Was sometimes impossible.

The present invention has been made in view of the above circumstances, and the adjustment bolt does not bend or break during tension adjustment work of the saw chain of the chain saw, etc. It is intended to provide a saw chain tension adjusting device for a chainsaw that can be performed.

[Means for solving the problem]

In order to solve the above problems, the present invention interposes a cushioning member between an adjusting bolt and a body portion of a chain saw, which are screwed with a tension metal fitting of a saw chain and arranged in parallel with a saw chain guide bar. The adjusting bolt is configured to be movable toward the machine body side.

[Action]

The present invention provides a cushioning member between the body 2 and the adjusting bolt 22.
The feature is that 35 is provided.

To adjust the tension of the saw chain 3, use the guide bar 4
After loosening the nuts 16 and 17 that are fixed to the machine body part 2, a screwdriver or the like is fitted to the driver fitting portion 24 at one end of the adjusting bolt 22 facing the outside, and the adjusting bolt 22 is rotated to the right, for example. , The saw chain tension metal fitting 27 is the adjusting bolt 22
Of the saw chain guide bar 4 engaged with it, moving outward in the longitudinal direction,
The span between the saw chain 3 and the drive sprocket is widened, and the tension of the saw chain 3 is properly adjusted.

In the adjustment work, conventionally, the guide bar 4 and the guide bar cover 5 are in a state in which the engagement hole 32 formed in the guide bar 4 and the tension metal fitting 27 of the saw chain 3 are not displaced and fitted.
The nuts 16 and 17 may be tightened to fix it to the machine body part 2. At that time, the adjustment bolt 22 may be bent or broken, and it becomes impossible to adjust the tension of the saw chain 3 thereafter. There was a case.

However, in the present invention, the adjusting bolt 22 and the body 2
By interposing the buffer member 35 between the guide bar cover 5 and the engagement hole 32 formed in the guide bar 4 and the chain tension metal fitting 27, the guide bar cover 5 is tightened with the nuts 16 and 17 in a state where the chain tension metal fitting 27 is not fitted. Even in the case, the adjusting bolt 22 automatically escapes to the side of the machine body 2 together with the cushioning member 35, and the adjusting bolt as in the prior art
22 is not bent or broken, and does not hinder the tension adjustment work of the saw chain 3 thereafter.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a side view of a chain saw 1 equipped with a saw chain tension adjusting device according to the present invention, and FIG. 2 is a II-I of FIG.
FIG. 1 is a cross-sectional view taken along the arrow I.

In the drawings, 2 is a body part of a chain saw 1, 3 is a saw chain, 4 is a guide bar for guiding the saw chain 3, 5 is a guide bar cover, 6 is a rear handle, 7 is a front handle, and 8 is a hand guard.

The saw chain 3 is slidably driven by being stretched between an outer peripheral end surface of the guide bar 4 and a drive sprocket (not shown) attached to the machine body 2.

As shown in FIG. 2, the machine body portion 2 is integrally formed with lateral wall portions 9, 10 and 11 which are laterally separated from each other and project substantially outward in parallel to the outer side of the machine body portion 2.

An inner plate 12 is interposed between the lateral wall portions 9, 10 and 11 and the guide bar 4, and an outer plate 13 is interposed between the inner plate 12 and the guide bar cover 5 and the guide bar 4. Configures receiving portions on both sides of the guide bar 4 so as to prevent the saw chain 3 from deviating from the guide bar 4 during driving.

In addition, stud bolts 14 and 15 projecting outward on the right side of the machine body are planted in the machine body portion 2, and the inner plate 12, the guide bar 4, and the outer plate 13 are provided in the stud bolts 14 and 15.
Also, the guide bar cover 5 is sequentially fitted and tightened with nuts 16 and 17.

The guide bar 4 is formed with an elongated hole 18 extending in the longitudinal direction thereof, and the stud bolts 14, 1 are formed in the elongated hole 18.
When the nut 5 is inserted and the nuts 16 and 17 are loosened, the relative position of the guide bar 4 can be adjusted by moving the guide bar 4 in the longitudinal direction with respect to the machine body 2.

Further, as shown in FIG. 2, by the body portion 2, the lateral wall portions 10 and 11 and the inner plate 12 provided therein,
An elongated rectangular space along the longitudinal direction of the guide bar 4.
19 are formed. An adjusting bolt 22 is arranged in the space 19.

In the present invention, the lateral wall portions 10 and 11 are provided with elongated holes 20 and 21 respectively.
The adjusting bolt 22 is inserted in the elongated holes 20 and 21 in parallel with the guide bar 4 so as to be rotatable.

The adjusting bolt 22 is provided with a head portion 25 having a screw portion 23 formed in a portion arranged in the space 19 and a driver fitting portion 24 formed at one end, and the head portion 25 is the body portion. It faces the outside of the front of 2.

A retaining member 26 such as a circlip is attached to the side of the adjusting bolt 22 opposite to the head portion 25 of the front side lateral wall portion 11 to prevent the adjusting bolt 22 from coming off in the axial direction.

Further, a chain tension metal fitting 27 is screwed into the thread portion 23 of the adjusting bolt 22, and the chain tension metal fitting 27 is engaged with the guide bar 4.

That is, the saw chain tension metal fitting 27 has a base 28
In the screw hole 29 formed in the threaded portion 23 of the adjustment bolt 22 is supported by being screwed, the tip portion 30 protruding outward of the saw chain tension fitting 27 is formed in the inner plate 12. It penetrates through the longitudinal slot 31 and is fitted into an engaging hole 32 formed in the guide bar 4.

Therefore, the saw chain tension fitting 27 can move in the axial direction along the threaded portion 23 of the adjustment bolt 22 in the rectangular space 19, but is held so as not to rotate.

Further, in the present invention, a cushioning member 35 is arranged between the adjusting bolt 22 and the machine body portion 2 of the chain saw 1.

In the embodiment shown in the drawings, a leaf spring is used as the cushioning member 35 as shown in FIGS.
4 is adapted to the adjusting bolt 22, the adjusting bolt 22 and the chain tension member 27 are constantly pressed to the guide bar 4 side, and the elongated holes 20, 11 provided in the lateral wall portions 10, 11 are provided.
The adjusting bolt 22 and the chain tension metal fitting 27 are movable along 21 toward the machine body 2 side of the chain saw 1.

According to the present invention having the above-described structure, the nuts 16 and 17 that fix the saw chain guide bar 4 to the machine body portion 2 are loosened, and a screwdriver or the like is fitted to the driver fitting portion 24 of the adjustment bolt 22 to adjust the adjustment bolt 22. , For example, when it is rotated to the right, the chain tension member 27 moves outward in the axial direction of the adjusting screw 22, and in conjunction with this, the guide bar 4 is moved outward in the longitudinal direction thereof so as to move between the drive sprocket and Span is widened and the tension of the saw chain 3 is properly adjusted.

Then, by tightening the nuts 16 and 17 again to firmly fix the saw chain guide bar 4 to the machine body portion 2, the saw chain 3 can be sawed while the tension of the saw chain 3 is properly maintained.

In the conventional device, as described above, when the guide bar 4 is attached and the nuts 16 and 17 are tightened, the saw chain tension metal fitting 27 is disengaged from the engagement hole 32 formed in the guide bar 4. Even if there is a case, it is not possible to confirm that it is displaced because it is covered by the guide bar cover 5, and the nuts 16 and 17 are tightened without the saw chain tension metal fitting 27 being inserted into the engagement hole 32. As a result, the adjustment bolt 22 may be bent or broken, and it becomes impossible to adjust the tension of the saw chain 3 thereafter.

However, in the present invention, since the cushioning member 35 is interposed, the saw chain tension metal fitting 27 and the engagement hole 32 are rarely disengaged even when the nuts 16 and 17 are loosened, and even if they are disengaged, the cushioning member 35 is used. The saw chain tension metal fitting 27 and the adjusting bolt 22 as a whole automatically escape to the machine body 2 side, so that the adjusting bolt 22 is not bent or broken,
When the adjusting bolt 22 is rotated slightly to the right or left, the saw chain tension metal fitting 27 is fitted into the engagement hole 32, and therefore the tension adjustment of the saw chain 3 thereafter does not become difficult.

[Effect of device]

According to the present invention, the cushioning member allows the adjustment bolt for screwing the saw chain tension fitting to be freely movable to the machine body side,
The adjustment bolt will not be bent or broken during the saw chain tension adjustment work of the chain saw, and the subsequent tension adjustment of the saw chain will not be difficult.

[Brief description of drawings]

1 is a side view of a chain saw equipped with a saw chain tensioning device according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. Third
The figure is a perspective view of the cushioning member. 1 …… Chain saw, 2 …… Aircraft part 4 …… Guide bar, 22 …… Adjustment bolt 27 …… Saw chain tension metal fittings, 35 …… Cushioning member

Claims (1)

[Scope of utility model registration request] 1. An adjusting bolt 22 in which a tension metal fitting 27 of a saw chain 3 is screwed and arranged in parallel with a saw chain guide bar 4.
A saw chain tension adjusting device for a chain saw, characterized in that a cushioning member 35 is interposed between the machine body 2 of the chain saw 1 and the adjusting bolt 22 is movably supported to the machine body 2 side.