JPH0315501A - Cutting ring for saw chain - Google Patents

Abstract

PURPOSE:To effectively prevent a pivotal action of a cutting link by deviating a pivot coupling position of a side link to the cutting link from the center between the back of the cutting link and the end of a cutting link edge toward the edge side. CONSTITUTION:When a chain sprocket 7 is rotatably driven by a rotary driver in a direction of an arrow A, a saw chain 3 is fed to cut a material M to be cut. In this case, when a preceding cutting edge 21R of a cutting link 15 is intruded into the material to be cut, the link 15 is rotated in a direction of an arrow C to be tended to be floated (pivotal action). However, since the back 23 of the link 15 is brought into plane contact with the bottom 9B of a guide groove 9 and a pivot coupler with a side link 17 is deviated to the edges 21R, 21L side, the rotation of the link 15 in the direction of the arrow C is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cutting link for a saw chain, and more particularly to a cutting link for a saw chain that can cut relatively hard synthetic resins, metals, etc., for example.

[Technical Background of the Invention] Conventionally, chain saws have generally been used to cut wood, and there are no chain saws that can cut relatively hard synthetic resins, metals, and the like. As a saw chain used for a general chainsaw, for example, U.S. Patent No. 3929049
There is something like the one described in the specification gazette of No. The cutting edge of the cutting link in this type of saw chain is shaped by bending one part, and a depth gauge part is provided on the front side of the cutting edge, so there are various problems, and it is difficult to combine them. It is difficult to use it in a chain saw for cutting resin, metal, etc. That is, it is difficult to create a chain saw for cutting relatively hard synthetic resins, metals, etc. by simply adopting the technology of saw chains used for wood cutting chainsaws.

[Objective of the Invention] In developing a chainsaw that can cut relatively hard synthetic resins, metals, etc., an object of the present invention is to provide a new cutting link suitable for the saw chain used in the above-mentioned chainsaw. It is something.

[Summary of the Invention] In order to achieve the above object, the present invention provides a guide bar for a saw chain that is provided with a guide groove on the circumferential surface and a chain sprocket on the base side, and is guided by the guide groove of the guide bar. The cutting link has a plurality of cutting edges that are set at least left and right edges closer to both ends than the center in the longitudinal direction of the cutting link. provided in contact with the cutting link, and the pivot connection position of the side link and the cutting link for forming the saw is offset toward the cutting edge side from the center between the back of the cutting link and the tip of the cutting edge. It is.

[Embodiment] Now, referring to FIG. 1, what is generally indicated by the reference numeral 1 is a chain saw, which includes a saw chain 3, a guide bar 5 for guiding the movement of the saw chain 3, and a saw chain 3 for driving the movement. It is more structured with chain sprocket 7.

The tip of the guide bar 5 is formed in an arc shape like a general chain saw, and a guide groove 9 for guiding the saw chain 3 is formed on the circumferential surface of the guide bar 5. A base portion of a handle handle 11 is fixed to the base side of the guide bar 5, which is appropriately bent and appropriately extended. The chain sprocket is disposed on the base side of the guide bar 5, and is attached to a drive shaft 13 that is operatively connected to a rotary drive device (not shown) such as a prime mover or a motor mounted on the handle handle 11. ing.

The saw chain 3 has a plurality of cutting links 15 and a pair of side links 17, which are extremely thin compared to the cutting links 15, arranged alternately and pivotally connected to each other by a plurality of hinge pins 19. It is structured in an endless manner. cutting link 1
A plurality of (two in this embodiment) cutting edges 21R, 21 are provided nearer to both ends of the central part in the longitudinal direction of 5.
L is formed. One cutting edge 21R is curved to the right with respect to the running direction of the saw chain 3 to form a right set tooth, and the other cutting edge 21L is curved to the left with respect to the running direction of the saw chain 3 to form a left set tooth. It is formed in Above cutting edge 21R, 2
The distance between the outer edges of 1L, that is, the width W, is shown in Figure 2.
As is clear from FIG. 3, the distance is greater than the distance between the outer surfaces of the side links 17 on both sides. Further, as is clear from FIG. 2, the inner edges of the cutting edges 21R and 21L are arranged at positions such that their travel trajectories overlap with each other. Back part 23 of cutting link 15
is formed almost straight, and a recess 25 is formed in the center of the back portion 23 of the chain sprocket 7 into which the teeth 7T of the chain sprocket 7 engage.

The cutting link 15 and the side link 17 are
The height from the back 23 of the cutting link 15 to the tips of the cutting edges 21R, 21L (i.e.,
The cutting link 15 is pivotally connected at a position deviated from the center of the height (height) H toward the cutting edge 21R12L. The back portion 23 of the cutting link 15 is located at the bottom 9 of the guide groove 9 in the guide bar 5.
Both side portions in sliding contact with B and near the back portion 23 are supported and guided by both side wall portions 9W of the guide groove 9. Also, side link 1
7 is slidably contacted and supported by the top surfaces of the both side wall portions 9W. That is, when the saw chain 3 is guided by the guide groove 9 of the guide bar 5, the bottom 9B of the guide groove 9 and both side walls 9
It will be supported by three points on the top surface of W.

In the above configuration, when the chain sprocket 7 is rotationally driven in the direction of arrow A by the rotary drive device, the saw chain 3 is moved in the direction of arrow B. When cutting the workpiece M by running the saw chain 3, when the leading cutting edge 21R of the cutting link 15 bites into the workpiece, the cutting link 15
In the figure, it tends to rotate in the direction of arrow C and float (this action is sometimes referred to as a pivot action).

However, in this embodiment, the back part 23 of the cutting link 15 is in surface contact with the bottom part 9B of the guide groove 9, and the pivot connection part with the side link 17 is biased toward the cutting edges 21R and 21L. By this,
Rotation of the cutting link 15 in the direction of arrow C is suppressed.

That is, in FIG. 1, when the cutting edge 21R of the cutting link 15 bites into the workpiece M,
There is a tendency to rotate in the direction of arrow C, but at this time, the tendency to rotate around the hinge pin 19 on the side of the cutting edge 21R (the side leading to the side of arrow B in FIG. 1) is as follows.
This is prevented because the back portion 23 of the cutting link 15 is in contact with the bottom portion 9B of the guide groove 9.

Further, the tendency of the cutting link 15 to rotate in the direction of arrow C using one end side of the back portion 23 of the cutting link 15 (the end opposite to the arrow B in FIG. It is easily suppressed by being connected to the side link 17 at a position that is biased towards the cutting edge side. In this case, the distance from the fulcrum of rotation to the hinge pin 19 is larger than when one hinge pin is located near the back 23 of the cutting link 15, and the load on the hinge pin l9 is smaller, so that the hinge pin 19 is Durability is further improved.

Similarly, when the subsequent cutting edge 21L of the cutting link 15 bites into the material to be cut M, the cutting link 15 is rotated in one direction of arrow C and floats; When the cutting edge 21R rotates, the leading cutting edge 21R touches the material M
Mode 7 in which the cutting edge 21L bites into the cutting edge 21L is restrained from rotating in one direction of the arrow C, and the cutting edge 21L is prevented from cutting into the cutting edge 21L excessively. Moreover, since the cutting link 15 is located at the center as shown in FIG. 2, when the cutting edges 21R and 21L bite into the workpiece M, the
There is no possibility that a large component of force will act in the left and right directions in the figure.

Therefore, in this embodiment, when cutting the material M to be cut, the vibration of the saw chain 3 in the vertical and horizontal directions in FIG. 2 is reduced, and noise is not generated.
It is possible to perform cutting with high precision. Furthermore, since the pivot joint between the cutting link 15 and the side link 17 is biased toward the cutting edges 21R and 21L, the load acting on the hinge pin l9 during the pivot action of the cutting link 15 is relatively small. Therefore, durability is further improved. Further, according to this embodiment, the back part 23 of the cutting link 15 in the saw chain 3 is in surface contact with the bottom part 9 of the guide groove 9 in the guide bar 5, and is sandwiched between the both side walls 9W, and the side link 17 are in sliding contact with the tops of both side wall portions 9W, unnecessary movement of the saw chain 3 is suppressed and vibration is reduced, and cutting links 15 are prevented from escaping from the workpiece M due to cutting resistance. Therefore, efficient cutting can be performed.

4 and 5 show reference examples, in which a tooth tip member 27 such as a carbide tip is appropriately fixed to the cutting edge 21 of the cutting link 15, and is shaped like a batten. Therefore, in this reference example,
It is not necessary to set out the left and right sides of the cutting edge 21. Note that the other configurations and effects are the same as those of the first embodiment described above, so detailed explanations thereof will be omitted.

In addition, in the above embodiment, the cutting link has two
Although the above description has been made regarding the case where two cutting edges are provided, the present invention is not limited to the above-mentioned embodiment, and other embodiments can be implemented by making appropriate changes. For example, cut the cutting edge 3 times including the straight teeth.
You can change the number of cutting edges, such as increasing the number of cutting edges. Moreover, in order to make it thinner, it is also possible to form a recess corresponding to the thickness of the side link in the connecting portion between the cutting link and the side link. That is, it can be implemented in various ways.

[Effects of the Invention] As can be understood from the above description of the embodiments, according to the present invention, the back of the cutting link, which is provided with a plurality of cutting edges near both ends in the longitudinal direction, fits into the guide groove of the guide bar. The pivot connection position of the side link and the cutting link, which are in contact with the bottom and form the saw chain, is shifted toward the cutting edge side from the center between the back of the cutting link and the tip of the cutting edge. This makes it possible to extremely effectively prevent the pivot action of the cutting link, reduce vibrations during cutting, and prevent the other cutting edge from digging into the workpiece too much. It is intended to prevent

Further, the load applied to the hinge pin in the pivot connection portion is reduced, and durability is further improved.

[Brief explanation of the drawing]

Figure 1 is a front view of the chainsaw with one part omitted, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a front view of the chainsaw with one part omitted.
4 is a front view showing a reference example, and FIG. 5 is a plan view of the same. 3... Saw chain 5... Guide bar 7...
・Chain sprocket 9...Guide groove 15...Cutting link 17...Side link 19...
Hinge pins 21R, 21L... Cutting edge 23... Back

Claims (1)

[Claims] A cutting link for a saw chain 3 that can freely run while being guided by the guide groove 9 of a guide bar 5 having a guide groove 9 on the circumference and a chain sprocket 7 on the base side is used to perform at least left and right shaving. At least both end portions of the back portion 23 of the cutting link 15, which is provided with a plurality of cutting edges 21R, 21L closer to both end sides than the longitudinal center portion of the cutting link 15, are brought into contact with the bottom portion 9B of the guide groove 9. The position of the pivot connection between the side link 17 and the cutting link 15 for configuring the sawn 3 is set between the back part 23 of the cutting link 15 and the cutting edges 21R, 21.
A cutting link for a saw chain characterized by being biased toward the cutting edge side from the center with the tip of the L.