JPS61136721A - Cutting link for saw chain - Google Patents

Abstract

PURPOSE:To simplify constitution by forming a concaved part for the free engagement with the tooth part of a chain sprocket onto the shoulder part of a cutting link having a cutting edge, thus omitting a driving link. CONSTITUTION:When a chain sprocket 7 is driven in the A direction, a saw chain 3 travels in the B direction, and when the preceding cutting edge 31R of a cutting link 15 bits into a member M to be cut, the link 15 tends to float-up in the C direction, but the shoulder part 23 contacts with the bottom part of guide groove 9, and since the pivotally supporting part for a side link 17 deflects to the edge 31R, 21L side, said floating-up is suppressed. Therefore, a driving link in the conventional saw chain can be cutting edge can be reduced furthermore.

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, chainsaws have generally been used to cut wood, and there are no chainsaws 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 formed by bending one part, and a depth gauge part is provided on the front side of the cutting edge, so there are various problems. It is difficult to use it in chain saws for cutting resin, metal, etc. In other words, it is difficult to create a chain saw for cutting relatively hard synthetic resins, metals, etc. by simply adopting the saw chain technology 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] The present invention provides a side link and a cutting link for constructing a saw chain by forming a recess in the back of a cutting link having an appropriate number of cutting edges in which the teeth of a chain sprocket can freely engage. The position of the pivot connection with the cutting link is shifted toward the cutting edge side from the center between the back of the cutting link and the tip of the cutting edge.

[Example Referring to FIG. 1, the reference numeral 1 generally indicates a chain saw; a saw chain 3; a guide bar 5 for guiding the saw chain and engine 3; and a guide bar 5 for driving the saw chain 3. It consists of a 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. On the base side of the guide bar 5, a base portion of a handle 11, which is appropriately bent and appropriately stretched, is fixed. The chain sprocket 7 is arranged on the base side of the guide bar 5, and is attached to the handle 11 by a rotating drive device such as a prime mover or a motor! ! (not shown).

The saw chain 3 has a plurality of cutting links 15 and a plurality 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, so that the saw chain 3 has an endless structure as a whole. It is structured like this. The cutting link 15 is formed with an appropriate number (2I in this embodiment!) of cutting edges 21R121L, and one of the cutting edges 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 and is formed into a left set tooth.

As is clear from FIGS. 2 and 3, the distance between the outer edges of the cutting edges 21R and 21L, that is, the set width W, is set larger than the distance between the outer surfaces of the side links 17 on both sides. Also, htuting edge 21
As is clear from FIG. 2, the inner edges of R and 21L are arranged in such a relationship that their traveling trajectories overlap.

The back portion 23 of the cutting link 15 is formed into a substantially straight line, and a recess 25 is formed in the center of the back portion 23, with which the tooth portion 7T of the chain sprocket I engages.

The cutting link 15 and the side link 17 are
The pivot connection is made at a position that is biased toward the cutting edge 21R121 from the center of the height (height) H of the cutting link 15 from the back 23 of the cutting link 15 to the tip of the cutting edge 21R, 21m. has been done. Cutting link 15 above
The back portion 23 of the guide bar 5 is in sliding contact with the bottom portion 9B of the guide 1II9, and both side portions near the back portion 23 are sandwiched and guided by both side wall portions 9W of the guide groove 9. Further, the side link 17 is supported in sliding contact with the top surfaces of the both side wall portions 9W. That is, the saw chain 3 is inserted into the guide groove 9 of the guide bar 5.
When guided by the guide groove 9, it is supported at three points: the bottom 9B of the guide groove 9 and the top surfaces of both side walls 9W.

In the above configuration, when the rotational drive device rotates the chain sprocket 7 in the direction of the arrow, the saw chain 3 travels in the direction of the 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 rotates in the direction of arrow C in FIG. 1 and floats up. (this action is sometimes called 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 edge 21R121L side. ,
Rotation of the cutting link 15 in the direction of arrow C is suppressed.

Similarly, when the cutting edge 21L of the connection of the cutting link 15 bites into the workpiece M, the cutting link 15 is rotated in one direction of arrow C and floats; When the cutting edge 21R rotates to
The rotation of the cutting link 15 in the force direction of arrow C' is suppressed. Furthermore, since the cutting link 15 is located at the center as shown in FIG. 2, when the cutting edge 21R121L bites into the material M to be cut, there is a large displacement in the left and right direction in FIG. There is no force acting on it.

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 no noise is 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 19 during the pivot action of the cutting link 15 is relatively small. Therefore, durability is further improved. Roughly speaking, according to this embodiment, the back portion 23 of the cutting link 15 in the saw chain 3 is in surface contact with the bottom portion 9B of the guide groove 9 in the guide bar 5, and both side wall portions 9W are in contact with the bottom portion 9B of the guide groove 9 in the guide bar 5.
Furthermore, the side link 17 is sandwiched between both side walls 9.
All of them are located at the top of W, so unnecessary movement of the saw chain 3 is suppressed and vibration is reduced, and the cutting link 15 does not escape from the workpiece M due to cutting resistance, which improves efficiency. It allows for good cutting.

FIGS. 4 and 5 show a second embodiment, 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 formed in the shape of a drumstick. be. Therefore, in this second embodiment, it is not necessary to set 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 case in which two cutting edges are provided has been described, the present invention is not limited to the above-mentioned embodiment, and other embodiments can be implemented by making appropriate changes. For example, the number of cutting edges can be changed, such as using one cutting edge or three cutting edges including straight teeth. 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 types B.

[Effects of the Invention] As can be understood from the above description of the embodiments, according to the present invention, a recess in which the teeth of the teeth blocket can freely engage is formed on the back of the cutting link provided with the cutting edge. Therefore, the drive link in a general saw chain can be omitted, the configuration becomes simpler, and the pitch of the cutting edges can be made smaller.

In addition, since the pivot connection position of the side link and cutting link for configuring the saw chain is tiled toward the cutting edge side from the center between the back of the cutting link and the tip of the cutting edge, the pivot 1 of the cutting link At the time of the lock action, the load applied to the hinge pin at the pivot joint is small;
Durability is further improved.

[Brief explanation of drawings]

Fig. 1 is a front view of the chainsaw with one part omitted, Fig. 2 is a sectional view taken along line II-II in Fig. 1, Fig. 3 is a view taken along the ■-■ arrow in Fig. 1, Fig. 4 5 is a front view showing the second embodiment, and FIG. 5 is a plan view thereof. 15... Cutting link 19... Hinge pin

Claims (2)

[Claims] (1) A cutting link with an appropriate number of cutting edges is provided with a recess in which the teeth of the chain sprocket can freely engage with the back of the cutting link. A cutting link for a saw chain, characterized in that the cutting link is offset toward the cutting edge side from the center between the back of the cutting link and the tip of the cutting edge. (2) The cutting link according to claim 1, characterized in that the cutting link is provided with cutting edges at least on both end sides.