JPH0440819Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Field of Application) The present invention relates to a cutting edge separating structure of a small chain saw suitable for cutting relatively hard synthetic resins, metals, lightweight concrete, etc. (Prior art and its problems) Conventionally, relatively hard synthetic resins, metals, etc. have been cut using circular saws with rotary motion, jigsaws with reciprocating motion, or something in between the two using a pair of rotors. A device that drives a band saw has been proposed, but the latter band saw has the disadvantage of being too large for on-site work, and for on-site work, circular saws with rotary motion or jigsaws with reciprocating motion are mainstream, and portable Currently, hand saws are still widely used for this purpose. However, with a circular saw, there is a problem that not only the cutting width is limited to the radius of the circular saw, but also that it is difficult to cleanly cut through a so-called flat plate, which limits the range of use. On the other hand, jigsaws have poor cutting efficiency due to their mechanism of converting the rotary motion of the motor into reciprocating motion, and it is difficult to make the drive unit more compact. Furthermore, there is a drawback that the cutting depth is limited to the reciprocating distance, and although it is easier to cut through a flat plate than with a circular saw, there remains the inconvenience of forming an introduction hole for cutting in advance. Therefore, we aimed to create a compact motorized saw that is as simple as a hand saw for cutting relatively hard synthetic resins and metals, and to make it easier to cut through flat plates, etc. Although the application of chain saws has been proposed, the chainsaws that have been put into practical use have mainly been improved for cutting soft wood (for example, U.S. Pat. No. 392,904), so as long as such chain saw structures are used, When cutting relatively hard synthetic resins, metals, lightweight concrete, etc., it is easy to cause tooth chipping and cracks in the cut material, and it also generates significant vibration, making it unsuitable for practical cutting. In view of these shortcomings, the inventors of the present invention have conducted extensive research and found that in order to cut relatively hard synthetic resins, metals, etc. with a chainsaw, it is first necessary to suppress the pivot action during cutting. This is important, and the first method is to minimize the cutting edge pitch by providing multiple cutting edges on one link instead of one cutting link in conventional wood chain saws. Instead of omitting the drive link used in wood chain saws, a drive recess is provided at the bottom of the cutting center link to form a saw chain with a small pitch. By lowering the blade height by eliminating the need for a deep depth gauge, locating the connecting pin of the center link above the height center, and arranging multiple blades on one link, the pivot action energy is reduced. An attempt was made to make the above-mentioned pivot action smaller while also trying to make effective use of it (Japanese Patent Application No. 59-255643). Also,
The second method is to make the bottom of the center link flat, eliminate the driving claw from the bottom, and guide the flat bottom of the center link by contacting the bottom of the groove provided on the periphery of the guide bar, as well as the side link that connects the center link. The lower part of the guide bar is brought into contact with the upper part of the guide bar to reduce the pivot action of the entire chain link (Japanese Patent Application No. 59-255645), and the pin that connects the center link and the side link is By reducing the load, improving the strength of the saw chain, and reducing the chain width, we solved the basic problem of downsizing chain saws. However, as the saw chain itself is made smaller and thinner, the overall tensile strength and other durability

[Table] According to the hardness of the material to be cut, there are large differences in the dimensions of the cutting links and side links that make up the saw chain, as well as the connection strength between the two. We have come to the conclusion that it is not possible to provide a practical chain saw even though the material is relatively hard compared to wood such as synthetic resin. (Issues of the invention) The present invention solves the above-mentioned factors that cause the saw chain to split during cutting, since unlike a single saw, a chain saw is not integrated as a whole. Considering that the cutting torque applied to the cutting edge has a subtle effect, the aim is to improve the cutting durability of relatively hard materials with a small and thin chain saw from the viewpoint of the cutting mode. (Means for Solving the Problems) In order to solve the above problems, the inventor of the present invention has conducted extensive research into the cutting edge separation mode and the cutting edge cutting phenomenon. Edges are likely to occur at discontinuous points, and the amount of work and work position of the first blade of the multiple cutting edges are particularly involved, increasing the pivot action and lateral blur torque during cutting, resulting in lateral twisting. When forming multiple cutting edges on the cutting links when forming a sort chain by pivotally connecting an even number of cutting center links with side links, based on the knowledge that this may lead to separation. The cutting edges 11R to 11L on each cutting center link 1 cross the center link 1 so that the chainsaw clears the entire width, and the cutting edges 11R to 11L on each cutting center link 1 cross the center link 1 so that the chain saw clears the entire width, and the cutting edges 11R to 11L on each cutting center link 1 cross the center link 1 so that the cutting edges 11R to 11L cross the center link 1 so that the chain saw clears the entire width, and the cutting edges 11R to 11L on each cutting center link 1 The first cutting edge 11R or L is cut in the opposite direction so as to be symmetrical, and the work position of each blade is balanced for the link as a whole (see Figure 7a). We discovered that cutting the cutting edge of the saw chain could be improved by cutting it continuously with the final cutting edge 11R or L to reduce the workload of the first cutting edge (see Figure 7b), and completed the cutting process. It is. In the present invention, an even number of center links 1...
When the number of sheets is odd, the saw chain C is constructed by pivotally connecting .... Even if the cutting edge is arranged so that the last blade and the first blade of the front and rear center links are continuous, it will not be possible to connect any of the saw chain. This is because a discontinuous point is formed at one location. Further, in the present invention, a plurality of cutting edges 11R to 11R on each cutting center link 1
11L is arranged so as to cross the center link 1 so as to clear the entire width of the chainsaw, but its specific form is based on the number of cutting edges arranged on one cutting center link (in the present invention, normally, 3 to 8). However, the amount of work for each cutting edge should be taken into consideration, and the balance between the left and right sides should be maintained. Hereinafter, the configuration of the present invention will be explained in detail based on the accompanying drawings showing specific examples thereof. FIG. 3 is a perspective view of a small chain saw employing the structure of the present invention, FIG. 4 is an assembled and disassembled perspective view of the same, and FIG. 5 is a front view showing details of the main structure. In the drawing, M is a small portable chainsaw,
A saw chain C, which is made up of an even number of cutting center links 1 having an appropriate number of cutting edges, pivotally connected by pins P so as to be sandwiched through a pair of side links 2, 2, is placed on a guide bar 3. The chain source sprocket 4 is installed in a recess formed in the base of the cutting link 1.
The teeth are engaged to drive the rotation. Such a chain saw M, as shown in FIG.
A guide bar 71 for guiding during cutting is attached to the protruding tip of the handle 6, and the elongated hole 3 of the guide bar 3 is connected to the clasp 7 which protrudes downward and the clasp 7 without a guide bar.
The tension of saw chain C can be adjusted with bolts B and B so as to sandwich 2 and 32, and
The components of the chain sprocket 4 are assembled so as to be connected by key grooves to a drive shaft 8 which is mounted on a bearing 61 located at the protruding center of the handle 6 and rotated by a motor (not shown). Further, as shown in FIGS. 3 and 4, the tip of the guide bar 3 is formed in an arc shape like a general chain saw, and the guide bar 3
A guide groove 31 for guiding the saw chain C is formed around the saw chain C. On the other hand, the chain sprocket 4 is arranged on the base side of the guide bar 3, and is attached to a drive shaft 8 that is operatively connected to a rotational drive device such as a motor (not shown) mounted on the handle 6. The sorting chain C has a plurality of cutting center links 1... and a plurality of side links 2, which are extremely thin compared to the cutting links 1, and are displaced above the height center position of the cutting links 1. They are pivotally connected to each other by pins P at certain positions, and are constructed in an endless shape as a whole.
As shown in FIG. 1, the cutting links 1, 1 adjacent to each other in front and rear are arranged so that the plurality of cutting edges 11 on each cutting center link 1 clear the entire width of the chain saw. The first cutting edge (first blade) is arranged to intersect the front and rear center links 1 and 1, facing in opposite directions so as to be symmetrical to each other between the front and rear adjacent center links 1, 1.
11 is cut out so that it is continuous with the final cutting edge 11 of the front center link 1. Specifically, as shown in FIG. 2, a suitable number (five in the drawing) of cutting edges 11R, 11 forming set teeth are attached to the front center link 1.
R', 11L', 11L use the center edge 11C as the center blade, and after being gradually cut into two pieces in the left and right direction, a series of cutting edges 11L, 11L', which form the set teeth of the subsequent center link 1, are formed.
11R' and 11R are gradually cut into two pieces to the left using the center edge 11C as the center blade, and are formed so as to intersect the center of the center link 1 (see Figs. 2 and 6), and cut the entire saw chain C. The edge pitches are equally spaced. Moreover, the plurality of cutting edges 11R to 11L on each of the cutting center links 1 are arranged between the front and rear adjacent center links 1, 1.
As one cycle is completed, cutting is carried out in a meandering manner, and the plurality of cutting edges between the front and rear cutting center links 1 and 1 are sorted until the last cutting edge (last cutting edge) of the front cutting center link is reached. The blades 11R or 11L are arranged so as to be continuous with the first cutting edge (first blade) 11R or 11L of the rear cutting center link, so that they can smoothly move to the next cutting edge. On the other hand, the base side is formed with a recess 12 into which the teeth 41 of the chain sprocket 4 engage. Therefore, the saw chain C engages with the teeth 41 of the chain sprocket 4 and the base recess 12 of the cutting center link, is rotationally driven in the direction of arrow A, and travels in the direction of arrow B. At this time, since the cutting link 1 is configured to be pivotally connected by a plurality of side links 2 which are extremely thin compared to the cutting link 1, the saw chain C does not have sufficient strength in the torsional direction. Although it tends to swing left and right, it runs while being held and guided by the guide groove 31 of the guide bar 3, with the swinging left and right being suppressed.
On the other hand, when cutting a material to be cut, the leading cutting edge 11R of the cutting ring 1 bites into the material to be cut, and the cutting ring 1 tends to cause a pivot action. Since the base portion of the cutting link 1 is held and guided by the guide groove 31, and the pivoting connection portion with the side link 2 is displaced toward the cutting edge, the pivot action of the cutting link 1 is suppressed. Furthermore, even when the saw chain C is rotated by the chain sprocket 4, it is prevented from swinging to the left and right, and the driving force is accurately transmitted.
In order to achieve a smooth transition from the chain sprocket 4 of saw chain C to the guide bar 3,
On both sides of the chain sprocket 4, polygonal guide plates 5, 5 are attached to the drive shaft 8 so as to rotate in synchronization with the chain sprocket 4, and a cutting link meshes with the teeth of the chain sprocket 4. Both guide plates 5, 5 near the base recess 12 of 1
The saw chain C is rotationally driven while being guided by the chain sprocket 4, and the shape of the trough 42 between the teeth 41, 41 of the chain sprocket 4 meshes with the chain sprocket 4. Corresponding to the bending angle of the base, it forms a mountain shape that rises toward the center of the valley. (Operation and Effect of the Invention) As is clear from the above explanation, according to the present invention, the cutting center link 1 having a plurality of cutting edges is connected to a pair of side links 2,
In the chainsaw M, which has been miniaturized by using the saw chain C which is pivotally connected by a pin through the cutting center link, the lateral shake torque that inevitably occurs during cutting due to the cutting edge separation on the cutting center link. is arranged so that the last blade of the front cutting link and the first blade of the following cutting link are continuous, so if the cutting of each blade progresses as shown in Fig. 7, As shown in the figure, the cutting edge of the cutting link at the front moves its cutting position from the right side to the left side while gradually increasing the cutting depth as shown in the figure, and then the following first blade moves forward. Since cutting is performed at the same position as the last cutting edge of the cutting link, the amount of work of the first cutting edge (shaded area) is, for example, as shown in Fig. 7b. The workload of the first blade (shaded area B in Figure 8) can be significantly reduced when the blades are disposed discontinuously (see Figure 8a), and the generation of lateral blur torque by the first blade is reduced. can be suppressed. In addition, the multiple cutting edges on each cutting link are distributed and divided to the left and right through the center of the cutting link so that they are balanced left and right, so the cutting torque applied to each cutting edge is unevenly distributed and It does not cause blur torque. Therefore, together with suppressing the generation of lateral wobbling torque by the first blade, it is possible to eliminate the lateral wobbling torque, which is the biggest cause of saw chain breakage, and the chain saw, which was considered to be a problem in terms of durability in such small and thin chain saws, can be eliminated. Insufficient strength in the lateral torsional direction of the link does not pose a problem in cutting, and it is possible to provide a chain saw that can substantially cut and cut off relatively hard workpieces. Therefore, its practical value is worth mentioning in detail.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the basic aspect of the cutting edge arrangement structure according to the present invention, and FIG.
Top view showing details of the shaving shown in the figure, No. 3
The figure is a perspective view showing the entire small chain saw to which the present invention is applied, excluding the drive motor part, and FIG. 4 is an exploded perspective view of FIG. 3. FIG. 5 is a partially cutaway front view, FIG. 6 is a cross-sectional view taken along the line -- in FIG. The primary cutting mode of each blade, b is the secondary cutting mode of each blade.
A schematic cross-sectional view showing the next cutting mode b, and Fig. 8 shows a case where the first blade of the cutting link that follows the last blade of the front cutting link is arranged discontinuously.
It is a schematic diagram of the workload of the first blade in the primary cutting mode and the secondary cutting mode of each blade. M...Chain saw, C...Saw chain, W...
... Material to be cut, 1 ... Cutting center link, 2 ... Side link, 3 ... Guide bar, 4
...Chain sprocket, 5...Guide plate, 1
1R to 11L... Cutting edge.

Claims (1)

[Scope of claim for utility model registration] A cutting center link 1 having a plurality of cutting edges is connected to a pair of side links 2 and 2.
A saw chain C, which is pivotally connected with a pin through
In the chainsaw M which is configured to be rotated by engaging with the bottom recess of the cutting center link 1, when forming the saw chain C by pivotally connecting an even number of center links 1..., a plurality of cutting center links 1 on each cutting center link 1 are Cutting edge 11R, 11R', 11C, 11L', 11
The set width is gradually changed from the rightmost edge 11R to the leftmost edge 11L so that L clears the entire width of the chain saw, and is arranged to intersect the center link 1 at the center edge 11C, and is adjacent to the front and rear. Between center links 1 and 1,
A plurality of cutting edge arrays are 11R,
11L for 11R', 11C, 11L', 11L,
11L', 11C, 11R', and 11R are arranged symmetrically, and the first cutting edge (first blade) 11R or 11L is the final cutting edge (last blade) 11R of the front center link 1. Or a cutting edge assorting structure characterized by being divided so as to be continuous with 11L.