JP2015066609A - Saw blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems in which there is a danger of smoking at last or deforming a cut tooth of an end part by heat since left-right end parts of a saw blade are heated in a slit after a little while in the case of a conventional saw blade, and there is also inconvenience in workmanship of a narrow width since a width of the slit is wide when using a circular cutter, when boring a slit hole in thick wood by the saw blase of a type of cutting by a tool having a driving form such as making a reciprocating circular arc motion of being very small in a vibration angle.SOLUTION: The saw blade for a power tool having a driving shaft making a reciprocating circular arc motion, has a connection part in the center to be connected-fixed to the driving shaft of a power saw tool, and is provided with a cut tooth on the outer periphery of a saw plate having an appearance of an ellipse.

Description

The present invention relates to a novel structure of a saw blade that cuts by being fixed to a drive source that performs reciprocating circular motion with a small amplitude (rotation angle).
In the following description, the term “reciprocating arc vibration” will be used, and this “reciprocating circular motion with a small amplitude (rotation angle)” will be used.

  The saw blade is often of either a reciprocating type (typically a hand saw) or a circular type (circular saw is typical). Both have high cutting ability but safety issues, chips are flying, loud noises, etc. are not ideal tools.

Under such circumstances, there are the following special power tools for cutting.
That is, as shown in FIG. 4, a dedicated saw blade B is installed and fixed with a tightening screw on a drive shaft A provided on the tool body. (The tool in the example of FIG. 4 is a tool that can also be used as an electric file or a polisher, for example, by attaching a polishing member instead of a saw blade.)

The drive shaft A does not rotate in one direction, but has a vibration form in which a reciprocating arc motion (arc vibration) having a very small vibration angle (many of about 3.0 degrees) is performed. When the tool is operated, the entire dedicated saw blade B reciprocates with a small central angle. Strictly speaking, each incisor has a circular motion, but since the angle is very small, it has a pseudo linear reciprocating motion. Moreover, since the amplitude is extremely small in reality, even if a tool is in a vibrating state, it only feels a vibration of the order of a vibrating electric razor, and does not give the impression that the blade is reciprocating left and right.
The cutting operation using this tool simply pushes the saw blade straight against the wood, thereby forming a slit hole in the plate. The saw blade shown in the Japanese translations of PCT publication No. 2000-512561 shown in the prior art document also basically has a structure like this dedicated saw blade B.

By the way, the slit hole can be formed even if a conventional hand-held round blade saw is used. However, since it is intended to cut by continuing to rotate in one direction, it basically tries to roll on the wood to be processed. Therefore, while enduring the force of rolling, first, a narrow through hole is formed, and the width is increased to a predetermined dimension. Unlike this tool, which simply needs to be pressed straight in the thickness direction of the wood, it is a matter of course to learn the work procedures. In the case of a circular saw, the problem is that the working environment is deteriorated because the chips are sprayed and scattered from the slit hole being cut at a considerable initial speed. That is, it can be said that it has various problems that are not limited to high risk.

JP 2000-512561 Gazette

  The method of cutting by utilizing “arc vibration” has such advantages, but when the cutting operation is actually performed using the dedicated saw blade B, at the beginning of the operation or in the case of thin wood Can be cut without hindrance, but there may be inconveniences when making slit holes in thick wood. In other words, the left and right ends of the saw blade continue to collide with the left and right sides of the wood in the slit, and they are heated, eventually smoking, and there is a risk that the end incisors will be deformed by heat. The case is also confirmed.

  The reason for this will be described later, but it seems that the saw blade collides with the left and right walls of the slit hole as the cutting operation proceeds. However, despite the fact that the generation of heat and deformation has been recognized and regarded as a problem, the actual situation is that a saw blade structure that does not cause such problems or has been improved at all is not commercially available or proposed. is there.

When the slit hole is formed using the dedicated saw blade B, the width of the hole is constant. If the width of the slit hole is to be increased after that, it is impossible to use the dedicated saw blade B as it is, and it can be removed once and rotated 90 degrees or installed again, or another saw blade (only for expanding the hole). It was necessary to replace it with a saw blade.

  In view of these points, the inventor of the present invention finally made the present invention as a result of earnest research, and the feature thereof is a saw blade for an electric saw tool having a drive shaft that reciprocates in a circular arc, The electric saw tool has a connecting portion for connecting and fixing to the drive shaft in the center, and is provided with cutting teeth on the outer periphery of a saw plate having an elliptical appearance.

  That is, the present invention has been found in a conventional saw blade for a tool of the same type by reciprocating circularly oscillating the cutting teeth arranged on the circumference of the ellipse, thereby creating a slit hole having a predetermined width. It is intended to solve the problem.

The structure in which the incisors are arranged on the circumference of the ellipse means that the incisors are arranged radially. Accordingly, there is no structure other than the cutting teeth in the surroundings, and the cutting teeth always come into contact with the wood regardless of which direction is pushed in, so that the phenomenon of heat and deformation is almost eliminated. As a result, the anti-collision strength required for the saw blade is reduced, and as a result, a secondary effect that it is easy to obtain a thin blade is brought about.
In the case of an elliptical saw blade, both ends of the major axis and minor axis of the ellipse exhibit cutting performance similar to that of a circular blade having a diameter of each of the four locations. Even in other parts, the cutting teeth always exist, so that the corresponding cutting performance is exhibited.

  The present invention relates to the structure of the saw blade, and the details of the structure of the tool body for driving the saw blade are not limited. However, the drive form transmitted from the tool body to the saw blade of the present invention is limited to “circular vibration”. Therefore, it is inappropriate to apply to a power tool of a drive form that performs a linear reciprocating motion such as a hand saw or a rotational motion in one direction such as a circular saw.

  The saw blade according to the present invention is attached to the tool body, and has a connecting portion for connecting and fixing to the drive shaft of the tool body. As described above, this type of tool body is often used by appropriately exchanging it with a member for other purposes, so that it is preferable that the tool body is easily detachable. In addition, if the connecting portion is configured in such a way that one surface of the saw blade (the surface opposite to the tool body mounting side) protrudes, it is desirable that the cutting portion is limited so that it is as flat as possible. I can say that. However, the structure of the connecting portion that can be easily attached and detached and the structure in which one side is flat are not essential requirements for the present invention.

The general shape of the saw blade according to the present invention is elliptical, and the drive shaft is at the center of the elliptical shape. An elliptical blade is a shape that cannot exist in a conventional circular saw blade that is a perfect circle.
For example, in the case of a circle, when the tool body is driven, the trajectory of each incisor arranged on the circumference becomes one arc, and the arcs of all incisors involved in wood cutting are on one circumference. However, in the case of the saw blade of the present invention having an elliptical shape, the cutting shape when cutting wood differs depending on whether the major axis is opposed to the lumber or the minor axis is opposed. Accordingly, the present invention has the same effect as arranging two types of cutting blades with a single cut shape.

In addition, the saw blade according to the present invention attached to the tool body is provided with cutting teeth over the entire circumference of the ellipse, but a part of it is involved in the cutting work. Accordingly, since at least the rear incisor portion is not used at the time of work, if the sharpness is reduced due to long-term use, it can be handled by turning it 180 degrees. In that sense, it can be said that the saw blade of the present invention has one replacement blade.

The saw blade according to the present invention is a saw blade for an electric saw tool having a drive shaft that reciprocally moves in a circular arc, and has a connecting portion for connecting and fixing to the drive shaft of the electric saw tool, It is characterized by the fact that incised teeth are provided on the outer periphery of the saw plate that has an elliptical appearance, and when it is attached to a tool having a drive shaft that vibrates in an arc at a small rotation angle, it generates heat or deforms in the past. Therefore, cutting work that was not suitable for thick wood is possible, and since there is almost no heat generation or deformation, it is easy to make a thin blade structure. Further, when expanding the cutting hole during or after cutting, Thus, there is no need to remove the saw blade once to change the mounting direction or replace it with another dedicated saw blade, and it is only necessary to push it in the direction of expanding the hole as it is, and it is an extremely advanced invention having various effects.

It is a schematic plan view which shows an example of the saw blade concerning this invention. It is a schematic perspective view which shows an example of the saw blade concerning this invention. (A) is a conventional saw blade, (b) is a schematic plan view both showing a saw blade according to the present invention. It is a top view which shows the prior art example of the saw blade conventionally installed in the electric saw tool which installs the saw blade which concerns on this invention.

FIGS. 1 and 2 show an example of a saw blade 1 according to the present invention (hereinafter referred to as “the present saw blade 1”). FIG. 1 is a plan view and FIG. 2 is a perspective view. As is apparent from the figure, the saw blade 1 of the present invention of this example has an elliptical shape.
The saw blade 1 of the present invention is a saw blade that is attached to a tool having a drive shaft having the property of circular vibration (for example, the tool shown in FIG. 4). In this example, the central angle of the circular vibration is 1.6 degrees. is there.

Cutting teeth 11 are provided over the entire circumference of the elliptical circumference of the saw blade. Each incisor 11 is formed symmetrically on the left and right of the line segment connecting the center of the arc vibration and the apex of each tooth, so that there is no difference in the cutting ability by reciprocation during the arc vibration. In this example, the number of cutting teeth 11 is about 250, which is more than twice the number of cutting teeth of a conventional hand-held circular saw blade.
In the present invention, each cutting tooth vibrates in an arc, but the separation distance (exactly the separation angle) between adjacent cutting teeth is restricted by the arc vibration angle. In other words, a certain incisor reciprocates only at a given angle, and an adjacent incisor reciprocates only at that angle, so if the incisors are separated from each other by more than the angle, there is a portion that cannot be cut. It will be. In other words, the total number of incisors is 225 (360 ÷ 1.6) or more when circularly vibrating at an angle of 1.6 degrees, and 180 (360 ÷ 2) or more when circularly vibrating at 2 degrees. Would be desirable.
From the above, if this arc vibration angle exceeds a certain value, the possibility of damaging the worker increases, which is a safety problem, and if it is less than a certain value, the total number of incisors becomes too large and the cutting ability decreases. Arise. Therefore, it is desirable that this angle is within a range of 1 to 3 degrees.

  Further, in the center of the saw blade 1 of the present invention is a connecting portion 2 with the tool body. The connecting portion 2 of this example has a structure that can be fixed with a mounting angle shifted by 45 degrees with respect to the tool. In addition, a convex bay portion is provided on the tool mounting side so that there is no protruding portion on the back surface (the surface facing the wood during cutting work) of the saw blade 1 of the present invention, and a mounting opening 21 is formed here. The connection with the tool body is performed by inserting the drive shaft A of the tool body into the mounting opening 21 and screwing the protruding portion with a connecting screw member (not shown). That is, the screw member is attached from the back side of the saw blade, but in the illustrated example, the screw member is accommodated in the internal space of the convex bay portion and has a structure having no protruding portion on the back side. Thereby, workability | operativity improves and a use spreads.

FIGS. 3A and 3B are schematic plan views for comparing the conventional saw blade B used in this type of tool and the present saw blade 1.
In addition, this figure shows a state in which cutting has progressed to some extent by pushing the tool body in the direction of the arrow against the relatively thick workpiece W.
For comparison, three incisors are named p · q · r in Fig. (A) and P · Q · R in Fig. (B). The incisors p, r, P, and R are located outside the portion that contributes to cutting, and the incisors q and Q are located approximately at the center thereof.

Of course, when the saw blade vibrates in the arc, all the incisors also vibrate in the arc, but in the case of the conventional saw blade B, that is, in the same figure (a), there are incisors in the radial direction from the center O of the arc vibration. Only the incisor q. As it goes outward from the incisors q, it shifts from the radial direction from the center O, and in the incisors p and r portions, there is a deviation that is no longer the radial direction. Further, there are no cutting teeth on the outside of the cutting teeth p · r, and they only collide with the wall C even if the saw blade vibrates.
Further, in the case of FIG. 9A, it is almost impossible to change the direction in which the tool is pushed in the middle of the cutting operation from the initial direction (the direction of the arrow). If it is not pushed in the direction of the arrow accurately, the frequency and force of the collision will increase, and the risk of causing smoke generation and saw blade deformation due to the heating described above will increase.

On the other hand, in the case of the saw blade 1 of the present invention, that is, in the same figure (b), the cutting holes are formed in an elliptical arc shape, and at this time, all the cutting teeth are arranged radially from the center O. The cutting teeth P, Q, and R are all arranged in a state where cutting is possible. When the tool body is pushed in the direction of the arrow, the left and right incisors centering on the incisor Q contribute mainly to cutting, and if the incisor is pushed in the direction of the incisor P, it will be cut in that direction. Become.

DESCRIPTION OF SYMBOLS 1 Saw blade concerning this invention 11 Cutting tooth 2 Connection part 21 Installation opening A Drive shaft B Dedicated saw blade (conventional product)
C Wall W Wood to be processed O Center of circular vibration p Cutting blade of dedicated saw blade (conventional product) q Cutting blade of dedicated saw blade (conventional product) r Cutting blade of dedicated saw blade (conventional product) P Saw according to the present invention Cutting teeth of blades Q Cutting teeth of saw blades according to the present invention R Cutting teeth of saw blades according to the present invention

Claims (1)

A saw blade for an electric saw tool having a drive shaft reciprocatingly oscillating and oscillating, and having a connecting portion for connecting and fixing to the drive shaft of the electric saw tool, and having an elliptical appearance. A saw blade characterized in that cutting teeth are provided on the outer periphery.

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