JP2019177515A - Saw blade - Google Patents

Abstract

To provide a saw blade that can cut objects without the teeth vibrating at the beginning of cutting work when cutting objects with a saw blade of a type that is attached firmly to a drive source making reciprocal and rotational motions with low amplitude (small rotational angle) in order to cut objects.SOLUTION: A saw blade 1 for an electric saw tool with a drive shaft that makes reciprocal, arcuate and vibrating motions. The front end of the saw blade 1 is provided with a line of cutting teeth 31, and the rear part is provided with a connection part 2 for connection to the center of the drive shaft. Only for cutting teeth 1 to 3 in the center of the tooth line on the front end, their heights being a distance between the tooth bottom and tooth tip are set to be high, and the cutting teeth 1 to 3 in the center of the tooth line are present in the most front position.SELECTED DRAWING: Figure 1

Description

The present invention relates to an anti-blur structure in a saw blade of a type that cuts by being fixed to a drive source that performs reciprocating rotational motion with a small amplitude (rotation angle).
Hereinafter, the phrase “reciprocating arc vibration” is used in the present specification, and this “reciprocating rotational motion with a small amplitude (rotation angle)” is meant.

  The saw blade is often of either a reciprocating type (typically a hand saw) or a rotary 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. 6, a dedicated saw blade B is installed and fixed on a drive shaft A provided on the tool body. (The tool in the example of FIG. 6 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.)
For fixing the saw blade to the main body, an elastic claw is provided on the main body side, and when this is shrunk, it is put into a hole provided on the saw blade side and passed by a one-touch method of locking with the restoring force of the claw, or There may be various methods such as a method of arranging a female screw on the main body side and sandwiching the saw blade with a separate male screw, a method of using a magnet together, and so on.

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 (mostly about 4.0 degrees or less) is performed. When the tool is operated, the entire dedicated saw blade B reciprocates with a small central angle. Strictly speaking, each of the cutting teeth at the tip of the saw blade B reciprocates circularly, but since it has a small angle, it has a pseudo linear reciprocating motion. In addition, since the amplitude is small, the behavior of a general reciprocating saw with power is quite different from that of a vibration type electric razor.
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 as 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, the saw blade 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.

Special Table 2000-512561

The technique of cutting by utilizing “arc vibration” has such advantages, but when the cutting operation is actually performed using the dedicated saw blade B, the vibrating saw blade cannot be controlled and is covered. There are not a few cases where the surface of the workpiece is roughened or the cutting is started at the wrong position by dancing on the workpiece (wood).

  Therefore, the present inventor has finally made the present invention as a result of earnest research in view of this point, the feature of which is a saw blade for an electric saw tool having a drive shaft that reciprocates in a circular arc, The front end is provided with a row of incisors, and the rear is provided with a connecting hole for connection to the center of the drive shaft. The height of the incisor, which is the distance from the bottom of the incisor to the tip of the tooth, Only the first to third incisors in the center of the dentition are designed to have a high incisor height, which is the distance between the root and the tip, and the first to third incisors in the center of the dentition are It exists in the point which exists in the forefront position.

  In the case of a saw blade that oscillates in a reciprocating circular arc, the rotation angle is usually about 3 degrees (that is, 1.5 degrees to the left and right), or less, so the amplitude of the cutting teeth is only about 4 mm. That is, it can be said that it is a very safe saw when compared with a general rotary saw (so-called circular saw) or a powered reciprocating saw.

  In the case of such a vibration type saw blade, if only 1 to 3 cutting teeth (hereinafter referred to as central cutting teeth) in the center of the cutting teeth are designed to be higher than the other cutting teeth, the root line If the curve is a straight line or a curved line or fold line that bulges toward the workpiece, this central incisor will pierce the workpiece (wood) first.

  “Incisor height” is defined as the distance from the root of the incisor to the tip. The tooth bottom refers to a portion corresponding to a valley bottom of a V-shaped cut (which is rounded at the bottom of the valley, or some U-shaped) cut by sharpening. Apart from this sharpening work, there are also saw blades that are intermittently provided with slit grooves to help drain the saw dust, but for the present invention, the bottom of this slit groove is used when calculating the `` cutting tooth height ''. It shall not be a standard.

  On the other hand, it is common to express the incisor that first contacts the workpiece as “the tallest incisor”, but the “height” in this expression is the “incisor height” in this specification. Is a different concept. Therefore, in order to clarify these differences, the direction of digging by cutting is called “front”, and the opposite direction is called “back”. Therefore, if the central incisor is in the forefront, the central incisor will first touch the workpiece.

In other words, it is not synonymous that the height of the central incisor is higher than the other incisors and that it is the central incisor that first contacts the workpiece during the cutting operation.
In the present invention, it is an essential requirement that the central incisor is the first in contact with the workpiece during the cutting operation. Therefore, the central incisor needs to be positioned in the forefront.
Therefore, in reality, the central incisor is positioned in the forefront by making the root of each incisor bulge forward or horizontal.

  In the case of the saw blade according to the present invention, the cutting is not started from a state in which a large number of cutting teeth are in contact with the workpiece at the same time, but first, the cutting is started after the central cutting blade is pierced. Compared to the case where teeth are pierced, a phenomenon called saw blade dance that occurs when the workpiece first collides with a workpiece is hardly generated. The reason is probably that if the number of cutting teeth is very small, such as 1 to 3, all of the force that presses the saw against the workpiece is concentrated on this 1 to 3, which is 1 This seems to be because the power received per book increases and it becomes easier to stab. Furthermore, when one to three incisors have entered the material in advance and other incisors hit the surface of the material, these already incised teeth support the lateral force of the dentition, thereby It seems that the undesirable behavior of the incisors can be regulated.

If the height difference between the central incisor and other incisors is too small, for example, if the surface smoothness of the workpiece is low, both the central incisor and other normal incisors can contact the workpiece Sexual and ineffective. In addition, the central incisor is intended to prevent teeth from dancing in the initial stage of cutting work, but it is also present during full-scale cutting operations past the initial stage. If the difference is too large, the cutting hole will be advanced only in the central portion, and the load applied to the central incisor will be large, and wear and breakage will be concentrated here.
Taking these into consideration, the height difference is preferably 0.5 mm or more and 2.0 mm or less.

  The method of changing the height between the central incisor and the other incisors is not particularly limited. For example, only the central incision portion may be designed to have a larger “pitch” (described later) of the incisors, or the upper-edge machining of the central incision portion may be reduced or omitted. In particular, when the center incisor is formed by processing that sharpens the incisors with a large pitch, it is effective because the strength can be easily maintained.

In the saw blade, the “cutting tooth pitch” is often expressed by “the number of tooth tips existing in one inch” or “the length of the tooth row formed by the reference number of cutting teeth”.
However, according to the present invention, only one to three central incisors are increased in incisor height, and as a structure for increasing the incisor height, a method for increasing the entire central incisor in the initial stage of sharpening and This includes both the method of increasing the incisor height by reducing the cutting amount at the time of upper eye machining without increasing it at the initial stage, and cannot be described in the conventional pitch expression method. .
Therefore, in this specification, “the pitch of the incisor” means the distance between the midpoint C of the incisal root and the midpoint C of the adjacent incisal root as shown in FIG. (Referred to as a distance).

  The saw blade is usually provided with a “clam”, but is not essential in the present invention. Therefore, it is not necessary to provide clams.

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.

A 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 is connected to a tooth row of a cutting tooth at a front end and a center of the drive shaft at a rear portion. A connecting hole is provided, and for the 1 to 3 incisors in the center of the front end dentition, only the 1 to 3 incisors in the center of the front end dentition are the distance between the root and the tip. The incisor height is designed to be high, and 1 to 3 incisors in the center of the dentition are present in the forefront position, and the number of teeth is small immediately after the start of the cutting operation. Since the central incisor pierces the workpiece in advance, and this reciprocates in the workpiece, it is an extremely advanced invention that has the effect of cutting as desired without the teeth dancing.

It is a schematic plan view which shows an example of the saw blade concerning this invention. (A) (b) is a schematic plan view which shows an example of the saw blade which concerns on this invention. (A), (b), and (c) are all schematic plan views showing the general shape of the cutting teeth of an example of the saw blade according to the present invention. (A) and (b) are all schematic plan views showing the general shape of the blade portion of the saw blade according to the present invention. It is a schematic plan view which shows the other example about the cutting-tooth shape of the saw blade which concerns on this invention. It is a top view which shows the conventional example of the electric saw tool which installs the saw blade concerning this invention, and the saw blade installed in this. It is a schematic plan view for demonstrating the pitch of an incisor.

FIG. 1 is a plan view showing an example of a saw blade 1 (hereinafter referred to as “the present invention saw blade 1”) according to the present invention. The saw blade 1 of the present invention is a saw blade attached to a tool (for example, the tool shown in FIG. 6) having a drive shaft having the characteristic of vibrating in an arc, and is connected and fixed to the drive shaft of the tool by a connecting portion 2. . The blade 3 composed of a large number of cutting teeth 31 is provided at the end opposite to the connecting portion 2.
In this example, the central angle of the arc vibration is 1.6 degrees.

FIGS. 2A and 2B show two examples of the blade portion of the saw blade 1 of the present invention. FIG. 4A shows an example in which postcard sharpening is applied, and FIG. 5B shows an example in which the postcard sharpening is not made and a chevron blade is formed. The incisors 31 are provided in a line, but the height is not constant, and only the central one protrudes. In this example, the protruding central incisor 311 has a larger incisor pitch than the other incisors 31.
In this example, only one central incisor 311 is provided, but two or three may be used.

  The general shape of the cutting teeth 31 of the blade 3 is not limited to a horizontal (straight) shape as illustrated so far, and may have various forms. FIG. 3 shows such an example other than horizontal. FIG. 3A is an arcuate example, FIG. 3B is a V-shaped example, and FIG. 3C is almost horizontal and left and right. An example in which only the vicinity of the edge is lowered is shown. There may be other forms.

  The shape of each cutting tooth 31 may be directional (asymmetry) like a normal saw cutting tooth, but may be non-directional (left-right symmetric). . FIG. 4 shows this, and FIG. 4 (a) shows an example with directionality, and FIG. Further, the present invention is not limited as to whether or not each incisor 31 has a structure called an Edo eye in which an upper eye (having a tooth tip cut with a file) is provided. In other words, the processing of the upper eye may be omitted (not shown).

FIG. 5 is an example in which the center point distance (pitch) between the central incisors 311 is the same as that of the other incisors. In this example, in order to increase the incisor height of the central incisor 311 (the separation distance between the bottom of the teeth and the tooth tip), the upper eye cut applied to the incisor tip is made different at the central incisor 311 portion. Is. Thereby, the excision part 4 by upper-eye processing is extremely small at the central incisor 311. This method has an effect that it is easy to manufacture because most of the sharpening process can be performed by a conventional method (only the upper eye processing is different).

DESCRIPTION OF SYMBOLS 1 Saw blade which concerns on this invention 3 Blade 31 Cutting blade 311 Long cutting blade 2 Connection part 4 Cutting part by upper-edge processing A Drive shaft B Dedicated saw blade
C Midpoint of the bottom of the incisor

Claims (4)

A saw blade for an electric saw tool having a drive shaft that reciprocates in a circular arc, and a front end is provided with a tooth row of cutting teeth, and a rear portion is provided with a connection hole for connection to the center of the drive shaft, About 1 to 3 incisors in the center of the front end dentition, only the 1 to 3 incisors in the center of the front end dentition are designed so that the incisor height, which is the distance between the root and the tip, is high. A saw blade characterized in that 1 to 3 cutting teeth in the center of the dentition are present at the foremost position. 2. The saw blade according to claim 1, wherein the incision pitch, which is the distance between the teeth of adjacent incisors, is large only for the first to third incisors. The saw blade according to claim 1 or 2, wherein the roots of all the incisors are curved or bent so that the bottoms thereof are horizontal or convex in the front-rear direction. 1. The bottom of all incisors is horizontal in the front-rear direction, and the difference between the incisor heights of 1 to 3 incisors in the center of the dentition and the incisor heights of other incisors is 0.5 mm or more. The saw blade according to claim 1 or 2, which is 0 mm or less.

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