JPH02185311A - Circular saw blade - Google Patents

Abstract

PURPOSE:To prevent amplification of vibration at a specified frequency to suppress chattering and noise by increasing the blade height gradually in the direction reverse to the cutting rotation to form a series of multiple blades as a set, and making the pitches of a set of multiple blades uneven with each other. CONSTITUTION:The pitches P1, P2, P3, and P4 of one set 1U of blades T1 to T4 are increased in order in the direction reverse to the cutting rotation and uneven with each other. The height differential H1, H2, and H3 of the blades T1, T2, and T3 are so set that the height of the blades T1 to T4 from the center line are increased gradually in the direction reverse to the cutting rotation. The height differentials H1 to H3 are calculated by obtaining the differences D1, D2 and D3 between the mean value P of the pitches P1 to P4 and the pitches P1, P2, and P3, and using the value of the differences D1, D2, and D3 or multiplying them by a specified constant. The height of the blades T1 to T4 is determined in relation to the uneven pitches P1, P5, P3, and P4 and set higher gradually in the direction reverse to the cutting rotation without any specified trend, to change the depth of cut of each blade top, cutting speed and the frequency of the blade. Thus vibrations with different phases counteract with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a circular saw blade as a rotary cutting tool that mainly cuts or cuts metal materials at room temperature.

<Prior Art> In the field of metal cutting, band saws, metal band saws, cutting wheels, etc. are widely used when cutting round bars, vibrators, angles, etc.

However, band saws and cutting wheels have the advantage of being able to set and cut a large number of round bars at once, but they do not apply much cutting pressure, so the cutting time is long, the perpendicularity of the machined surface is poor, and it is difficult to round up. It has the disadvantage that it can cause flakes on the surface.

On the other hand, cutting methods have traditionally been used in which metal materials are cut using a circular saw blade. Cutting with a circular saw blade generally takes less time to cut, has a good perpendicularity to the machined surface, and produces sharp edges on the cut surface. Because it has the advantage of not causing any generation, it is becoming increasingly used in on-site processing of metal materials and in mass production processing.

<Problems to be Solved by the Invention> Although circular saw cutting has many advantages as described above, vibration and noise due to the chattering peculiar to circular saw blades during cutting work with circular saw blades are caused by the following reasons. There were issues arising from this.

In other words, the cutting edge of a circular saw blade is a type of wedge like other cutting tools, and as the direction of cutting resistance acting on the cutting edge deviates from the direction of the bisector of the wedge, the cutting edge curves. Circular saw blades are disk-shaped and have an extremely thin thickness relative to their external dimensions, and are subject to a large force in the direction of the circular saw blade.Furthermore, the rotating main shaft of general circular saw machines is cantilevered, so during cutting operations, the circular saw blade The result is that the blade always experiences a curvature phenomenon.

Therefore, since the cutting edge repeatedly curves during cutting, the cutting depth of the cutting edge changes greatly, and forced vibration, or chatter, occurs due to interrupted cutting or the like. Furthermore, the waviness of the machined surface caused by the forced vibration acts as a disturbance during cutting by the subsequent blade, which further generates automatic vibration, causing so-called regenerative chatter, which increases vibration and noise.

In particular, the chatter that occurs on circular saw blades has the property of rapidly increasing when the depth of cut or cutting thickness exceeds a certain value, and the chatter phenomenon of circular saw blades is caused by the finish of the workpiece. This not only deteriorates the surface but also rapidly accelerates the wear of the cutting edge.

This chatter phenomenon can be prevented to some extent by increasing the thickness of the circular saw blade and the diameter of the mounting hole (spindle of rotation), or by increasing the rigidity of the blade by making the blade material more hard. Due to the toughness required for the part, economic efficiency of cutting work, and practicality, it is not possible to increase the size without permission, and it is quite difficult to effectively reduce the vibration and noise of the circular saw blade. there were.

Means for Solving the Problems> As a result of intensive research and development efforts by the present inventors to solve the above problems, the present inventors have found that by changing the depth of cut and cutting speed of each cutting edge of a circular saw blade, It was discovered that the vibration and noise of a circular saw blade could be reduced by changing the frequency and amplitude, leading to the idea of a circular saw blade that produces less chatter and noise during cutting.

The circular saw blade of the present invention has a series of multiple blades formed as a set so that the height of the blade from the shaft center gradually increases in the direction of rotation opposite to cutting, and the multiple sets are connected to the outer periphery of the disk. It is characterized by the fact that the pitches of a set of multiple blades are mutually unequal. For example, a saw blade has a set of blades T
It is composed of four blades from 1 to T4 (signed in the opposite direction of cutting rotation), and the heights of adjacent blades T1 to T4 are set so that the difference in height between T1 and T2 is Hl. The difference is H
1 to H3, when considering a certain cutting point during cutting, first the blade T1 starts cutting, then the blade T2 cuts across the height difference H from the previous blade T1. The blade of T3 is T
The blade of T4 cuts by a height difference H2 from T3, and the blade T4 cuts by a height difference H3 from T3. This completes the cutting of one set of blades, and then the next set of blades sequentially cuts in the same manner as above, and the same cutting is repeated by each set of blades as the circular saw blade rotates. Since the cutting of the circular saw blade or the feeding of the material to be cut is performed manually or automatically, the cutting edge of the circular saw blade is always in contact with the material to be cut, and especially the first blade T1 of each set is
Even in this case, cutting is carried out with the load reduced, rather than being in a no-load state.

With such a circular saw blade, vibration occurs due to the curvature of the blade during cutting as described above, but the depth of cut at each cutting edge varies, albeit slightly, and the pitch of the multiple blades is unequal. In addition, the cutting speed of each cutting edge (cutting timing)
Since the number of blades changes constantly, the frequency of vibration generated when the multi-blade cuts constantly changes. For this reason, the amplification effect of vibrations due to a specific frequency does not occur, and vibrations with different phases cancel each other out, so that the vibration energy and amplitude are significantly reduced. Therefore, chatter and noise generated in the circular saw blade during cutting are effectively suppressed, and cutting efficiency and blade life can be improved.

<Example> Embodiments of the present invention will be described below based on the drawings.

1 shows a front view of the circular saw blade 1, FIG. 2 shows a side view thereof, and FIG. 3 shows a partially developed view of the blade 3 of the circular saw blade 1. This circular saw blade 1 has a shaft hole 2 bored in the center of its body, and a plurality of sets of blades 3 each having a set 1u of four blades T1 to T4 are arranged in series on the outer peripheral edge of the body. It is formed by

The blades T1 to T4 of this set 1u are the blade T
The pitch of the blade T2 is P2, the pitch of the blade T3 is P3, and the pitch of the blade T4 is 24.The pitches P1 to P4 of these four blades are in the anti-cutting rotation direction. In addition, the height of the multi-blade T1 to T4 of one set 1U is set to increase in order and become unequal to each other.The height of the first blade T1 (from the center of the circular saw blade In other words, the height of the next blade T2 after the blade T1 is the height difference H between the height H of the blade T1.
The height of the blade T3 is the value obtained by adding the height difference H2 to the height of the blade T2. Further, the height of the blade T4 is set to be the value obtained by adding the height difference H3 to the height of the blade T3, and the height of the blades T1 to T4 from the center is set to gradually increase in the anti-cutting rotation direction. .

In addition, the height differences H1 to H3 used above are multi-blade T1 to
It is calculated based on pitches P1 to P4 of T4. That is,
First, calculate the average value P of the pitches P1 to P4, calculate the difference D1 between this average pitch P and the pitch P1 of the blade T1, calculate the difference D2 between the average pitch P and the pitch P2 of the blade T2, and then calculate the difference D1 between the average pitch P and the pitch P2 of the blade T2. A difference D3 in pitch P3 of T3 is determined. Then, the values of the differences DI, D2, and D3 are directly applied to the above height differences H1, H2%H3, or these differences D1~
D3 is multiplied by a certain constant to calculate height differences H1 to H3 proportional to the differences D1 to D3, respectively.

In this way, the heights of the set of multi-blade T1 to T4 are determined in relation to their unequal pitches, and do not have a constant tendency, but gradually increase in the direction of rotation opposite to cutting. It is set as follows.

Note that the cutting edge of the circular saw blade 1 in the figure is not chamfered, but depending on the purchase of the workpiece material and the intended use, the cutting edges may be alternately chamfered to form a helical alternating bevel square shape, or every other cutting edge may be chamfered. It is also possible to chamfer both sides to create a helical alternate double-sided bevel moon shape.

FIG. 4 shows a partially exploded view of the blade of another embodiment.

The pitches P1 to P4 of the set of blades T1 to T4 in this example are as shown in the figure, the pitch pt of the first blade T1 is the minimum, the pitch P4 of the fourth blade T4 is the maximum, and the pitch pt of the second blade T2 is the maximum. The pitch P2 is the second largest, the pitch P3 of the third blade T3 is the third largest, and the pitches P1 to P4 of the set of multi-blade T1 to T4 are disordered and have mutually unequal values. It has become.

The heights of the blades T1 to T4 in the circular saw blade shown in FIG. determined by
The height of the blade T2 next to the blade T1 is the height H of the blade T1 plus the height difference H1, and the height of the blade T3 is the height of the blade T2 plus the height difference H2. The height of blade T4 is
3 plus the height difference H3. The height differences H1 to H3 are determined based on the differences D1 to D3 between the average pitch P of the blades T1 to T4 and the multi-blade pitches P1 to P4, and the differences DID2. Either the value of D3 is directly applied to the height differences H1, H2, H3, or these differences D1 to D3 are multiplied by a certain constant to obtain the differences D1 to D3.
Height differences H1 to H3 proportional to D3 are calculated respectively.

In this way, the heights of the multi-edges T1 to T4 are determined in relation to their unequal pitches, and do not have a constant tendency, but gradually increase in the direction of rotation opposite to cutting. Set.

The circular saw blade I configured as described above is fixed to the rotating main shaft of a circular saw machine by inserting its shaft hole 2, and is rotated in the direction of the arrow in the figure to be used for cutting and cutting metal materials.

Looking at the cutting phenomenon at a certain cutting point during cutting with circular saw blade 1,
First, the leading blade T1 of a set of blades starts cutting, then the second blade T2 cuts by the height difference H1 from the previous blade T1.Then, the third blade T3 starts cutting with the blade T2. height difference H2
The fourth blade T4 cuts by a height difference H3 from the blade T3. This completes the cutting of one set of blades, and then the next set of blades sequentially cuts in the same manner as above, and as the circular saw blade 1 rotates, the same cutting is repeated by each set of blades.

Since the cutting of the circular saw blade 1 or the feeding of the workpiece is performed manually or automatically, the cutting edge of the circular saw blade 1 is always in contact with the workpiece, and especially the leading blade T1 of each set is Cutting is performed in a state where the load is reduced, rather than in a no-load state.

When cutting with such a circular saw blade 1, vibration occurs due to the curvature of the blade during cutting, but since the height of each set of blades is formed to gradually increase, the depth of cut of each blade edge is The cutting speed (cutting timing) of each cutting edge changes constantly, as the pitch of the multi-blade blades is formed at an uneven pitch that does not have a fixed tendency. The vibration frequency of the blade that occurs when cutting constantly changes. As a result, vibration amplification at a specific frequency no longer occurs, and vibrations with different phases cancel each other out, resulting in a significant reduction in vibration energy and amplitude, allowing cutting with less chatter and noise. It will be done.

<Effects of the Invention> As explained above, according to the circular saw blade of the present invention, a set of multiple blades is arranged such that the height of the blade from the shaft center gradually increases in the direction of rotation opposite to cutting. Since multiple sets of these blades are arranged around the outer periphery of the disc, and the pitches of each set of blades are unequal, vibrations are generated due to the curvature of the blades during cutting. The depth of cut of each cutting edge varies, albeit slightly, and the cutting speed (cutting timing) of each cutting edge constantly changes, and the vibration frequency generated when the multi-blade cuts constantly changes. For this reason, the amplification effect of vibrations due to a specific frequency no longer occurs, and vibrations with different phases cancel each other out, so that the vibration energy and amplitude are significantly reduced. Therefore, chatter and noise generated in the circular saw blade during cutting can be effectively suppressed, cutting efficiency can be improved, wear and fatigue of the blade can be reduced, and the life of the blade can be extended.

[Brief explanation of the drawing]

The figure shows an embodiment of the invention, Figure 1 is a front view of the circular saw blade. Figure 2 is the same side view; Figure 3 is a partially developed view of the blade. FIG. 4 is a partially exploded view of another embodiment. 1...Circular saw blade, 3 (T1-T4)...blade, 1u...one set of blades H1~H3...Difference in height of the blade, P1-P4...Pitch of the blade. Figure 1 Figure 2 Patent application Man OnisG Sales Co., Ltd.

Claims (2)

[Claims] (1) A series of multiple blades are formed as a set so that the height of the blades from the center of the shaft gradually increases in the anti-cutting rotation direction, and the multiple sets are arranged consecutively around the outer periphery of the disk. A circular saw blade featuring (2) The circular saw blade according to claim 1, wherein pitches of the plurality of blades in the set are formed to be unequal.