WO1996021545A1

WO1996021545A1 - Low-noise circular saw

Info

Publication number: WO1996021545A1
Application number: PCT/JP1996/000054
Authority: WO
Inventors: Seizo Itaya; Yoshio Yamamoto; Yoshihiro Inoue
Original assignee: Kanefusa Corporation
Priority date: 1995-01-13
Filing date: 1996-01-12
Publication date: 1996-07-18
Also published as: JPH08187702A

Abstract

Teeth of a circular saw are shaped to reduce cutting noises. Teeth (1-6) of six or more kinds form a group. The teeth of the respective kinds protrude radially at locations which are varied in a thicknesswise direction of the circular saw. Amounts by which the teeth protrude are preferably made substantially constant, and protruding ends of the teeth preferably extend in the thicknesswise direction of the circular saw. In particular, it is preferable that a sum of partial protruding ends of the teeth of the respective kinds in a group is made to be equal to a thickness of the teeth. When the teeth are six or more in kind, cutting widths of the respective teeth in the thicknesswise direction can be reduced to suppress noises.

Description

Description Low noise circular saw

[Technical field]

The present invention relates to a circular saw to which a tip is fixed, and more particularly to a circular saw capable of reducing noise during cutting.

[Background technology]

In order to improve the durability of the circular saw, the straightness of cutting, or the quality of the cut surface, various modifications have been made to the shape of the teeth of the circular saw. FIG. 1 systematically shows the shape of a known tooth, and schematically shows the shape of the tooth as viewed from the front in a plane perpendicular to the rotation direction of the circular saw body.

1 in Fig. 1 indicates type B of JIS (B4805), and each cutting edge 1 1 extends over the entire length T of the tooth thickness, and the same type of tooth is used to cut the circular saw body. It is provided periodically along the edge. Reference numeral 2-1 in FIG. 1 denotes the J-type D of the above JIS, which has two types of teeth, and the height 1, L2 of the cutting edge 21, 22 is changed for each type.

In a D-shaped circular saw, two types of teeth are provided alternately along the outer peripheral edge of the circular saw body. When a plurality of types of teeth are used, each tooth cuts a part of the thickness T, so that noise during cutting can be reduced.

Reference numeral 2-2 in FIG. 1 shows an example having four types of teeth, which is disclosed in Japanese Patent Application Laid-Open No. Hei 6-2797938. Circular saws of this type have cutting edges 24, 25, 26, and 27 with different heights L4, L5, L6, and L7. Has been done. Four types of teeth are provided in a group along the cutting edge of the circular saw body. Type 2 shown in 2-1 and 2-2 in Fig. 1 can be said to be a type that uses multiple types of teeth with different cutting edge heights.

Reference numeral 3-1 in FIG. 1 denotes the JIS C type, and shows an example in which inclined right teeth and inclined left teeth having a tip inclination angle are provided alternately along the cutting edge of the circular saw body. In this example, the tooth tip protrudes in the radial direction D of the circular saw body, and two types of teeth with different protruding positions (P1, P2) in the thickness direction T are grouped. it can. Reference numeral 3-2 in FIG. 1 shows an example in which both inclined central teeth are provided between the inclined right teeth and the inclined left teeth. In this example, the projections (P 1, P 2, P 3) in the thickness direction T are grouped together with three types of teeth each having a different position. Fig. 3-3 shows an example in which the protruding ends 3 1, 3 2, 3 3 extend along the thickness direction T. When the extensions along the thickness direction are accumulated in a group, that is, the teeth overlap. FIG. 4 shows an example in which the thickness is equal to the blade thickness.

Type 3 indicated by 3-1 to 3-3 in FIG. 1 can be said to be a type in which a plurality of types of teeth whose protruding positions change in the thickness direction are used as a group. In this type, the protrusion amounts L 8 and L 9 of each tooth are almost constant within each group.

In the figure, reference numeral 4 is a mixture of types 2 and 3, with different cutting edge heights (projection amounts) and multiple types of teeth whose projection position changes in the thickness direction. The type used is shown.

For example, in the case of Fig. 42, the height of the blade changes from L10 to 16, and the protruding position also changes from P10 to 16. The one shown in Fig. 412 is a circular saw made entirely of steel with teeth directly provided on the circular saw body. The teeth are bent to form a set, and both the set and the lateral center angle are large. The shape of the circular saw is different from that of other circular saws to which the tip is fixed by brazing or the like. The various shapes shown in FIG. 1 are not limited to the above-mentioned JIS and Japanese Patent Application Laid-Open No. 6-2797938, but also Japanese Patent Application Laid-Open No. 61-23081 and Japanese Utility Model Application No. 58-5705. It is disclosed in Japanese Patent Publication No. Sho 59-85225.

All-steel circular saws with sharpened bends to avoid friction between the circular saw body and the material to be cut tend to have a large lateral center angle to ensure sufficient set. —The circular saw to which the tip is fixed is formed by grinding the side of the tip, which is projected sideways in advance by the amount of the set, and the side center angle can be arbitrarily selected, and is generally quite small. On the other hand, there is a close relationship between the lateral center angle and the machined surface roughness (see Figure 28, Source: Bulletin of the Faculty of Agriculture, Tokyo Kyoiku University, No. 8, 21? -297 (1 962)). Circular saws cannot be used for finish cutting, and circular saws with tips have become widespread. According to the circular saw with a tip, it is possible to secure a sufficient set by reducing the lateral center angle, and it is possible to finish cut all kinds of workpieces.

In FIG. 1, reference numeral 4_2 denotes the all-steel circular saw, which is provided with a set by bending the main body. The cutting edges are dispersed in the blade thickness direction by gradually changing the bending angle of the cutting edge. Therefore, a bending angle (lateral center angle) that is equal to or greater than that of the all-steel circular saw is required, and it is inevitable that the cut surface of the material to be cut will have a rough machined surface, and is used for finish cutting. It has not been.

[Disclosure of the Invention]

In the above-mentioned all-steel circular saw, the cutting edge obliquely abuts the workpiece, so that a lateral force is generated by the cutting force, and the large lateral eccentric angle also has an effect. Easy to chatter. For this reason, noise during cutting tends to be high, and as described later, the property that noise can be reduced by using a combination of multiple types of teeth whose protruding positions differ in the thickness direction is recognized, but the body is folded. In the case of the 4-2 type to be manufactured, chatter is likely to occur in the horizontal direction, and this effect cannot be obtained.

The chip types shown in 2-1, 2-2-3-1, 3-2, 3-3, and 4-1 have at most four types of teeth in a group. This means that by increasing the number of types, the effective cutting amount in the thickness direction of each tooth can be reduced and the cutting resistance can be reduced.However, if the number of types is increased too much, the appearance ratio of the same type will decrease. This is because there is a concern that the effective cutting amount in the feed direction will increase, and in fact the actual cutting amount will increase. For example, if 10 types of teeth are used, there is an element that cutting should be performed with 10 types of teeth when viewed in the thickness direction, but if the feed rate is constant, 10 times the amount of cutting per tooth is cut There is a concern that adverse effects may occur due to the factor that must be performed, and currently two to four types are used separately.

When two to four types of teeth are used, the cutting resistance is smaller and noise can be reduced as compared with the type 1 in Fig. 1 that uses one type of teeth. However, for example, when cutting an aluminum sash, it is inevitable that a loud noise is generated. Therefore, the present invention seeks to realize a circular saw with better noise suppression capability.

The circular saw according to the present invention comprises a plurality of teeth formed by fixing a plurality of teeth serving as teeth along a cutting edge of a circular saw body having a thickness. It protrudes in the direction (radial direction) perpendicular to the rotation direction of the main body, and at least six types of teeth that differ in the protruding position in the thickness direction are grouped with six or more teeth. It is characterized in that a plurality of chips are fixed to the circular saw body in one group.

In the circular saw of the present invention, at least six or more types of teeth are grouped together with at least six different types of protruding positions in the thickness direction of the circular saw. The noise is remarkably reduced as compared with the conventional example shown in FIG. This phenomenon was first recognized by the present inventors.In the past, it was preferable to use a plurality of types of teeth, but if the number of types was too large, the appearance ratio of one type was too low. Therefore, contrary to the common belief that the number of types is preferably two to four, the optimum number is larger than the value expected in the past, and the better noise suppression effect is obtained with six or more types. Began to work. The present invention is based on the finding of such a phenomenon, and has succeeded in remarkably suppressing noise by using six or more types.

In the case of the circular saw of the present invention, as shown in FIG. 1, types 3-1, 3-2 and 3-3, there are six types of constraints in which the amount of protrusion of each tooth is substantially constant in a group of teeth. It is preferable to set the above. In this case, the height of the cutting edge (projection amount) becomes almost constant irrespective of the type, and the polishing operation of the cutting edge is facilitated. Further, when the groove protruding process is performed by the circular saw of the present invention, the groove bottom becomes substantially flat.

In addition, when there are six or more types of blades and the amount of protrusion is almost constant, the protruding end of each tooth extends in the thickness direction, as shown in 3-3 in Fig. 1, and the thickness direction It is preferable that the total elongation in a group is equal to the blade thickness. According to this type of circular saw, the groove bottom at the time of groove projection can be made flat. Further, the cutting load of each tooth can be homogenized.

It is preferable that there are six or more types, given the restriction that the protrusion amount at both ends in the thickness direction is large and the protrusion amount at other positions is slightly smaller. In this way, the portions that protrude greatly at both ends in the thickness direction form a sharp cut surface. Further, the appearance ratio of a specific type of tooth among the six or more types of teeth may be increased. For example, by making more teeth projecting at both ends in the thickness direction than others, a sharper (smooth) cut surface is formed.

In a circular saw with a group of teeth consisting of 6 or more types, At least one low protruding tooth may be added. This has the effect of facilitating the discharge of swarf.

The standard blade thickness of a circular saw with a diameter of 100 to 100 mm to which the tip is fixed is about 1 to 5 mni, and this should be equally divided into, for example, 1/6 to 1/10. As a result, the thickness of each tooth in the blade thickness direction can be made extremely small, about 0.1 to 0.8 mm, and cutting can be performed quietly using the minute cutting edge.

[Brief description of drawings]

FIG. 1 is a diagram systematically showing the tooth shape of a conventional circular saw.

FIG. 2 is a partial view of the circular saw of the first embodiment viewed from a radial direction.

FIG. 3 is a partial view of the circular saw of the first embodiment viewed from the axial direction.

FIG. 4 is a diagram showing the shape of the teeth of the circular saw of the first embodiment.

FIG. 5 is a diagram of hearing characteristics.

FIG. 6 is a diagram showing the relationship between the sound pressure spectrum and the noise spectrum.

FIG. 7 is a diagram showing the noise level of Ι Κ に対してに対して with respect to the number of divisions.

FIG. 8 is a diagram showing a noise level of 2 KHz with respect to the number of divisions.

FIG. 9 is a diagram showing a tooth shape according to the second embodiment.

FIG. 10 is a diagram showing the tooth shape of the third embodiment.

FIG. 11 is a view showing a modified example of the tooth shape of the third embodiment.

FIG. 12 is a diagram showing the tooth shape of the fourth embodiment.

FIG. 13 is a view showing a modification of the tooth shape of the fourth embodiment.

FIG. 14 is a diagram showing another modification of the tooth shape of the fourth embodiment.

FIG. 15 is a diagram showing the tooth shape of the fifth embodiment.

FIG. 16 is a view showing a modified example of the tooth shape of the fifth embodiment.

FIG. 17 is a diagram showing the tooth shape of the sixth embodiment.

FIG. 18 is a diagram showing a modification of the tooth shape of the sixth embodiment.

FIG. 19 is a view showing a modification of the tooth shape of the sixth embodiment.

FIG. 20 is a diagram showing a modified example of the tooth shape of the sixth embodiment.

FIG. 21 is a diagram showing a modification of the tooth shape of the sixth embodiment.

FIG. 22 is a diagram showing a modification of the tooth shape of the sixth embodiment. FIG. 23 is a diagram showing a modified example of the tooth shape of the sixth embodiment.

FIG. 24 is a diagram showing a modified example of the tooth shape of the sixth embodiment.

FIG. 25 is a diagram showing a modified example of the tooth shape of the sixth embodiment.

FIG. 26 is a diagram showing a modified example of the tooth shape of the sixth embodiment.

FIG. 27 is a diagram showing a modification of the tooth shape of the sixth embodiment.

FIG. 28 is a diagram showing the relationship between the lateral center angle and the roughness of the cut surface.

[Best mode for carrying out the invention]

Next, an embodiment of the present invention will be described.

(First embodiment)

2 to 4 show a first embodiment. This embodiment shows an example in which a group of teeth is composed of six types and the amount of protrusion is substantially constant within the group.

As shown in FIGS. 2 and 3, the circular saw 42 has a substantially disk-shaped circular saw body 40, and support walls 43 are formed at a constant pitch on the circumference of the circular saw body 40. Have been. The hard tip 41 is fixed to the support wall 43.

There are six types of hard tips 41 (each shown as 1 to 6 in the figure), which are fixed in the order of 1 to 6 in the rotation direction M of the circular saw. The teeth 1 to 6 form a group by this, and the teeth are formed on the entire circumference of the circular saw body 40 by repeating this group.

FIG. 4 shows the front view shape of each tooth in a plane perpendicular to the rotation direction M of the circular saw of the tip 41. As is clear from the figure, the tooth thickness T is divided into six, and the six divided cutting blades 1 to 6 are assigned to each type of tooth. Then, when the teeth of the 6 types and 1 group pass through the grove of the material to be cut, a flat grove bottom is formed in the grove for the entire blade thickness T. For this reason, a flat groove bottom is obtained when grooving is performed.In this case, the width of each cutting edge of 1 to 6 of the six types of teeth is TZ6, which is the same, so that a uniform The cutting burden is increased, and the durability is improved.

The circular saw of this embodiment has an outer diameter of 455, a blade thickness T of 3.0, and a number of teeth per revolution of 120 (20 groups). This cuts an aluminum sash with a rotation speed of 2500 rpm, a feed rate of 5 in / ni in, a top cut down of 15 mm wide and a height of 5 mm, and a maximum inner thickness of 3 mm. When the noise was measured at a distance of 1 m, it was confirmed that the noise level of 1 KHZ and 2 KHZ of A characteristic can be suppressed to as low as about 74 dB.

Figure 5 shows the well-known human ear hearing characteristics. The dashed line in FIG. 6 shows the sound pressure spectrum generally observed during the cutting operation. The solid line in Fig. 6 shows the sound pressure spectrum generated by adding the auditory characteristics shown in Fig. 5, that is, the noise spectrum showing the strength with which the generated noise can be heard by human ears. Torr.

Obviously, at 1-4 KHZ, the strongest noise is heard. Fig. 7 shows the relationship between the number of types of teeth that make up a group and the noise that can be heard during cutting work, and the noise level indicates the noise level at Ι Κ ζ ζ. Here, the number of divisions 1 indicates the case of the undivided type shown in 1 of FIG. 1, that is, the type B of JIS. The number of divisions of 2 indicates that two types of blades are used as shown in 3-1 in FIG. However, specifically, the measurement was made with the flat rake left at the right and left halves at the rake angle of 0 ', and the other parts chamfered. The number of divisions of 3 used was as shown in 3-3 in Fig. 1. Similarly, the blade thickness T in Fig. 4 was divided according to the number of blades, and a group was formed by teeth with a horizontal rake angle of 0 ° and each divided part as a cutting blade. The measurement conditions are the same as those described above. Clearly, the noise reduction effect is remarkable when the number of divisions is 6 to 12 compared to the case where the number of divisions is 5 or less. Fig. 8 shows the results of noise measurement at 2 KHz. Also in this case, the noise level is clearly different between divisions 5 or less and 6 or more. That is, when the number of divisions is 6 or more, the noise is remarkably suppressed in the range of 1 KHz to 4 HKz that is most strongly heard by the human ear. It is known that when the number of divisions exceeds 20, noise starts to increase, and it has been found that 6 to 20 types of division numbers are preferable.

(Second embodiment)

FIG. 9 shows a second embodiment. In this case, the protruding end has an apex and does not extend in the thickness direction. Each vertex corresponds to a point obtained by dividing the blade thickness T into six, and a group is composed of six types of teeth. Note that the number of divisions is not limited to 6, but can be 6 or more. It is practical that the number of divisions is set to 20 or less. When grooved with these teeth, the groove bottom can be formed as a whole with flat and fine streaks extending in the longitudinal direction.

(Third embodiment) FIG. 10 shows a third embodiment, in which each tooth has a flat blade obtained by dividing the blade thickness T into six. The number of divisions is not limited to six, as in the other embodiments. As a modification, the shape shown in FIG. 11 is also possible.

(Fourth embodiment)

In the case of Figs. 10 and 11, the blades in the group are arranged in the order of left-right-> left-> right and gradually move toward the center. <As shown in Fig. 12, cutting is performed in order from one direction. You may do so. In addition, the arrangement order of the teeth in a group may be the order shown in FIGS. 13 and 14 in addition to the order shown in FIGS. 4, 9, 10, and 12.

(Fifth embodiment)

Fig. 15 shows an example in which one group is composed of 10 teeth with 6 types, and Fig. 16 shows an example in which a group is composed of 8 teeth with 6 types. Note that this order of appearance is merely an example.

(Sixth embodiment)

Figures 17 to 27 show three or four types of teeth of six or seven types indicated by solid lines, the other three types indicated by broken lines, and all six or seven types superimposed. Is shown in FIG. In the case of FIG. 17, an example is shown in which each type of tooth has a flat blade extending in the thickness direction at the protruding end, and the flat blades have the same distance in the thickness direction. FIG. 18 shows an example in which each tooth has a flat blade, but the distance in the thickness direction is unequal. Fig. 19 shows an example in which both ends in the thickness direction are chamfered. Since the blades at both ends in the thickness direction of this embodiment are small and chamfered, they have a characteristic that they are not easily chipped.

FIG. 20 shows an example in which the protruding amount 1 (ell) of the other tooth is slightly smaller than the protruding amount L of the tooth protruding at both ends in the thickness direction. This circular saw is suitable for woodworking, and a good cut surface can be obtained because the edges at both ends in the thickness direction cut off the wood fibers. FIG. 21 shows an example in which each tooth has an apex, and the distance between each apex is made equal. Fig. 22 shows that, in addition to the tooth with seven types of split protruding ends shown in (a), the protruding height of the cutting teeth shown in (b) is slightly lower than that of the seven types (a) (0.1 to 0). 3mm) An example is shown where a tooth set low is added as the eighth type. In this case, eight kinds of teeth are used as a group. According to this circular saw, the discharge of chips is promoted by the spur teeth having a low protruding height, and vibration of the circular saw in the left-right direction in the figure is suppressed. Figure 23 shows an example in which teeth with a low protruding height are divided into two types (b) and (c). In this case, a total of nine types of teeth form a group. Figure 24 An example is shown in which teeth having flat blades whose protruding ends extend in the thickness direction and teeth having no flat blades are combined to form a group. FIG. 25 shows an example in which the amount of protrusion slightly changes in a group of teeth, and the overall shape is a convex curve. Figure 26 shows an example of a downwardly convex curve. Further, FIG. 27 shows an example in which a combination of a tooth having a flat blade and a tooth having no flat blade has a downwardly convex curve as a whole.

The present invention may be embodied in various other forms other than those specifically exemplified. For example, an arbitrary tooth may be provided with a lateral rake angle. Each tooth may be provided at an irregular pitch. Also, the appearance ratio of certain teeth in a group may be increased. In addition, a group of teeth may be used basically, and the other teeth may be mixed irregularly.

[The invention's effect]

According to the present invention, six or more types of teeth form a group, and each type of teeth protrudes at different positions in the thickness direction. Compared with the circular saw, which has been constructed as described above, it is possible to significantly reduce noise. In particular, it has been confirmed that the 1 to 4 KH2 sound, which is most often heard by the human ear, can be significantly suppressed.

Further, in the present invention, in particular, when the amount of protrusion is made substantially constant, the polishing operation of the blade is facilitated, and a groove having a substantially flat bottom can be processed.

If the protruding end of each blade extends in the thickness direction, and the elongation accumulated in one group is equal to the blade thickness, the flatness of the bottom surface of the groove is improved.

In addition, according to the type that protrudes largely only at both ends in the thickness direction, the wood fibers are cut satisfactorily at the protrusions at both ends, and a good cut surface is obtained.

Also, if teeth with a low protruding height are added to the teeth having a group of divided protruding ends, the effect of smooth chip discharge can be obtained.

As the number of types further increased, the cutting depth per tooth increased, and the vertical / horizontal dimension ratio of the chips approached 1, resulting in the formation of particles, which prevented the chips from flying up and adhering to clothes. Is facilitated.

Claims

The scope of the claims

1. In a circular saw having a plurality of teeth formed by fixing a plurality of chips serving as teeth along a cutting edge of a circular saw body having a thickness,

The tip of each tooth protrudes in the radial direction of the circular saw body,

At least six types of teeth with different projection positions in the thickness direction are grouped with six or more teeth,

The low-noise circular saw characterized in that the tip is fixed to a circular saw body in a unit of one group.

2. The low noise circular saw according to claim 1, wherein the amount of protrusion of each tooth is substantially constant within the group.

3. The low-noise circular saw according to claim 2, characterized in that the protruding end of each tooth extends in the thickness direction, and the sum of the extension in the thickness direction in the group is equal to the blade thickness. And low noise circular saw.

4. The low-noise circular saw according to claim 1, wherein the protruding amounts of the other protruding ends in the group are slightly smaller than the protruding amounts of the protruding ends of the teeth located at both ends in the thickness direction. A low-noise circular saw characterized by being cut down.

5. The low noise circular saw according to claim 1, wherein at least one tooth having a low protruding height is added to the group.