JPH07276304A - Tip saw of circular saw and its manufacture - Google Patents

Abstract

PURPOSE:To provide the tip saw of a circular saw in which weight reduction is contrived and also durability and sharpness equal to the conventional tip saw of the circular saw are obtained and to provide the manufacturing method thereof. CONSTITUTION:The tip saw of a circular saw is equipped with a disk-like base 2 molded of a resin, an edge part 3 which is stuck to the outer circumference part of the base 2 and made of a metal and tips 8 brazed in the outer circumference of the edge part 3. The edge part is stuck to the base 2 by providing a fitting part in the inner circumference edge of the edge part 3 and welding the base 2 to the fitting part. Welding of the base 2 to the edge part 3 is performed by applying high-frequency induction heating to the edge part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular saw tip saw in which a tip is brazed and fixed to an outer peripheral edge and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a circular saw used for cutting grass, cutting wood, etc., a steel plate having a uniform thickness is generally punched out to form a base metal, and a blade part of the base metal is cut. A circular saw tip saw in which a large number of tips are brazed and fixed to the outer peripheral edge is known. By the way, this tip saw is heavy in weight, and when it is used for a mower, for example, the head portion of the mower becomes heavy, which makes it difficult to work. Therefore, a circular saw in which the blade portion and the base metal as a whole are formed of synthetic resin is proposed as disclosed in, for example, Japanese Patent Publication No. 6-12.

In this circular saw, a base metal and a blade portion are made of synthetic resin having a uniform thickness, a plate material is punched into a predetermined shape, and the shape of each blade portion is the front surface portion or the back surface portion of the cutting blade. It should be formed in a right angle with respect to the other side and polished from one side so as not to be pointed. In addition, the outer peripheral portion of the blade portion is divided into a plurality of arcs, and the outer peripheral surface of each arc is a cutout portion, and a half or three minutes from the longest top to the shortest top of the center fitting hole The blade portion is formed only on the circular arc portion of about 2 and the portion without the blade is a cutout portion.

[0004]

However, this circular saw has a problem that it is inferior in durability and sharpness although it is possible to reduce the weight. That is, since the blade portion itself is also made of synthetic resin, it is inferior in hardness to a tip made of cemented carbide, and is easily chipped when hit by stones, for example, and is far less durable than a tip saw. Further, it becomes difficult to obtain the same sharpness as a chip with a synthetic resin blade.

The present invention has been made in view of the above circumstances, and an object thereof is a circular saw tip saw which can be reduced in weight, and which has durability and sharpness equivalent to those of a conventional circular saw tip saw. It is to provide a manufacturing method.

[0006]

In order to achieve such an object, a circular saw tip saw according to claim 1 has a disk-shaped base formed of resin and a metal circle fixed to the outer peripheral portion of the base. In a circular saw tip saw having an annular blade portion and a tip fixed to the outer peripheral edge of the blade portion by brazing, an engaging portion is provided on the inner peripheral edge of the blade portion, and a base is welded to the engaging portion. According to the above, the base and the blade are integrally fixed.

The circular saw tip saw according to claim 2 is
The engaging portion is a hole penetrating in the front-back direction, and the circular saw tip saw according to claim 3 is characterized in that the engaging portion is a groove formed with a narrow width on the opening side. .

According to a fourth aspect of the present invention, there is provided a method for manufacturing a circular saw tip saw, which is made of a metal and is formed in an annular shape so that an outer peripheral portion of a disk-shaped base formed of resin has an engaging portion at an inner peripheral edge thereof. The blade portion is brought into contact with the heating coil, and the heating coil is disposed close to the contact portion, and the blade portion of the portion is subjected to high frequency induction heating to weld the base to the engaging portion. Further, in the manufacturing method according to claim 5, a step portion is formed on the outer peripheral edge of the base, and one surface of the blade portion is brought into contact with the step portion, and then an annular resin is formed on the other surface of the blade portion. The fixing member made of abutment is brought into contact with the blade, and then the blade is induction-heated.

[0009]

According to the circular saw tip saw of the first aspect, the base corresponding to the base metal is molded from resin, and the metal blade is welded to the outer periphery of the base. At this time, the blade portion is provided with an engaging portion, and the resin of the base is welded to the engaging portion to integrally fix the base and the blade portion. Chips are brazed to the outer circumference of the blade. By making the base made of resin, it is possible to reduce the weight, and the engagement part prevents the blade part from falling off in the centrifugal direction. In addition to improving the durability, the tip provides the same sharpness as the conventional one.

Further, according to the circular saw tip saw of the second aspect, by the holes penetrating in the front and back directions, and by the circular saw tip saw of the third aspect, the blade portion is formed by the groove having a narrow opening edge side. The base is firmly fixed, and the blade part is surely prevented from falling off in the centrifugal direction.

Further, according to the method of manufacturing a circular saw tip saw of claim 4, the blade portion having the engaging portion at the inner peripheral edge is brought into contact with the outer peripheral edge of the resin base, and the contact portion is heated. Place the coils in close proximity. When a high-frequency current is supplied to the heating coil, an eddy current is induced in the metal blade to induce induction heating, and the heat melts the base resin in contact with the blade. The molten resin enters the engaging portion of the blade portion and is solidified, so that the base and the blade portion are fixed.

According to the method for manufacturing a circular saw tip saw of the fifth aspect, a step portion is formed on the outer peripheral edge of the base, and one surface of the blade portion is brought into contact with this step portion. On the other surface of the blade portion, for example, an annular fixing member made of the same resin as the base is brought into contact. That is, the blade is in a state of being sandwiched between the base and the fixing member. In this state, when the blade is induction-heated, the fixing member and the base are melted and welded to the blade.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 to 4 show a circular saw tip saw according to the present invention, FIG. 1 is a plan view thereof, and FIG. 2 is a sectional view thereof.
3 is a cross-sectional view of the main part, and FIG. 4 is a plan view of the main part. Figure 1
Further, in FIG. 2, the circular saw tip saw 1 has a disk-shaped base 2 corresponding to a conventional base metal, and an annular blade portion 3 fixed to the outer peripheral edge of the base 2.

The substrate 2 is injection-molded by, for example, a fluorine-based resin, an acetal-based resin, a silicon-based resin, or a combination of these resins, and a through hole 4 as a mounting hole is formed in the center thereof. A plate thickness portion 5 is formed on the outer peripheral edge of the base 2, and the inner peripheral edge of the blade portion 3 is fixed to the plate thickness portion 5.

The blade portion 3 is formed in an annular shape by punching and pressing a steel plate such as SK material or SKS material. Has been drilled. The resin of the base 2 enters and solidifies into the holes 6 by the method described later, and the blade portion 3 is fixed to the base 2. Further, a plurality of tip mounting portions 7 (see FIG. 1) are formed on the outer peripheral edge of the blade portion 3,
A chip 8 made of superhard metal is brazed and fixed to the chip mounting portion 7.

Next, a method of manufacturing the circular saw tip saw 1 will be described with reference to FIG. First, a base 2 having an annular step portion 10 formed on the plate thickness portion 5 and a blade portion 3 having a hole 6 formed on the inner peripheral edge thereof are prepared. As shown in, the inner peripheral edge of the blade portion 3 is fitted. Then, as shown in FIG. 5 (B), the fixing member 11 formed in a predetermined shape in advance is fitted and placed on the upper surface of the blade portion 3. The fixing member 11 is made of the same resin as the base 2 and is formed into an annular shape so as to fit into the step portion 10 of the base 2.

In this state, as shown in FIG. 5C, the heating coil 12 is arranged close to the lower surface (or upper surface) of the thick plate portion 5. The heating coil 12 is formed by winding a copper pipe, and both ends of the heating coil 12 are connected to a high frequency generator 13 including, for example, a transistor inverter. Then, when the high frequency generator 13 is operated to supply the high frequency current of the predetermined frequency to the heating coil 12, the magnetic flux generated from the heating coil 12 induces an eddy current in the blade portion 3 to perform induction heating.

The heat generated by the induction heating melts the base 2 and the fixing member 11 which are in contact with the blade 3, and the melted resin flows into the hole 6 of the blade 3. After supplying the high frequency current for a predetermined time, the operation of the high frequency generator 13 is stopped. Then, when the heated portion is naturally cooled or forcedly cooled, the resin that has entered the hole 6 is solidified, and the blade 3 is integrated with the base 2, that is, the blade 3 and the base 2 are as shown in FIG. Will be fixed to. By the heating of the blade portion 3, the contact surface between the step portion 10 of the base 2 and the fixing member 11 is also welded, and the fixing member 11 is integrated with the base 2. afterwards,
The circular saw tip saw 1 is manufactured by brazing and fixing the tip 8 to the tip mounting portion 7 of the blade portion 3.

In this embodiment, for example, it may be manufactured as shown in FIG. That is, as shown in FIG. 6 (A), with the blade portion 3 fitted to the stepped portion 10 of the base 2, as shown in FIG. 6 (B), a projection 11a is previously provided on the lower surface thereof. The fixing plate 11 is fitted so that the protrusion 11 a is located in the hole 6. Then, as shown in FIG. 6C, the heating coil 12 is arranged in proximity to the blade portion 3 to induction-heat it, and the fixing plate 11 and the substrate 2 are welded to the blade portion 3. By doing so, it is possible to prevent the occurrence of depressions on the surfaces of the fixed plate 11 and the plate thickness portion 5 after welding due to the resin flowing into the holes 6. In this case, instead of the protrusion 11a, a protrusion may be provided on the bottom surface 10a (see FIG. 6C) of the step portion 10, or a protrusion may be provided on both the fixing plate 11 and the bottom surface 10a.

As described above, in the circular saw tip saw 1 described above, since the base 2 is formed of resin, the weight can be reduced. For example, when the circular saw tip saw 1 is used in a mower, the head portion of the mower becomes light. , Work can be performed easily. In addition, since the tip 8 is brazed to the blade portion 3, it is less likely to be hit by stones or the like and chipped, which improves durability as compared with a resin blade and has the same sharpness as a conventional tip saw. Is obtained.

Further, a hole 6 is provided in the inner peripheral edge of the blade portion 3,
Since the resin of the base 2 and the fixing member 11 is introduced and solidified from both sides of the hole 6, the blade portion 3 is firmly fixed to the base 2,
Due to the centrifugal force generated by the rotation of the circular saw tip saw 1, the blade portion 3 does not fall off the base 2 and can be used stably for a long period of time. In addition, the buckling phenomenon can be suppressed by setting the resin material, thickness, etc. as appropriate, eliminating the need for quenching or annealing of the base metal, which is required in the past. 1 can be manufactured at low cost.

In the above embodiment, the hole 6 was formed in the inner peripheral edge of the blade 3 and the resin or the like of the substrate 2 was melted and introduced into the hole 6, but the present invention is not limited to this. Instead, for example, the configuration may be as shown in FIGS. 7, 8 or 9 and 10. That is, as shown in FIG. 7, the elliptical groove 14 in which the opening edge 14 a is formed narrowly at the inner peripheral edge of the blade portion 3.
As shown in FIG. 8, the resin of the base 2 and the fixing member 11 is introduced and solidified in the groove 14.

Further, as shown in FIG. 9, an inverted triangular groove 15 is provided in the inner peripheral edge of the blade portion 3, and the groove 15 has the shape shown in FIG.
As shown in 0, the resin of the base 2 and the fixing member 11 is entered and solidified. As described above, even if the grooves 14 and 15 having various shapes having narrow opening edge sides are used, the centrifugal force can surely prevent the blade portion 3 from falling off the base plate 2, and the same operation as the above embodiment. It is clear that the effect will be obtained.

Further, in the above embodiment, the heating coil 12 is arranged close to one surface side of the blade portion 3 when the blade portion 3 is induction-heated, but it may be arranged on both sides of the blade portion 3. Alternatively, as the resin of the base 2 and the fixing member 11, an appropriate resin such as a resin containing glass fiber or a resin containing wire mesh may be used. Further, in the above embodiment, the tip is brazed to the blade portion fixed to the base, but the blade portion to which the tip is brazed in advance is fixed to the base, etc. within a range not departing from the gist of the present invention. It goes without saying that it can be changed.

[0025]

As described above in detail, in the circular saw tip saw and the manufacturing method thereof according to the present invention, the circular saw tip saw can be reduced in weight by molding the base corresponding to the base metal with resin. In addition, the blade portion and the base can be firmly fixed to each other, and durability and sharpness equivalent to those of the conventional tip saw can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of a circular saw tip saw according to the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a sectional view of the main part.

FIG. 4 is a plan view of a main part of the blade section.

FIG. 5 is a sectional view showing the manufacturing method thereof.

FIG. 6 is a sectional view showing another example of the manufacturing method.

FIG. 7 is a plan view of an essential part showing another embodiment of the circular saw tip saw according to the present invention.

FIG. 8 is a sectional view of the main part thereof.

FIG. 9 is a plan view of a main part showing still another embodiment of the circular saw tip saw according to the present invention.

FIG. 10 is a sectional view of the main part thereof.

[Explanation of symbols]

 1 Circular Saw Chip Saw 2 Base 3 Blade 5 Plate Thickness 6 Hole 8 Chip 10 Step 11 Fixing Member 11a Protrusion 12 Heating Coil 13 High Frequency Generator 14, 15 Groove 14a Open Edge

Claims (5)

[Claims] 1. A disk-shaped base formed of resin, and a metal annular blade portion fixed to the outer periphery of the base,
In a circular saw tip saw including a tip brazed and fixed to the outer peripheral edge of the blade portion, an engaging portion is provided on the inner peripheral edge of the blade portion, and the base is welded to the engaging portion to form a base board. A circular saw tip saw with a blade and a blade integrally fixed. 2. The circular saw tip saw according to claim 1, wherein the engaging portion is a hole penetrating in the front-back direction. 3. The circular saw tip saw according to claim 1, wherein the engaging portion is a groove having a narrow width on the opening side. 4. A disk-shaped base formed of resin is brought into contact with an outer peripheral portion of an annular metal blade portion having an engaging portion at its inner peripheral edge, and the contact portion is brought into contact with the outer peripheral portion. A method for manufacturing a circular saw tip saw, wherein heating coils are arranged in proximity to each other, and a blade portion of the portion is subjected to high-frequency induction heating to weld the base to the engaging portion. 5. A step portion is formed on the outer peripheral edge of the base, and one surface of the blade portion is brought into contact with the step portion, and then an annular resin fixing member is attached to the other surface of the blade portion. The method for manufacturing a circular saw tip saw according to claim 4, wherein the blade portion is brought into contact with the blade portion and then the blade portion is induction-heated.