JPH0739335U - Slicing tip saw - Google Patents

Abstract

(57) [Summary] [Purpose] The tip and body should be brazed well, and the tip should be a shape that does not easily break, making it a powerful cutting saw. [Structure] A disk-shaped main body 10 that is driven to rotate, a blade base 11 provided at appropriate intervals in the circumferential direction on the peripheral edge of the main body, and side surfaces formed on each of the blade bases have a rotational direction. A mid-sized bay-shaped recess 12 that opens at the front end and gradually expands on the way obliquely rearward from the opening and then narrows, and is formed in a shape corresponding to this bay-shaped recess in the bay-shaped recess. It consists of a tip 13 having a brazed base 22 which fits in and a part of which projects from the opening to form a blade 23.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tip saw for brush cutting, mainly to the structure of a brazing part of a tip constituting a cutting edge, and to a tip saw to which a tip is brazed firmly.

[0002]

[Prior art]

 Although there are various tip shapes of the conventional cutting saws for cutting brush, they are roughly classified into an elongated shape, a square shape, and a complicated irregular shape. In general, a long and slender shape is often used because it expects normal wear from the tip and expects a long life. For example, as shown in FIG. 4 (a), a substantially rectangular chip 1 when viewed from the side has a substantially hooked shape in a chip mounting recess 3 of a blade base 2 formed on the peripheral edge of a disk-shaped main body. As shown in (b) of the figure, when the two sides are brazed together, even if the shape of the tip 4 is slightly deformed, the tip mounting recess 6 of the blade base 5 has a substantially U-shape (side surface). In most cases, the three sides connected to each other are brazed together. In addition, a cutting saw for cutting brushes is different from a normal circular saw for metal or woodworking in that its usage conditions are considerably severe. In other words, in the case of circular saws for metal or woodworking, the material to be cut is constant, and the feed is also mechanically constant. Often mixed with grass and shrubs, contact with soil and stone is often unavoidable.

[0003]

[Problems to be solved by the device]

 As mentioned above, since the conditions of use are severe, in the case of a mowing tip saw, a sharpness is also necessary, but first of all it is necessary that the tip not fall off. For this purpose, it is conceivable to increase the brazing area between the chip and the main body. As a result, it is assumed that the one shown in FIG. 4 (b) is appropriate. However, in the case of Fig. 4 (b), the flow of brazing is bad during brazing, and the brazing does not surely reach the entire area of the surface to be brazed. Some of these bad wax conditions are not always easy to find. As a result, even if the length of the brazing surface is increased when viewed from the side, the chip 4 is not necessarily strongly bonded to the main body 5, so that a defect such as breakage or falling of the chip is found during use. .

In the cases of FIGS. 4 (a) and 4 (b), looking at past breakage conditions, it is very often broken at a position near the middle in the longitudinal direction indicated by broken lines 7 and 8. Estimating the cause of chip breakage in this way, it is when the long and narrow chips are not evenly brazed over the entire brazing surface and, in extreme terms, they are partially brazed, and chip 4 strikes. When a typical cutting load is applied, the firmly brazed portion serves as a fulcrum, and an action force for bending the chip 4 is likely to work. And, as can be understood from the harsh operating conditions of the cutting brush saw, as mentioned above, the cutting load does not always act only on the cutting edge, so there is an opportunity to work more to bend the tip. There are many. Therefore, if the chip is long and slender and bad brazing overlaps with each other, it is easily damaged. An object of the present invention is to provide a cutting saw having a stronger cutting force than conventional ones, in which the tip and the brazing surface of the main body have a shape in which the wax is easily spread, and the tip is not easily broken by the bending force. .

[0005]

[Means for Solving the Problems]

 The means of the present invention comprises a disk-shaped main body that is driven to rotate, a blade base portion provided at the peripheral edge of the main body at appropriate intervals in the circumferential direction, and a side surface shape formed in each of the blade base portions in the rotational direction. It has a mid-sized bay-shaped recess that opens at the front end of the car and goes diagonally rearward toward the center of the body from that opening, and then gradually expands in the middle, forming a shape corresponding to this bay-shaped recess. It is characterized in that it is composed of a tip having a base portion formed and brazed within the bay-shaped recess and partially protruding from the opening to form a blade portion. In the above means, the bay-shaped recess is preferably elliptical and has a shape excluding one end in the longitudinal direction. Further, in the above-mentioned means, it is preferable that the bay-shaped recess has an arc shape and an arc shape larger than a semi-circle. Further, in the above-mentioned means, the bay-shaped recess may be one in which a part of a curved edge on one side is replaced with a straight edge or a different curved edge on the way from the opening toward the rear obliquely toward the center of the main body. .

[0006]

[Action]

 According to the above-mentioned means, since the side shape of the brazing surface is a medium shape that smoothly expands and then narrows, it is a smooth series without a bent surface portion having a small radius. The brazing is good when brazing, and a very good brazing condition is obtained. Therefore, chip bending force due to poor brazing is less likely to act. Further, even if the shape of the chip is elongated, it is a side surface shape and is a medium-thick shape that bulges in the middle of the longitudinal direction, so that it is difficult to break near the middle of the longitudinal direction.

[0007]

【Example】

 A first embodiment of the present invention will be described with reference to FIG. In the figure, 10 is a cutting saw main body, 11 is a blade base, 12 is a bay-shaped recess, and 13 is a tip. The main body 10 is a disc having a diameter of 255 mm and a thickness of 1.25 mm, and has a mounting hole 21 at the center for mounting on a rotary shaft of a brush cutter. On the peripheral edge of the main body 11, 40 blade base portions 11 projecting at regular intervals are formed. The blade base 11 has an opening at a front end in a predetermined rotation direction, and is formed to extend obliquely rearward (diagonally lower right in FIG. 1B) toward the center of the main body 11 from the opening, and the diagonal rear There is a generally oval bay-shaped recess 12 that narrows smoothly and narrows on the way to. A tip 13 is attached to the bay-shaped recess 12 by brazing.

The tip 13 is made of, for example, cemented carbide and includes a base portion 22 having a shape corresponding to the bay-shaped recess 12 and a blade portion 23 integrally formed with the base portion 22, and the base portion 22 has a bay-shaped shape. It is brazed so that it is fitted into the recess 12. The blade portion 23 projects from the blade base portion 11 on the front side in the rotation direction indicated by the arrow, and has the tip as a front cutting blade and has a scooping angle α = 8 ° and a clearance angle θ = 8. The longitudinal direction of the tip 13, that is, the direction of the long axis of the bay-shaped recess 12 and the elliptical portion of the base 22 is such that the angle β with respect to the radius line 24 of the main body 10 passing through the tip of the blade 23 is about 45 °. Is. 1 (b) and 1 (c), this tip saw has only one blade portion, but the blades are arranged in a staggered manner along the circumferential direction.

In the tip saw according to the first embodiment, the tip 13 is joined to the blade base portion 11 by a long brazing portion, but the side shape of the brazing portion does not include a circular arc having a small radius of curvature. Since it is a smooth curve with a large radius of curvature, the brazing flow during brazing is extremely good, resulting in a very good brazing condition. Since the shape of the chip 13 is close to an ellipse and is a large and medium-sized shape in the middle of the longitudinal direction, it is also a shape that is unlikely to break. Therefore, the tip 13 is a tip saw that is hard to peel off at the brazing portion and is not easily broken. Further, the middle-thick shape in which the bay-shaped recess 12 is enormous on the way has an advantage that the brazing work is facilitated because the tip 13 having a corresponding shape is difficult to be ejected when being held prior to brazing. . However, since the tip 13 is to be brazed and the bay-shaped recess 12 is provided with a brazing allowance, when the tip 13 can be inserted from the outside in the radial direction when the tip is installed during brazing. There can be. Even in that case, if the tip 13 is brazed over the short diameter portion (maximum width portion) of the elliptical shape toward the cutting edge side, sufficient brazing strength can be obtained.

A second embodiment of the present invention is shown in FIG. The difference from the first embodiment is that the side surface shape of the brazing surface between the bay-shaped recess 12a and the base portion 22 of the tip 13a is a slightly elongated ellipse, and the front edge of the blade base 11 is formed into a bulge portion 25. The points are formed to increase the strength and wear allowance of the blade base 11, and the angle β is set to 30 °. The other parts are substantially the same, and therefore the description is omitted. In the second embodiment, since the angle β is slightly small, the strength and wear margin between the front edge of the blade base 11 and the tip 13a are so small that the bulge portion 25 compensates for this. ing. Therefore, it is as robust as or more robust than that of the first embodiment.

A third embodiment of the present invention is shown in FIG. The difference from the first embodiment is that the side surface of the brazing surface between the bay-shaped recess 12b and the base portion 22 of the tip 13b is formed in an arc shape having about 2/3 of the circumference. A third embodiment of the present invention is shown in FIG. The difference from the first embodiment is that the side shape of the brazing surface between the bay-shaped recess 12c and the base portion 22 of the tip 13c has a part of the curve on one side with respect to the major axis of the ellipse replaced by a straight line. It is a modified elliptical shape. A third embodiment of the present invention is shown in FIG. The difference from the first embodiment is that the side shape of the brazing surface between the bay-shaped recess 12d and the base 22 of the tip 13d is such that a part of the curve on one side with respect to the major axis of the ellipse has a relatively radius of curvature. The point is the shape of a magatama that replaces the large S-curve.

In the above-mentioned embodiment, the shape of the blade of the tip is not particularly limited so that it is not described in detail. Generally, the scooping angle α is 0 ° to 15 ° and the tip clearance angle θ is 0. The angle is about 15 ° to 15 °, and these can be arbitrarily adopted. The angle β in FIG. 1B can be set to about 20 ° to 50 °. Moreover, the arrangement of the blades formed by the chips in the circumferential direction is not limited to zigzag.

[0013]

[Effect of device]

 According to the present invention, the side shape of the bay-shaped recess of the blade base portion is a mid-sized bay-shaped recess that smoothly expands and narrows as it goes from the opening side to the back side, and the tip wax Since the base part to be brazed has a shape corresponding to this, the brazing area during brazing is good, and even if the brazing part is long, a good brazing condition can be obtained over the entire length. In addition, since the shape of the base portion brazed to the tip portion of the chip is medium-thick, the conventional slender tip is liable to break due to the thick middle portion. In addition, since the tip has a medium-thick shape, it does not come out of the bay-shaped recess toward the cutting edge side, so it is held even more strongly. Therefore, it has the effect of exhibiting robustness under severe operating conditions and preventing chipping due to defective brazing and chipping or breakage.

[Brief description of drawings]

1 shows a first embodiment of the present invention, (a) is a side view of a tip saw, (b) is a partially enlarged view of (a), and (c) is a plan view corresponding to (b).

FIG. 2 is a partially enlarged side view showing a second embodiment of the present invention.

FIG. 3 shows another embodiment of the present invention, (a) is a partially enlarged side view of the third embodiment, (b) is a partially enlarged side view of the fourth embodiment, and (c) is a fifth embodiment. It is a partially expanded side view of FIG.

FIG. 4 shows an example of a conventional brush cutting tip saw, (a)
Is a partially enlarged side view of an example, and (b) is a partially enlarged side view of another example.

[Explanation of symbols]

 10 Tip Saw Main Body 11 Blade Part 12 Bay-shaped Recess 12a Bay-shaped Recess 12b Bay-shaped Recess 12c Bay-shaped Recess 12d Bay-shaped Recess 13 Chip 13a Tip 13b Chip 13c Tip 13d Tip 22 Base 23 Blade

Claims (3)

[Scope of utility model registration request] 1. A disk-shaped main body that is rotationally driven, a blade base portion provided at the peripheral edge of the main body at appropriate intervals in the circumferential direction, and a side surface shape formed in each of the blade base portions has a rotational direction. A mid-sized bay-shaped recess that opens to the front end and extends diagonally toward the center of the main body from the opening and expands smoothly along the way, and a bay formed in a shape corresponding to this bay-shaped recess A cutting saw having a base portion brazed within the concave portion and brazed to form a blade portion protruding from the opening. 2. The mowing tip saw according to claim 1, wherein the bay-shaped recess has an elliptical shape with one end in the longitudinal direction thereof being removed. Tipped saw. 3. The mowing tip saw according to claim 1, wherein the bay-shaped recess has an arc shape and an arc shape larger than a half arc.