JPH0553448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION Field of the Invention The present invention relates generally to a method for welding a chip to the blade of a saw, particularly for mowing saws, which are subject to severe wear and tear. A typical chip material is the well-known tungsten carbide. Welding here mainly refers to brazing (especially silver brazing).

"Prior art and its problems" The chip welding (brazing) method using a conventional chip welding saw will be explained using the example shown in Figure 1 (the saw blade 1 moves from right to left in the figure). ).

In the case shown in FIG. 1A, all of the welded parts 2, 2', and 3 of the tip 5 are aligned with the advancing direction of the saw blade 1.
The lines in the diagram are
Please note that the thickness is perpendicular to the plane of the paper, and that brazing is done from both the front and back sides of the saw blade. ), the welded parts 2, 2', and 3 are orthogonal to each other to form a square cylinder bottom. What is shown in Figure B is
Since the welded part 3 is parallel to the direction of movement of the saw blade 1, the welded part 2' is omitted, which is superior to the one shown in FIG. 1A.

However, in both of the chips shown in Figures A and B, the welded part of the chip has a rectangular (square tube with thickness) bottom shape in the figure, and the welded parts 2, 2', Since the difference in area (difference in length in the diagram) between the two parts is large, a load is particularly applied to one of the surfaces when a strong cutting force is applied from one direction during use. In addition, welding of perpendicular welding parts has the disadvantage that residual strain tends to occur, making it difficult to obtain strong welding, and even when machining blades,
Chip withdrawal is often seen. The method shown in FIG. 1C was devised to eliminate these drawbacks, but it is very difficult to maintain the machining accuracy of the welded surface. In other words, since the force that presses the welding surface of the chip against the welding surface of the saw blade is limited to one direction, the number of welded parts is mainly limited to two, and when welding is applied to welded part 3, The pressure will be uneven. In addition, since the cross-sectional area of the part indicated by S in the figure, which applies the largest load to the chip 5 during cutting and therefore requires the most strength, is small,
Inevitably, it becomes weaker against shock. Furthermore, the strength in the welding direction of the chips is limited only in the direction opposite to the cutting force.

An object of the present invention is to improve the above-described conventional tip welding method using a rectangular cylindrical tip to a disc-shaped saw blade, so that the welded portion forms a "V" shape on the saw blade surface. An object of the present invention is to provide a method for welding a tip to a saw blade.

"Means for Solving the Problems" In order to solve the above problems, the present invention has the following configuration.

That is, the present invention: When welding a chip including a cutting edge to a saw blade: A "V"-shaped notch opening on the saw tooth side is provided in the saw blade; a "V"-shaped notch abuts on the notch; A method for welding a tip to a saw blade characterized by: brazing and engaging a tip having a welded portion of the saw blade;

"Operation" Since the chip of the present invention has a "V"-shaped welding surface, by applying pressure from the direction that bisects the corner surrounding the "V" and welding, the welded part shown in FIG. 2 can be welded. An average and equal pressure can be applied to 2 and 3. Generally speaking, the welding strength increases depending on the welding area, the pressure applied during welding, and the accuracy of the seat of the welding surface (the degree of fit), and the strength of the welding increases depending on the shape of the chip and the saw blade of the present invention. The cutout part is extremely convenient for satisfying this condition.

"Embodiment" FIG. 2 shows an embodiment of the present invention. A chip 5 having welded parts 2 and 3 that accurately abuts and engages with the "V"-shaped notch provided in the saw blade 1 is brazed from both the front and back sides. The part S that requires the most strength is shown in Figure 2a,
Its length (actually, the area taking into account the thickness)
is sufficiently large compared to conventional products.

Figure 2a shows a cut where the attached blade 4 of the tip 5 is perpendicular to one side of the "V"-shaped notch and perpendicular to the direction of saw movement during cutting (from right to left in the figure). Fig. 2b shows a case where the chip 5 is welded to the saw blade 1 in a direction substantially perpendicular to the direction of saw movement (from right to left in the figure), This is an example of a case in which the chip 5 is provided at the left end of the chip 5 in the figure. (Please compare the brazing position of the tip 5 to the saw blade 1 and the relative position of the cutting blade 4 to the tip 5.) The type shown in Fig. 2a allows the welded part to be sufficiently wide, and Since welding is performed near the teeth of the saw blade, it is suitable for cases where the width of the saw blade 1 is narrow or for small-diameter rotating saw teeth.

In Fig. 3a, the welded part 3 is not a straight line (planar when considering the thickness direction) in Fig. 2a, but in the figure,
In the case of an upwardly convex curve, Fig. 3b shows a case where the welded portion 2 is the same as above, but a leftwardly convex curve.
In the present invention, it is shown that a "V"-shaped line part (considering the thickness, a plane part) does not necessarily mean a straight line (a plane part).

"Effects of the Invention" As described above, the present invention provides the following advantages: When welding chips to the saw blade to form saw teeth, weld the chips to the saw blade, on the saw tooth side (in the direction approaching the saw teeth and reaching the saw teeth). This is a method of welding a chip to a saw blade, in which a cutout portion having an approximately "V" shape is provided, and a chip having a welding part of the same shape that comes into contact with the cutout part is welded to the saw blade, and the chip made in this way is The serrations and chips are installed precisely and accurately, the welding is strong, and the residual strain is small.

In addition, the amount of welding work is small, resulting in energy and labor savings.

In addition, the chip having the "V" shaped notch and the "V" shaped welded part is made to have a radially symmetrical structure,
By keeping the shape substantially the same even when turned upside down, a disc-shaped saw that has been worn out due to rotation in one direction can be used upside down.

[Brief explanation of the drawing]

FIG. 1 is a plan view of three examples showing the welded state of the tips of a conventional tipped saw. FIG. 2 is a plan view of two embodiments a and b showing the chip welding method of the present invention. FIG. 3 is a plan view showing another modification of the chip welding part of the present invention. 1... Saw blade, 2, 2', 3... Welded part, 4...
Cutting blade, 5...chip.

Claims (1)

[Scope of Claims] 1. When welding a chip including a cutting blade to a disc-shaped saw blade: A "V"-shaped notch opening on the saw tooth side is provided in the saw blade; A method of welding a tip to a saw blade, comprising: brazing and engaging a tip with an abutting "V" shaped weld. 2. Welding of saw blade and tip forming a "V" shape The method of welding a tip to a saw blade according to claim 1, wherein two side surfaces are abutting curved surfaces that can be approximated to a plane.