Tipped saw blade for gypsum board

Abstract

To provide a tip saw for gypsum board, which reduces the amount of scattering of dust, prevents undulation during rotation, and has a lighter cutting edge. [Solution] The chip saw 1 for gypsum board is disk-shaped and consists of a mounting hole 20 that opens at the center of the circle when viewed from the front, a base metal portion 2 that is arranged on the outer periphery of the mounting hole 20, a blade body 3 that is arranged on the outer periphery of the base metal portion 2, and a tip 4 that is attached to the tip of the blade body 3.The base metal portion 2 consists of a first base metal portion 2a that is located on the inner periphery and a second base metal portion 2b that is located on the outer periphery of the first base metal portion 2a, and the second base metal portion 2b is formed to be thinner than the first base metal portion 2a.

Description

[Technical Field]

[0001] This invention relates to a tip saw that is attached to a handheld power tool and used to cut gypsum board. [Background technology]

[0002] Conventionally, electric circular saws have been widely used to cut gypsum boards used for the interior of buildings, etc. However, when cutting gypsum boards with electric circular saws at construction sites, the rotary cutting blades mainly used are chip saws, which have carbide tips at the tip of the blade body, and therefore have the drawback of stirring up a large amount of dust from the cut pieces and scattering it around, contaminating the construction site, and also of scattering dust upward in the direction of the chip saw's movement, causing dust to fall on workers and hinder the cutting work.

[0003] For this reason, cutting work was carried out while attaching a dust collector to the electric circular saw to collect dust, but the hose attached to the dust collector took up space at the construction site, and because cutting work was carried out with the dust collection hose attached to the electric circular saw, the work process including cutting and the handling of the work equipment became cumbersome, reducing the efficiency of the cutting work.In addition, cutting with a chip saw left rough cut edges on the gypsum board, requiring finishing work such as planing.

[0004] To solve the above-mentioned problems, the applicants have provided a round blade without a tip, which has a blade body consisting of a flat rake face with a negative rake angle and a cutting edge with a tip relief angle and a blade sharpening angle in the circumferential direction (Patent Document 1). This has the sharpness of a tipped saw, and by discharging dust in the direction of travel without kicking it up and scattering it, it is possible to suppress pollution of the surrounding environment and prevent workers from being hindered in their work by dust. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-83242 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the invention described in the above patent document is a sharp knife blade, and there is a demand for a chip saw with sharpness. Therefore, there is a demand for a chip saw with sufficient sharpness that scatters less dust when cutting gypsum board. In addition, a thin chip saw will scatter less dust, but in that case, undulation will occur when rotating, so there is a demand for a chip saw that does not cause such undulation.

[0007] Therefore, an object of the present invention is to provide a chip saw for gypsum boards that reduces the amount of dust scattered even when it is a chip saw, prevents undulation during rotation, and has a lighter cutting edge. [Means for solving the problem]

[0008] In view of the above problems, the tip saw for gypsum board according to the present invention is a disk-shaped mounting hole that opens at the center of the circle when viewed from the front, a base metal part that is arranged on the outer periphery of the mounting hole, a blade body that is arranged on the outer periphery of the base metal part, and a tip that is attached to the tip of the blade body, The base metal portion is characterized in that it consists of a first base metal portion located on the inner periphery and a second base metal portion located on the outer periphery of the first base metal portion, and the thickness of the second base metal portion is formed thinner than that of the first base metal portion.

[0009] The thickness of the first base metal portion and the second base metal portion is changed by a step portion, It is preferable that the radial length of the first base metal portion is longer than the radial length of the second base metal portion.

[0010] The blade has a brazed portion to which the tip is attached, The thickness of the brazed portion is preferably thinner than that of the first base metal portion and equal to or thicker than that of the second base metal portion.

[0011] In addition, the blade body to which the tip is attached extends from the outer peripheral edge of the second base metal part at an inclined angle on the front side and the back side, when viewed from the side, It is preferable that the horizontal length between the apex on the front side and the apex on the back side of the chip is formed to be equal to or thicker than the thickness of the first base metal portion.

[0012] The chips include a first chip inclined toward the front side, a second chip inclined toward the back side, and a third chip in a horizontal direction; It is preferable that the first tip, the second tip, the first tip, the second tip, and the third tip are grouped together to form a set of consecutive blades. [Effects of the Invention]

[0013] According to the invention described in claim 1, the second base metal part is formed thinner than the first base metal part, so the cutting edge can be made thinner, which makes it possible to reduce the amount of dust that is scattered when cutting gypsum board.

[0014] According to the invention described in claim 2, by separating the first base metal portion from the second base metal portion by a step portion and making the radial length of the first base metal portion longer than that of the second base metal portion, stable cutting is possible without any undulations occurring when rotating.

[0015] According to the invention described in claim 3, the brazed portion of the tip has the same or thinner shape as the first base metal portion, which prevents undulations during rotation while enabling thin cutting, resulting in a light cutting edge and reducing the amount of dust scattering.

[0016] According to the invention described in claim 4, the tip and the brazed portion are tapered at the same angle when viewed from the side, which prevents undulation, resulting in a light cutting edge and reducing the amount of dust scattering.

[0017] According to the invention described in claim 5, by using a combined blade, it is possible to ensure a clean cut surface while also cutting on the front and back sides, improving straightness and achieving a lighter cutting edge. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a front view showing an example of a tip saw for gypsum board according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partially enlarged plan view of the AB portion of FIG. [Figure 3] FIG. 2 is a partially enlarged side view of the AB portion of FIG. [Figure 4] FIG. 2 is a partially enlarged plan view of the AB portion of FIG. [Figure 5] 2A and 2B are enlarged end views taken along the line CC in FIG. 1, where (a) is an overall end view and (b) is a partially enlarged end view further enlarging part F in (a). [Figure 6] 2A and 2B are enlarged end views taken along the line D-D in FIG. 1, where (a) is an overall end view and (b) is a partially enlarged end view of a portion G in (a). DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0020] As shown in Figures 1 to 4, the rotary tipped saw blade 1 for gypsum board has a mounting hole 20 drilled at the center of a circular base metal portion 2, with multiple blades 3, 3 on its outer periphery and tips 4, 4 at the ends of the blades 3. The base metal portion 2 is a circular steel plate with strength similar to tool steel, and is formed by pressing so that the blades 3, 3 are spaced evenly. The tips 4, 4 are tungsten carbide tips that are fixed to brazed portions 3a, 3a around the tip fixing positions of the blades 3, 3, and are ground to a sharp edge.

[0021] In this embodiment, the base metal portion 2 is appropriately provided with surface grooves 8, 8 and through grooves 9 formed to extend from the recessed portions 3b of the blade body 3. In this embodiment, the blade body 3 is located outward from an imaginary line E (see FIG. 1) connecting the center edges of the recessed portions 3b, and the base metal portion 2 is located inward from the imaginary line E.

[0022] Generally, when cutting gypsum board, a tipped saw is attached to an electric circular saw, and the user presses the electric circular saw against the gypsum board to cut it. A typical tipped saw has a blade at the tip of a circular base metal part, which has a tungsten carbide tip attached to it, and the blade thickness is inevitably wide, which has the disadvantage of generating a lot of dust when cutting gypsum board.

[0023] This invention focuses on narrowing the cutting range by making the base metal thin to prevent the generation of a large amount of dust when using a tip saw, but when the base metal is thin, the rotation of the electric circular saw does not rotate smoothly and undulation occurs. Therefore, this invention provides a tip saw with a thin base metal that does not undulate even when subjected to the rotational power of the electric circular saw and does not generate a large amount of dust, and is suitable for cutting gypsum board.

[0024] 1 to 4, the base metal portion 2 of the tip saw 1 of this embodiment has a step portion 10, and is formed with a first base metal portion 2a on the mounting hole 20 side and a second base metal portion 2b on the blade body 3 side. In other words, the first base metal portion 2a is located on the inner periphery and the second base metal portion 2b is located on the outer periphery of the base metal portion 2, and as shown in Fig. 5 in particular, the thickness is changed by the step portion 10, with the thickness L3 of the first base metal portion 2a being thick and the thickness L4 of the second base metal portion 2b being thin.

[0025] The tip saw 1 of the first embodiment has an overall radius of 50 mm (diameter of 100 mm). The radius of the central mounting hole 20 is 10 mm, the length from the center of the mounting hole 20 to the step portion 10 is 29.5 mm, and the length from the outer edge of the mounting hole 20 to the step portion 10 (radial length L1 of the first base metal portion 2a) is 19.5 mm. In addition, the length from the center of the mounting hole 20 to the outer periphery of the second base metal portion 2b, which is the base end position of the brazed portion 3a of the blade body 3, is 44 mm, and the length from the step portion 10 to this base end position (radial length L2 of the second base metal portion 2b) is 14.5 mm.

[0026] The tip saw 1 of the second embodiment has an overall radius of 62.5 mm (diameter of 125 mm). The radius of the central mounting hole 20 is 10 mm, the length from the center of the mounting hole 20 to the step portion 10 is 37 mm, and the length from the outer edge of the mounting hole 20 to the step portion 10 (radial length L1 of the first base metal portion 2a) is 27 mm. The length from the center of the mounting hole 20 to the outer periphery of the second base metal portion 2b, which is the base end position of the brazed portion 3a of the blade body 3, is 56 mm, and the length from the step portion 10 to this base end position (radial length L2 of the second base metal portion 2b) is 19 mm. The drawings of the second embodiment are omitted.

[0027] As described above, the tip saw 1 of the above embodiment preferably has a diameter of 100 mm or 125 mm, and more preferably a diameter of 135 mm or less. The base metal portion 2 of the tip saw 1 has a first base metal portion 2a on the inside side of the mounting hole 20 and a second base metal portion 2b on the outside side of the blade body 3, with the step portion 10 as the boundary, and the radial length L1 of the inside first base metal portion 2a is longer than the radial length L2 of the outside second base metal portion 2b.

[0028] In both the first and second embodiments, the thickness L3 of the first base metal portion 2a is 0.7 mm, the step portion 10 forms a 0.2 mm step, and the thickness L4 of the second base metal portion 2b is 0.5 mm. As shown in FIG. 6, the thickness L5 of the brazed portion 3a of the blade body 3 is 0.6 mm, and the horizontal length (left-right protrusion width) L6 between the front vertex and the back vertex of each tip 4, 4 is 0.9 mm. As will be described later, some tips protrude from each other and some are flat, but the left-right protrusion width for all of these is 0.9 mm.

[0029] In this way, in both the first and second embodiments, the second base metal portion 2b is made thinner than the first base metal portion 2a by the step portion 10. This not only prevents a large amount of dust from being generated when cutting a gypsum board, but also prevents the second base metal portion 2b from excessively contacting the gypsum board during cutting, thereby achieving a light and fast cutting edge.

[0030] Furthermore, if the circular chip saw 1 attached to the electric circular saw is too thin, it may cause undulations when rotating. However, the first base metal portion 2a, which surrounds the mounting hole 20 for attaching to the electric circular saw, is located inside the step portion 10 and has a predetermined thickness, which prevents undulations during use.

[0031] Next, the configuration of the blade body 3 in this embodiment, including the first and second embodiments, will be described. The multiple dorsal fin-shaped blade bodies 3 are located outward from the outer edge of the second base metal portion 2b and have a brazing portion 3a at the base end on one side in the rotation direction to which a tip 4 is attached. The rectangular tip 4 is brazed to the brazing portion 3a of the blade body 3 and is ground from both sides.

[0032] 6, the tip 4 is formed into a tapered shape through the brazed portion 3a by grinding. In other words, in plan view and side view, the tip 4, 4 and the brazed portion 3a, 3a are inclined at the same angle on the front and back sides of the tip saw 1. For this reason, the brazed portions 3a, 3a are also formed to be slightly inclined (widening outward), but in other embodiments, the brazed portion 3a may not be formed into a tapered shape, and only the tip 4, 4 may be tapered.

[0033] As shown in Figures 3 and 4, the tip 4 of this embodiment is a combination of a first tip 4a that protrudes from the front side, a second tip 4b that protrudes from the back side, and a third tip 4c that has a straight, horizontal edge. Specifically, the first tip 4a, the second tip 4b, the first tip 4a, the second tip 4b, and the third tip 4c form a set, and these sets are connected together. Using this combination of blades allows for a clean cut on the gypsum board, resulting in a tip saw 1 with excellent cutting performance.

[0034] Furthermore, the tip is inclined outward at the same angle on both the front and back sides, allowing for smooth cutting, resulting in a tip saw 1 that has good cutting ability on gypsum boards.

[0035] Furthermore, in terms of thickness, the first base metal portion 2a, the brazed portion 3a, and the second base metal portion 2b are tapered so that both sides are inclined at the same angle, which prevents the gypsum board from coming into contact with the second base metal portion 2b when cutting with the blade body 3, ensuring a specified gap and achieving a light, smooth cutting edge. [Explanation of symbols]

[0036] 1...tipped saw, 2...base metal portion, 2a...first base metal portion, 2b...second base metal portion, 3...Blade body, 3a...Brazed portion, 4...Tip, 10...Step portion, 20...Mounting hole, L1: Radial length of the first base metal portion; L2: Radial length of the second base metal portion 2b; L3: Thickness of the first base metal part, L4: Thickness of the second base metal part, L5: Thickness of the brazed part L5, L6: The horizontal length between the front and back vertices of the chip.

Claims

1. The cutting tool has a disk shape and comprises an attachment hole with an opening at the center of the circle when viewed from the front, a base metal part disposed on the outer periphery of the attachment hole, a blade body disposed on the outer periphery of the base metal part, and a tip attached to the tip of the blade body, The base metal portion comprises a first base metal portion located on the inner periphery and a second base metal portion located on the outer periphery of the first base metal portion, and the thickness of the second base metal portion is formed thinner than that of the first base metal portion.

2. The thickness of the first base metal portion and the second base metal portion is changed by a step portion, The tip saw for gypsum board according to claim 1, wherein the radial length of the first base metal portion is longer than the radial length of the second base metal portion.

3. The blade has a brazed portion to which the tip is attached, 3. The tip saw for gypsum board according to claim 2, wherein the thickness of the brazed portion is thinner than that of the first base metal portion and is equal to or thicker than that of the second base metal portion.

4. The blade body to which the tip is attached extends from the outer peripheral edge of the second base metal portion at an inclined angle on the front side and the back side, when viewed from the side, The tip saw for gypsum board according to claim 3, characterized in that the horizontal length between the front apex and the back apex of the tip is formed to be the same as or thicker than the thickness of the first base metal portion.

5. The chips include a first chip inclined toward the front side, a second chip inclined toward the back side, and a third chip in a horizontal direction; The chip saw for gypsum board according to claim 4, characterized in that the first tip, the second tip, the first tip, the second tip, and the third tip form a set, and the set is connected to form a combined blade.

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