JP6420810B2 - Rotary cutting blade for plasterboard - Google Patents

Description

  The present invention relates to a rotary cutting blade for a gypsum board that is used by being attached to a hand-held power tool to cut the gypsum board.

  Conventionally, when cutting gypsum boards used for interiors of buildings, etc., electric circular saws are often used. Especially when cutting gypsum boards with electric circular saws, tip saws are mainly used as rotary cutting blades. The Since this tip saw is equipped with a carbide tip at the tip of the blade body, the cutting width becomes large, and a large amount of dust is wound up and scattered around to contaminate the construction site and in the direction of travel of the tip saw. On the other hand, there is a drawback that the dust is rolled up vertically and the worker is dusted and obstructs the cutting work.

  Therefore, by attaching a dust collector to the electric circular saw, the above-mentioned drawback is solved by cutting the gypsum board while collecting dust, but on the other hand, attaching the dust collector to the electric circular saw, etc. As a result, the work efficiency of the cutting work has been reduced. Moreover, since the cut surface which is the cut surface of the gypsum board becomes rough due to cutting with a tip saw, finishing work such as hooking is required.

  In order to solve the above-mentioned drawbacks, a rotary cutting blade having a knife blade with a sharp tip that can improve the amount of generated dust and the cut end has been proposed. For example, Patent Document 1 discloses a radial direction. An invention of a slitter knife for rotary cutting provided with a protruding blade body is disclosed.

Japanese Utility Model Publication No. 5-67491

  However, in the invention described in the above-mentioned patent document, a rotary cutting blade having a knife blade with a sharp tip has few surfaces in contact with the gypsum board which is a workpiece and the knife blade, and the rotational driving force of the electric tool is reduced. Since it cannot fully be utilized for the cutting process of a workpiece, there exists a fault which cannot fully ensure sharpness like a tip saw.

  Therefore, it aims at providing the rotary cutting blade for gypsum boards which has sharpness like a chip saw, reduces the amount of dust, and does not wind up dust.

A rotary cutting blade for a gypsum board for use with a circular blade plate and a hand-held power tool in which a plurality of blade bodies are arranged at equal intervals on the outer periphery of the blade plate, the blade body is formed by pressing on the outer periphery of the cutting plate, and away pile surface having a negative rake angle, the tip relief angle toward the outer periphery toward the rear on the opposite side of the rake face from the rake face , a double-edged blade sharpening angle formed by polishing the both sides of the blade body, and a cutting edge having, Ri Tona, said rake face has a surface is characterized by a flat triangular.

In addition to the above-described configuration, the blade body is positioned substantially parallel to the cutting edge and has a margin formed to have a width longer than the width of the cutting edge, and the blade from the rear end of the cutting edge. And a back surface formed in a curved shape recessed in the center direction of the plate .

  In addition to the above-described configuration, when the rake angle is set to negative 18 degrees and the blade grinding angle is set to 18 degrees, the tip clearance angle is preferably set to 10 degrees or more and 30 degrees or less.

  According to the first to third aspects of the present invention, when cutting a gypsum board, it has a sharpness like a tip saw, and pollutes the surrounding environment by winding up dust and discharging it in a traveling direction without scattering. It is possible to suppress the operation, and it is possible to prevent the worker from being obstructed by the dust.

It is a front view which shows an example of the rotary cutting blade for gypsum boards which concerns on embodiment of this invention. It is the elements on larger scale of the blade body of FIG. It is a partial expanded side view of the blade body of FIG. It is a partial expansion perspective view of the blade body of FIG. It is a conceptual diagram which shows the cutting mechanism of this invention.

  An embodiment of the present invention will be described in detail with reference to FIGS.

(Embodiment)
The gypsum board rotary cutting blade 1 is a circular blade plate 2 and has a mounting hole 20 formed at the center position. The blade plate 2 is a steel plate having toughness such as tool steel, and is formed by pressing so that a plurality of blade bodies 3 and 3 are arranged at equal intervals on the outer periphery thereof.

As shown in FIGS. 2 and 3, the blade bodies 3 and 3 formed on the outer peripheral portion of the blade plate 2 include a substantially triangular rake face 4 having a flat surface having a negative rake angle α, and a back face from the rake face 4. 8, a cutting edge 6 having a tip clearance angle γ and a blade grinding angle δ in the outer circumferential direction. Here, the rake angle α is an angle formed by the center line and the rake face 4 from the center position of the blade plate 2 to the cutting edge 5, and the tip clearance angle γ is a tangent line and a tangent line that touches a circumscribed circle whose radius is the center line. The angle formed with the blade 6 is used. Further, the blade grinding angle δ is an angle of a double blade formed by polishing both side surfaces of the blade bodies 3 and 3.

Furthermore, the back surface 8 on the opposite side to the rake face 4 of the blade bodies 3 and 3 has a curved shape that is gently recessed from the rear end of the cutting blade 6 toward the center of the blade plate 2. It is preferable to form the margin 7 having a long width w ₂ as compared with the width w ₁ of the cutting edge 6. Further, it is preferable to form the margin 7 so as to be positioned in parallel to the cutting edge 6.

  Further, the blade plate 2 is hung from the center position of the gypsum board rotary cutting blade 1 in the outer peripheral direction in order to suppress heat dissipation and distortion of the gypsum board rotary cutting blade 1 during cutting, and is substantially S-shaped. Slits 21, 21, circular openings 22, 22, elliptical openings 23, 23, square holes 24, 24 opened in the outer circumferential direction are formed in order, and are arranged in the radial direction at equal angular intervals. It is preferable to do.

  Further, since the blade plate 2 is cut while being in contact with the gypsum board 9 which is a processing object at the time of cutting, the friction coefficient with the gypsum board 9 is given to both side surfaces of the outer peripheral portion of the rotary cutting blade 1 which can be contacted. It is preferable to provide a friction-resistant coating so as to reduce the friction. The friction-resistant coating is more preferably formed with a width of 15 mm or more from the blade edge 5 toward the center position of the blade plate 2.

  Next, a cutting mechanism for cutting the gypsum board of the rotary cutting blade 1 for gypsum board of the present embodiment according to the above-described configuration will be described with reference to FIG.

FIG. 5 shows that a gypsum board 9 having a thickness of about 9 mm to 15 mm is cut by rotating the rotary cutting blade 1 for gypsum board in the direction of movement V ₁ and rotating in the direction of rotation V ₂ (approximately 7000 revolutions per minute). It is the conceptual diagram which showed the cutting mechanism which goes. At this time, part of the gypsum board 9 is cut into dust 10 by the rake face 4 around the cutting edge 5 of the blade bodies 3 and 3 by the rotation of the rotary cutting blade 1 for gypsum board. At this time, since the rake face 4 has a negative rake angle α, the component force pushed out in the traveling direction V ₁ is larger than the component force in the rake direction along the rake face 4 toward the center of the blade plate 2. When the blade bodies 3 and 3 are positioned above the gypsum board 9, the dust 10 can be discharged in the traveling direction V ₁ , and the cutting edge 6 formed by the blade grinding angle δ and the margin 7 It is possible to let the dust 10 escape to the side.

Further, while cutting with the rake face 4 of the blade bodies 3 and 3 in the rotation direction V ₂ of the above-described gypsum board rotary cutting blade 1, by the force of pushing the gypsum board rotary cutting blade in the advancing direction V ₁ , The cutting blade 6 formed on the outer periphery can be pressed against the gypsum board 9 to cut only a part thereof to form a cut, and the cutting can be facilitated by this cutting to improve the sharpness. Is possible.

Next, according to the above-described configuration, the blade plate 2 has a diameter R of about 100 mm and a thickness t of about 0.8 mm, and the blade bodies 3 and 3 have a height h ₁ of the rake face 4 of 3.7 mm. The tip clearance angle when the width w _{1 of the} blade 6 is 3.3 mm, the width w ₂ of the margin 7 is 4.4 mm, the height h _{2 of the} back surface is 2.5 mm, and the rake angle α is negative 18 degrees. The rotary cutting blade 1 for gypsum board of Experimental Examples AD in which the angle γ and the blade grinding angle δ are different as shown in Table 1 are respectively mounted on the electric tool, and the gypsum board is used with this electric tool. The evaluation test regarding the sharpness, the small amount of dust, and the cut surface when 9 was cut was performed. This evaluation method is a summary of the evaluations of about 10 applicants in the company and cooperators. The evaluation was made in four stages: sharpness, small amount of dust, and excellent, good, acceptable and impossible for the cut end. (As a reference example, in the case of a tip saw, the sharpness is excellent, the amount of dust is not possible, and the cut is not possible).

  As is apparent from the results of the evaluation test shown in Table 1, in Example B, the rake angle α is 18 degrees negative, the tip clearance angle γ is 20 degrees, and the blade grinding angle δ is 18 degrees. When the gypsum board 9 was cut using the gypsum board rotary cutting blade 1, the grit board 9 had an excellent sharpness substantially equivalent to that of a conventional chip saw, and obtained excellent evaluation with respect to a small amount of dust and a cut end.

Therefore, when the rake angle α is set to negative 18 degrees and the blade grinding angle δ is set to 18 degrees, the tip clearance angle γ is less than 10 degrees, and it becomes difficult to cut the gypsum board 9. If the angle exceeds 20 degrees, the cutting becomes too large and it becomes difficult to rotate the gypsum board rotary cutting blade. Therefore, the gypsum board rotary cutting blade 1 having the blade shape of Experiment Example B, which is approximately 20 degrees, is used. but which has a sharpness such as tipped in cutting plasterboard 9, it is possible to suppress the contamination of the surrounding environment by discharging the traveling direction V ₁ without being scattered by wind the dust 10 upwardly It is possible to provide the most preferable gypsum board rotary cutting blade 1 capable of preventing the worker from hindering the work due to the dust 10. The angle allows an error of plus or minus 1 to 2 degrees.

  In addition, with respect to Experimental Example D, when the blade grinding angle δ is set to 26 degrees that is greater than 18 degrees, the cutting range increases, but the dust 10 increases, and as a result, the sharpness, the small amount of dust, and the cut end are all satisfied. Evaluation was not obtained.

  In addition, in order to reduce dust, when a simple round blade with a sharp edge 4 without a rake face 4 like a so-called cheese cutter is used, the cut dust is clogged and the user pushes the electric circular saw forward. The sharpness was extremely poor.

DESCRIPTION OF SYMBOLS 1 ... Rotary cutting blade for gypsum boards, 2 ... Blade plate, 20 ... Mounting hole, 21 ... Slit, 22 ... Opening part, 23 ... Opening part, 24 ... Square hole, 25, 3 ... Blade body, 4 ... Rake face, 5 ... Cutting edge, 6 ... Cutting edge, 7 ... Shinogi, 8 ... Back surface, 9 ... Gypsum board, 10 ... Dust, α ... Rake angle, β ... Cutting edge angle, γ ... Tip clearance angle, δ ... Blade grinding angle, R ... diameter of rotating cutting blade, t ... thickness of blade plate, h ₁ ... height of rake face, h ₂ ... height of back face, w ₁ ... width of cutting edge, w ₂ ... width of shinoki, V ₁ ... progress Direction, V ₂ ... direction of rotation

Claims (3)

A rotary cutting blade for a gypsum board for use with a circular blade plate and a hand-held power tool in which a plurality of blade bodies are arranged at equal intervals on the outer periphery of the blade plate, the blade body is formed by pressing on the outer periphery of the cutting plate, and away pile surface having a negative rake angle, the tip relief angle toward the outer periphery toward the rear on the opposite side of the rake face from the rake face a cutting blade having a double-edged blade sharpening angle formed by polishing the both sides of the blade body, Tona is, the rake face, gypsum board, wherein the surface is flat triangular Rotating cutting blade. The blade body is positioned substantially parallel to the cutting edge, and has a margin formed to have a longer width than the cutting edge width, and a curved surface recessed from the rear end of the cutting edge toward the center of the blade plate. The rotary cutting blade for gypsum board according to claim 1 , further comprising a back surface formed in a shape .   3. The tip clearance angle is set to 10 degrees or more and 30 degrees or less when the rake angle is set to negative 18 degrees and the edge sharpening angle is set to 18 degrees. 4. Rotating cutting blade for gypsum board as described.

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