JP4522472B2 - Composite saw blade of cutting machine - Google Patents

Description

  The present invention relates to a composite saw blade having a cutting blade and a chamfering blade in a cutting machine such as a portable circular saw.

In Patent Document 1, in a portable circular saw which is a kind of cutting machine, a cutting blade for cutting a workpiece and a groove forming blade for forming a groove at the same time as cutting with the cutting blade are integrally integrated with the workpiece. A composite saw blade is disclosed.
JP-A-2005-22376 (paragraph 0034 column, paragraph 0035 column, FIGS. 1 to 3)

  By the way, as a building material, for example, there is a gypsum board in which decorative paper is bonded to the outer surface of a base material. Such a gypsum board has a chamfered end face. This is because when you finish the wallpaper on the surface of the gypsum board, if you leave the subtle steps of the adjacent gypsum board as it is, it will stand out as a seam when you stretch the cross, so the chamfer between the adjacent gypsum boards After putting the putty on the V-shaped recess formed by the above, and making the gap between the adjacent gypsum boards flush, the cloth is pasted. However, since the gypsum board having the standard size needs to be cut depending on the size of the wall, in this case, a cutting operation for cutting to a predetermined size and a chamfering operation by a chamfering plane or the like are required.

  From the viewpoint of improving work efficiency, it is desired that the cutting work and the chamfering work be performed in one step in conjunction with each other as described in Patent Document 1.

  However, when chamfering a workpiece such as gypsum board with a commonly used circular saw blade, the decorative paper is hooked on the cemented carbide tip of the chamfering blade and remains as a burr on the edge of the chamfered portion, and the building after construction There is a risk of adversely affecting the surface properties (finished state) of the material.

  The present invention has been made in view of this point, and an object of the present invention is to reduce the amount of burrs generated during chamfering as much as possible.

  In order to achieve the above object, the present invention is characterized in that the rake angle and the side rake angle of the chamfering blade are appropriately set.

Specifically, the solution provided by the present invention is such that a large number of blade portions are formed on the outer periphery, carbide tips are provided on the blade edges of the respective blade portions, and decorative paper is bonded to the outer surface of the substrate. A disc-shaped cutting blade that cuts the workpiece into a predetermined dimension by the above-described carbide tip, and a smaller diameter than the cutting blade, and a large number of blade portions are formed on the outer periphery. A disc-shaped chamfering blade in which a cemented carbide tip is provided at the cutting edge of each blade, and the workpiece is chamfered with the cemented carbide tip following the cutting operation by rotating integrally with the cutting blade. The carbide tip of the chamfering blade has a rake angle of −30 °, which is the angle formed by the rake face of the carbide tip with respect to the line connecting the tip of the carbide tip and the rotation center of the chamfering blade . More than -16.7 degrees or less, carbide tip with respect to the center of rotation of the chamfering blade The side rake angle, which is the angle formed by the rake face, is set to -15 ° to 2.4 °.

  According to this invention, the sharpness of the cemented carbide tip becomes sharp due to the relationship between the rake angle of the cemented carbide tip in the chamfering blade, and the amount of burrs generated at the edge of the chamfered portion is reduced as much as possible. Due to the rake angle of the carbide tip in the chamfering blade, burrs are efficiently cut. Thereby, the surface property of the building material after construction improves.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show a portable circular saw 1 as a cutting machine. In this example, the gypsum board W (refer FIG. 4) whose work material is a building material is illustrated, as for this gypsum board W, the decorative paper w2 is bonded on the outer surface of the base material w1.

  The circular saw 1 includes a housing 9 including a motor case 3, a gear case 5, and a saw cover 7.

  A handle 3a gripped by an operator is integrally projected on the upper side outside the motor case 3, and a motor (not shown) is accommodated in the motor case 3.

  The gear case 5 contains a gear meshing mechanism (not shown) as a power transmission mechanism, which is a well-known technique in the circular saw 1, and the rotational torque of the motor is transmitted to the gear meshing mechanism. Yes. The gear meshing mechanism is drivingly connected to a saw blade shaft 11 (see FIG. 1) arranged in parallel to the motor shaft of the motor, and a composite saw blade 13 as a feature of the present invention is connected to the saw blade shaft 11. They are connected together with the same rotation center. The rotational torque of the motor is transmitted from the motor shaft to the saw blade shaft 11 via the gear meshing mechanism, thereby rotating the composite saw blade 13.

  The saw cover 7 has a substantially U-shaped cross section and a substantially semicircular shape, and covers a substantially upper half portion of the outer periphery of the composite saw blade 13.

  Inside the saw cover 7, a safety cover 15 having a substantially U-shaped cross-section and covering a substantially lower half of the outer periphery of the composite saw blade 13 is rotatably arranged to cut the gypsum board W. At this time, the safety cover 15 is pushed by the gypsum board W and goes around into the saw cover 7.

  A rectangular surface plate 17 is disposed below the housing 9. A surface plate column 19 is erected on one end side of the surface plate 17, and a bracket 21 is fixed to the surface plate column 19. One end of the saw cover 7 is pivotally connected to the bracket 21 by a rotating shaft 23 (see FIG. 2). The composite saw blade 13 is rotated by rotating the surface plate 17 in the vertical direction with the rotating shaft 23 as a fulcrum. The amount of protrusion downward of the surface plate 17, that is, the depth of cut with respect to the gypsum board W is adjusted. In FIG. 2, reference numeral 25 denotes a cutting depth adjusting mechanism that adjusts the cutting depth, and reference numeral 27 denotes a gypsum board W by tilting the composite saw blade 13 with respect to the surface plate 17 as shown in FIG. 1. An inclination angle adjusting mechanism 29 for forming an oblique cut surface is a parallelism adjusting mechanism for making the surface of the composite saw blade 13 parallel to the edge of the surface plate 17.

  As shown in FIG. 4, the composite saw blade 13 is composed of two disk-shaped blades of a cutting blade 31 and a chamfering blade 33. The cutting blade 31 has a large number of blade portions 31a (see FIG. 7) formed on the outer periphery thereof, and a cemented carbide tip 35 is integrally joined to the blade tips of the blade portions 31a by brazing, and gypsum is rotated by a rotating operation. The board W is cut to a predetermined size with the carbide chip 35 (see FIG. 4A).

  The chamfering blade 33 is set to have a smaller diameter than the cutting blade 31, and a large number of blade portions 33 a (see FIGS. 5 to 7) are formed on the outer periphery, and the cutting edge of each blade portion 33 a is made of carbide. The chip 37 is integrally joined by brazing. The chamfering blade 33 is connected to the saw blade shaft 11 together with the cutting blade 31 so that the center thereof is integrally rotated. The chamfering blade 33 rotates integrally with the cutting blade 31 and follows the cutting operation by the cutting blade 31 to the gypsum board W. A chamfering process is performed with a carbide tip 37 (see FIG. 4B).

  As shown in FIG. 6, the cemented carbide tip 37 of the chamfering blade 33 has a rake angle α of −30 ° to −16.7 ° and a lateral rake angle β of −15 ° to 2.4 °. Is set. This is one of the greatest features of the present invention. The chamfering angle γ varies depending on the use and purpose of the building material, but is set to 45 ° in this example (see FIG. 4).

The rake angle α is a line C (line in the radial direction of the chamfering blade 33) connecting the tip of the carbide tip 37 and the rotation center of the chamfering blade 33 (rotation axis of the saw blade shaft 11). The angle formed by the front surface (rake face 37a) of the carbide tip 37 (see FIG. 6A). In FIG. 6A, D indicates the rotation direction of the chamfering blade 33, and E indicates the traveling direction of the chamfering blade 33. In FIG. 6A, an arrow G indicates the minus direction of the rake angle α.

The lateral rake angle β is an angle (lead angle) formed by the rake face 37a of the carbide tip 37 with respect to the rotation center of the chamfering blade 33 (rotation axis of the saw blade shaft 11) (FIG. 6B). )reference). In FIG. 6B, F indicates the rotation center line of the chamfering blade 33. In FIG. 6B, the arrow H indicates the minus direction of the side rake angle β.

  The reason why the rake angle α and the side rake angle β are set to the above values is based on the experimental data graph shown in FIG. The evaluation conditions employed in obtaining this experimental data are as follows. Moreover, the cutting | disconnection attitude | position with respect to the gypsum board W of the cutting blade 31 and the chamfering blade 33 at that time is shown in FIG.

<Evaluation conditions>
[Chamfering blade]
Carbide tip width: 3.5mm
Chip hardness: HRC93
Chamfer angle: 45 °
Surface treatment: Fluorine processing [Cutting blade]
φ125 × 40P
Plate thickness: 0.8mm
[Work material]
Plasterboard
Width: 450mm
Plate thickness: 9mm
[Cutting machine]
Made by Hitachi Koki
C5YC 100V / 11A / 9600min-1 / 1050W
[How to cut]
Cutting using a ruler over 150 mm in a direction perpendicular to the paper fiber orientation direction [Evaluation Method]
The amount of burrs is visually scored in 5 steps (5: no burrs)
The rank of “5” is omitted in the data
Acceptance reference point: 1.5 or more As is clear from the graph of the experimental data shown in FIG. 8A, in order to make the rake angle α of the carbide tip 37 in the chamfering blade 33 less than −30 °, the processing is performed. On the other hand, if it exceeds -16.7 °, the decorative paper w2 is peeled off and lifted up, so that a large amount of burrs are generated at the edge of the chamfered portion and the burrs are cut. This is because the remaining reference point is less than 1.5.

  Further, as apparent from the experimental data graph shown in FIG. 8B, when the side rake angle β of the carbide tip 37 in the chamfering blade 33 is less than −15 °, the wear resistance of the carbide tip 37 is lowered. On the other hand, if the angle exceeds 2.4 °, the sharpness of the rake face 37a of the cemented carbide tip 37 becomes dull and many burrs are generated at the edge of the chamfered portion.

  Therefore, the surface property of the construction material after construction can be improved by setting the rake angle α and the side rake angle β of the cemented carbide tip 37 in the chamfering blade 33 within the above ranges.

  The present invention is useful for a cutting machine such as a portable circular saw.

It is a front view of the circular saw which concerns on embodiment. It is a top view showing a part of circular saw concerning an embodiment in a section. FIG. 2 is a right side view of FIG. 1 showing the safety cover in a broken state. 4A is a cross-sectional view showing a state in which a gypsum board is cut with a cutting blade, and FIG. 4B is a cross-sectional view showing a state in which the gypsum board is cut with a cutting blade and chamfered with a chamfering blade. . It is a front view of a chamfering blade. FIG. 6A is an enlarged view of a portion A in FIG. 5, and FIG. 6B is a view taken in the direction of arrow B in FIG. It is explanatory drawing which shows the cutting attitude | position with respect to the gypsum board of a cutting blade and a chamfering blade. FIG. 8A is a graph showing experimental data of the rake angle of the cemented carbide tip in the chamfering blade, and FIG. 8B is a graph showing experimental data of the rake angle of the cemented carbide tip in the chamfering blade.

Explanation of symbols

1 Circular saw (cutting machine)
13 Composite Saw Blade 31 Cutting Blade 33 Chamfering Blade 31a, 33a Cutting Edge 35, 37 Carbide Tip α Rake Angle β Lateral Rake Angle W Gypsum Board (Workpiece)

Claims (1)

A large number of blades are formed on the outer periphery, a carbide tip is provided on the blade edge of each blade, and a workpiece having decorative paper bonded to the outer surface of the base material is rotated with a predetermined motion by the carbide tip. A disc-shaped cutting blade that cuts into dimensions;
The blade is set to have a smaller diameter than the cutting blade, and a large number of blade portions are formed on the outer periphery. A carbide tip is provided at the blade edge of each blade portion, and rotates integrally with the cutting blade. A disc-like chamfering blade that chamfers the workpiece with the carbide tip following the cutting operation by
The carbide tip of the chamfered blade has a rake angle of −30 ° or more, which is the angle formed by the rake face of the carbide tip with respect to the line connecting the tip of the carbide tip and the rotation center of the chamfered blade . Cutting machine characterized in that the side rake angle, which is the angle formed by the rake face of the carbide tip with respect to the rotation center of the chamfering blade, is set to -15 ° or more and 2.4 ° or less at 7 ° or less. Composite saw blade.

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