JPS625763B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary tool for machining flat surfaces, cylindrical surfaces, rotating surfaces, etc. by rotating a cutting edge with a two-dimensional contour formed on a flat surface. The objective is to realize machining with less noise and vibration by using a cutting edge that is easy to re-grind and assemble.

Although the present invention can be applied to tools such as planing machines, electric planers, and milling machines, it is especially important to apply it to wood planing machines that work on flat plates, so the embodiment will first be described using this case as an example.

Using a helical blade is said to be effective for smooth cutting and reducing noise on a planer, but it is not only difficult and expensive to manufacture the blade, but also requires special equipment to re-grind the blade. Because it requires technology and time, it is expensive, and is not welcomed in the field, hindering its widespread use. The present invention eliminates this drawback and provides a rotary tool that is easy to regrind and assemble, and which provides performance and effectiveness substantially similar to that of a helical blade.

In the following description, the term "cutting edge" refers to the tip of a blade that has a rake face and a flank surface and performs a cutting action. In particular, when only the tip is meant, it will be referred to as a cutting edge.

Now, the cutting edge of a rotary planer that cuts a flat surface draws a cylindrical surface. In FIG. 1, the axes of both end surfaces 1 and 2 of the rotary planer 100 are taken as O ₁ and O ₂ , and the circles where the cylindrical surface 3 (radius R) drawn by the cutting edge and the end surfaces 1 and 2 intersect are 10 and 20, respectively. do. Among the intersections of the vertical plane ₄ including the axis ₁₂ and the end face circles 10 and 20, the ones closer to the cutter 101 are defined as V ₁ and V ₂ , respectively. End circles 10 and 2
Let β be the angle formed by the vertical plane 5 passing through points A ₁ and A ₂ on 0 and the vertical plane 4. Let 1 1 and 2 2 be _the intersection lines _{of the vertical plane 5 and the end faces 1 and 2} . Here, H ₁ and H ₂ are the legs of the perpendicular lines drawn from O ₁ and O ₂ to _{1 1} and _{2 2} , respectively, and _{1 2} and
The angle between ₁ and ₂ is β.

On both end faces 1 and 2, _{1 1} and
Straight lines _{1 1} and _{2 2} forming angles γ with _{2 2,} respectively
Considering, G ₁ and G ₂ are respectively O ₁ and O ₂ to A ₁ G ₁ ,
If we take the foot of the perpendicular line drawn down to A ₂ G ₂ , then the straight line _{1 1} and
Since A ₂ G ₂ is parallel, one plane 6 including both straight lines is determined. The intersection line 7 between this plane 6 and the cylindrical surface 3 drawn by the cutting edge forms an elliptical arc. This elliptical arc 7
Consider a cutter whose contour is the cutting edge of the cutter 101, the plane 6 is the flank of the cutting edge, the elliptical arc 7 is the conducting wire, and the cylindrical surface 8 (its generatrix is parallel to A ₁ H ₁ ) is the rake surface. When this is rotated around the axis O ₁ O ₂ , the cutting edge draws a cylindrical surface, so if a relative linear feed motion is applied between the plate material in contact with this and the tool axis, it is possible to cut the correct plane. The cutting situation is similar to that of a helical blade. However, the shaft angle rake angle is ∠O ₁ A ₁ H ₁ (=α
₁ ) and ∠O ₂ A ₂ H ₂ (= α ₂ ), and _{1 2} =
If W, sinα ₁ = O ₁ H ₁ /R, sinα ₂ = O ₂ H ₂ /R _{2 2} = _{1 1} +Wtanβ ∴sinα ₂ = sinα ₁ +W/Rtanβ (1) Therefore, α ₂ > α ₁ , The rake angle α changes along the cutting edge, and it has the disadvantage that it cannot be kept constant like a helical blade. However, it is not necessary to keep the rake angle α perpendicular to the axis constant, and there is no problem as long as it is within a practically allowable range. Since the angle γ is the cutting edge angle perpendicular to the axis and is kept constant over the blade width, the clearance angles perpendicular to the axis δ ₁ and δ 2 at the end faces 1 and ₂ are δ ₁ =90°−γ−α ₁ δ ₂ =90° −γ−α ₂
(2), the clearance angle δ also changes along the cutting edge. It is necessary to determine the allowable value by also considering the values of α ₁ and α ₂ clearance angles. In general, the larger the rake angle, the smaller the cutting force, and the larger the relief angle, the smaller the cutting force becomes.However, if the cutting edge angle is kept constant, the larger the rake angle, the smaller the relief angle, so the cutting force changes with the axial position. It remains almost constant regardless.

Since the rake face has a cylindrical surface with the contour of the cutting edge as a conductor, when re-grinding the cutting edge, the correct contour of the cutting edge will always appear just by sharpening the flat flank. When assembling the cutter to the planer body, make sure that the opposite surface 9 of the rake face is placed so that the cutting edge is in the correct position.
is a plane parallel to the generatrix of the rake face 8, and in order to make contact with the plane 9' on the opposing planer body side, and to set the height of the cutting edge correctly, set a close contact near the end of the flank and parallel to this. A flat surface 14 (flank receiving surface) is provided on the plane body side, and when assembling after re-grinding, the flank surface 6 is moved in parallel by the re-ground depth while suppressing the movement of the cutter 101 in the axial direction. 6 onto the opposing flat surface portion 14 on the side of the planer barrel. The opposing surface 9 of the rake face also serves as a reference surface when finishing the rake face 8 (elliptical cylindrical surface). In addition, since the back surface of the flank (bottom surface 11 of the cutter) is used as a reference surface when grinding the flank 6, it is preferable to make it a plane perpendicular to the generatrix of the rake face (a horizontal plane in the figure). Then, the cross section of the cutter will be quadrilaterals A ₁ B ₁ C ₁ D ₁ and A ₂ B ₂ C ₂ D ₂ at both end faces 1 and 2, respectively, and quadrilateral ABCD at any arbitrary location.

FIG. 5 shows a cross section of the cutter including the center line of the screw 13 that fixes the cutter, and 12 is a chip reservoir.

Now consider a cross section perpendicular to the axis that includes an arbitrary point A on the contour 7 of the cutting edge, let G be the foot of the perpendicular line drawn from the axis O to the line of intersection AG with the flank 6, and let AHA ₁ H ₁ be,
=R, ∠OAH=α=rake angle, ∠HAG=γ
= cutter angle, 90° - α - γ = δ = clearance angle. In Figure 2, the angle formed by _{1 2} and _{1 2} is β', and if ₁ = ζ=, = η, then _{1 1} = Rsin (α ₁ + γ), _{2 2} = Rsin (α ₂ + γ) = Rsin (α ₁ + γ) + ζ tan β′ Therefore, _{2 2} = Rsin (α ₁ + γ) + Wtan β′ Therefore, tan β′ = R/W {sin (α ₂ + γ) − sin (α ₁ + γ)}△OGA, η = √ ² −{( ₁ +)+′}
The coordinates of ^two points A are expressed in the illustrated coordinate system (X, Y, Z), where X axis: O ₁ → H ₁ Y axis: O ₁ → O → O ₂ Z axis: O ₁ → V ₁ , As shown in the figure, if a triangle OGA is tilted on the plane O ₁ O ₂ -G ₁ G ₂ with OG as the axis and A comes to be A', the following relationship is obtained.

X=ζ, Y=Rsinα, Z=Rcosα cos(α+γ)=η/R The curve represented by the coordinates (X, Y) represents a cross section perpendicular to the generatrix of the rake face.

If the flank of the blade is flat and the back side is also flat, you can use an appropriate jig to line up multiple blades on the table of a surface grinder so that their flanks are on one plane and process them simultaneously, allowing you to quickly change the dimensions. It is possible to re-sharpen the aligned blades.

If a wide tool is required, tools with a rake angle within the limit may be used in tandem.
However, in order to avoid creating gaps, it is best to carefully overlap the blades at the joints, as shown in Figure 6. In this figure, a tool 100 (having blades 101, 102, etc.)
Fig. 2 is a schematic plan view showing the joining of the tool 200 (having cutters 201, 202, . . . ), and shows an example in which the joining portion of both tools has a clutch tooth shape as shown in 15. Note that in order to eliminate the thrust that occurs during cutting due to the inclination of the cutting edge, tools with opposite inclination directions may be used in combination as shown in FIG.

If the machined surface is not a flat surface but a cylindrical surface, the rotating surface whose axial cross-sectional shape is congruent with the cross-sectional shape perpendicular to the generatrix of the cylindrical surface becomes a curved surface drawn by the cutting blade, and the surface is inclined to the tool rotation axis. The required curved surface is created by using a tool that uses a flat plane as a flank surface, a curved line of the cut that cuts the rotating surface drawn by the cutting blade on the flank plane as the outline of the cutting blade, and a columnar surface as a rake face with that outline as a conducting wire. It becomes possible to cut.

In the present invention, if rotational feed is applied to the workpiece, machining of the rotating surface becomes possible.

According to the present invention, when re-sharpening the cutting edge, the correct blade shape can be obtained by simply grinding the flat flank surface, and reassembly can be done quickly and accurately, making re-sharpening and reassembling of the blade difficult. The advantage is that a rotating tool with almost the same cutting performance as a helical blade can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the principle of the present invention, showing the case where the generatrix of the rake face of one cutter is perpendicular.
Figure 2 is a diagram showing the dimensional relationship of the part including O ₁ O ₂ G ₁ G ₂ in Figure 1, Figure 3 is a front view of one tool,
Fig. 4 is a plan view thereof, Fig. 5 is a part of a cross section perpendicular to the tool rotation axis, showing the structure of the tool shown in Fig. 1, and Fig. 6 is a plan view of the tool.
The figure is a schematic diagram showing how to join when tools with the same direction of blade inclination are used in tandem.
The figure shows a tandem combination of tools with opposite blade inclination directions. The main symbols used for these are as follows. 100, 200, 300... rotary planer shaped tool, 101, 102,... cutter making up 100, 201, 202,... cutter making up 200, 301, 302,... cutter making up 300, 1, 2... Both end surfaces of the tool 100 (shown in front view), 3... Cylindrical surface drawn by the cutting edge, 4... Vertical plane including the tool rotation axis, 5... Vertical plane including both ends of the cutter 101, 6... Flank surface of knife 101, 7...
Cutting edge contour of the cutter 101, 8... Rake face (elliptical cylindrical surface) of the cutter 101, 9... Opposite surface of the rake face of the cutter 101, 9'... Planer barrel plane in contact with 9, 10, 20... ...Cutting edge circles of end faces 1 and 2, 11...
...Bottom surface of the cutter 101, 12...Chip collection, 13...
Bolt for fixing the blade, 14...Tangential plane on the plane body side (flank surface receiving surface) against which the terminal end of the flank is pressed, 15...Tandem joint of the tool.

Claims (1)

[Claims] 1 The contour of the cutting edge is defined as the intersection line between the rotational surface that the cutting edge should draw while touching the finished surface of the workpiece as the tool rotates, and the plane 6 inclined to the rotational axis, and this plane is defined as the flank surface of the cutting edge. At the same time, a cylindrical surface with the contour as a conductor and a group of straight lines in a certain direction as a generatrix is the rake surface of the cutting edge, and the opposing surface 9 on the cutting edge of the rake surface is a plane parallel to the generatrix, and the end of the flank surface is A flank receiving surface 14 is provided on the planer barrel side as a plane that contacts the flank surface at the part, and a plane 9' that contacts the opposing surface 9 of the rake surface, and while maintaining the axial position of the cutter at a regular position, A rotary tool characterized by being configured so that a blade can be set.