JP4653300B2 - Turning tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turning tool such as a throw-away slot mill used for grooving a metal workpiece. The present invention can also be applied to an internal pin mirror cutter, an external pin mirror cutter, or the like, but the following description will be given by taking a slot mill as an example.
[0002]
[Prior art]
When machining deep grooves in a metal workpiece using a slot mill, the groove depth is gradually increased by feeding. As shown in FIG. 9, a parallelogram negative throw away tip T is employed for the processing, and the side surface 3 forming a rectangle is the rake face of the outer peripheral blade 7, and the upper surface 1 of the parallelogram is the outer periphery. The other end of the outer peripheral blade when the cutter 7 is mounted in a direction that becomes the flank face of the blade 7 and is so-called negative or positive blade shape (radial rakes R and R are negative and axial rakes A and R are positive). In order to move B onto the outer diameter circle D (point B ′) of the cutter where one end A is located so that the locus of the outer peripheral blade 7 is parallel to the groove bottom of the machining groove (perpendicular to the groove side surface), the tip T Is tilted by Δθ (about 30 ′ to 1 °).
[0003]
Due to the influence of the inclination, the side blade 8 is also inclined to give a back taper of Δθ to the side blade 8, and as shown in FIG. 10, a feed mark M is attached to the side surface of the groove in the processing with feed f. In this case, the surface roughness of the groove side surface is represented by Rmax≈ftanΔθ ′ and is rough when the feed mark has the geometric shape shown in the figure.
[0004]
Therefore, when high surface roughness is required, finish processing is performed to remove the feed mark, or a wiper tip (sweeper tip) is separately included in the cutter for grooving to remove the feed mark with the wiper tip. It has been done.
[0005]
[Problems to be solved by the invention]
If the feed mark is removed in a separate process, productivity will deteriorate. Further, in the case where the wiper tip is provided and the feed mark is removed at the same time as the groove processing, the addition of the wiper tip reduces the total number of groove processing tips to be mounted on the same cutter, thereby lowering the processing efficiency.
[0006]
Accordingly, an object of the present invention is to increase the surface roughness of the groove side surface of the processed groove without using a dedicated wiper tip.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, a negative type throwaway tip having a parallelogram as a basic shape has a rectangular side surface as a rake face of the main blade, and a substantially parallelogram upper surface as a flank surface of the main blade. Furthermore, the radial rake is negative, the axial rake is positive, and both ends of the main blade are mounted on the cutter body so as to face the outer diameter or inner diameter of the cutter. In addition, the throwaway tip has a chamfered portion at an acute angle corner portion located in front of the cutter in the rotation direction with a θ inclination with respect to a line perpendicular to the upper surface and a β inclination with respect to the side surface serving as a rake face. The ridge line between the chamfered portion of the tip and the side surface that forms the flank face of the side blade forms a side blade that is substantially perpendicular to the axis of the cutter.
[0008]
Such a tool is preferably produced by making the surface of the chamfered portion a curved surface and generating a side edge of a gently created arc. The side blade substantially perpendicular to the axis of the cutter referred to in the present invention includes the side blade of the created arc.
[0009]
It is also preferable to form the chamfered portion symmetrically with respect to the thickness center of the throw-away tip.
[0010]
Here, the main blade refers to an outer peripheral blade such as a side milling cutter or an external pin mirror cutter, or an inner peripheral blade such as an internal pin mirror cutter.
[0011]
[Action]
When the chamfered portion described above is applied to the acute angle corner portion of the parallelogram throwaway tip, the side blade 8 inclined by Δθ ′ in FIG. 9 is removed. Instead, as shown in FIG. 7, the chamfered portion 10 and the side blade are removed. A ridge line (new side blade 8 ′) inclined by Δθ _{1 in the} direction opposite to the side blade with respect to the removed side blade (blade between points A and C) between the flank and the side surface 5 Occurs. This slope Δθ ₁ of the ridge line is a composite angle of the chamfering angles θ and β of the chamfered portion. Therefore, by appropriately setting the values of θ and β, the inclination of the side blade caused by tilting the tip T by Δθ is set. It can be corrected. If Δθ ₁ = Δθ ′, the inclination of the side blade after correction becomes zero, and the side blade also has a function of a wiping blade, and no feed mark is attached to the side surface of the groove after processing (see FIG. 8). In order to prevent a feed mark from being attached to the side surface of the groove, the feed f during processing is naturally larger than the effective length of the side blade 8 ′ (the length between A ′ and C in the figure). Make it smaller.
[0012]
Note that the squareness of the side blade 8 ′ with respect to the cutter axis varies depending on the dimensional error or mounting error of the tip. When the side blade 8 ′ is a straight blade, the surface roughness of the processed groove side surface is unstable. become. Accordingly, it is desirable that the side blade 8 'is a loose arcuate blade. When the arcuate side blade is provided, the influence of the angle change does not appear, and a stable surface roughness can be obtained.
[0013]
In addition, the chamfered portion that corrects the inclination of the side blade is formed symmetrically with respect to the center line in the thickness direction of the tip, and the throw-away tip having the upper surface as the flank of the main blade and the lower surface of the main blade The throw-away tip with the flank face can be mounted on both sides of the cutter body in a zigzag state, and the opposite side of the groove can be machined with the side blades of those tips. The advantage that can be combined is generated.
[0014]
In addition, if the ridge line portion between the side surface and the upper and lower surfaces of the tip serving as the flank of the side blade is rounded, a groove where the corner portion is connected by the R surface can be processed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a throw-away tip employed in the tool of the present invention. This throw-away tip T is a negative tip with a hole having a parallelogram as a basic shape, and has an upper surface 1, a lower surface 2, two parallel side surfaces 3, 4, and a side surface 3 with an acute angle and an obtuse angle with respect to the side surface 4. The side face 5 and the side face 3 have an obtuse angle and the side face 6 has an acute angle. Further, a ridge line portion between the side surfaces 5 and 6 and the upper surfaces 1 and 2 is formed as an arc surface 9.
[0016]
This chip actually has no vertical relationship, but here, for convenience of explanation, 1 is an upper surface and 2 is a lower surface.
[0017]
This throw-away tip T has a side surface 3 or 4 as a rake face, and a ridge line between the side surface 3 or 4 and the upper and lower surfaces 1 and 2 is used as an outer peripheral blade 7 (or inner peripheral blade). The chamfered portions 10 are respectively provided at two acute angle corner portions of the chip T. The chamfered portion 10 is inclined by θ (about 30 ° in the drawing) with respect to a line perpendicular to the upper and lower surfaces 1 and 2 when the side surface 3 (or 4) is viewed directly from the front, and further, the side surface 3 (or 4). Is inclined with respect to β (the one in the figure is about 8 °), whereby the angle-corrected ridge line (side edge 8 ′) having a combined angle of θ and β is formed between the chamfered portion 10 and the side surface 5 (or 6). It has occurred between. Here, α in FIG. 1 is set to 80 °.
[0018]
The chamfered portion 10 is provided in the same corner portion in a symmetrical state with respect to the thickness center of the tip T, the tip having the upper surface 1 as the flank of the outer peripheral blade 7, and the lower surface 2 the outer peripheral blade 7. Using the tip that became the flank face, it is possible to create cutting edges with different left and right sides.
[0019]
2 is a countersunk screw with the throwaway tip T of FIG. 1 oriented such that the side surface 3 is the rake face of the outer peripheral blade 7, the upper surface 1 is the flank surface of the outer peripheral blade 7, and the side surface 5 is the flank surface of the side blade 8 '. 11 shows the blade unit 13 attached to the holder 12.
[0020]
FIGS. 3 to 5 show slots in which a right-handed cutting tool unit 13R and a left-handed cutting tool unit 13L are mounted on the outer periphery of both sides of the cutter body 14 in a zigzag manner using clamp pieces 15 and bolts 16. 1 illustrates an embodiment of a mill. In the mounted state, both ends of the outer peripheral blade 7 are placed on the outer diameter circle D of the cutter, and a negative and positive blade shape with radial rakes R and R being negative and axial rakes A and R being positive is created.
[0021]
Further, as shown in FIG. 5, the side blade 8 'is perpendicular to the cutter axis, and the side blade 8' is fed to the side surface of the machined groove by making the feed smaller than the effective length of the side blade 8 '. Make sure that the mark is not attached.
[0022]
In the slot mill of FIGS. 3 and 4, an intermediate tip T ′ for cutting the central portion of the groove bottom is set on the locator 17 between the cutting tool units 13 </ b> R and 13 </ b> L. The intermediate tip T ′ uses the ridge line between the lower surface 2 and the side surface 3 and the ridge line between the upper surface 1 and the side surface 4 of the throw-away tip T of FIG. 1 as an outer peripheral blade. Rotation of the tip is performed at the positions of {circle around (1)} to {circle around (4)}, so that the four cutting edge ridges of the tip of FIG.
[0023]
The intermediate chip T ′ is provided according to the width of the machining groove, and may be omitted.
[0024]
6 shows a chamfered portion 10 having an inclination of β with respect to the side surface 3 (or 4) of the chip when viewed from the side of the side surface 5 (or 6) and having a radius R as shown in FIG. It is a curved surface. Thereby, as shown in FIG.6 (c), the side blade 8 'becomes a blade of a generating arc with a considerably large radius R', and the surface roughness of the processed surface by the side blade is stabilized. The surface roughness in this case is obtained by the equation Rmax≈f ² / 8R ′, and is not affected by the inclination of the side blades.
[0025]
【The invention's effect】
As described above, the rolling tool of the present invention has a basic shape of a parallelogram arranged so as to be a negative or positive blade shape with the side face being the rake face of the main blade and the upper face being the flank face of the main blade. Since the chamfering part that corrects the inclination of the ridgeline between the side surfaces is provided at the acute corner part of the negative tip to create a side blade that also functions as a wiping blade, the processing surface of the processing surface by the side blade is not provided without a dedicated wiper tip. The surface roughness can be improved, and the number of effective blades of the chip can be increased to increase the machining efficiency.
[0026]
In addition, unlike the case having a straight side blade, the one having a circular side blade can obtain a stable surface roughness regardless of the tool accuracy.
[0027]
Furthermore, when the chamfered portion is formed symmetrically with respect to the thickness center of the chip, a main blade with a different shape can be formed with the same chip, which is economically advantageous.
[Brief description of the drawings]
FIG. 1A is a plan view showing an example of a throw-away tip used in the tool of the present invention, FIG. 1B is a front view of the same tip, FIG. 1C is a side view, and FIG. Directional view [FIG. 2] (a) Front view of a blade unit constructed by mounting the tip of FIG. 1 on a holder (b) Top view of the same blade tool unit (c) Left side view of the same blade tool unit [ 3 is a side view showing a part of the embodiment (slot mill) of the tool of the present invention. FIG. 4 is a side view showing a part of the outer periphery of the slot mill of the same. FIG. FIG. 6A is a diagram showing the inclination of β of the chamfered portion of the curved surface. FIG. 6B is a view of the same chamfered portion as viewed from the direction of FIG. 1A. FIG. FIG. 7 is a diagram illustrating the side edge of the generated arc. FIG. 7 is an explanatory diagram of the action of the chamfered portion. Figure [EXPLANATION OF SYMBOLS] shown Figure 9 surface which is machined over a feed Remarks view Figure 10 is a side blade with a back taper of back taper caused by the inclination of the tip showing the situation
T, T 'Throw-away tip 1 Upper surface 2 Lower surface 3, 4 Side surface 5 to be rake face, 6 Side surface to be a flank face 7 Peripheral blade 8, 8' Side blade 9 Arc surface 10 Chamfered portion 11 Countersunk screw 12 Holder 13 Blade unit 13R Right-handed blade unit 13L Left-handed blade unit 14 Cutter body 15 Clamp piece 16 Bolt 17 Locator A, R Axial rake R, R Radial rake

Claims (4)

A negative throw-away tip with a parallelogram as a basic shape. The rectangular side is the rake face of the main blade, the upper surface of the substantially parallelogram is the flank face of the main blade, the radial rake is negative, and the axial rake is positive. Attach to the cutter body so that both ends of the main blade are on the outer diameter or inner diameter of the cutter. It has a chamfered portion that is inclined and β inclined with respect to the side surface that is the rake face, and the ridgeline between the chamfered portion and the side surface that forms the relief surface of the side blade is a side blade that is substantially perpendicular to the cutter axis. The forming tool. The rolling tool according to claim 1, wherein the chamfered portion has a curved surface to generate a side edge of a gently created arc. The cutter body has a throwaway tip with the chamfered portion formed symmetrically with respect to the thickness center of the throwaway tip, the upper surface serving as the flank face of the main blade, and the throwaway tip having the lower surface as the flank surface of the main blade. The turning tool according to claim 1 or 2, which is mounted in a zigzag state on both sides of the outer periphery or the inner periphery of the . The rolling tool according to any one of claims 1 to 3, wherein the ridge line portion between the side surface and the upper and lower surfaces of the tip serving as the flank of the side blade is rounded.

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