JPS58143901A - Turning and cutting method by fine and high speed oscillation - Google Patents

Abstract

PURPOSE:To turn and cut a bar steel precisely so that the cut surface becomes finely jagged by giving a cutter ultrasonic oscillation, cutting a material at a high cutting speed and giving a fine feeding. CONSTITUTION:A cutter 2 is oscillated in the direction 12 of back components at an oscillation frequency (f), an amplitude (a), a high cutting speed (v) exceeding 200m/min, and a feed (depth of cut) S to make a two-dimensional cutting. In this case, the relief angle theta of the cutter is a value to be determined by the frequency (f), the amplitude (a) and the cutting speed (v). The cutting surface shape similar to a triangular wave shape is designed not to be brought into contact with the relief surface of the cutter. Crests and troughs are created, the cutting surface becomes finely jagged and chips 13, 14, 15 are cut into pieces.

Description

DETAILED DESCRIPTION OF THE INVENTION Cutting howls have become increasingly faster in recent years. High-precision machining is now possible. However, although this raised bed cutting has the effect of improving machinability, it is currently very difficult to deal with continuous high-temperature chips.

Today, there is a remarkable trend toward unmanned and robotized manufacturing, but there are still many cases where unmanned and robotized production processes have not been realized due to the lack of chip processing technology. The ideal method of chip disposal is to cut continuous chips into pieces, suck them in with a dust collector, etc., and dispose of them. It is also hoped that these shredded chips can be used to strengthen plastic materials.

The present invention was invented to meet these expectations.In two-dimensional cutting, the cutting tool is ultrasonically imaged in the direction of its back force, and the cutting speed is 200~3QQ m/mil or more. Cutting is carried out with one cutting curve, and the feed is set to the amplitude (half amplitude), for example, K. By cutting with enough cutting fluid as a minute feed age, all industrial materials from plastic materials to carbon medium materials can be shredded into needle-like chips, and the shape of the agency etc. This invention relates to an innovative chip-shredding precision turning method that allows precision turning to be performed with conventional turning accuracy without any adverse effects.

Next, the present invention will be explained in detail with reference to the drawings.

Figure 1 shows the cutting process of a plate-shaped workpiece l with a thickness t and a length l.
This is a case where two-dimensional cutting is performed by giving the cutting depth S to the tool 2 with fv. The chip shape at this time is generally continuous like chip 3. Conventionally, attempts have been made to break up these continuous chips by installing a chip breaker on the tool or using methods such as vibration feed cutting.

Although these seem to have been successful for some specific cutting conditions, they have not yet been put into general use. In other words, if the machining accuracy is not affected, the chips may not be separated enough, and if the chips are separated, the machining ftfIe will deteriorate and the production efficiency will decrease. The current situation is that a practical method has not yet been developed.

As shown in No. 21-1, by moving the tool 2 in the cutting direction 4, that is, in the direction of the principal force component, the length of the chip 3 will not become as long as the chip 5. Research on vibration cutting between and,
In research on vibration cutting, it has been found that cutting by moving a tool in the direction of thrust force or feed force is a method that cannot be put to practical use except in special cases. For example, in the back force direction, there is a phenomenon in which the cutting surface of the workpiece is impacted by the flank of the cutting tool, which damages the tool cutting edge and makes cutting impossible. It is said that this is not a common method.

However, the present inventor discovered that the above phenomenon has been observed in the past 10
0m/mil is the parent at the lower low cutting strength.

It has been clarified that this is just a phenomenon that occurs.

In other words, not bringing the tool flank into contact with the workpiece surface means that when the tool vibration frequency f1 and amplitude a are constant, the cutting speed V can be increased to 1.00 m 1 m i
200 m/min over n, 3QQm/m
in.

This can be achieved by using a high cutting speed of 4QQ m/min, and by cutting with the depth of cut S much smaller than the amplitude α, the chips are broken into pieces and the surface roughness of the cut surface is reduced to several μmR, max.
It was discovered that precision turning can be used as a method. In principal force direction vibration cutting, the cutting speed that can change various effects is approximately 50 to 6Q m.
/mil, and for a long time overlooked the challenge of cutting at an order of magnitude higher cutting speed. Recently, approximately 50 to 60
The vibration cutting method of the present invention has excellent cutting effects obtained at low cutting speeds of less than 30 m/min.
0 m/min -400m/rnin ~5QQ m
It has been investigated and discovered that this can be obtained at high cutting speeds of about 1/min. In other words, the chips are shredded by Aragoto,
Therefore, the cutting force waveform becomes a pulsed cutting force waveform,
It was discovered that the cutting heat is also pulsed, which prevents the cutting flow rate from becoming obsolete, similar to the effect in the principal force direction, and has a groundbreaking effect that enables precision machining.

In FIG. 3, the tool 2 is vibrated in the thrust force direction 12 at a frequency f1 and amplitude α, and the cutting speed V is set to a high cutting speed of 200 m/min or higher as described above, and the feed amount (depth of cut) is Two-dimensional cutting is performed by giving S. At this time, the clearance angle θ of the tool is set to a value determined by the frequency fX amplitude a and the cutting speed V, so that the tool clearance surface does not come into contact with the surface shape of the cutting surface approximated by a triangular waveform as shown.

When the present invention is carried out as shown in FIG. 3, in the conventional cutting method, the tool 2 advances at a constant speed υ in the length direction of the workpiece as shown in FIGS. 1 and 2, as shown by diagonal lines. If the vibration displacement of the cutting tool is a sinωt, then aωCO5′ωt is obtained by cutting the cutting part 16 with a long and narrow area AxS at a constant rate, resulting in long continuous chips of 3.5 cm.
The cutting edge moves in the triangular waveform b', which is approximated by the motion locus of the cutting tool tip drawn by combining the photographing speed of the cutting tool and the cutting speed υ, which is expressed by . A small rectangular block fs with a small area, 7.8...
- will be cut.

That is, in Figures 1 and 2, the length l of the workpiece was the cutting length, but by implementing the present invention, it is in the form of a collection of minute lengths divided into extremely small lengths as shown in Figure 3. l=ΣruΔl
It is possible to cut -19J by dividing it into small pieces. Because it is a combination of both speeds, these small blocks 6, 7, 8... cannot be divided parallel to the direction of the cutting speed V, as shown in the figure, and the cutting It has a shape in which minute areas are subdivided in the cutting direction from the inside of the workpiece toward the workpiece surface for each cycle of tool movement expressed by the speed υ, and are arranged so as to be inclined in the direction of the cutting speed υ. Therefore, peaks and valleys occur, and the cut surface becomes uneven. In order to cut this, the chips are roughly cut into pieces, chips 13, 14.1
5... becomes. When two-dimensional cutting is performed by applying a depth of cut (feed amount) S from a cutting surface with an uneven surface shape having a peak of the peak and a point a, the peak of the peak shifts to a point, and the difference between the peaks of the peak is the depth of cut (feed amount) S corresponds to Similarly, small block 9゜1 (1
, 11... are formed, and the chips are shredded. One of the features of the present invention is that this tool is provided with a relief angle θ, which will be described later.

The cutting shown in FIG. 3 is performed by the method shown in FIG. That is, a pipe-shaped workpiece 1 is chucked onto the main spindle of a lathe and rotated at high speed to achieve a cutting speed υ. The bite shank 2 is glued and fixed to the tail of the bite shank 2, and the bite shank is vertically driven by a sound wave with a frequency f and an amplitude a in the direction of the arrow 14, and a cutting tool tip is glued to the tip of the bite shank. to form a cutting edge for two-dimensional cutting. Then, a feed S rran/reυ is applied to two-dimensionally cut the end face of the pipe-shaped workpiece. That is, both ends of the cut H are kept out of contact with the workpiece, and cutting is performed in such a state that only two components of force, the main component force and the back component force, act on the workpiece.

At this time, the feed Smm/rev is made smaller than the amplitude a of the bite. For example, α-16 μm, s-0,3 μm/
It should be about rev~3μm/rev. The motion locus of the cutting edge is synthesized by the curve represented by the displacement α pin (2πf)·t of the cutting tool and the cutting speed V, and is represented by a curve C as shown in FIG. 5(A). At this time, since the cutting speed is fast, this is approximated to form a triangular waveform d. This θ is important, and the relief angle θ' of the cutting tool needs to be larger than this θ. On the contrary, after setting the relief angle θ' of the cutting tool and forming the cutting tool, when the frequency f and the amplitude a are constant, the cutting speed V is set to high 1, contrary to the case of vibration cutting in the principal force direction. By choosing the direction of vermilion, the machinability can be improved.

Starting cutting from the end face of the workpiece, each part of the end face has a constant feed S
When m+n/re U, the cutting surface is the fifth
The triangular waveform ABCDEPG shown in figure (b) is obtained. Furthermore, as the workpiece rotates once, the cutting edge advances by the feed S, and in the shaded area, BCIi (DEKJ in the first vibration cycle, FGMT in the next vibration cycle, etc.), etc. The block is divided into pieces and each small block is generated as chips and cut.The cutting direction is at an angle θ with respect to the direction of the cutting speed υ [7, which is the direction from the inside of the workpiece toward the surface of the workpiece. The angle θ is smaller than the relief angle θ of the cutting tool and is expressed as tanθ−[.
= 16 μm, since α2 is 0, it can be considered as Δll.

That is, in FIGS. 1 and 2, the cutting length is represented by a set of lengths Δl of the cut small blocks, and a sample chip-shredding cutting mechanism that generates chips from the divided small blocks is shown in FIGS. It becomes. The depth of cut (feed) at this time is expressed as 2 Scos θ, and is approximately 1.5 times larger than the depth of cut (feed) in the cases of FIGS. 1 and 2. The acting time of the cutting force at this time is the duration of one cycle of the cutting tool a, and the cutting force waveform is a pulse-like cutting force waveform.

As a cutting mechanism that generates shredded chips, the present invention provides an epoch-making effect in which a pulsed cutting force waveform with short synchronization and a short action time, which is ideal in a cutting force waveform, can be applied to a workpiece.

In addition to the above, the turning operations include cylindrical turning as shown in FIG. 6, side cutting of the IE surface of the end face as shown in FIG. 7, boring as shown in FIG. 8, and parting as shown in FIG. Each figure shows a basic implementation method when implementing the present invention in each of these operations. In the case of the parting shown in FIG. 9, as can be easily understood from FIG. 4, the direction of vibration of the cutting blade is from the outer periphery of the workpiece toward the center of the workpiece, that is, in the radial direction. At this time, if the parting length is long as shown in the left diagram of FIG. 9, a back taper is provided from the tip of the cutting blade to prevent abnormal middle rubbing on the side surface of the cutting blade. In the case of cutting off a pipe as shown in the right diagram of FIG. 9, it is possible to cut off the pipe without providing a back taper.

In order to realize the ideal effect and implement the present invention in a simple manner, it is necessary to select the clearance angle of the cutting edge that is responsible for chip formation, as described above. The reason for explaining the cylindrical machining using a cutting tool with a nose angle of 90 in FIG. 6 lies in the selection of the side relief angle of the side blade.

Then, in a horizontal section including the tip of the tool cutting edge and the center axis of rotation of the workpiece, the transverse blade is vibrated from the outer periphery of the workpiece toward the center of the workpiece in a direction that makes an angle ψ with the feeding direction of the tool vTf'=
Ultrasonic imaging is performed with amplitude a. At this time, consideration must be given to prevent the front flank of the front cutting edge of the tool from acting. In other words, it is important to position the front cutting edge in the same position as the vibration direction or give it a clearance angle γ, that is, to make the nose angle smaller than 9♂ so that the front cutting edge does not come into contact with the workpiece at all. .

In the case of a round-tip cutting tool, the side clearance angle and the 11th clearance angle are the same, so when performing 8-dimensional cutting, make sure that the feed direction and vibration direction are not the same.

The feature of the muff ζ of the present invention is that the clearance angle is specified, and the clearance angle is larger than the 7 to 8° angle of conventional tools. As a result, the mechanical strength of the cutting edge decreases, so the rake face is reinforced by giving a negative rake angle (+α) according to the strength of the workpiece.

In the case of iE surface milling as shown in Figure 7 and boring as shown in Figure 8, the 6th
It is carried out in the same manner as shown in the figure. As can be seen from these figures, the present invention can be applied to all types of turning processing including thread processing. In the figure, the explanation was given in the case of a vertical ultrasonic vibration type bite shank, but it can be carried out in the same way in the case of a bending type bite shank, a torsion type type, etc.

As shown above, the cutting hardness is subdivided into lengths of about It cannot be devised by manipulating only υ and f.It becomes necessary to add a separate method.If this cutting length is divided into fine sections, the surface roughness can of course be made smoother.There is a method suitable for this purpose. It is created as shown in Fig. 10. Fig. 10 shows the case of high-speed two-dimensional cutting.

That is, as described above, the tool 2 is vibrated in the direction of the arrow 18 at the frequency f1 and the amplitude a, and the uneven surface A B CD B F G obtained by cutting at the variable cutting speed V is vibrated. A triangular shape 19 on the protruding peak is cut using a normal cutting tool 21 fixed to a tool rest at a distance behind the tool 2.

The point where the cutting edge X of this tool 21 is located is the amplitude 2a of the tool 2
Within. In the case of FIG. 10, the tool 2 is located at the same position as the vibration stopping position, that is, at the midpoint of 2a shown in the figure.

When cutting in this way, if only tool 2 is used, the surface,
Since part of the triangular area 19 is deleted by tool 2 when cutting the clear D E K J, the area D' i is narrower than the one-sided flat D E K J.
6 K'J' will be cut. In other words, cutting quality can be reduced. The length of the cut made by the tool 21 is short, and the cuts are intermittent, so the chips are cut into thinner pieces.

The present invention is carried out by the method shown in Figure 5 (b),
The cutting edge of the tool mostly cuts the shaded area and shreds the chips, but sometimes the cutting edge cuts the uneven surface A as shown in Figure 11.
B CD E F” Cutting surfaces A, B, in the same phase as G
This also occurs when cutting C, D, B, F', and G.

The chips in this case are continuous. However, the phase gradually shifts and shredded chips begin to form again. This tends to occur when the feed is close to the amplitude of Fb and the feed is relatively large. Therefore, continuous chips are mixed here and there with the group of finely chopped chips, or the shape of glue scum is formed. The cutting edge position of the tool 21 in FIG. 11 is an uneven surface formed by the amplitude 2a of the tool 2 A B CD E F G
The feed amount S is set from winter mountains A, C, B, and Q. With the tool 21 installed at such a cutting edge position, only the tool 2 can cut out part of the triangle 2 in the continuous area 22.
The minute surfaces and bonds corresponding to No. 3 are intermittently removed, and the chips are shredded by cutting 24 parts of the V-shaped area with the vibrating tool 21, thereby achieving complete chip shredding according to the present invention. Implementation can be subsidized. That is, this is the case where the cutting edge of the tool 21 is placed near the peaks of an uneven surface such as ACEQ of the cutting surface formed by the tool 2 vibrating away from the workpiece 1. At this time, since no significant cutting resistance acts on the tool 21, mechanical considerations for the tool 21 do not require total heat, but are of no use in improving the surface roughness.

Therefore, the tool 2 vibrates and the fifth tool closest to the workpiece 1
HJI shown in Figure (B) or B shown in Figure 11,
It is conceivable to install the tool 21 near the valleys of the uneven surface within the amplitude 2a of the tool 2, as shown at points D and P. With this installation, the area to be cut by the vibrating tool 2 becomes 26, which makes it easier to cut, and the length of the chips becomes shorter. The surface roughness is smoother than in FIGS. 11 and 10.

However, the area of the tool 21- is shown as the area 25 shown in the figure, which is wider than the area 23 in FIG. 11 and the area 19 in FIG. 21 requires some mechanical consideration.

The position of the tool 21 relative to the tool 2 within the amplitude 2a as described below is a feature of the present invention. These positions are selected depending on the cutting condition. Then, cutting can be carried out under optimal chip cutting conditions and cutting conditions that provide a smooth surface roughness.

FIG. 13 shows the relationship between the mounting positions of the tool 2 and the tool 21- in the case of cutting the end face of the pipe-shaped workpiece 1.

The workpiece 1 is rotated at a constant rotational speed and used as a cutting wheel seat υ, and the cutting edge of the tool is ultrasonically vibrated in the direction shown by the arrow with a vibration knife ffX, ff5 width a, as explained in Fig. 5. The ultrasonic vibration cutting device is mounted on the tool post on the lathe carriage, and the tool 21 is placed, for example, on the tool post on the opposite side of the carriage 1, with the rake face in the opposite direction to the rake face of the tool 2, and the tool 21 is placed on the lathe bed surface. The present invention is carried out by attaching the blade so that the cutting edge is facing the position shown in FIG. Since the tool 2]- does not vibrate like the tool 2, there is no limit to the clearance angle and the relief angle is set to about 7 to 8 degrees. A method of implementing the present invention for general turning processing is shown in FIGS. 14 to 17. Figure 14 shows cylindrical turning, Figure 15 shows side turning of the LE surface of one end, Figures 1-6 show boring,
FIG. 17 shows the case of cut-off processing.

The manner in which various angles are given to the tool 2 in the 8th position and the direction of G movement are the same as in the case of FIGS. 6 to 9 described above. As shown in each figure, the cutting edge of tool 21 is given the cutting depth t or feed from the outer circumference of the workpiece so that the cutting edge of tool 21 is the same distance from the rotation center of the workpiece as shown in each figure. Perform boring, face turning, and parting.

Now, as mentioned above, in the present invention, which is characterized by cutting chips and smoothing the surface roughness, one further improvement is made to the tool 21. That is, as has been conventionally done, a wiper edge is added to the front cutting edge as shown in FIG. 15. By doing so, the surface roughness is further smoothed, and a cut surface with a smooth surface roughness of about 1 to 2 μm can be obtained.

FIG. 18 shows a specific embodiment of the present invention.

A workpiece 1 made of carbon tool scraps with a diameter of 54mm and a length of 100mm is chucked onto the main spindle of a lathe and rotated at 'zzooγpm. Rake angle α-〇1 Side relief angle 25, Nose angle 9♂,
A bite shank with a cutting edge with a front cutting edge angle of 20 degrees and a side edge angle of 70 degrees glued to the tip of a mold width expanding horn provided at one end of a vertical ultrasonic vibration transducer 17 with a natural frequency of 21.7 kHz. Molded on the tip of 2, number of shots 21.7H-Iz
, vibrate in the direction of arrow 18 with one hem width of 16 μm. Then, the vertical vibration type cutting tool is attached to the tool rest 28 using the fastening fittings 27 at two positions of the vibration nodes generated in the cutting tool shank 2. Furthermore, the attachment of the heavy tool rest on the vibrator side is reinforced by a reinforcing jig 29 using the vibration nodes of the amplitude-enlarging horn. In this way, the cutting edge can be made to have a vibrational shape exhibiting regular and stable f and α. Cut into this cutting edge t = l van,
Prepare to feed S=9 μm/r ev and sufficiently lubricate with cutting fluid. Then, a tool rest 30 facing the same carriage is provided, and the tool rest has the same cross-cutting angle, and in this case, the length is about 0.5 (turn) for the purpose of smoothing the surface roughness. A cutting tool 21 having a wiper blade 81 is attached. Then, the position of the blade edge is adjusted so that the same depth of cut t is obtained.

In the examples, the case of carbon tool steel was shown, but the present invention can be applied not only to organic synthetic resin materials such as Teflon and nylon, but also to soft materials such as aluminum alloys as non-ferrous metal materials, and further to carbon steel of iron alloys. , stainless steel materials and hard materials obtained by quenching them. Of course, the present invention covers workpiece materials ranging from inorganic materials that are recent industrial materials.

When the workpiece material is a hard and brittle material, careful attention must be paid to the tool clearance angle. That is, the clearance angle is not the clearance angle in the triangular waveform approximated in FIG. 5, but the angle H obtained by combining the vibration speed and the cutting speed. Workpiece diameter D1 rotation speed le, single amplitude aX frequency f, I
(is 7 to 10 more than θ obtained from the approximated triangular waveform.
°Thick. The mechanical strength of the cutting edge, which is reduced due to this large relief angle, is reinforced by providing a negative rake angle.

As described above, the present invention applies vibrations in the ultrasonic range to the cutting tool so that the distance between the workpiece and the cutting tool changes, and cutting is performed intermittently, making chips finer and easier to dispose of. Become. Since cutting is performed intermittently, the temperature rise of the workpiece and the cutting tool can be reduced. This means that when cutting carbon tool steel as a workpiece, the chips are white-gray! , it has been proven that it does not discolor due to high temperatures. In addition, since the frequency of vibration is extremely high even though it is intermittent cutting, it is possible to maintain sufficient surface roughness.
A roundness of m is obtained. Since the cutting speed was set above the limit determined by the clearance angle, swing width, and frequency of the cutting tool,
The flank surface of the cutting tool does not come into contact with the workpiece.

Furthermore, by using a non-vibrating cutting tool in combination with the above-mentioned moving cutting tool to intermittently cut the convex portions of the cutting surface that have irregularities immediately after being formed, an even smoother cutting surface can be obtained. At the same time, the burden on the vibrating tool can be reduced.

[Brief explanation of the drawing]

1 and 2 are side views showing the conventional method, and FIG. 3 is a side view showing the state of cutting by the method of the present invention. FIG. 4 is a side view showing an example of an apparatus for carrying out the method of the present invention;
The figure is an enlarged view showing the cross-sectional shape of the cutting surface, and FIGS. 6 to 9 are plan views showing various cutting modes. FIGS. 10 to 12 are enlarged sectional views showing cutting conditions when a non-vibrating cutting tool is used, and FIGS. 13 to 18 are plan views showing each embodiment of the present invention. 1... Workpiece, 2... (Pictured) part-time tool, 17 Ultrasonic stationary element, 19.28.25... Convex part, 21... (
J Shinmai) Part-time job. Patent Applicant Ko Kumabe> Master and Disciple 1 Figure 3 Figure 7- Figure 6 (Ino Figure 6 c-portion) Figure 7 NuH Ino Figure 7 (Rono Figure 8 (Ino Figure 8 (0)) Figure 74 (Iri Figure 14 (.) Figure 11 (A) Figure ″ (0) Figure 16 (Inno
Figure 16 (“Ri1

Claims (2)

[Claims] (1) So that the distance between the workpiece and the cutting tool changes by 1',
Apply vibrations in the ultrasonic range to the cutting tool, make the depth of cut (feed amount) of the cutting tool sufficiently smaller than the width of the vibration, and set the cutting speed to a level lower than the minimum speed determined by the clearance angle, frequency, and amplitude of the cutting tool. A precision high-speed vibration turning method in which cutting is performed intermittently by preventing the flank surface of the cutting tool from contacting the workpiece. (2) Apply vibrations in the ultrasonic range to the cutting tool so that the distance between the workpiece and the cutting tool changes, and reduce the depth of cut (feed amount) of the tooling tool to be sufficiently smaller than the amplitude of the vibration, and reduce the cutting speed. The cutting speed is lower than the minimum speed determined by the clearance angle, vibration frequency, and swing width of the cutting tool, so that the flank surface of the cutting tool does not come into contact with the workpiece, and cutting is performed intermittently. A precision high-speed vibration turning method characterized in that a cutting tool intermittently cuts convex portions of a cutting surface having fine 7#I unevenness immediately after being formed by the vibrating cutting tool.