JP2000246501A - Ultrasonic vibration cutting tool and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the vibration direction in cutting, prevent a tool from contacting with a flank by change in the vibration direction, and prevent the tool from chipping thereby by fixing a cutting blade element into an orthogonal direction in the vibration antinode zone of a tool shank and supporting the tool shank part corresponding to the vibration node to a tool holder. SOLUTION: A vibrator 2 is connected to axial one end of a tool shank 1 and then connected to an ultrasonic oscillator 3. The tool shank 1 is set to such a length as resonating at 1λ of the vertical wave by the vibrator 2 and two vibration nodes n1, n2 are arranged in equidistant positions from the axial end face of the tool shank 1. A cutting edge element 4 is fixed to the central part of the tool shank 1, namely in a position corresponding to a vibration antinode 1. A tool holder 5 is fixed to a tool rest 8 in the projecting part 50 in the back. On the other hand, the tool shank 1 is arranged between holding bowls 5a, 5b projecting oppositely from the front part of a tool holder 5 and fixed to the respective holding bowls 5a, 5b by the respective vibration nodes n1, n2 separated vertically from the cutting edge element 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibration cutting tool suitable for precision finishing of difficult-to-cut materials and difficult-to-machine shapes, and an ultrasonic vibration cutting method using the same.

[0002]

2. Description of the Related Art An ultrasonic vibration cutting method is known as one of precision finishing cutting methods. In this ultrasonic vibration cutting method, a tool is vibrated regularly at a frequency f and amplitude a in an ultrasonic range of about 15 to 120 kHz in a cutting direction, and a cutting speed v is set to v <2.
This is a method of cutting as πaf (f: frequency, a: amplitude), characterized by intermittent cutting in small increments while alternately repeating cutting and rest. This cutting method can reduce the elastic deformation of low-rigidity workpieces and tools and perform precision cutting, and because of intermittent cutting, it has the effect of improving cutting properties such as cutting temperature rise and work material welding phenomenon can be reduced. There are advantages. However, when trying to cut hard-to-cut materials such as hardened steel, stainless steel or Ni-based alloys at the production processing level using this ultrasonic vibration cutting method, tool breakage and flank abnormal wear are likely to occur. In fact, it has not been practically used for cutting hard-to-cut materials.

More specifically, as a conventional ultrasonic vibration cutting tool, a bending vibration system tool using a transverse wave of an elastic body as shown in FIG. 1A or a torsion vibration of the elastic body in the same form as this is used. Fig. (B) with the torsional vibration tool used
There is a longitudinal vibration system tool utilizing a longitudinal wave of an elastic body as shown in FIG. In the former, the tool shank is fixed with a fixture so that the front end area including the cutting tip protrudes to the side, and the vertical vibration horn and the vibrator or the torsional vibration horn on the same axis are orthogonal to the rear end of the tool shank. And a vibrator. In the latter, the tool shank arranged in the vertical direction was fixed to the fixture with a brim, the cutting tip was attached to the horizontal overhang at the tip of the tool shank, and the horn and the vibrator were attached in series at the rear end of the tool shank. Things. However, with these conventional tools, the cutting edge vibration direction, which must be exactly in the cutting direction, changes due to relatively large cutting resistance when cutting difficult-to-cut materials, and the tool flank collides with the workpiece when the cutting edge retreats due to vibration. There has been a problem that the blade is rubbed or rubbed, thereby causing a cutting edge defect.

[0004] One of the factors is that the tool rigidity is low. That is, since the bending vibration tool and the longitudinal vibration tool both resonate and vibrate, the tool can be fixed to the tool rest only at one or two portions of the vibration node n. Furthermore, if the wavelength is λ, the distance from the fixed point at the leading edge of the tool to the tool edge l, which is the antinode of vibration, must be 1 / 4λ in principle. It is much longer than that. As a result, as a result, the ultrasonic vibration cutting tool has significantly lower tool rigidity than the conventional method of fixing a cutting tool, and is liable to be elastically deformed or vibrated due to cutting resistance. This means that tool breakage will occur.

Another is that the stability in the vibration direction is poor. In other words, it is generally said that the vibration direction of an ultrasonic vibration cutting tool is easily affected by the shape of the cutting edge, and that in the case of a longitudinal vibration tool, the vibration direction is relatively insensitive to the tool shape. Although it is stable, in the case of a bending vibration system tool, a problem is that the change in the vibration direction is large. As a countermeasure against this, conventionally, a dedicated tool adjusted so that the vibration direction becomes the cutting direction is prepared for each cutting edge shape, or the tool mounting posture is changed each time the cutting edge shape changes with one tool. Adjustment such as is necessary. However, in the former case, the productivity is remarkably inferior. In the latter case, it is necessary to adjust the tool mounting angle by several tens of degrees. At this time, there is a problem that the most important cutting edge angle in cutting goes out of control at the same time. Occurs
It was hard to say practical.

[0008] Further, as a cause of the tool breakage caused by the ultrasonic vibration cutting method, there is a case where a tool flank hits a workpiece when the cutting edge is retracted or separated by vibration. That is, the normal cutting force RF generated when the tool flank rubs against the workpiece when the tool is retracted and released
This is a phenomenon in which a cutting force RR in the opposite direction is generated, which causes the cutting edge to break. The cause of this phenomenon is when the tool escapes due to the cutting back force during cutting, it is unloaded when the tool comes off, and the flank hits due to elastic recovery.
This is the case when cutting difficult-to-cut materials such as hardened steel and stainless steel. However, in the conventional vibration cutting method using the bending vibration system tool or the vertical vibration system tool, there is a problem that the above-described cause cannot be removed and chipping is inevitably generated.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and a first object of the present invention is to provide a stable vibration direction at the time of cutting and to receive a large cutting resistance. Even if the vibration direction does not change easily, the contact of the flank due to the change in the vibration direction and the resulting tool breakage can be prevented, and the cutting tool tip angle is always constant and cutting and reproducibility can be improved. It is an object of the present invention to provide a cutting ultrasonic vibration cutting device which can be implemented with a simple structure and at a low cost. Further, the second object is that, in addition to the above object, it is possible to completely prevent tool breakage, and to stably and accurately cut hard-to-machine workpieces such as hard-to-cut materials and interrupted workpieces. An ultrasonic vibration cutting tool and a cutting method are provided. The present invention can be applied as any cutting means such as planing, shaping, boring, deep groove machining, turning, pocket machining with a machining center, and character line machining.

[0008]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention provides a tool shank having a longitudinal vibration length of 1λ arranged in a vertical direction, and attaching a cutting edge element to the tool shank. In a longitudinal vibration type ultrasonic vibration cutting device in which a vibrator is attached in series at a rear end portion, a cutting blade element is fixed to a vibration antinode region in an intermediate portion of a vertical direction of the tool shank in a direction perpendicular to a tool shank axis. And a tool shank portion which is vertically separated from the tip holder and corresponds to a vibrating node is supported by the tool holder. Preferably, the cutting element has a tapered holder, and the tool shank has a tapered hole orthogonal to the axis, and the holder is fitted in the tapered hole. Also, the second
In order to achieve the above object, the present invention is characterized in that ultrasonic vibration cutting is performed with the vibration direction of the cutting edge element of the tool being inclined from the cutting direction to the direction of biting into the workpiece.

[0009]

According to the present invention, since the longitudinal vibration type tool type is adopted, the adjustment of the vibration direction, which has been conventionally performed by trial and error when manufacturing the ultrasonic vibration tool or mounting the device, is unnecessary. However, there is little loss such as heat generation even with high vibration power. In addition, the cutting blade element is fitted and fixed orthogonally to the tool shank axis in the vibration antinode area at the middle part of the tool shank in the vertical direction, and the tool shank corresponding to the vibrating node is vertically separated from the tip holder. Since the tool is supported by the tool holder, the vibration direction is stable, and the vibration direction does not change easily even if it receives a large cutting force. Vibration disturbance is reliably prevented.

Further, the present invention provides a cutting tool in which the vibration direction of the cutting edge element of the tool is not inclined in the same direction as the conventional cutting direction, but is inclined at a maximum of about 30 ° from the cutting direction toward the workpiece. Therefore, the flank of the tool flank is not rubbed, the tool loss during cutting of difficult-to-cut materials can be greatly reduced, and the tool life can be greatly extended.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 2 and 3 show a first embodiment of the ultrasonic vibration cutting tool according to the present invention. 1 is a column-shaped tool shank having an arbitrary cross-sectional shape such as a polygon, and 2 is a vibrator connected to one end in the axial direction of the tool shank, for example, an electrostrictive vibrator, and is connected to an external ultrasonic oscillator 3. . The tool shank 1 has such a length as to resonate at 1λ of the longitudinal wave by the vibrator 2 and FIGS.
As shown in (a), the two vibration nodes n1 and n2 are set at positions within the entire length of the tool shank 1, and preferably, the vibration nodes n1 and n2 are respectively positioned at the same distance from the axial end surface of the tool shank 1. Have been. The cutting blade element (cutting tip) 4 is fixed to the center of the tool shank 1, that is, to a position corresponding to the vibration antinode 1. The cutting blade element 4 has a holder part 4a and a tip part 4b fixed to the tip of the holder part 4a. The tip part 4b may be of an integral type or a throw-away type.

The fixing of the cutting blade element 4 to the tool shank 1 is optional, but in this embodiment, a tapered coupling type throw-away type is used so that it can be fixed easily and firmly. That is, as shown in FIG. 3B, the holder portion 4a has a tapered shape in which the outer diameter becomes smaller toward the rear, and the tool shank 1 is provided with a tapered hole 100 that matches the taper of the holder portion 4a. I have. And taper hole 1
A through-hole 101 is provided from the bottom of 00 to the end face, a bolt 11 is inserted into this through-hole 101, and the tip is screwed into the female screw hole 400 of the holder portion 4a to achieve a firm fixation. . Although the holder portion 4a and the tapered hole 100 have a circular cross section in the drawing, the present invention is not limited to this, and may be a polygon or the like.

Reference numeral 5 denotes a tool holder, which has a projection 50 on its back.
And is supported and fixed to the tool post 8 by the protruding portion 50. The front portion of the tool holder 5 has holding bowl portions 5a and 5b projecting in opposing shapes and has a substantially U-shaped cross section, and the tool shank 1 is arranged between the holding arm portions 5a and 5b. The holding arm 5 has two vibrating nodes n1 and n2 vertically separated from the cutting blade element 4.
a, 5b.

The fixing mechanism is a vibration node n of the tool shank 1.
A method may be used in which collars are provided at portions corresponding to 1, 1 and n2, and these are supported by the holding arms 5a and 5b. However, in this embodiment, V-shaped grooves 102a and 102b are provided at portions corresponding to the vibration nodes n1 and n2, and the holding arm 5b has a V-shaped tip corresponding to the V-shaped grooves 102b and 102b. The metal fittings 6b, 6b are attached to support the vibrating nodes n1, n2 on one side of the tool shank 1, and the holding arm 5a has V-shaped grooves 102a, 102a corresponding to the V-shaped grooves 102a.
The movable fixtures 6a, 6a having the shape-like tip portions are arranged, and the movable fixtures 6a, 6a are made to enter 102a, 102a corresponding to the vibration nodes n1, n2 on the other side of the tool shank 1,
In addition, the movable fixing brackets 6a, 6a are fixed to the fixing screws 7,
By moving forward by 7, it is tightened and fixed. Although two holding arms 5a and 5b are shown on the left and right in the drawing, they may be one on the left and right.

FIGS. 4 and 5 show a second embodiment of the present invention. This embodiment shows an apparatus for ultrasonic vibration cutting in which the vibration direction of the cutting blade element 4 is set to the vibration direction inclined from the cutting direction to the direction of biting into the workpiece W. Specifically, a turning jig 9 is fixed to the back of the tool holder 5, and the turning jig 9 has a first disk portion 9 a having a back surface fixed to the tool holder 5 and a protruding plate for the tool post 8. A second disk portion 9b to which the portion 50 is fixed, and the second disk portion 9
The first disk portion 9a is connected to b so that the rotation angle can be relatively changed. Specifically, as shown in FIG. 5B, the first disc portion 9a is provided with a bearing hole 90 in the center in the plate thickness direction.
Are provided, and a plurality of female screw holes 91 are provided at equal intervals in a ring portion surrounding the hole. A shaft portion 92 fitted in the bearing hole is provided at the front portion of the second disk portion body 9b, and a ring portion surrounding the shaft portion has a plurality of arc-shaped portions at intervals corresponding to the female screw holes 91. An adjustment hole 93 is provided through the thickness direction. The arc-shaped adjustment hole 93 has a counterbore. The first disk portion 9a and the second disk portion 9b are superimposed, and the first disk portion 9a is
The bolt 9 is rotated relative to the disc body 9b, and the bolt 9 is inserted into the female screw hole 91 through the arc-shaped adjusting hole 93 at a desired position.
4 is screwed and tightened so as to be inclined to a desired angle. The second disk portion 9b has an angle scale, and the first disk portion 9a has a pointer.

When this inclined tool is used, in the case of two-dimensional cutting, the cutting edge element 4 is rotated in the direction of cutting into the workpiece by an angle θ from the cutting direction as shown in FIG. 6B. The tool 9 inclines the entire tool including the tool holder 5. FIG. 6A shows the case of the first embodiment (θ = 0 °).
Is shown. In the case of three-dimensional cutting such as cylindrical turning, as shown in FIG.
The entire tool including the tool holder 5 is tilted by operating the turning jig 9 and the tool rest 8 so as to give an inclination angle の in the cutting direction. In this case, the sum of the inclination angle φ in the feed direction and the inclination angle ψ in the cutting direction is the inclination angle θ. As a supplementary explanation, in the case of three-dimensional cutting, a tilt angle φ is formed by the turning jig 9, and ψ is obtained by the turning ψ ′ of the tool rest 8, and the combined angle is θ.

The inclination angle θ in the direction from the cutting direction into the work is required to be at least 10 °. This is based on the knowledge of the present inventors, because if the inclination angle is less than 10 °, rubbing of the flank due to elastic recovery cannot be completely prevented. The upper limit is about 35 °. If the inclination angle is larger than this, when the cutting edge at the start of cutting bites into the workpiece, the flank contacts the workpiece first, and normal cutting cannot be performed. Therefore, 10-35
The optimum angle may be determined in consideration of the material of the workpiece, cutting conditions, etc. within the range of °, but within this range, it is effective for any material and cutting conditions of the workpiece, and It is not necessary to adjust the material and cutting conditions. This point is greatly different from the case where the conventional bending vibration tool needs to be adjusted each time, and is advantageous in improving productivity and stability.

Before reaching the first embodiment, the present inventors assumed that FIG.
Were considered. In this method, a cutting tool is divided into an upper shank 7a and a lower shank 7b of equal length, and a cutting blade element 13 having a flattened shank portion is interposed between the upper and lower shank 7a, 7b. The screw shaft 14 is screwed into the plurality of holes provided in the thickness direction of the plate and the screw holes provided in the axial direction of the upper and lower shanks 7a and 7b so as to correspond thereto, and the cutting blade element 13 is fixed at the vibration antinode. ing. The upper and lower shanks 7a, 7b are provided with collars 120, 121 at portions corresponding to vibrating nodes.
21 is fixed to the tool holder 16
It is fixed to. Although such a tool has a certain degree of rigidity, the strength tends to be insufficient due to the flatness of the cutting blade element 13 and the plurality of holes in the plate thickness direction, and the life of a hard workpiece is reduced. There is a problem in that the length of the screw shaft is reduced, the time and labor is required because the long screw shaft has to be rotated when the cutting blade element 13 is exchanged, and that the number of parts increases and the cost increases. It was not a target. In contrast, the present invention is practical because it can solve all such problems.

The present invention is not limited to the embodiments described above. FIG. 19 shows an example thereof, and FIG. 19A shows an example of a tool suitable for boring. A tapered hole 100 is formed at a position corresponding to the vibration antinode l of the tool shank 1 so as to be orthogonal to the tool shank 1. The cutting blade element 4 ′ having a tapered bending vibration type is fitted and fixed therein. The holder 4 a of the cutting blade element 4 ′ projects sufficiently from the end face of the tool shank 1. (B) shows an example of a tool suitable for deep groove machining. In the intermediate region including a portion corresponding to the vibration antinode l of the tool shank 1, overhanging portions 1a, 1a projecting to both sides are formed, and the overhanging portions 1a, 1a are formed. 1a, a tapered hole 100 is formed orthogonally to the tool shank 1 and a tapered cutting blade element 4 is fitted and fixed therein.

The present invention is not limited to the case where the present invention is used by being mounted on a tool post such as a lathe as described above. FIG.
Shows an example of application of an ultrasonic vibration cutting tool according to the present invention, and includes an ultrasonic vibration cutting tool A including a tool holder 5 on a main shaft 20 of a machining center (MC) capable of U-axis control (main axis angle θ control). To process the workpiece W attached to the MC table 21. According to this method, it is possible to perform high precision machining such as planing, pocket machining, and character line machining that is impossible with an end mill.

[0021]

In the first embodiment, similarly to the conventional vibration cutting method, the tool holder 5 is held and fixed on the tool post 8 as shown in FIGS.
Vibration is performed at a frequency f and amplitude a selected from an ultrasonic range of about 120 kHz, and V <2πaf
Cutting is performed by establishing the relationship At this time, in the tool of the present invention, the cutting blade element 4 is fitted and fixed at the position of the vibration antinode l at the center in the longitudinal direction of the tool shank 1, and the upper and lower two points are located at the same distance from the vibration antinode l. The vibrating nodes n1, n2 are clamped and fixed by the fixtures 6b, 6b and the movable fixtures 6a, 6a. For this reason, there is no variation in the vibration direction due to the influence of the tool shape and the like seen in the conventional tools (particularly, bending vibration tools), and therefore, it is not necessary to adjust the tool mounting posture. Moreover, since a high tool rigidity is achieved, even if a relatively large cutting force is applied, the vibration direction does not change, and the cutting blade element vibration direction is accurately and stable without being affected by the cutting force. be able to.

In the case of the second embodiment, the turning jig 9
As a result, the tool holder 5 and the entire tool shank 1 held by the tool holder 5 can be easily tilted to a desired angle, so that the vibration direction is increased from the fundamental cutting direction to the direction of cutting into the workpiece by, for example, 30 °. The vibration cutting is performed in this state. In this way, even if the workpiece is a hard material such as quenched steel or stainless steel, or an intermittent workpiece (a difficult-to-machine shape material), the tool flank is formed when the cutting element is retracted due to vibration. A vibration trajectory that does not collide with the workpiece can be realized, whereby sudden loss of the cutting edge element is completely prevented, and finish cutting can be performed in a steady wear state.

8 (a), 8 (b) and 8 (c) show two-dimensional cutting.
FIGS. 9A, 9B, and 9C show the vibration trajectory of the cutting blade element and the cutting resistance applied to the cutting blade element when the vibration direction is 0 ° with respect to the workpiece. 45 ° on object side
The vibration trajectory of the cutting blade element and the cutting resistance applied to the cutting blade element when the blade is inclined (b) are shown. V is the cutting speed, Vf is the chip outflow speed, and Vv (t) is the cutting speed (2
πafcosωt), V <Vvmax, Nr is the rake face normal force, Fr is the rake face friction force, Nf is the flank face normal force,
Ff is the flank friction force, Rf is the resultant force of Nf and Ff, f is the frequency, and a is the amplitude.

In the case of FIG. 8, when the cutting edge is retracted, the flank of the tool has a friction force -Fr and a normal force N in the opposite direction to the normal cutting.
f, the resultant force Rf is directed upward in the blade direction,
It is believed that this force causes the cutting edge to chip. On the other hand, in the case of FIG. 9, the vibration trajectory draws an elliptical trajectory by combining the vibration velocity Vv (t) and the cutting velocity V. Therefore, when the tool is retracted, the tool flank separates from the workpiece. The trajectory is taken, whereby the force acting on the cutting edge when the cutting edge retreats is eliminated, and chipping is eliminated. In addition, although the elliptical vibration cutting method is also known, this method has a low rigidity because the blade edge is circularly vibrated, a complicated vibration system, a large heat loss, and a power cannot be increased.
There is a problem in that the cutting edge requires a special shank for each product, which increases the cost.In addition, it is possible to handle only minute cutting with a depth of cut of about several μm, so cutting at the production level is not possible. is there. The present invention is advantageous and practical in that there are no such problems.

[0025]

Next, embodiments of the present invention will be described. Example 1 1) A rigid ultrasonic vibration cutting tool shown in FIGS. 2 and 3 was manufactured so that the vibration direction was stable even when a cutting load was applied. Nominal frequency 21 for ultrasonic vibration generator
A volt Langevin type electrostrictive vibrator having a kHz and a nominal maximum electric input of 1 kW was used. The tool shank has a length that resonates at 1λ of the longitudinal wave. A hole is provided at the center of the vibration antinode in the center, a cutting tip is fitted here, and the upper and lower two vibrating nodes are fixed to the tool holder. The metal fitting was fixed by a method of fastening with screws. Cutting tip has a maximum thickness of 12
mm and a taper (taper angle 5 °).

The ultrasonic oscillator for driving the ultrasonic transducer used had a nominal output of 1.2 kW. The tool vibration condition of this ultrasonic vibration cutting tool is as follows: vibration frequency f = 21.1 kHz
z, amplitude a = 20 μm, and the critical vibration cutting speed Vc (= 2πaf) by this device is 118.7 m / min. 2) The cutting experiment was carried out by fixing the tool holder to the tool rest of a four-length ordinary lathe. Basic cutting conditions, tool conditions, workpiece conditions, and other processing conditions are as follows. Tool: K10 (0-0-10-10-10-30-0.2) Workpiece: S45C, SUS304, SUS440B (HRC55), SCM435 (40HRC) Cutting speed V: 7.9 to 28 m / min Depth of cut: 0 0.05 to 1 mm Feed F: 0.127 to 0.5 mm Cutting oil: Dry, wet (water-insoluble)

3) For comparison, cutting was also performed using a conventional longitudinal vibration type and bending vibration type ultrasonic vibration cutting device. The longitudinal vibration system device is of a type that is fixed at one flange of a vibrating node portion, and the cutting tip is a method that is fixed to the tip of a shank with a screw. The tool vibration conditions are a frequency f: 21.5 kHz and an amplitude a: 17 μm. The bending vibration system device is a system that is fixed at two vibrating nodes with a fastening bracket. The cutting tip is a system that is fixed to the tip of the shank with a screw. The tool vibration condition is a vibration frequency f: 14.5 kHz.
z, amplitude a: 18 μm. Vibration cutting was performed using the tool shown in FIG. 7 as a comparative example. The condition of the tool was such that a flat cutting tip having a thickness of 3 mm was interposed between the upper and lower cutting shanks, and a screw shaft passing through the flat cutting tip was screwed into the cutting shanks and fixed. The tool vibration conditions are a frequency f: 21.1 kHz and an amplitude a: 15 μm.

4) For the work material SUS304, the carbide K1
0, cutting speed V: 28 m / min, d: 0.1 to
1.0 mm, F: 0.1-0.5 mm / rev, cutting distance: 73.8 m. Longitudinal turning is performed, and the cutting and feed amount are sequentially increased. The defect generation limit was investigated. The result is shown in FIG.
As shown in (a), both the conventional type tools (longitudinal vibration type and bending vibration type tools), when the depth of cut t and feed F exceeded 0.2 mm at the same time, a small chipping occurred at the cutting edge.
On the other hand, according to the comparative tool, as shown in FIG. 11, chipping does not occur up to a range where the cut t is up to 0.6 mm and the feed F is up to 0.4 mm, and the chipping occurrence limit is improved. However, this is still not at a practically usable level. In addition, as a more severe cutting, SUS440B quenched material (55HRC) is cut at a cutting speed of 18 m / min, a depth of cut of 0.2 mm, and a feed of 0.12 using carbide K10.
When cutting under the condition of mm / rev, the cutting distance is 80m
At the point when cutting was performed to a small extent, minute defects occurred.

5) Next, the tool of the present invention was tested under the above cutting conditions. The result is as shown in FIG.
Up to 0.8 mm and a feed F of up to 0.5 mm, no chipping occurred, indicating that the chipping occurrence limit was further improved. It is considered that the reason for this is that the tool according to the present invention has a very stable vibration appearance compared to the comparative tool and is less affected by the cutting force.
Under relatively light cutting conditions with a depth of cut of up to about 0.2 mm for SUS304, the tool life is about three times the flank wear compared to conventional cutting, and compared to ultrasonic vibration cutting using conventional longitudinal vibration tools. It was found that the tool life was improved by about 2 times and the tool life was greatly improved.

Example 2 1) The tool shown in Example 1 was used, and the entirety including the tool was attached to the turret in an inclined manner, and the limit of tool chipping was investigated. As shown in FIG. 6B, the vibration direction in this case was inclined by 30 ° in the −Z-axis direction and 7 ° in the X-axis direction with respect to the y-axis direction, which is the cutting direction. 2) The results are shown in FIG. By inclining the vibration direction as shown in FIG.
It has been found that the defect generation limit is further improved as compared with the case of Example 1 in which the feed F does not generate a defect up to a range of 0.5 mm or more and the inclination is not inclined. The cause of this is that the vibration direction is inclined from the basic cutting direction to the direction that cuts into the workpiece, so that the vibration trajectory shows the cutting speed v and the vibration speed v
From the relation of v, it becomes a locus that draws a loop, and it is thought that it will draw an elliptical orbit. It is considered that this method of tilting the vibration direction eliminated the flank of the tool flank. At higher cutting conditions, there was a phenomenon that the cutting force was too large and the vibration stopped. 3) In order to examine the optimum inclination angle, using a carbide K10, cutting speed V: 28 m / min, d: 0.1 mm,
f: 0.165 mm / rev, frequency: 21 kHz, amplitude: 20 μm, and S4 when the inclination angle θ is 0 to 45 °
I performed 2D cutting of 5C. The resulting surface roughness is shown in FIGS. 14 (a) to (d). From this figure, when the angle θ was 15 ° and 30 °, the peak shape was clear, and this was confirmed in the photograph of the cut surface. Therefore, the tilt angle should be about 10-35 °, more preferably 15-3.
It turns out that it is about 0 degree.

Example 3 Using a conventional tool and the tools of the first and second embodiments of the present invention, a long material (diameter 18 mm, length 450 mm) of SUS304 was cut at a cutting speed of 17 using carbide K10. .5
m / min, depth of cut 0.05mm, feed 0.4mm / rev, frequency 2
Cutting was performed under the conditions of 1 kHz and an amplitude of 20 μm, and the processing dimensional accuracy was measured. The cutting speed of a conventional tool is 80 m / min, at which the best machining accuracy is obtained. The vibration direction according to the second embodiment is 3 in the −Z-axis direction with respect to the y-axis direction which is the cutting direction.
0 ° and 7 ° in the X-axis direction. FIG. 15 shows the relationship between the measurement position and the diameter difference. As is apparent from FIG.
In the first embodiment, good accuracy is obtained, but in the second embodiment, much better accuracy is obtained.

Example 4 Using a conventional tool, a comparative example tool and the tool of the second embodiment of the present invention, a quenched material of SUS440B (55HRC) using carbide K10.
Cutting speed 8 m / min, depth of cut 0.2 mm, feed 0.
FIG. 16 shows the result of examining the relationship between the cutting distance and the flank wear width when cutting under the condition of 12 mm / rev.
The cutting speed of the conventional tool was 80 m / min at which the best finished surface accuracy was obtained. In the case of conventional cutting, at a cutting speed of 80 m / min, the cutting distance was about 330 μm at a cutting distance of 550 m as shown in FIG. In the case of using the comparative example tool, the tool was not inclined in the vibration direction, so a sudden tool loss occurred, and at that time, the finished surface rapidly deteriorated, thereby reaching the tool life. On the other hand, as a result of cutting with the tool of the present invention inclined, the flank wear width was only 100 μm,
It is greatly improved as compared with the conventional cutting tool and the comparative example tool. It was observed that the form of wear at that time was not due to clearance wear as in the case of conventional cutting, but due to the accumulation of microchipping. That is, in the conventional ultrasonic vibration cutting, a sudden tool loss that is most disliked at the production site has occurred and the tool life has been shortened by the present invention. It is clear that cutting is possible.

Example 5 Finished cutting of an intermittently shaped workpiece was performed according to the present invention (the tool of the second embodiment) and a conventional method. Workpiece material is SUM4
Using a hardened K1 hardened material with a hardness of 40 HRC and a disk with four grooves in the longitudinal direction of the outer circumference, and the outer peripheral surface of which is finish-cut.
0 was used. The cutting speed was 12.6 m / min, the depth of cut was 0.1 mm, the feed was 0.127 mm / rev, the frequency was 21 kHz, the amplitude was 20 μm. The result is shown in FIG.
FIG. In conventional cutting, regardless of the cutting speed conditions of 12.6, 58.4 and 102 m / min, an impulsive sound is generated every time the tool passes through the groove, and the tool is severely chipped. The finished surface roughness of 2 μmRy reached 15 μmRy when about half of the first workpiece was cut, and finish cutting was not possible. On the other hand, in the case of ultrasonic vibration cutting according to the present invention, no impact sound is heard when the tool passes through the groove, there is no tool breakage, and the initial finished surface roughness of the workpiece is maintained at 3 μmRy up to the 20th. The finished surface roughness at the time when 36 pieces were cut was 4 μmRy, which was equivalent to the initial value. That is, the tool life was 36 times or more that of conventional cutting. There was no tool loss. From this, it can be seen that tool breakage, which was a problem of ultrasonic vibration cutting, can be stably prevented, and thereby, high-hardness workpieces having a shape difficult to machine with conventional cutting can be finished.

[0034]

According to the present invention described above, in the ultrasonic vibration cutting device of the longitudinal vibration system, the cutting edge element is placed in the vibration antinode area at the middle part in the vertical direction of the tool shank, perpendicular to the axis of the tool shank. In addition to fixing, the tool shank part equivalent to the vibrating node is supported by the tool holder by being vertically separated from the tip holder, so that even when a large cutting load is applied to the cutting edge vibration direction, it is accurate without disturbing the vibration appearance. A highly rigid ultrasonic vibration cutting tool that can be set in the cutting direction can be eliminated, thereby eliminating the tool defect which is a problem in ultrasonic vibration cutting.
Moreover, excellent effects such as simple structure and low cost can be obtained. According to the second aspect, in addition to the effect of the first aspect, since the cutting blade element can be easily and firmly fixed to the tool shank, an excellent effect that the frequency and the vibration direction can always be stabilized. Is obtained. Claim 3
According to the above, because the above cutting tool is used, and the vibration direction is inclined from the principle cutting direction to the direction in which it cuts into the workpiece, vibration cutting is performed, so when cutting hard-to-cut materials such as hardened steel or interrupted shapes, etc. However, an excellent effect that stable finishing can be performed without tool breakage is obtained.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram of a conventional ultrasonic vibration cutting tool (bending vibration system tool), and FIG. 1B is an explanatory diagram of another conventional ultrasonic vibration cutting tool (longitudinal vibration system tool).

FIG. 2 is a longitudinal sectional front view showing a first embodiment of the ultrasonic vibration cutting tool of the present invention.

FIG. 3 (a) is a partially cutaway side view showing a first embodiment of the ultrasonic vibration cutting tool of the present invention. (B) is a partial enlarged view which shows the engagement of the cutting blade element and the tool shank.

FIG. 4 is a front view showing a second embodiment of the ultrasonic vibration cutting tool according to the present invention.

FIG. 5A is a side view of the second embodiment, and FIG. 5B is a partially cutaway side view showing an example of a turning jig.

FIG. 6A is an explanatory view showing the vibration direction of the first embodiment in the case of two-dimensional cutting, FIG. 6B is an explanatory view showing the inclination direction and the vibration direction of the second embodiment, and FIG. It is explanatory drawing which shows the inclination direction in the case of the cylindrical cutting of 2nd Example, and a vibration direction.

7A is a front view of a comparative example tool, FIG. 7B is a side view thereof, and FIG. 7C is a perspective view showing the engagement between the cutting blade element and a cutting tool shank.

FIG. 8A is a diagram illustrating a first example of vibration cutting in the case of the first embodiment.
FIG. 7B is an explanatory diagram illustrating a second process, and FIG. 7C is an explanatory diagram illustrating a third process.

FIG. 9A is a diagram illustrating a first example of vibration cutting in the second embodiment.
FIG. 7B is an explanatory diagram illustrating a second process, and FIG. 7C is an explanatory diagram illustrating a third process.

FIG. 10 is a diagram showing a chipping limit when the conventional tool of FIG. 1 is used.

FIG. 11 is a diagram showing a chipping limit when a comparative example tool is used.

FIG. 12 is a diagram showing a chipping limit when the first embodiment of the present invention is used.

FIG. 13 is a diagram showing a chipping limit when the second embodiment of the present invention is used.

14A and 14B are measurement diagrams of surface roughness when the inclination angle is changed in the present invention. FIG.
(B) is a tilt angle of 15 °, (c) is a tilt angle of 30 °, (d)
Indicates a case where the inclination angle is 45 °.

FIG. 15 is a diagram illustrating measurement results of processing dimensional accuracy when a long workpiece is cut by a conventional tool, a second embodiment, and a conventional tool.

FIG. 16 is a diagram showing a relationship between a cutting distance and flank wear when hardened steel is cut with a second embodiment, a comparative example tool, and a conventional tool.

FIG. 17 is a diagram showing the relationship between the number of cuts and the flank wear width when cutting is performed on an intermittent shape with the second embodiment and a conventional tool.

FIG. 18 is a diagram showing the relationship between the number of cuts and the finished surface roughness when cutting is performed on an intermittent shape with the second embodiment and a conventional tool.

FIG. 19A is a perspective view showing a main part of a tool when the present invention is applied to boring, and FIG. 19B is a perspective view showing a main part of a tool when the present invention is applied to deep groove processing. .

FIG. 20 is a perspective view showing an example of use of the ultrasonic vibration cutting tool according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool shank 2 Vibrator 4 Cutting blade element 4a Holder part 4b Tip part 5 Tool holder 5a, 5b Holding arm part 6a Fixing metal 6b Movable fixing metal n1, n2 Vibration node l Vibration antinode

Claims (3)

[Claims] 1. A longitudinal vibration system comprising a tool shank having a longitudinal vibration length of 1λ arranged longitudinally, a cutting edge element attached to the tool shank, and a vibrator attached in series to a rear end of the tool shank. In the ultrasonic vibration cutting device, a cutting blade element is fixed in a vibration antinode region at an intermediate portion in a vertical direction of the tool shank in a direction perpendicular to a tool shank axis, and a tool corresponding to a vibration node which is vertically separated from the tip holder. An ultrasonic vibration cutting tool wherein a shank portion is supported by a tool holder. 2. The cutting tool according to claim 1, wherein the cutting element has a tapered holder, and the tool shank has a tapered hole orthogonal to the axis, and the holder is fitted into the tapered hole. Ultrasonic vibration cutting tool. 3. The tool according to claim 1 or 2,
An ultrasonic vibration cutting method characterized in that ultrasonic vibration cutting is performed with the vibration direction of the cutting blade element being inclined from the cutting direction to the direction of biting into the workpiece.