JP2022082377A - Vibration suppressing device, turning device, and vibration suppression method - Google Patents

Abstract

To provide a vibration suppressing device capable of suppressing vibration of a work.SOLUTION: A vibration suppressing device 18 is a vibration suppressing device used for a turning device 10 including: a headstock 12 which holds one end of a workpiece W extending along a shaft core and rotates the workpiece W around an axis center; a tailstock 14 having a rotation center 24 supporting the other end of the workpiece W and rotating together with the workpiece W. The vibration suppressing device includes a conductive member 34 having conductivity and a magnetic field generating member 36 for generating a magnetic field acting on the conductive member 34. By making the conductive member 34 rotate with respect to the magnetic field generating member 36 with the workpiece W, the conductive member applies, to rotation of the workpiece W, braking force F generated on the basis of eddy current flowing in the conductive member 34 and generated at an interval shorter than a period of the rotation of the workpiece W.SELECTED DRAWING: Figure 4

Description

Application for application of Article 30, Paragraph 2 of the Patent Act has been applied. .Zip) published a collection of lecture papers On September 1, 2020, the website of the academic lecture of the 2020 Society of Precision Engineering Autumn Meeting (http://www.jsp.or.jp/event/jspe_meating/ Lecture presentation video released at 2020-09 autumn /)

The present invention relates to a vibration suppression device, a turning device, and a vibration suppression method.

Conventionally, a turning device for rotating a work to cut or polish is known. For example, Patent Document 1 describes a spindle device that grips one end of a rod-shaped work to rotate the work, a tailstock that supports the other end of the work and rotates with the work, and a mandrel for cutting the work. Machine tools equipped with the tools of are disclosed.

Japanese Unexamined Patent Publication No. 2017-213658

However, in the machine tool of Patent Document 1, when the tool is brought into contact with the rotating work, the work vibrates, which may lead to deterioration of the surface texture of the work.

Therefore, an object of the present invention is to provide a vibration suppressing device or the like capable of suppressing the vibration of the work.

The vibration suppression device according to one aspect of the present invention supports a headstock that grips one end of a work extending along the axis and rotates the work around the axis, and the other end of the work. A vibration suppression device used in a turning device having a tailstock having a rotation center that rotates with the work, and a magnetic field generation that generates a conductive member having conductivity and a magnetic field acting on the conductive member. One of the conductive member and the magnetic field generating member is provided with a member, and by rotating with respect to the other together with the work, the rotation of the work is generated based on the eddy current flowing through the conductive member. Moreover, a braking force generated at intervals shorter than the rotation cycle of the work is applied.

The turning device according to one aspect of the present invention supports a headstock that grips one end of a work extending along the axis and rotates the work around the axis, and the other end of the work. A mandrel having a rotation center that rotates with the work, a conductive member having conductivity, and a magnetic field generating member that generates a magnetic field acting on the conductive member, the conductive member and the magnetic field generating member. One is generated based on the eddy current flowing through the conductive member with respect to the rotation of the work by rotating with respect to the other with the work, and is generated at intervals shorter than the rotation cycle of the work. Apply braking force.

The vibration suppression method according to one aspect of the present invention supports a headstock that grips one end of a work extending along the axis and rotates the work around the axis, and the other end of the work. It is a vibration suppression method used in a turning device provided with a tailstock having a rotation center that rotates together with the work, and is a magnetic field generating member that generates a magnetic field acting on the conductive member having conductivity and the conductive member. By rotating one side together with the work with respect to the other, it is generated based on the eddy current flowing through the conductive member with respect to the rotation of the work, and is generated at intervals shorter than the rotation cycle of the work. Apply braking force.

According to the present invention, it is possible to provide a vibration suppressing device or the like capable of suppressing the vibration of a work.

FIG. 1 is a perspective view showing a turning device according to an embodiment. FIG. 2 is a cross-sectional view showing a tailstock of the turning device of FIG. FIG. 3 is a diagram for explaining a braking force generated based on an eddy current. FIG. 4 is a diagram for explaining a vibration suppression method by the vibration suppression device used in the turning device of FIG. 1. FIG. 5 is a diagram showing another example of the magnetic field generator. FIG. 6 is a diagram showing another example of the vibration suppression device. FIG. 7 is a diagram showing another example of the conductive member. FIG. 8 is a diagram showing a location where a hammering test was performed. FIG. 9 is a diagram showing the conditions of the hammering test. FIG. 10 is a graph showing compliance at each position for each of the turning device according to the comparative example and the turning device according to the present invention. FIG. 11 is a graph showing vibration displacement at each frequency for each of the turning device according to the comparative example and the turning device according to the present invention.

Hereinafter, embodiments of the present invention will be described. In addition, all of the embodiments described below show a specific example of the present invention. Therefore, the numerical values, the components, the arrangement positions and connection forms of the components, the steps, the order of the steps, and the like shown in the following embodiments are examples and do not limit the present invention.

Further, each figure is a schematic view and is not necessarily exactly illustrated. In each figure, the same reference numerals are given to substantially the same configurations, and duplicate explanations will be omitted or simplified.

Further, in the present specification and the drawings, the x-axis, the y-axis and the z-axis represent the three axes of the three-dimensional Cartesian coordinate system, and the x-axis and the y-axis are orthogonal to each other and are both orthogonal to the z-axis. It is an orthogonal axis.

Further, in the following embodiments, expressions indicating relative postures in two directions such as parallel and orthogonal may be used, but these expressions also include cases where the postures are not strictly the same. For example, the fact that two directions are orthogonal not only means that the two directions are completely orthogonal, but also that they are substantially orthogonal, that is, for example, a few percent, unless otherwise noted. It also means to include differences in degree.

(Embodiment)
FIG. 1 is a perspective view showing a turning device 10 according to an embodiment. FIG. 2 is a cross-sectional view showing a tailstock 14 of the turning device 10 of FIG. FIG. 2A shows a cross section orthogonal to the x-axis, and FIG. 2B shows a cross section taken along the line IIb-IIb of FIG. 2A. The configuration of the turning device 10 will be described with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, the turning device 10 is a device for turning the work W. In this embodiment, the turning device 10 is a cutting device for cutting the work W. For example, a cutting device is a lathe that processes a work W by bringing a cutting tool into contact with the rotating work W. The turning device 10 includes a headstock 12, a tailstock 14, a base 15, a cutting tool 16, and a vibration suppression device 18.

The headstock 12 grips one end of the work W extending along the shaft core and rotates the work W around the shaft core. That is, the axis of the work W and the rotation axis O of the work W coincide with each other. In this embodiment, the work W is rod-shaped. The headstock 12 has a chuck 20 that grips and grips the work W, and the chuck 20 is fixed to a spindle (not shown) included in the headstock 12. When the spindle is rotated by a motor (not shown), the work W held by the chuck 20 together with the chuck 20 rotates about the rotation axis O.

The tailstock 14 is provided on the side opposite to the headstock 12 with respect to the work W, and supports the other end of the work W. For example, the tailstock 14 is a tailstock. The tailstock 14 has a housing 22, a rotation center 24, a bearing 26, and a seal member 28.

The housing 22 houses a part of the rotation center 24, a bearing 26, a sealing member 28, and a vibration suppressing device 18. The housing 22 is supported by the base 15 so as to be movable in the rotation axis O direction with respect to the headstock 12. As a result, the rotation center 24 and the like can move in the direction of the rotation axis O with respect to the headstock 12.

The rotation center 24 supports the other end of the work W and rotates together with the work W. The rotation center 24 is rotatably supported by a bearing 26 about the rotation axis O. The rotation center 24 has a conical conical portion 30 that protrudes toward the headstock 12 from the housing 22 and shrinks in diameter toward the headstock 12. The rotation center 24 supports the other end of the work W by being pressed against the work W with the top 32 of the conical portion 30 fitted in the recess provided in the center of the other end surface of the work W. Rotates around the rotation axis O together with the work W.

The base 15 is provided integrally with the headstock 12, and as described above, supports the housing 22 so as to be movable in the rotation axis O direction.

The cutting tool 16 cuts the work W by coming into contact with the rotating work W from the outside in the radial direction about the rotation axis O. In the following description, the radial direction centered on the rotation axis O is also simply referred to as the radial direction. For example, the cutting tool 16 is a cutting tool.

The vibration suppression device 18 applies a braking force F generated based on an eddy current and generated at intervals shorter than the rotation cycle of the work W to the rotation of the work W to suppress the vibration of the work W. Is. As described above, the vibration suppression device 18 is an eddy current type brake that applies a braking force F generated based on the eddy current. The vibration suppressing device 18 has a conductive member 34 and a magnetic field generating member 36. The conductive member 34 and the magnetic field generating member 36 are built in the tailstock 14.

The conductive member 34 is a member having conductivity, and rotates with respect to the magnetic field generating member 36 together with the work W. The conductive member 34 is fixed to the rotation center 24 in the housing 22, and rotates about the rotation axis O together with the rotation center 24 and the work W. For example, the conductive member 34 is made of metal or the like. The conductive member 34 has a main body 38 and a plurality of (four in this embodiment) convex portions 40.

The main body 38 has a cylindrical shape along the circumferential direction about the rotation axis O, and a rotation center 24 is inserted inside the main body 38. In the following description, the circumferential direction centered on the rotation axis O is also simply referred to as a circumferential direction. The main body 38 is fixed to the outer peripheral surface of the rotation center 24. For example, the main body 38 is fixed to the rotation center 24 by press-fitting the rotation center 24 inside the main body 38.

Each of the plurality of convex portions 40 projects radially outward from the outer peripheral surface of the main body 38. The plurality of convex portions 40 are arranged at equal intervals in the circumferential direction, and the widths of the plurality of convex portions 40 in the circumferential direction are the same. Each of the plurality of convex portions 40 has an outer peripheral surface 42 facing the inner peripheral surface 43 of the magnetic field generating member 36 at a distance. The outer peripheral surface 42 of each of the plurality of convex portions 40 is curved along the inner peripheral surface 43 of the magnetic field generating member 36. Both end faces of the plurality of convex portions 40 in the circumferential direction are inclined toward the rotation axis O. In the conductive member 34, the radial thickness of the portion provided with the convex portion 40 is larger than the radial thickness of the portion not provided with the convex portion 40.

The magnetic field generating member 36 generates a magnetic field acting on the conductive member 34. The magnetic field generating member 36 is an annular shape along the circumferential direction, and is provided on the outside of the plurality of convex portions 40 in the radial direction. That is, the magnetic field generating member 36 faces the conductive member 34 in the radial direction. The magnetic field generating member 36 is fixed to the housing 22 and does not rotate together with the work W.

The magnetic field generating member 36 generates a magnetic field in a direction orthogonal to the rotation axis O. The magnetic field generating member 36 is an annular magnet having one N pole and one S pole that oppose each other across the rotation axis O. Each of the N pole and the S pole has a semicircular shape along the circumferential direction. The boundary 44 between one end of the N pole and the S pole in the circumferential direction and the boundary 46 between the other end of the N pole and the S pole in the circumferential direction face each other with the rotation axis O interposed therebetween. That is, the boundary 44 and the boundary 46 are provided at positions displaced by 180 ° in the circumferential direction. Such a magnetic field generating member 36 generates a magnetic field from the boundary 46 toward the boundary 44 between the boundary 44 and the boundary 46, that is, a magnetic field is generated in a direction orthogonal to the rotation axis O. In other words, the magnetic field generating member 36 generates a magnetic field from the rotation axis O side to the boundary 44 side between the rotation axis O and the boundary 44 in the circumferential direction, and at the same time, between the rotation axis O and the boundary 46. A magnetic field is generated from the boundary 46 side toward the rotation axis O side. In this way, the magnetic field generating member 36 generates a magnetic field in the radial direction in a part of the circumferential direction.

The configuration of the turning device 10 has been described above.

FIG. 3 is a diagram for explaining a braking force generated based on an eddy current. The braking force generated based on the eddy current will be described with reference to FIG.

As shown in FIG. 3, for example, when a metal cylinder 2 is rotated in the vicinity of a fixed magnet 1, when the magnetic flux penetrating a certain region of the cylinder 2 changes with time, the outer surface of the cylinder 2 is affected by the electromagnetic induction effect. Generates an induced electromotive force. The direction of the induced electromotive force is determined by the right-hand rule, and the flowing current draws two vortices in opposite directions with the magnet 1 in between, and these are called eddy currents. Eddy currents generate magnetic flux on the outer surface of the cylinder 2 according to the right-handed screw rule. The magnetic flux generated by the magnet 1 and the magnetic flux generated by the eddy current on the front side in the rotational direction of the magnetic flux attract each other. On the other hand, the magnetic flux generated by the magnet 1 and the magnetic flux generated by the eddy current on the rear side in the rotational direction with respect to the magnetic flux repel each other. As a result, a braking force in a direction that hinders rotation is generated in the cylinder 2.

The braking force generated based on the eddy current has been described above.

FIG. 4 is a diagram for explaining a vibration suppression method by the vibration suppression device 18 used in the turning device 10 of FIG. 1. A vibration suppression method using the vibration suppression device 18 will be described with reference to FIG. 4.

As shown in FIG. 4, the conductive member 34 rotates with respect to the magnetic field generating member 36 together with the work W to generate an eddy current in the conductive member 34, and the work W rotates with respect to the rotation of the work W. The braking force F generated at intervals shorter than the cycle of is applied.

As described above, the radial thickness of the portion of the conductive member 34 where the convex portion 40 is provided is larger than the radial thickness of the portion where the convex portion 40 is not provided. Therefore, the braking force F generated when the portion of the conductive member 34 provided with the convex portion 40 passes between the rotation axis O and the boundary 44 or between the rotation axis O and the boundary 46 is , It is larger than the braking force generated when the portion where the convex portion 40 is not provided passes.

As shown in FIG. 4A, the portion of the conductive member 34 provided with the convex portion 40 passes between the rotation axis O and the boundary 44 or between the rotation axis O and the boundary 46. At that time, a braking force F is generated. On the other hand, as shown in FIG. 4B, the portion of the conductive member 34 where the convex portion 40 is provided is between the rotation axis O and the boundary 44 and between the rotation axis O and the boundary 46. When not passing, the braking force F is not generated.

When the conductive member 34 rotates with respect to the magnetic field generating member 36 together with the work W, the portion of the conductive member 34 where the convex portion 40 is provided is between the rotation axis O and the boundary 44 or with the rotation axis O. Since it passes intermittently between the boundary 46 and the boundary 46, the braking force F is intermittently generated, and the braking force F is intermittently applied to the rotation of the work W.

Further, during one rotation of the work W, the portion of the conductive member 34 provided with the convex portion 40 passes between the rotation axis O and the boundary 44 or between the rotation axis O and the boundary 46 a plurality of times. Therefore, the braking force F is generated at intervals shorter than the rotation cycle of the work W, and the braking force F is applied to the rotation of the work W at intervals shorter than the rotation cycle of the work W.

In this way, by applying the braking force F generated at intervals shorter than the rotation cycle of the work W to the rotation of the work W, the chatter vibration of the work W can be suppressed.

The vibration suppression method by the vibration suppression device 18 has been described above.

The vibration suppression device 18 according to the embodiment supports a headstock 12 that grips one end of the work W extending along the axis and rotates the work W around the axis, and the other end of the work W. A vibration suppression device 18 used in a turning device 10 including a tailstock 14 having a rotation center 24 that rotates together with a work W, and is a conductive member 34 having conductivity and a magnetic field acting on the conductive member 34. The conductive member 34 is provided with a magnetic field generating member 36 for generating a magnetic field, and the conductive member 34 is rotated with respect to the magnetic field generating member 36 together with the work W. The braking force F that is generated and is generated at intervals shorter than the rotation cycle of the work W is applied.

According to this, the rotation of the work W is rotated by applying a braking force F generated based on the eddy current flowing through the conductive member 34 and generated at intervals shorter than the rotation cycle of the work W. It is possible to suppress an increase in the vibration of the work W, and it is possible to suppress the vibration of the work W.

Further, in the vibration suppressing device 18 according to the embodiment, the conductive member 34 and the magnetic field generating member 36 are built in the tailstock 14.

According to this, it is possible to suppress the turning device 10 from becoming large by providing the vibration suppressing device 18. For example, by providing the vibration suppressing device 18 in place of the bearing originally built in the existing tailstock to support the rotation center, it is possible to suppress the size of the existing turning device.

Further, in the vibration suppression device 18 according to the embodiment, the conductive member 34 is fixed to the rotation center 24 and rotates together with the work W.

According to this, by fixing the conductive member 34 to the rotation center 24 that supports the work W, the braking force F due to the eddy current can be easily applied to the rotation of the work W, and the work W can be easily applied. Vibration can be easily suppressed.

Further, in the vibration suppressing device 18 according to the embodiment, the conductive member 34 has a plurality of convex portions 40, each of which projects outward in the radial direction and is arranged at intervals in the circumferential direction, and the magnetic field generating member 36. Is an annular shape along the circumferential direction, and is provided on the outer side of the plurality of convex portions 40 in the radial direction.

According to this, since each of the plurality of convex portions 40 protrudes outward in the radial direction, the radial thickness of the portion of the conductive member 34 where the convex portion 40 is provided and the convex portion The radial thickness of the portion where the 40 is not provided can be made different. As a result, the braking force F generated when the portion of the conductive member 34 where the convex portion 40 is provided passes through the magnetic field formed by the magnetic field generating member 36, and the convex portion 40 are provided. The braking force generated when the missing part passes can be easily different. Further, since the plurality of convex portions 40 are arranged in the circumferential direction, the braking force F can be easily generated at a time interval shorter than the rotation cycle of the work W. As a result, the braking force F generated at intervals shorter than the rotation cycle of the work W can be easily applied to the rotation of the work W, and the vibration of the work W can be easily suppressed.

Further, in the vibration suppressing device 18 according to the embodiment, the magnetic field generating member 36 is an annular magnet having one N pole and one S pole facing each other across the rotation axis O.

According to this, a magnetic field from the boundary 46 to the boundary 44 can be generated between the boundary 44 and the boundary 46 between the north pole and the south pole. That is, in the circumferential direction, a magnetic field can be generated in the radial direction between the rotation axis O and the boundary 44, and a magnetic field can be generated in the radial direction between the rotation axis O and the boundary 46. As a result, the braking force F can be easily applied each time the portion of the conductive member 34 provided with the convex portion 40 passes between the rotation axis O and the boundary 44 or between the rotation axis O and the boundary 46. Since it can be generated, the braking force F generated at intervals shorter than the rotation cycle of the work W can be easily applied to the rotation of the work W, and the vibration of the work W can be easily suppressed.

FIG. 5 is a diagram showing another example of the magnetic field generating member. Another example of the magnetic field generating member will be described with reference to FIG.

As shown in FIG. 5, the magnetic field generating member 36a has a laminated body 50 formed by laminating a plurality of electromagnetic steel sheets, and a plurality of magnets 52 arranged in a Halbach array. The magnetizing directions of the plurality of magnets 52 are determined so that a magnetic field is generated in the direction orthogonal to the rotation axis O, and the magnets 52 are arranged in a Halbach array and embedded in the laminated body 50. Specifically, the plurality of magnets 52 are arranged in a Halbach array and embedded in the laminated body 50 so that a magnetic field in the axis P direction is generated about the axis P orthogonal to the rotation axis O. That is, the magnetic field generating member 36a generates a magnetic field in the axis P direction in the vicinity of the axis P in the circumferential direction. By using the magnetic field generating member 36a instead of the magnetic field generating member 36, it is possible to apply the braking force F to the rotation of the work W as in the case of using the magnetic field generating member 36.

The magnetic field generating member 36a has been described above.

The magnetic field generating member 36a has a plurality of magnets 52 arranged in a Halbach array.

According to this, since the magnetic field acting on the conductive member 34 can be easily generated in a predetermined direction, the vibration of the work W can be easily suppressed.

FIG. 6 is a diagram showing another example of the vibration suppression device. Another example of the vibration suppression device will be described with reference to FIG.

As shown in FIG. 6, the conductive member 34a of the vibration suppressing device 18a has a plurality of convex portions 40a, 40b, 40c, 40d instead of the plurality of convex portions 40, and the vibration suppressing device 18 Is mainly different.

In the circumferential direction, the widths of the plurality of convex portions 40a to 40d are different. Specifically, in the circumferential direction, the width of the convex portion 40a is equal to the width of the convex portion 40c and larger than the width of the convex portion 40b and the width of the convex portion 40d. In the circumferential direction, the width of the convex portion 40b is equal to the width of the convex portion 40d.

Further, in the circumferential direction, the intervals between the plurality of convex portions 40a to 40d are different. Specifically, in the circumferential direction, the distance from one end of the convex portion 40a to one end of the convex portion 40b is equal to the distance from one end of the convex portion 40c to one end of the convex portion 40d, and the distance between the convex portions 40b is equal to that of the convex portion 40b. It is larger than the distance from one end to one end of the convex portion 40c and the distance from one end of the convex portion 40d to one end of the convex portion 40a. In the circumferential direction, the distance from one end of the convex portion 40b to one end of the convex portion 40c is equal to the distance from one end of the convex portion 40d to one end of the convex portion 40a. That is, the angle formed by the straight line connecting the rotation axis O and one end in the circumferential direction of the convex portion 40a and the straight line connecting the rotation axis O and the one end in the circumferential direction of the convex portion 40b, and the rotation axis O and the convex portion 40c. The angle formed by the straight line connecting one end in the circumferential direction and the straight line connecting the rotation axis O and the one end in the circumferential direction of the convex portion 40d is A [°], and the angle between the rotation axis O and the convex portion 40b in the circumferential direction. A straight line connecting one end and an angle formed by a straight line connecting the rotation axis O and one end in the circumferential direction of the convex portion 40c, and a straight line and a rotation axis connecting the rotation axis O and one end in the circumferential direction of the convex portion 40d. When the angle formed by the straight line connecting O and one end of the convex portion 40a in the circumferential direction is B [°], A [°] is larger than B [°].

The convex portion 40a and the convex portion 40c are targets with the rotation axis O interposed therebetween, and the convex portion 40b and the convex portion 40d are objects with the rotation axis O interposed therebetween.

The vibration suppression device 18a has been described above.

In the vibration suppressing device 18a, the widths of the convex portions 40a and 40c and the widths of the convex portions 40b and 40d are different in the circumferential direction.

According to this, since the period in which the braking force F is generated can be made different, the vibration of the work W can be further suppressed.

Further, in the vibration suppressing device 18a, in the circumferential direction, the distance between the convex portion 40a and the convex portion 40b, the distance between the convex portion 40c and the convex portion 40d, the distance between the convex portion 40b and the convex portion 40c, and the distance between the convex portion 40d and the convex portion 40a. Is different from the interval of.

According to this, since the time interval in which the braking force F is generated can be made different, the vibration of the work W can be further suppressed.

FIG. 7 is a diagram showing another example of the conductive member. Other examples of the conductive member will be described with reference to FIG. 7.

As shown in FIG. 7, the conductive member 34b has a plurality of convex portions 40e, 40f, 40g, 40h.

Here, the suppression of the regeneration effect by using the unequal pitch tool will be described. For example, when using a two-blade tool, two blades are considered by breaking down into a regeneration effect component, which is a component in which the vibration of the front blade is regenerated by the regeneration effect, and a cutting component, which is the vibration component of the current blade. If the phase difference π in which the regeneration effect components of the blade cancel each other out, the regeneration effect is canceled and chatter vibration is suppressed. From this principle, if the difference between the phase lag of the second blade with respect to the first blade and the phase lag of the first blade with respect to the second blade satisfies the following equation, the reproduction effect is eliminated. Will be done.

n [min ^-1 ] is the rotation speed of the tool, θ ₁ [°] and θ ₂ [°] are each pitch angle, and f _c [Hz] is the chatter vibration frequency.

In the case of a 4-flute tool, if θ ₁ = θ ₃ , θ ₂ = θ ₄ , and θ ₁ + θ ₂ = π, the optimum pitch angle for suppressing the reproduction effect can be obtained by the following equation.

For example, the most optimum pitch angle for suppressing the reproduction effect can be obtained only by measuring the chatter vibration frequency with an acceleration sensor or the like.

For example, if the rotation speed of the spindle is 3000 [rpm], the chatter vibration frequency is 720 [Hz], and m = 0, then θ ₁ = 85 [°] and θ ₂ = 95 [. °]. Here, since the pitch angle of the recessed portion between the adjacent convex portions among the plurality of convex portions 40e to 40h is set to 30 [°], the pitch angle of the convex portion 40e and the pitch angle of the convex portion 40g are set. , 65 [°], and the pitch angle of the convex portion 40f and the pitch angle of the convex portion 40h are 55 [°].

The conductive member 34b has been described above.

In this way, the conductive member 34b can suppress the reproduction effect most when the rotation speed of the spindle is 3000 [rpm], the chatter vibration frequency is 720 [Hz], and m = 0. Since it is formed, in this case, the vibration of the work W can be further suppressed.

FIG. 8 is a diagram showing a location where a hammering test was performed. FIG. 9 is a diagram showing the conditions of the hammering test. FIG. 10 is a graph showing compliance at each position for each of the turning device according to the comparative example and the turning device according to the present invention. FIG. 11 is a graph showing vibration displacement at each frequency for each of the turning device according to the comparative example and the turning device according to the present invention. The experimental results will be described with reference to FIGS. 8 to 11.

As shown in FIG. 8, hammering tests were performed at seven locations (see dot portions in FIG. 8) at the chuck, workpiece, and rotation center. In the turning device according to the present invention, a vibration suppression device (conductive member and magnetic field generating member) according to the present invention is provided instead of one of the plurality of bearings that originally supported the rotation center. Then, a hammering test was conducted. That is, the turning device according to the present invention is a comparative example in that a vibration suppressing device (conductive member and magnetic field generating member) is provided in place of one of the bearings among the plurality of bearings supporting the rotation center. It is mainly different from the turning equipment related to.

As shown in FIG. 9A, a work made of SUS having a diameter of 15 [mm] and a length of 300 [mm] and a columnar shape was used. Further, as shown in FIG. 9B, the spindle rotation speed is set to 4760 [mm], the peripheral speed is set to 224 [m / min], the feed rate is set to 0.2 [mm / rev], and the tailstock thrust is set. Was 3.0 [kN] and the experiment was conducted.

As shown in FIG. 10, in the turning apparatus according to the comparative example, the primary mode 678 [Hz] is dominant, and in the turning apparatus according to the present invention, the secondary mode 648 [Hz] is dominant and dominant. In the mode, both the turning device according to the comparative example and the turning device according to the present invention have a mode shape that vibrates at the central portion of the work. It can be seen that the compliance of the turning device according to the present invention tends to be larger than the compliance of the turning device according to the comparative example. The distance around 350 [mm] in the graph of FIG. 10 is the vicinity where the rotation center is provided, and the compliance of the turning device according to the present invention in this vicinity is larger than the compliance of the turning device according to the comparative example. That is, it is considered that the rigidity in the vicinity of the rotation center of the turning device according to the present invention is reduced by providing the vibration suppressing device instead of the bearing.

As shown in FIG. 11A, when cutting is performed with the turning device according to the present invention having a cutting amount of 0.1 [mm], the cutting amount is set to 0.1 [mm] with the turning device according to the comparative example. The vibration displacement was reduced by 87.0 [%] at the peak value as compared with the case where the cutting was performed. Further, as shown in FIG. 11B, when cutting is performed with the turning device according to the present invention having a cutting amount of 0.2 [mm], the cutting amount is set to 0.2 [m] with the turning device according to the comparative example. The vibration displacement was reduced by 75.4 [%] at the peak value as compared with the case of cutting with [mm]. As described above, although the rigidity of the turning device according to the present invention is lower than the rigidity of the turning device according to the comparative example, the chatter vibration displacement can be significantly reduced. It is considered that this is because the vibration suppressing effect by the braking force of the vibration suppressing device outweighs the influence of the tendency to chatter due to the decrease in rigidity.

(Other embodiments, etc.)
Although the vibration suppression device and the turning device according to the present invention have been described above based on the embodiments, the present invention is not limited to the embodiments. The present invention also includes a form obtained by subjecting an embodiment to a modification that a person skilled in the art can think of, and another form realized by arbitrarily combining components in a plurality of embodiments.

In the above-described embodiment, the case where the turning device 10 is a cutting device has been described, but the present invention is not limited to this. For example, the turning device may be a polishing device. For example, a polishing device is a device that processes a work by bringing fine abrasive grains into contact with a rotating work.

Further, in the above-described embodiment, the case where the conductive member 34 and the magnetic field generating member 36 are built in the tailstock 14 has been described, but the present invention is not limited thereto. For example, the conductive member and the magnetic field generating member may be built in the headstock. In this case, for example, one of the conductive member and the magnetic field generating member may be fixed to the spindle included in the headstock and rotate together with the work.

Further, in the above-described embodiment, the case where the conductive member 34 is fixed to the rotation center 24 in the housing 22 has been described, but the present invention is not limited to this. For example, the conductive member may be fixed to the rotation center outside the housing. In this case, the magnetic field generating member may also be provided outside the housing. Further, for example, the conductive member may be fixed to a member that rotates together with a work other than the rotation center.

Further, in the above-described embodiment, the case where the conductive member 34 rotates with respect to the magnetic field generating member 36 together with the work W has been described, but the present invention is not limited to this. For example, the conductive member may not rotate with the work W, and the magnetic field generating member may rotate with the work W with respect to the conductive member.

Further, in the above-described embodiment, the case where the magnetic field generating member 36 faces the conductive member 34 in the radial direction has been described, but the present invention is not limited to this. For example, the magnetic field generating member may face the conductive member in the direction of the rotation axis.

Further, in the above-described embodiment, the case where the magnetic field generating member 36 has one N pole and one S pole has been described, but the present invention is not limited to this. For example, the magnetic field generating member may have a plurality of N poles and a plurality of S poles.

The turning device according to the present invention can be used as a device for rotating a work to grind or polish the work.

10 Turning device 12 Headstock 14 Mandrel 15 Base 16 Cutting tool 18, 18a, 18b Vibration suppression device 20 Chuck 22 Housing 24 Rotation center 26 Bearing 28 Sealing member 30 Conical part 32 Top 34, 34a, 34b Conductive member 36 , 36a Magnetic field generating member 38 Main body 40, 40a, 40b, 40c, 40d, 40e, 40f, 40g, 40h Convex part 42 Outer peripheral surface 43 Inner peripheral surface 44, 46 Boundary 50 Laminated body 52 Magnet

Claims (10)

A heart pusher having a headstock that grips one end of a work extending along a shaft core and rotates the work around the shaft core, and a rotation center that supports the other end of the work and rotates together with the work. A vibration suppression device used in a turning device equipped with a table.
Conductive members with conductivity and
A magnetic field generating member that generates a magnetic field acting on the conductive member is provided.
One of the conductive member and the magnetic field generating member rotates with the work with respect to the other, so that the rotation of the work is generated based on the eddy current flowing through the conductive member and the work of the work. Applying braking force generated at intervals shorter than the rotation cycle,
Vibration suppression device. The conductive member and the magnetic field generating member are built in the tailstock.
The vibration suppression device according to claim 1. The conductive member is fixed to the rotation center and rotates together with the work.
The vibration suppression device according to claim 1 or 2. Each of the conductive members has a plurality of convex portions that protrude outward in the radial direction about the rotation axis of the work and are arranged at intervals in the circumferential direction around the rotation axis.
The magnetic field generating member is an annular shape along the circumferential direction, and is provided on the outer side of the plurality of convex portions in the radial direction.
The vibration suppression device according to any one of claims 1 to 3. In the circumferential direction, the widths of the plurality of convex portions are different.
The vibration suppression device according to claim 4. In the circumferential direction, the distance between the plurality of convex portions is different.
The vibration suppression device according to claim 4 or 5. The magnetic field generating member is an annular magnet having one N pole and one S pole facing each other across the rotation axis.
The vibration suppression device according to any one of claims 4 to 6. The magnetic field generating member has a plurality of magnets arranged in a Halbach array.
The vibration suppression device according to any one of claims 4 to 6. A spindle that grips one end of the work extending along the shaft core and rotates the work around the shaft core.
A tailstock that supports the other end of the work and has a rotation center that rotates with the work.
Conductive members with conductivity and
A magnetic field generating member that generates a magnetic field acting on the conductive member is provided.
One of the conductive member and the magnetic field generating member rotates with the work with respect to the other, so that the rotation of the work is generated based on the eddy current flowing through the conductive member and the work of the work. Applying braking force generated at intervals shorter than the rotation cycle,
Turning equipment. A heart pusher having a headstock that grips one end of a work extending along a shaft core and rotates the work around the shaft core, and a rotation center that supports the other end of the work and rotates together with the work. A vibration suppression method used for turning devices equipped with a platform.
By rotating one of the conductive member having conductivity and the magnetic field generating member for generating a magnetic field acting on the conductive member together with the work with respect to the other, the conductive member with respect to the rotation of the work. A braking force that is generated based on the eddy current flowing through the work and is generated at intervals shorter than the rotation cycle of the work is applied.
Vibration suppression method.

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