WO2014111972A1

WO2014111972A1 - Non-contact power supply device

Info

Publication number: WO2014111972A1
Application number: PCT/JP2013/000171
Authority: WO
Inventors: 修平 ▲高▼櫻; 俊和向井; 昇奥山
Original assignee: 三重電子株式会社
Priority date: 2013-01-16
Filing date: 2013-01-16
Publication date: 2014-07-24
Also published as: JPWO2014111972A1

Abstract

Provided is non-contact power supply device that supplies power between a main body side and a load side capable of being displaced relative to the main body side, said power supply occurring from the main body side and without the device being in contact with a resonance circuit such as an ultrasonic oscillator provided on the load side. The non-contact power supply device has a novel construction and is capable of more effectively driving the load-side resonance circuit. A primary-side power coil (66a) is provided on the main body (16) side and a secondary power coil (66b) is provided on the load (22) side. The non-contact power supply device is configured such that: drive power is supplied to the load (22) resonance circuit (50) from power supply devices (100, 102) on the main body (16) side, via the primary-side power coil (66a) and the secondary power coil (66b); the primary-side power coil (66a) is enclosed by a core member (70); and the secondary power coil (66b) is not enclosed by a core member.

Description

Contactless power supply device

The present invention relates to a contactless power supply device for supplying power using mutual induction between coil members between a relatively displaceable main body side and a load side, and in particular, provided on the load side. The present invention relates to a contactless power supply device used to supply drive power to a resonant circuit from the main body side.

Conventionally, a main body side provided with a power feeding device and a main body side, such as machine tools described in, for example, Japanese Patent Application Laid-Open Nos. 2002-346817 (Patent Document 1) and 2010-207971 (Patent Document 2) The rotational movement and the vibration by the ultrasonic transducer are superimposed on the tool by providing an ultrasonic transducer on the load side and connecting it with the tool. ing. In such a machine tool, a slip ring is used as one of means for supplying power from the power supply device on the main body side to the ultrasonic transducer as the load on the load side. The slip ring has a structure in which a brush provided on the main body side is brought into contact with an electrode plate provided on the load side, and is widely used to electrically connect members which are relatively rotated.

However, since the slip ring has a physical contact point between the electrode plate and the brush, there is a problem of deterioration due to mechanical wear. In addition, it is difficult to cope with tens of thousands of high-speed rotations per minute because the number of rotations is several thousand per minute.

Therefore, as described in Japanese Patent Application Laid-Open No. 2002-28808 (Patent Document 3) and Japanese Patent Application Publication No. 2008-504138 (Patent Document 4), a non-contact type power supply device may be used. In this non-contact type power supply device, coil members to which a core member made of a magnetically permeable material is assembled are disposed on the main body side and the load side, and a magnetic path is formed by the core members to mutually induction between both coil members. By utilizing the action, it is possible to transmit power from the main body side to the load side. According to such a non-contact type power supply device, it becomes possible to transmit electric power in a non-contact state between the main body side and the load side, and the problem of mechanical wear can be eliminated and the rotation speed is higher. It can also respond to

By the way, it is known that an ultrasonic transducer as a load provided in a machine tool described in Patent Documents 1 to 4 can be considered equivalent to an electrical resonant circuit having a resonant frequency. Therefore, in order to drive the ultrasonic transducer effectively, application of a drive voltage of the resonance frequency of the ultrasonic transducer or a frequency near that is performed.

However, in a machine tool using a non-contact power supply device as described in Patent Document 3 and Patent Document 4, the vibration of the ultrasonic transducer is not effectively transmitted to the tool, and is effective as the tool amplitude. In some cases, stable processing can not be performed due to waviness or heat generation in the ultrasonic transducer.

JP 2002-346817 A Unexamined-Japanese-Patent No. 2010-207971 Japanese Patent Application Publication No. 2002-28808 Japanese Patent Application Publication No. 2008-504138

The present invention has been made against the background described above, and the problem to be solved is that the power is contactless from the main body side to the load side provided with a resonant circuit such as an ultrasonic transducer or the like. It is an object of the present invention to provide a contactless power supply having a novel structure capable of driving the resonant circuit on the load side more effectively in the supply of the contactless power supply.

The inventors of the present invention have intensively studied the problem, and in the non-contact type power supply device, the core member assembled to the coil member used for power transmission on the load side reduces the driving efficiency of the resonant circuit on the load side. Discovered that it could be a cause.

That is, as described above, it is known that, for example, an ultrasonic transducer is considered to be equivalent to the resonant circuit shown in FIG. 24 in the vicinity of the resonant frequency. The equivalent circuit shown in FIG. 24 is an LCR circuit in which a coil component (L) and a capacitor (C) representing mechanical vibration characteristics (series resonance characteristics) and a resistance component (R) representing a mechanical load are connected in series. A braking capacitance (Cd) is connected in parallel by the piezoelectric elements constituting the ultrasonic transducer acting as a capacitor. Therefore, by applying a voltage with a resonance frequency f _r = 1 / (2π√ (L · C)) at which the LCR circuit resonates in series to this equivalent circuit or a frequency near that frequency, an ultrasonic transducer is obtained. It can be driven efficiently.

However, the noncontact power supply device as described in Patent Document 3 and Patent Document 4 is applied to such a resonant circuit, and a core member is used as a coil member for power transmission on the load side (resonant circuit side). As a result, the high permeability of the core member increases the inductance (L) of the resonant circuit, which causes the resonant frequency _fr to be largely changed. An increase in inductance (L) generally manifests as a decrease in resonant frequency. Therefore, for example, in the case of an ultrasonic transducer, a decrease in resonance frequency may appear as a decrease in drive frequency.

Furthermore, for example, in the machine tools described in Patent Document 3 and Patent Document 4 and the like, the resonance frequency of the ultrasonic transducer is included in the tool in order to effectively express the vibration of the ultrasonic transducer as the stroke of the tool. Tuning is performed near the mechanical natural frequency on the load side. However, if the resonance frequency of the ultrasonic transducer (resonance circuit) is largely changed by assembling the core member to the coil member for power transmission on the load side, the driving frequency of the ultrasonic transducer becomes mechanical on the load side. It has been difficult to make the natural frequency close to the natural frequency, and the vibration of the ultrasonic transducer may not be effectively expressed as the vibration of the tool without being coordinated with the vibration of the tool.

Further, in the conventional non-contact type power supply device, the core member is provided on both the power coil on the main body side and the power coil on the load side, and the magnetic flux from the coil member is provided between the opposed end faces of both core members. The coupling coefficient between the coil members is increased by concentrating the However, for example, as shown in FIG. 25, when power is transmitted as a square wave from the main body side to the load side, the square wave is applied almost as it is to the ultrasonic transducer on the load side. On the other hand, as also shown in FIG. 25, the mechanical vibration of the ultrasonic transducer draws a sine wave. Therefore, when a square wave is applied to the ultrasonic transducer as it is, the ultrasonic transducer does not follow the steep voltage increase and decrease of the square wave and may cause waviness, and the surplus energy shown by oblique lines in the figure is The inventor has discovered that the heat may cause the generation of heat. The present invention has been completed based on such findings.

The following describes aspects of the present invention made to solve such problems. In addition, the component employ | adopted in each aspect described below can be employ | adopted as much as possible in arbitrary combination.

According to a first aspect of the present invention, there is provided a pair of a main body provided with a feeding device for outputting an alternating voltage and a load that is relatively displaceable with respect to the main body and is provided with a resonant circuit. The primary side power coil and the secondary side power coil are provided to make it possible to supply driving power from the power feeding device on the main body side to the resonant circuit on the load side through these power coils. In the non-contact type power supply device, a core member made of a magnetically permeable material is provided on the main body side so as to surround the primary power coil, while the secondary power coil is provided on the load side. Is characterized in that the core member surrounding the is not provided.

In the present invention, the core member is provided around the primary-side power coil on the main body side, but the core member is not provided around the secondary-side power coil on the load side. As a result, it is possible to avoid an increase in the inductance of the resonant circuit provided on the load side, and to prevent a large decrease in the resonant frequency of the resonant circuit. As a result, the resonant frequency of the resonant circuit can be set higher, and for example, when the resonant circuit is an ultrasonic transducer, it can be driven at a higher driving frequency. At the same time, the resonance frequency of the ultrasonic transducer can be easily set in the vicinity of the mechanical natural frequency on the load side, and the stroke of the tool connected to the ultrasonic transducer can be effectively obtained. Thereby, more excellent processing accuracy can be obtained.

Furthermore, by not providing the core member surrounding the secondary power coil, the coupling coefficient between the primary power coil and the secondary power coil can be positively reduced. As a result, for example, as shown in FIG. 25, when a square wave is oscillated from the main body side, the mechanical vibration of the ultrasonic transducer whose power waveform input to the resonant circuit on the load side is also shown in FIG. It can be brought close to a sine wave. Thereby, for example, when the resonance circuit is an ultrasonic transducer, the vibration of the ultrasonic transducer that becomes a sine wave can be easily tuned to the change of the applied voltage, and the undulation of the ultrasonic transducer can be reduced. The ultrasonic transducer can be stably vibrated. At the same time, it is possible to suppress the generation of surplus energy and to suppress heat generation.

Furthermore, by avoiding the concentration of magnetic flux on the core member on both the main body side and the load side, the coupling coefficient drops sharply with only a slight displacement of the load side relative to the main body side. It is possible to prevent the transmission efficiency from being sharply reduced, and power transmission can be performed more stably. In addition, the weight on the load side can be reduced, and, for example, when the load side is rotationally driven relative to the main body side, it can be rotated at higher speed.

In the present invention, it is possible to further provide a coil member other than the secondary power coil on the load side, such as a signal coil to be described later, and assemble the core member to the other coil member. is there. However, preferably, an aspect in which no core member is provided on the load side may be employed. That is, in the case where the core member is formed by sintering fine particles of iron or the like, there is a high risk of cracking or breakage if the core member is rotated at a high speed of several tens of thousands per minute, but on the load side By not providing the core member, the problem of damage to the core member on the load side can be eliminated.

The resonant circuit in the present invention is not limited as long as it has an electrical resonant frequency. For example, not only the resonant circuit composed of a coil and a capacitor but also the above-mentioned ultrasonic transducer Thus, it also includes those which are considered to be equivalent to the physical resonance characteristics of the electrical resonance circuit. Furthermore, it goes without saying that various electrical components are appropriately connected to the resonant circuit, and for example, a servo motor, a stepping motor, a solenoid, a valve, various sensors, various types of electric A circuit or the like may be connected. Further, the relative displacement direction of the main body side on which the primary power coil and the secondary power coil are provided and the relative displacement direction on the load side is not limited at all, and the noncontact transmission device of the present invention is widely used in various machines. It is applicable. Furthermore, as the specific shape of the core member, various shapes can be appropriately adopted in consideration of the relative displacement direction between the main body side and the load side, the required number of transmission lines of electric power and electric signals, etc. .

According to a second aspect of the present invention, in the first aspect, a signal coil forming a pair is provided between the main body side and the load side, and the load side includes: A detection means for detecting the vibration state of the resonance circuit is provided, and a detection signal by the detection means can be transmitted from the load side to the main body side using the signal coil, while the main body side Is provided with a feeding frequency adjustment mechanism for the primary side power coil, and the feeding frequency to the primary side power coil corresponds to the signal in response to changes in the resonant frequency of the resonant circuit. It controls based on the said detection signal transmitted to the said main body side from the said load side through the coil for coils.

In this aspect, the vibration state of the resonance circuit can be detected by the detection means on the load side, and can be transmitted as a detection signal to the main body side via the pair of signal coils. Thereby, the vibration state of the resonant circuit on the load side, which is relatively displaced, can be detected on the main body side, and power can be supplied at an optimal frequency based on the received detection signal by the feed frequency adjustment mechanism. . As a result, for example, in an ultrasonic transducer as a resonant circuit to which a tool is connected, when the resonant frequency of the ultrasonic transducer changes due to a mechanical load applied to the tool, the resonant frequency of the ultrasonic transducer on the main body side It is possible to detect a change in V. and to change the frequency of the applied voltage following the change, so that a suitable drive state can be stably maintained.

In addition, various things can be employ | adopted as a feed frequency adjustment mechanism, for example, a phase locked circuit (PLL: Phase Locked Loop) may be used and the detection signal obtained using the arithmetic unit provided with CPU The power supply frequency to the primary side power coil may be controlled according to a predetermined program based on the above.

In addition, as described above, the resonance circuit in the present invention includes an ultrasonic transducer or the like that expresses mechanical vibration, and the detection means for detecting the vibration state of the resonance circuit includes electricity of the resonance circuit. It may be one that detects mechanical vibration generated by dynamic vibration. Therefore, the detection means may be, for example, an acceleration sensor or the like which detects a physical drive state of an actuator driven by a resonant circuit. Furthermore, the detection means provided on the load side is not limited to one having a special sensing function such as an acceleration sensor or a Hall element for detecting the current flowing in the resonance circuit, for example, to pick up the current flowing in the resonance circuit. It may be a wire or the like.

In the present aspect, an electrical signal may be transmitted from the main body side to the load side. A pair of signal coils may be separately provided on the main body side and the load side as such an electric signal transmission path, or the signal coil for transmitting the electric signal from the load side to the main body side may be provided from the main body side It can also be used as a transmission line of the electrical signal to the load side.

Further, the relative positions of the primary side power coil and the signal coil provided on the main body side, and the relative positions of the secondary side power coil and the signal coil provided on the load side are not limited. For example, taking the main body side as an example, the primary side power coil and the signal coil may be arranged concentrically or eccentrically. Furthermore, the number of core members is not limited. For example, the primary power coil and the signal coil may be assembled to the common core member on the main body side, or the primary power coil and the signal coil May be assembled to each different core member and provided on the main body side. Furthermore, as described above, when it is desired to increase the relative displacement between the main body side and the load side, for example, in order to adjust the flux linkage of the signal coil for the load side, the core member is used for the signal coil for the load side. It may be assembled.

According to a third aspect of the present invention, in at least one of the main body side and the load side according to the second aspect, the signal coil is affected by the magnetic flux generated by the power coil. The first winding portion and the second winding portion are formed in opposite directions so as to offset the electromotive force generated in the signal coil.

In this aspect, at least one of the signal coils on the main body side and the load side is formed with a first winding portion and a second winding portion wound in opposite directions to each other. Here, the directions opposite to each other refer to the center of the power coil (the primary side power coil for the signal coil on the main body side and the secondary side power coil for the signal coil on the load side). The second winding portion and the second winding portion are oppositely wound. As a result, when the magnetic flux generated by the power coil passes through the signal coil, an induced current is generated in which the current flow direction is opposite between the first winding portion and the second winding portion. And mutually offset. Therefore, the noise electromotive force due to the influence of the power coil is reduced using the specific shape of the signal coil without separately providing a coil member for noise suppression or providing a feed control device for canceling the noise electromotive force. I can do it. As a result, the transmission of the electrical signal by the pair of signal coils can be performed more accurately.

Furthermore, since the first winding portion and the second winding portion formed in the signal coil generate induced electromotive forces opposite to each other with respect to the common magnetic field, they are generated from the power coil. Even when the amount of magnetic flux changes, an induced electromotive force is generated in each of the first winding portion and the second winding portion according to the change in the amount of magnetic flux. Thus, for example, the power supply control device monitors a change in noise electromotive force generated in the signal coil, and changes the voltage applied to the signal coil for noise reduction according to the change in noise electromotive force. An excellent noise suppression effect can be obtained with an extremely simple structure without requiring control.

In addition, according to this aspect, the electrical signal can be transmitted more quickly. That is, for example, in the case of wireless communication, in general, multistage processing is required, in which a received electric signal is detected and then amplified and noise is removed to reproduce the signal, which takes time. In particular, in the feedback control as in the second aspect, when it takes time from the generation of the detection signal on the load side to the reproduction on the main body side, it is necessary to consider the time delay of the detection signal. , Complicate control. On the other hand, according to this aspect, by providing the noise reduction effect to the structure of the signal coil itself, it becomes possible to transmit the electric signal more quickly, and the real time property of signal transmission can be improved. .

And, since it is possible to reduce the influence of the magnetic flux by the power coil, it has been difficult to arrange in the prior art due to the influence of the magnetic flux by the power coil. The coils can be disposed space-efficiently, and the contactless power supply device can be made compact.

The number of turns of the first winding portion and the second winding portion is arbitrarily set in consideration of the electromotive force generated in the first winding portion and the electromotive force generated in the second winding portion. Are set so that electromotive forces of equal magnitude in opposite directions are generated in the first winding portion and the second winding portion with respect to the common magnetic field. Therefore, the number of turns of the first winding portion and the number of turns of the second winding portion may be different from each other.

According to a fourth aspect of the present invention, in the one described in the third aspect, a coil winding of the power coil and a coil winding of the signal coil are disposed in an overlapping manner.

As described in the third aspect, according to the third aspect, the first coil portion and the second coil portion generate electromotive forces opposite to each other with respect to the common magnetic field in the signal coil. Is provided. Therefore, even if the signal coil is disposed at a close position affected by the magnetic flux from the power coil, the noise electromotive force due to the magnetic flux from the power coil can be reduced. As a result, as in the present embodiment, it is possible to arrange the signal coil and the power coil in an overlapping manner, so that the contactless power supply device can be further miniaturized. Note that "overlap" in this aspect means that the coil winding of the power coil and the coil winding of the signal coil are disposed at a position where they overlap with each other in a projection view in the axial direction of these coils. Of course, the coil windings of both coils are not in contact with each other, and it does not mean that the coil windings of both coils are in contact. In addition, the coil winding of the power coil and the coil winding of the signal coil may be overlapped over substantially the entire circumference, or may be overlapped so as to partially cross.

According to a fifth aspect of the present invention, in the third or fourth aspect, the power coil and the signal coil are coaxially disposed.

The contactless power supply device structured according to this aspect can be suitably applied to, for example, an ultrasonic milling device or the like in which the load side provided with a tool and an ultrasonic transducer is rotated with respect to the main body side, Power and electrical signals can be transmitted at the rotating parts of the main body side and the load side. And since it does not have a physical contact part like a slip ring, while being able to respond to high-speed rotation, excellent durability and maintainability can be obtained.

Furthermore, since the first coil portion and the second coil portion for reducing noise electromotive force due to the influence of the power coil are formed in the signal coil, the signal coil is coaxial with the power coil. It is also possible to arrange the coil windings of each other completely on top of each other, and further downsizing can be achieved.

According to a sixth aspect of the present invention, in any of the second to fifth aspects, only the secondary power coil on the load side or the secondary power coil and the signal Coils are prepared for the primary side power coil and the signal coil on the main body side, and it is possible to selectively combine the primary side power coil and the signal coil on the main body side It is supposed to be.

In this aspect, a plurality of load sides are provided to the main body side, and it is possible to selectively combine the plurality of load sides with the main body side. Thus, for example, in a machine tool or the like, a plurality of load sides provided with various tools can be prepared, and can be selectively assembled to the main body side. And, according to the non-contact type power supply device of the present invention, since power and electric signal can be transmitted without contact between the main body side and the load side, the main body side and the load side can be easily separated. It can be done. In addition, the load side in this aspect may be provided with only the secondary side power coil, or may be provided with the secondary side power coil and the signal coil.

A seventh aspect of the present invention according to any one of the first to sixth aspects is that the resonance circuit on the load side is configured to include an ultrasonic transducer. .

As described above, the ultrasonic transducer can be treated equivalently to an electrical resonant circuit. And, by adopting the non-contact type power supply device of the present invention between the load side and the main body side provided with the ultrasonic transducer as the resonant circuit, the increase of the inductance of the resonant circuit is suppressed, and the ultrasonic transducer is Can be made close to the mechanical natural frequency on the load side to improve the ease of tuning. At the same time, the voltage applied to the ultrasonic transducer is brought close to a sine wave by lowering the coupling coefficient between the primary-side power coil on the main body side and the secondary-side power coil on the load side. While being able to suppress a swell and to drive more stably, heat generation can be suppressed.

In particular, the present aspect can be suitably used in combination with the second aspect, wherein the vibration state of the ultrasonic transducer is detected by the detection means provided on the load side, and the feeding frequency of the main body side as an electric signal It can be transmitted to the adjustment mechanism. Thereby, in a machine tool or cleaning machine using an ultrasonic transducer, the change in the resonant frequency of the ultrasonic transducer caused by a change in temperature conditions, a change in mechanical load on the ultrasonic transducer, etc. Thus, it is possible to supply a drive voltage of an appropriate frequency.

An eighth aspect of the present invention is the one described in the seventh aspect, wherein the ultrasonic transducer is a Langevin type transducer in which a plurality of piezoelectric elements are stacked, and is stacked together with the plurality of piezoelectric elements. The detecting means is constituted by the piezoelectric element.

According to this aspect, the vibration of the ultrasonic transducer can be detected as a voltage using the piezoelectric effect of the piezoelectric element as the detection means. Thereby, the detection means can be realized with a simple structure. Furthermore, since the piezoelectric element as the detection means can be coaxially arranged with the plurality of piezoelectric elements constituting the Langevin type vibrator, the detection means can be provided with space efficiency, and the weight balance on the load side is unbalanced. Can also be reduced.

In the present invention, the core member is provided to surround the primary power coil on the main body side on the relatively displaced main body side and the load side, while the core member is provided on the load side to surround the secondary power coil. I did not. This can suppress an increase in the inductance of the resonant circuit. As a result, it is possible to maintain a high resonant frequency while avoiding a large decrease in the resonant frequency of the resonant circuit. Furthermore, when the resonant circuit is an ultrasonic transducer, etc., the resonance frequency of the ultrasonic transducer is set to the mechanical natural frequency on the load side by suppressing a large change in the resonant frequency of the ultrasonic transducer. It can be made easy to tune. Furthermore, by lowering the coupling coefficient between the primary side power coil and the secondary side power coil, it is possible to prevent the transmission efficiency from being sharply reduced even when the load side is displaced with respect to the main body side. It is possible to improve the stability of power transmission.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows in model the machine tool provided with the non-contact-type power supply apparatus as 1st embodiment of this invention. FIG. 2 is an explanatory view of a vertical cross section of an essential part of the machine tool shown in FIG. 1; Explanatory drawing of an ultrasonic transducer. The disassembled perspective view of the coil for primary side electric power, the coil for secondary side electric power, the coil for signals, and a core member. FIG. 5 is an explanatory view schematically showing the signal coil shown in FIG. 4; The front view of the main body side coil head. Explanatory drawing for demonstrating the relative displacement direction of a main body side coil head and a load side coil head. BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which illustrates roughly the non-contact-type power supply apparatus as 1st embodiment of this invention. The graph which shows the impedance characteristic of a resonance circuit. The graph which shows the measurement result of the electric current which flows into a resonance circuit. The graph which shows the measurement result of the voltage and electric current in the resonance frequency vicinity of a resonance circuit. The graph at the time of applying the voltage of a square wave in the graph which shows the measurement result of the voltage and the current in the frequency domain which deviated from near the resonant frequency of a resonant circuit. The graph at the time of applying the voltage of a sine wave in the graph which shows the measurement result of the voltage and the current in the frequency domain which deviated from near the resonant frequency of a resonant circuit. It is an explanatory view for explaining a situation of change of voltage and current when resonance frequency of a resonance circuit changes, (a) is a case where amplitude of current changes, (b) is a case where phase of current changes. FIG. It is explanatory drawing for demonstrating the direction of the induced current which arises in the coil for signals, (a) shows at the time of transmission of an electric signal, (b) shows the time of noise generation. It is a longitudinal cross-sectional view for demonstrating the direction of the induced current which arises in the coil for signals, (a) shows at the time of transmission of an electric signal, (b) shows the time of noise generation. The graph which measured the transmission timing of the detection signal in the load side, and the reception timing of the detection signal in the main body side. Explanatory drawing which shows several tool units selectively attached to the machine tool shown in FIG. Explanatory drawing for demonstrating the connection aspect to the computer network of the machine tool shown in FIG. Explanatory drawing which shows the detection means which comprises the non-contact-type power supply apparatus as 2nd embodiment of this invention. The disassembled perspective view which shows the coil for primary side electric power which comprises the non-contact-type electric power supply as 3rd embodiment of this invention, the coil for signals, and a core member. The longitudinal cross-sectional view of the coil for primary side electric power which comprises the non-contact-type power supply apparatus as 4th embodiment of this invention, the coil for secondary side electric power, the coil for signals, and a core member. The front view which shows the coil for signals which comprises the non-contact-type power supply apparatus as 5th embodiment of this invention in model. Explanatory drawing for demonstrating the resonance circuit provided in the load side. Explanatory drawing for demonstrating the voltage applied to the ultrasonic transducer as an example of a resonance circuit, and the vibration state of an ultrasonic transducer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, FIG. 1 schematically shows a machine tool 12 provided with a noncontact power supply 10 according to a first embodiment of the present invention. The machine tool 12 has a structure in which a tool unit 22 as a load side provided with a tool 20 is attached to a spindle 18 of a spindle head 16 provided on a machine main body 14 as a main body side. The tool unit 22 is rotatable relative to the spindle head 16 by rotating the spindle 18.

The machine body 14 is supported by a base 24. In the base 24, a table 28 is provided on the front side (the lower side in FIG. 1) of the tool 20 for detachably holding a work 26 which is an object to be processed. The table 28 is supported by a drive mechanism 30 provided on the base 24, and a guide rail (not shown) provided in the drive mechanism 30, a servomotor, etc. In (1), relative displacement is possible in X axis direction and Y axis direction orthogonal to the vertical direction), and orthogonal three axis directions of Z axis direction which is the front-rear direction with respect to the tool 20. Thus, the tool 20 can be displaced relative to the workpiece 26 in the directions of three orthogonal axes. The machine tool 12 may be, for example, one in which the table 28 can be moved in the directions of two orthogonal axes in the X-axis direction and the Y-axis direction, and the spindle head 16 can be moved in the Z-axis direction.

The longitudinal cross section of the spindle head 16 and the tool unit 22 is shown in model in FIG. The spindle head 16 is provided with a motor 34 as a rotational driving means in a casing 32. The main shaft 18 is rotatable about the central axis O by fixing the main shaft 18 to the output shaft of the motor 34. The main shaft 18 is supported by the casing 32 via

bearings

36 and 36, and its tip end projects from the casing 32. A labyrinth seal 38 is provided between the main shaft 18 and the casing 32 on the tip end side of the main shaft 18 to prevent foreign matter such as dust from entering the casing 32 from the outside.

A holder mounting hole 40 having a tapered inner peripheral surface expanded in diameter toward the tip end of the main spindle 18 is formed at the tip of the main spindle 18. Inside the main shaft 18, inside the reduced diameter end of the holder mounting hole 40 in the axial direction of the main shaft 18, a pull chuck 42 for holding a pull stud 48 formed at the tip of a tool holder 44 described later It is provided.

On the other hand, the tool unit 22 has a tool holder 44. In the tool holder 44, a shank portion 46 having a tapered outer peripheral surface is formed on the central axis in close contact with the inner peripheral surface of the tapered holder mounting hole 40 formed in the main shaft 18. A rod-like pull stud 48 is formed at the tip end of the shank portion 46. Further, the tool holder 44 is formed with a coil receiving groove 49 which is open on the side of the spindle head 16 (upper side in FIG. 2) and extends around the central axis of the tool holder 44.

Furthermore, the ultrasonic transducer 50 is provided in the tool unit 22. As shown as a model in FIG. 3, the ultrasonic transducer 50 is a so-called bolt-clamped Langevin type transducer, and has a plurality of annular piezoelectric elements 52 formed of, for example, a ceramic thin plate or the like having a piezoelectric effect; The

annular electrodes

54 and 56 are extrapolated to the bolts 57 and alternately stacked, and are tightened by the metal block 58 screwed to the bolts 57 from both sides and the horn 60. The

electrodes

54 and 56 disposed at every other interval are connected to a secondary power coil 66b described later. The number of stacked piezoelectric elements 52 is set to an arbitrary number in consideration of the required stroke of the tool 20 and the like.

Further, particularly in the present embodiment, between the metal block 58 and the electrode 56 of the piezoelectric element 52 and between the horn 60 and the electrode 56 of the piezoelectric element 52 on both sides sandwiching the stacked piezoelectric element 52, Insulating

layers

61, 61 are provided respectively. These insulating layers 61 are formed of a non-conductive material which is difficult to elastically deform, and are formed of, for example, ceramics of a brittle material. Thereby, while effectively transmitting the vibration of the ultrasonic transducer 50 to the horn 60, it is possible to avoid the possibility of an electric shock or the like. The tool 20 is attached to the tip of the horn 60 via a chuck mechanism 63 such as a collet or a shrink fit. Thus, the vibration of the ultrasonic transducer 50 is amplified by the horn 60 and transmitted to the tool 20. As the tool 20, various kinds of tools such as an end mill and a drill can be adopted. Further, the specific shape and the forming material of the horn 60 may be appropriately set in consideration of, for example, the material of the work 26, the vibration condition of the tool 20, and the like. For example, the horn 60 may be configured from a plurality of stages, or may be configured alone. The shape of the horn 60 may be any of various shapes, such as a step type, an exponential type, a catenoid type, a conical type, etc. For the material of the horn 60, for example, titanium, aluminum alloy, steel Various materials such as nonmetals such as copper alloy and synthetic resin can be adopted.

As shown in FIG. 2, such an ultrasonic transducer 50 is attached to the tool holder 44 so that the stacking direction of the piezoelectric elements 52 is in the axial direction of the main shaft 18 on the same axis as the main shaft 18. As described above, the ultrasonic transducer 50 can be considered equivalent to the resonant circuit shown in FIG. 24. In the present embodiment, the ultrasonic transducer 50 is included to form a resonant circuit on the load side. ing.

The shank portion 46 of such a tool unit 22 is inserted into the holder mounting hole 40 of the main shaft 18, and the pull stud 48 of the shank portion 46 is gripped by the pull chuck 42 to fix the tool unit 22 to the main shaft 18. Be done. Then, as the spindle 18 is rotated by the motor 34, the tool unit 22 is rotated with respect to the spindle head 16, and the tool 20 provided in the tool unit 22 is rotated.

A noncontact power supply 10 is provided between the spindle head 16 and the tool unit 22. FIG. 4 shows the main body side coil head 62 and the load side coil head 64 which constitute the non-contact type power supply device 10.

The body side coil head 62 has a structure in which a primary side power coil 66a and a body side signal coil 68a as a signal coil are accommodated in a pot-shaped core 70 as a core member. The primary side power coil 66a is formed by winding a lead wire 72 as a coil winding made of copper or the like in a circle a predetermined number of times. The size and the number of turns of the primary power coil 66a may be arbitrarily set in consideration of the magnitude of the power to be transmitted, the relative position with the secondary power coil 66b described later, and the like. Further, although the primary power coil 66a in the present embodiment is formed by winding the lead wire 72 around a substantially cylindrical bobbin 74 formed of synthetic resin or the like, the bobbin 74 is not necessarily required.

On the other hand, the main body signal coil 68a is formed of a lead wire 76 as a coil winding formed of copper or the like. As shown as a model in FIG. 5, the body side signal coil 68a is formed in a circular shape as a whole, and the first winding portion 78 wound on the outside in the radial direction and the first winding portion 78 on the inside in the radial direction One winding portion 78 and a second winding portion 80 wound in the opposite direction are formed by a single lead wire 76.

Specifically, first, the outer wound portion 82a is formed by the lead wire 76 being approximately half-turned from point A in FIG. 5, and then it is bent inward in the radial direction, and The inner winding portion 84a is formed by being rotated approximately in a direction opposite to the outer winding portion 82a (counterclockwise in FIG. 5). Then, the lead wire 76 is further bent outward in the radial direction from the inner winding portion 84a, and is semicircularly rotated in the opposite radial direction to the inner winding portion 84a (clockwise in FIG. 5) to point A By returning, the outer winding portion 82b is formed. Thereafter, by repeating this, the outer winding portion 82c, the inner winding portion 84b, and the outer winding portion 82d are sequentially formed. Thus, the first winding portion 78 is formed by the outer winding portions 82a to 82d, and the second winding portion 80 is formed by the inner winding

portions

84a and 84b. In short, the lead wire 76 is turned around in a half turn around the outside and then turned back inside, and is turned around in a reverse direction on the inside. Then, the first winding portion 78 is further wound outward in one direction (clockwise in FIG. 5) to the outside of the body signal coil 68a by being folded back and being semi-circled on the remaining outside. And a second winding portion 80 wound in the direction opposite to the first winding portion 78 (counterclockwise in FIG. 5) inside the body-side signal coil 68a. Ru. By repeating this, the number of turns of the main body signal coil 68a can be set arbitrarily. Although FIG. 5 illustrates that the lead wire 76 does not overlap for the sake of easy understanding, the lead wire 76 is formed of the first winding portion 78 and the second winding portion 80. Each of them may be overlapped.

The main side signal coil 68a of the present embodiment is formed in a circular shape having substantially the same size as the primary side power coil 66a. Further, the first winding portion 78 and the second winding portion 80 are respectively wound in a substantially circular shape, and are formed on the same plane and concentric axes. In addition, as shown in FIG. 4, the main body side signal coil 68a has a winding shape by fixing the lead wire 76 to the holding plate 86 made of synthetic resin etc. in a thin, annular plate shape by adhesion or the like. Is supposed to be maintained. However, the holding plate 86 is not necessarily required.

The primary power coil 66 a and the main signal coil 68 a are accommodated in the pot core 70. The pot core 70 is made of, for example, a magnetically permeable material such as iron, silicon steel, permalloy, or ferrite. The pot core 70 has a cylindrical shape in which a central hole 88 extending on the central axis is provided, and a circumferential groove 90 is formed open in one of the axial directions and extending around the central axis. The circumferential groove 90 is a receiving recess for receiving the primary power coil 66a and the main signal coil 68a. Note that various shapes can be adopted as the specific shape of the pot-shaped core 70, and the pot-shaped core 70 may be an integrally molded product, for example, the outer wall 92 of the circumferential groove 90, the inner wall 94, and the three parts of the bottom wall May be made of a plurality of parts formed by bonding or the like. Furthermore, for example, the outer wall 92 may be divided into a plurality of parts in the circumferential direction, or the forming member of the pot core 70 may be disposed close to the primary power coil 66a or the main signal coil 68a.

The primary side power coil 66a and the main body side signal coil 68a are accommodated in the circumferential groove 90, whereby the main body side coil head 62 is formed. In the present embodiment, the primary power coil 66a and the main signal coil 68a are accommodated in the pot core 70 in this order, but the order of accommodation in the pot core 70 may be reversed. As a result, as shown in FIG. 2, the primary power coil 66a is surrounded by the pot core 70, and the primary power coil 66a and the main signal coil 68a are arranged on a substantially concentric axis with each other. The

lead wires

72 and 76 are accommodated in the circumferential groove 90 in a state of being overlapped in the axial direction (vertical direction in FIG. 2). Thus, by arranging the primary side power coil 66a and the body side signal coil 68a on substantially concentric axes, the first winding portion 78 and the second winding of the body side signal coil 68a are provided. The portions 80 are wound in opposite directions with respect to the center of the primary power coil 66a. A bobbin 74 is interposed between the primary power coil 66a and the main signal coil 68a, whereby the primary power coil 66a and the main signal coil 68a are disposed with a gap therebetween. At the same time, contact between the

lead wires

72 and 76 is prevented.

Further, as shown in FIG. 6, the main side signal coil 68 a is accommodated in the circumferential groove 90 so that the first winding portion 78 of the body side signal coil 68 a is on the outer wall 92 side of the circumferential groove 90. The second winding portion 80 is disposed on the inner wall 94 side of the circumferential groove 90. Here, the first winding portion 78 and the second winding portion 80 are spaced apart and the first winding portion 78 and the second winding portion 80 in the radial direction of the pot core 70. Separation distance D: the separation distance between the first winding portion 78 and the outer wall 92 outside the body signal coil 68a: d1, the second winding portion 80 inside the body signal coil 68a The separation distance with the inner wall 94 is larger than any of d2. That is, the first winding portion 78 is closer to the outer wall 92 side than the second winding portion 80 side, and the second winding portion 80 is closer to the inner wall 94 side than the first winding portion 78 side. Is located in

On the other hand, as shown in FIG. 4, the load side coil head 64 is configured to include a secondary side power coil 66b and a load side signal coil 68b as a signal coil. The secondary power coil 66b and the load signal coil 68b have the same structure as the primary power coil 66a and the main signal coil 68a provided in the main coil head 62, respectively. Therefore, the explanation is omitted by attaching the corresponding reference numerals in the figure. That is, the load side coil head 64 does not have the pot type core 70 of the main body side coil head 62 and has the same structure as the main body side coil head 62 except for the pot type core 70.

Then, as shown in FIG. 2, the main body side coil head 62 is provided on the spindle head 16, and the load side coil head 64 is provided on the tool unit 22. The main body side coil head 62 is assembled to the casing 32 of the spindle head 16 via the shield member 96. The shield member 96 is formed of a nonmagnetic material such as, for example, aluminum alloy, copper alloy, titanium alloy, nickel alloy, ceramics, synthetic resin material, and has a substantially bottomed cylindrical shape in which a through hole is formed at the center There is. The main body side coil head 62 is inserted into such a shield member 96 and fixed by bonding, press-fitting or the like. The main body side coil head 62 is attached to the spindle head 16 by overlapping the flange portions 97 formed on the shield member 96 with the casing 32 and fixing the flange portions 97 with bolts 98 at a plurality of locations. Thereby, the outside of the main body side coil head 62 is covered with the shield member 96, and the leakage magnetic flux from the pot core 70 is reduced, and the external motor 34 etc. is particularly reduced in the main body side signal coil 68a. Protected from magnetic disturbances.

The main spindle 18 of the main spindle head 16 is inserted through the through hole formed in the center of the shield member 96 and the central hole 88 of the pot core 70. In the assembled state to the spindle head 16, the main body side coil head 62 is disposed at the end of the spindle head 16 on the tool unit 22 side, and the circumferential groove 90 of the pot core 70 is on the tool unit 22 side. It is disposed in the opening direction.

On the other hand, the load side coil head 64 is accommodated in the coil accommodation groove 49 of the tool holder 44 and fixed by bonding, press fitting or the like, and is disposed at the end of the tool unit 22 on the spindle head 16 side. Thereby, the main body side coil head 62 and the load side coil head 64 are arranged coaxially with each other on the central axis O of the main shaft 18 and in the axial direction of the main shaft 18 (vertical direction in FIG. 2) They are arranged opposite to each other with a gap. Then, by rotating the main shaft 18, the load-side coil head 64 can be relatively rotated around the central axis: O of the main shaft 18 with respect to the main body-side coil head 62.

That is, the main body side coil head 62 and the load side coil head 64 of this embodiment are X, Y, Z in a state before being assembled to the spindle head 16 and the tool unit 22 as shown in FIG. 7 as a model. Relative to the load side coil head 64 in the three directions of the longitudinal direction (X axis direction), the left and right direction (Y axis direction), and the vertical direction (Z axis direction) extending in the axial direction of the main body side coil head 62 While displacement is permitted, tilting or turning is permitted in three directions of roll around the X axis, pitch around the Y axis, and yaw around the Z axis. As a result, the primary power coil 66a and the secondary power coil 66b, and the main signal coil 68a and the load signal coil 68b can be displaced relative to each other with six degrees of freedom. The load side coil head 64 is mounted to the main body side coil head 62 by assembling the main body side coil head 62 and the load side coil head 64 to the spindle head 16 and the tool unit 22 of the machine tool 12. It is disposed opposite to each other with a gap in a state where the roll around the X axis is allowed.

Here, the main body side coil head 62 and the load side coil head 64 have the pot type core 70 only in the main body side coil head 62, and the load side coil head 64 does not have the pot type core 70. That is, while the spindle head 16 is provided with the pot type core 70 as a core member surrounding the primary side power coil 66a, the tool unit 20 is provided with a core member surrounding the secondary side power coil 66b. It is not done.

For example, as shown in FIG. 8, the main body side coil head 62 and the load side coil head 64 are power supplies for supplying DC power to the primary side power coil 66a on the machine main body 14 side provided with the spindle head 16 Circuit 100 is connected via inverter 102. The power supply circuit 100 and the inverter 102 are provided on the machine body 14 side. Further, the control device 106 is connected to the main body signal coil 68 a via the communication circuit 104 having a demodulation circuit. The communication circuit 104 and the control device 106 are provided on the machine body 14 side. The control device 106 includes a CPU, a ROM, a RAM, and the like, and adjusts the drive frequency of the inverter 102 in accordance with the electric signal received from the communication circuit 104 and a predetermined program determined in advance.

On the other hand, on the tool unit 22 side, the ultrasonic transducer 50 is connected to the secondary power coil 66b. As shown in FIG. 8 as well, the correction capacitor 107 is provided in parallel with the ultrasonic transducer 50 as necessary to cancel the current flowing to the braking capacitance (Cd) of the ultrasonic transducer 50. It is good. Furthermore, a detection circuit 108 as a detection means is connected to the ultrasonic transducer 50, and the detection circuit 108 is connected to the load signal coil 68b via the amplification circuit 110. The detection circuit 108 is configured to include, for example, a Hall element, and detects a voltage applied to the ultrasonic transducer 50 and a current flowing through the ultrasonic transducer 50 as a vibration state of the ultrasonic transducer 50. The detection circuit 108 and the amplification circuit 110 are provided on the tool unit 22 side.

The non-contact type power supply device 10 of this embodiment includes the main body side coil head 62, the load side coil head 64, the power supply circuit 100, the inverter 102, the communication circuit 104, the control device 106, the detection circuit 108, and the amplification circuit 110. The power supply device is configured to output an AC voltage to the primary side power coil 66 a including the power supply circuit 100 and the inverter 102.

By using such a non-contact type power supply device 10, driving power is supplied from the machine main body 14 as the main body side to the ultrasonic vibrator 50 as the resonant circuit provided in the tool unit 22 as the load side. You can do it. Then, when the resonance frequency of the ultrasonic transducer 50 changes due to a change in mechanical load or temperature condition applied to the ultrasonic transducer 50 by detecting the vibration state of the ultrasonic transducer 50, ultrasonic vibration is generated. By performing feedback control to change the frequency of the voltage applied to the transducer 50, the ultrasonic transducer 50 can be efficiently driven. Hereinafter, supply of drive power to the ultrasonic transducer 50 and an example of feedback control will be shown.

First, as a premise, the ultrasonic transducer 50 composed of a plurality of piezoelectric elements 52 can be considered equivalent to the circuit shown in FIG. 8 in the vicinity of the resonance frequency. The equivalent circuit is known to have an impedance characteristic shown in FIG. 9, the impedance (Z) is the smallest becomes the frequency, the resonance frequency f _r of the ultrasonic transducer 50, the ultrasonic transducer 50 is When an alternating voltage of the resonance frequency f _r is applied, it vibrates most efficiently, and a large amplitude can be obtained. At the resonance frequency f _r , the phase difference between the voltage and the current flowing to the ultrasonic transducer 50 is zero, and the largest current flows to the ultrasonic transducer 50. Also, the frequency at which the impedance (Z) is the largest is the antiresonance frequency f _n .

Therefore, as a preliminary preparation, for example, 0.1 kHz, 0.5 kHz, 1 kHz, etc. over a predetermined range sandwiching the resonance frequency which is estimated to some extent from the composition of the piezoelectric element 52 with respect to the ultrasonic transducer 50. An alternating current voltage whose frequency is gradually changed at predetermined intervals is applied to measure the current flowing through the ultrasonic transducer 50. For example, when it is estimated that the resonance frequency f _r of the ultrasonic transducer 50 is around 20 kHz, the applied voltage is changed to 10 kHz to 40 kHz, and the current flowing through the ultrasonic transducer 50 is measured. FIG. 10 shows an example of the result of measurement of the current flowing through the ultrasonic transducer 50. As shown in FIG. From the measurement results obtained, the frequency of flow of greatest current (in FIG. 10, about 23 kHz) in the vicinity of, can be estimated as a resonance frequency f _r of the ultrasonic transducer 50 resides.

As described above, the ultrasonic transducer 50 is driven most efficiently at the resonance frequency f _r . However, as apparent from FIG. 9, in the vicinity of the resonance frequency f _r , the change of the impedance (Z) is steep, and the vibration state of the ultrasonic transducer 50 is rapid only by slightly deviating from the resonance frequency f _r Change to Therefore, in order to ensure the stability of the driving of the ultrasonic transducer 50, in the present embodiment, the resonance frequency f _r slightly deviates from the resonance frequency f _r from the resonance frequency f _r to the anti-resonance frequency f _n in FIG. The position is set as the drive frequency f _d . Specifically, a voltage in the range of (π / 2) ± (π / 4) is applied to the phase difference between the voltage and the current, and in the present embodiment, the measurement result is shown in FIG. As shown, an alternating voltage with a drive frequency f _d with a phase difference of π / 2 is applied. FIGS. 12 and 13 show the measurement results in the case where a voltage in a frequency range deviated from the vicinity of the resonance frequency is applied to the ultrasonic transducer 50. FIG. 12 shows a square wave input as an AC voltage, and the amplitude of the current is small. On the other hand, FIG. 13 shows a sine wave input as an AC voltage, and since the electrical vibration is unstable, it can be confirmed that it is in a non-resonance state.

Then, with the motor 34 (see FIG. 2) of the spindle head 16 driven and the tool unit 22 rotated with respect to the spindle head 16, the DC voltage of the power supply circuit 100 shown in FIG. It is converted into a high frequency voltage and supplied to the primary power coil 66a. Here, the driving frequency of the inverter 102 is controlled by the controller 106, the AC voltage of the drive frequency f _d obtained above is adapted to be supplied to the coil 66a for the primary-side power.

Thereby, the primary side power coil 66a is penetrated through the primary side power coil 66a, and the magnetic flux which changes according to the output frequency is generated. The magnetic flux is focused by the pot core 70, and the magnetic flux from the pot core 70 is linked to the secondary power coil 66b. As a result, the primary side power coil 66a and the secondary side power coil 66b are electromagnetically coupled, and an induced electromotive force is generated in the secondary side power coil 66b due to mutual induction. In this manner, transmission of power is possible in a non-contact state between the primary power coil 66a and the secondary power coil 66b, which are relatively rotated, and occurs in the secondary power coil 66b. The squeezed high frequency voltage is supplied to the ultrasonic transducer 50 as driving power. As a result, the ultrasonic transducer 50 is vibrated, and the rotation by the motor 34 and the vibration of the ultrasonic transducer 50 are superimposed on the tool 20, so that the processing of the work 26 (see FIG. 1) is more accurate. It is possible to do.

At the time of processing of the workpiece 26, the resonance frequency f _r of the ultrasonic transducer 50 changes due to a change in mechanical load applied via the tool 20, a change in temperature conditions, and the like. For example, the magnitude (amplitude) of the voltage applied to the ultrasound transducer 50, the magnitude (amplitude) of the current flowing through the ultrasound transducer 50, and the change of the resonance frequency _fr of the ultrasound transducer 50 It appears as a change in phase difference between voltage and current. For example, as indicated by I 'in FIG. 14 (a), the amplitude of the current decreases when the load increases, or when the load increases as indicated by I' in FIG. 14 (b). Produces a phase difference different from that of Then, by using the non-contact type power supply device 10 of the present embodiment, the frequency of the AC voltage applied to the ultrasonic transducer 50 corresponding to the change of the resonant frequency _fr of the ultrasonic transducer 50 Feedback control can be performed.

First, the vibration state of the ultrasonic transducer 50 is detected by the detection circuit 108 shown in FIG. The detection circuit 108 is provided with, for example, a Hall element, and the vibration state of the ultrasonic transducer 50, for example, the amplitude of the voltage applied to the ultrasonic transducer 50, the amplitude of the current flowing through the ultrasonic transducer 50, The phase and the like of these voltage and current are detected.

The amplitude, phase, and the like of the voltage and current of the ultrasonic transducer 50 detected by the detection circuit 108 are amplified by the amplifier circuit 110 as a detection signal, and applied as an AC voltage to the load-side signal coil 68b. As a result, the load-side signal coil 68b is penetrated to generate a magnetic flux that changes according to the output frequency, and the magnetic flux is linked to the main-body signal coil 68a. As a result, an induced electromotive force occurs due to mutual induction with the load signal coil 68b in the main signal coil 68a, and the detection signal transmitted from the detection circuit 108 is transmitted to the main signal coil by the communication circuit 104. It is taken out from 68a. In this manner, transmission of an electrical signal is enabled in a non-contact state between the load-side signal coil 68b and the body-side signal coil 68a which are relatively rotated.

The detection signal extracted from the main body side signal coil 68 a is input to the control device 106. The control device 106 compares the amplitude of the voltage and current of the ultrasonic transducer 50 obtained from the detection signal, the phase difference between the voltage and the current, etc. with the state before receiving the detection signal, and detects the detection signal. When changing from the state before reception, the drive frequency of the inverter 102 is changed to change the power supply frequency to the primary side power coil 66a so as to return to the state before receiving the detection signal. . As the change amount of the drive frequency of the inverter 102, the change amount of the drive frequency corresponding to the change amount of the amplitude of the voltage or current or the change amount of the phase difference is stored in advance in the control device 106 as a table. For example, while receiving the amplitude of the voltage or the amplitude of the current in the ultrasonic transducer 50, the phase of the voltage and the current, etc. from the detection circuit 108, the drive frequency of the inverter 102 is 0.1 kHz or It may be adjusted by changing it little by little, such as 5 kHz. As a result, it is possible to apply to the ultrasonic transducer 50 an AC voltage of the drive frequency f _d corresponding to the changed resonance frequency f _r, and to restore the expected vibration state shown in FIG. . Thus, in the present embodiment, the power supply frequency adjustment mechanism is configured including the control device 106 and the inverter 102.

If the non-contact type power supply device 10 of this embodiment is used, the driving power to the ultrasonic vibrator 50 provided in the tool unit 22 from the spindle head 16 between the spindle head 16 and the tool unit 22 displaced relative to each other It becomes possible to supply Moreover, toward the tool unit 22 to the spindle head 16, which is possible to transmit the vibration state of the ultrasonic transducer 50 as an electrical signal, follow manner the change in the resonant frequency f _r of the ultrasonic transducer 50 In response to the above, it is possible to realize feedback control that changes the frequency of the AC voltage applied to the ultrasonic transducer 50. As a result, the stroke of the tool 20 can be secured more stably, and more excellent processing accuracy can be obtained. In addition, when a short circuit or disconnection occurs on the tool unit 22 side due to any cause, the resonance condition in the ultrasonic transducer 50 changes and the applied voltage deviates from the resonance frequency, which is large on the tool unit 22 side. Energy can also be prevented from being supplied.

And, in the non-contact type power supply device 10 having a structure according to the present embodiment, the pot core 70 is provided only on the spindle head 16 side, and on the tool unit 22 side where the ultrasonic transducer 50 is provided. Is not provided. As a result, it is possible to avoid an increase in the inductance in the resonant circuit of the ultrasonic transducer 50 and to avoid a decrease in the resonant frequency of the ultrasonic transducer 50. As a result, the ultrasonic transducer 50 can be driven at a high frequency, and more excellent processing accuracy can be obtained. Furthermore, the resonant frequency of the ultrasonic transducer 50 is adjusted to the mechanical natural frequency of the tool unit 22 including the horn 60 and the tool 20 while avoiding a large change in the resonant frequency of the ultrasonic transducer 50. This can be facilitated, tuning is facilitated, and the stroke of the tool 20 can be effectively obtained.

Furthermore, by not providing the pot type core 70 on the tool unit 22 side, for example, as in the case where core members are provided on both the spindle head 16 and the tool unit 22, a coil for primary side power is provided between opposing surfaces of the core members. There is no concentration of magnetic flux from 66a. Thereby, it is avoided that the interlinkage magnetic flux of the secondary side power coil 66b is rapidly reduced only when the tool unit 22 is slightly misaligned with respect to the spindle head 16, and stable power transmission is performed. I can do it. Further, as shown in FIG. 25, for example, as shown in FIG. 25, a leakage current is positively generated between the primary side power coil 66a and the secondary side power coil 66b as a square wave from the primary side power coil 66a. When AC power is transmitted, the AC voltage received on the secondary power coil 66 b side can be brought close to the sine wave of the mechanical vibration of the ultrasonic transducer 50. As a result, the drive of the ultrasonic transducer 50 can be expressed more stably, and the undulation or the like of the ultrasonic transducer 50 can be reduced, and more excellent processing accuracy can be obtained. It is also possible to reduce the resulting heat generation and the like. In addition, by not providing the core member on the tool unit 22 side, the weight of the tool unit 22 can be reduced to cope with higher speed rotation, and problems such as damage to the core member due to high speed rotation can be avoided. Can do.

Furthermore, in the non-contact type power supply device 10 according to the present embodiment, the first winding portion 78 and the opposite winding are wound in the main signal coil 68a and the load signal coil 68b, respectively. A second winding portion 80 is formed. As a result, the noise electromotive force induced in the main side signal coil 68a and the load side signal coil 68b by the magnetic flux generated by the energization of the primary side power coil 66a can be reduced, and the transmission of the electric signal is performed. It can be done more accurately.

That is, as shown in FIG. 15A and FIG. 16A as a model, when transmitting an electrical signal from the load signal coil 68b to the main signal coil 68a, first, for the load signal By applying an alternating voltage to the coil 68b, the current _iso flows through the first winding portion 78 of the load signal coil 68b, and the current _isi flows through the second winding portion 80. In FIG. 16, the current flowing to the front side of the drawing is indicated by an arrow extending obliquely downward, and the current flowing to the back side of the drawing is indicated by an arrow extending obliquely upward. The current _iso and the current _isi are the same current, and flow in the same direction in the lead wire 76 of the load-side signal coil 68b. The current _iso and the current _isi flow through the load-side signal coil 68b, _so that the magnetic flux b _i inside the second winding portion 80, the second winding portion 80 and the first winding portion 78. flux b _c between the magnetic flux b _o is caused outside the first winding portion 78. Here, since the first winding portion 78 and the second winding portion 80 are wound in the opposite directions to each other, the current _iso and the current _isi appear when the lead wire 76 is viewed from the outside. It flows in the opposite direction to each other. As a result, magnetic lines of flux b _i and the magnetic flux b _o whereas towards the same direction, magnetic lines of flux b _c is the direction opposite to the magnetic lines of flux b _i and the magnetic flux b _o.

While the magnetic flux rb _{o in the} opposite direction to the magnetic flux b _o is generated outside the first winding portion 78 by the current i _si flowing through the second winding portion 80, the second winding portion inside the 80, the current i _so through the first winding portion 78, but the magnetic flux b _i the opposite direction of the magnetic flux rb _i is caused, the first winding portion 78 second winding portions 80 are spaced apart and there is a distance from the second winding portion 80 to the outside of the first winding portion 78 and from the first winding portion 78 to the inside of the second winding portion 80 from, these magnetic flux rb _o, rb _i is, the magnetic flux b _o, small enough not to affect almost b _i.

Then, an induced current i _ro is generated in the first winding portion 78 of the opposing main body signal coil 68a by the magnetic fluxes b _i , b _c and b _o generated by the load side signal coil 68b. The induced current _iri is generated in the second winding portion 80. The induced currents _iro and _iri flow in the same direction in the lead wire 76 of the main body signal coil 68a and are not canceled out. In this manner, it is possible to transmit an electrical signal from the load signal coil 68b to the main signal coil 68a. In particular, in the present embodiment, the main side signal coil 68a is assembled to the pot core 70, and the first winding portion 78 is disposed close to the outer wall 92 of the pot core 70, and the second winding is performed. Since the wire portion 80 is disposed close to the inner wall 94, focusing the magnetic flux b _i , b _o on the outer wall 92 and the inner wall 94 respectively enables the first winding portion 78 and the second winding portion 80 to In each of them, induced currents i _ro and i _ri flowing in the same direction in the lead wire 76 can be effectively generated.

On the other hand, as shown in FIG. 15B and FIG. 16B as a model, when an AC voltage is applied to the primary power coil 66a, the magnetic flux B _i inside and outside the primary power coil 66a. The magnetic flux B _o is generated at. The direction of the magnetic field lines of the magnetic flux B _i and the direction of the magnetic field lines of the magnetic flux B _o are opposite to each other. The magnetic fluxes B _i and B _o pass through the inside of the second winding portion 80 and the outside of the first winding portion 78 in each of the body side signal coil 68 a and the load side signal coil 68 b. Thus, when describing a coil 68a for main unit signal as an example, the induced current i _no as a noise current in the first winding portion 78, the induced current i _ni as a noise current to the second winding portions 80 It is born. Since the magnetic flux B _i and the magnetic flux B _o are directed in opposite directions on both sides of the first winding portion 78 and the second winding portion 80, the induced current _ino and the induced current _ini are on the main body side When the lead wires 76 of the signal coil 68a are viewed from the outside, they flow in the same direction. And, since the first winding portion 78 and the second winding portion 80 are wound in opposite directions to each other, the induced current _ino and the induced current _ini are opposite to each other in the lead wire 76. In the first winding portion 78 and the second winding portion 80, electromotive forces are generated in opposite directions with respect to the common magnetic field. As a result, the induced current i _no inductive current i _ni becomes possible to cancel each other, so that the magnitude of the induced current i _no inductive current i _ni approaches as possible, the first winding portions 78 and By adjusting the size and the number of turns of the second winding portion 80, noise caused by the magnetic flux B _i and B _o generated by the primary power coil 66a is generated in the main signal coil 68a and causes noise. Power can be offset. In this manner, transmission of an electrical signal can be performed while reducing noise due to the influence of the primary power coil 66a.

As shown in FIG. 15 (b) and FIG. 16 (b), the noise electromotive force can be similarly reduced also in the load side signal coil 68b, and in the present embodiment, the electricity is reduced. It is possible to reduce noise on both the transmitting side (load side signal coil 68b) and the receiving side (body side signal coil 68a) of the signal. Further, by adopting the specific coil winding path as described above for each of the main body side signal coil 68a and the load side signal coil 68b, a special control device and a coil member for noise suppression are separately provided. Therefore, the transmission quality of the electrical signal can be improved with an extremely simple configuration. Furthermore, since the electromotive force in the reverse direction is generated and canceled using a coil winding path of a specific shape, even if the amount of magnetic flux affecting the main side signal coil 68a and the load side signal coil 68b changes. It is possible to automatically cope with changes in the amount of magnetic flux without requiring retuning etc., and to obtain an excellent noise suppression effect.

And since the influence from the primary side power coil 66a can be offset, it becomes possible to arrange the body side signal coil 68a at a position extremely close to the primary side power coil 66a, and in the present embodiment, The main side signal coil 68a is accommodated in the same circumferential groove 90 of the pot core 70 together with the primary side power coil 66a. As described above, in the related art, it is also possible to dispose the

lead wires

72 and 76 so as to overlap with each other, which is difficult because the magnetic paths interfere with each other. Space complexity can be avoided to obtain extremely excellent space efficiency. Further, by accommodating the body side signal coil 68a inside the pot core 70, for example, the body side signal coil 68a can be protected from disturbance due to magnetism from the motor 34 or the like.

In addition, a specific coil winding path is adopted for the body side signal coil 68a and the load side signal coil 68b, and the noise electromotive force is reduced by the structure itself of the body side signal coil 68a and the load side signal coil 68b. Since it is possible, a special noise removal process is not required, and the detection signal transmitted from the tool unit 22 can be promptly reproduced on the machine body 14 side. Further, the timing at which the noise electromotive force is generated in the main side signal coil 68a and the load side signal coil 68b should be clearly controlled from the conduction timing to the primary side power coil 66a and the secondary side power coil 66b. Can do. As a result, it is possible to improve the real-time property of signal transmission from the tool unit 22 to the machine main body 14, and to perform feedback control with higher responsiveness. FIG. 17 shows the results of measuring the transmission timing of the detection signal on the tool unit 22 side (transmission signal in the figure) and the reception timing on the machine body 14 side (reception signal in the figure). As indicated by ΔX in the lower part of the graph in FIG. 17, the time required for signal transmission from the time when the detection signal was transmitted on the tool unit 22 side: X1 to the time when the detection signal was received on the machine body 14: X2 The time was 64.0 ns, and it was confirmed that extremely rapid signal transmission was possible.

The machine tool 12 of the present embodiment is provided with a plurality of (two in FIG. 18, two)

tool units

22 and 120 as shown as a model in FIG. 18, and the plurality of

tool units

22 and 120 are shown. It is also possible to selectively assemble the spindle head 16. Hereinafter, in the tool unit 120, the same structure as that of the tool unit 22 will be omitted by assigning the same reference numerals in the drawings.

The tool unit 120 is obtained by removing the load signal coil 68 b from the load coil head 64 of the tool unit 22. That is, the load-side coil head 122 of the tool unit 120 includes only the secondary-side power coil 66 b, and the secondary-side power coil 66 b is connected to the ultrasonic transducer 50. Further, the tool unit 120 is not provided with the detection circuit 108 and the amplifier circuit 110 (see FIG. 8) in the tool unit 22. Therefore, when the tool unit 120 is attached to the spindle head 16, the main body signal coil 68a is not used, and for example, an AC voltage of a frequency set in advance in the control device 106 is transmitted to the tool unit 120 Thus, the ultrasonic transducer 50 is driven at a predetermined frequency. The tool 20 of the tool unit 120 may be different from or the same as the tool 20 of the tool unit 22. Although not shown, these

tool units

22 and 120 are provided with a so-called V flange gripped by an arm of an automatic tool changer (ATC: Automatic Tool Changer), and are automatically replaced with respect to the spindle head 16 It is good.

In this way, various kinds of processing can be performed by preparing a plurality of tool units provided with various tools. For example, when it is desired to detect the vibration state of the tool 20 and perform feedback control, the tool unit 22 may be used, while when the feedback control is not necessary, the tool unit 120 may be used. And, by using the non-contact type power supply device 10 of the present embodiment, even between the spindle head 16 and the

tool unit

22, 120 which are separated from each other, the transmission of the electric power and the electric signal can be carried out without contact. .

Furthermore, as shown in FIG. 19 as a model, the machine tool 12 of this embodiment can be remotely operated by being connected to a computer network 124 such as a LAN, a WAN, or the Internet. For example, by connecting the network interface 126 to the control device 106 provided in the machine main body 14, the control device 106 can be connected to the computer network 124 via the network interface 126. Further, to the computer network 124, a client 128 composed of a computer and a server 130 are connected.

Then, as indicated by an arrow R ₁ in FIG. 19, the client 128 is connected to the server 130 via a computer network 124, as indicated by the arrow R _2, machine tool 12 is connected to the server 130 as a client Ru. Thereby, the client 128 and the machine tool 12 are mutually connected through the server 130, and the server 130 provides a routing mechanism for buffering the data packets of both and transmitting them to the client 128 and the machine tool 12 mutually. The machine tool 12 in a network environment isolated by a firewall can be remotely controlled from the client 128, and the vibration characteristic of the ultrasonic transducer 50 in the machine tool 12 can be remotely monitored by the client 128. In addition, a database 132 storing the vibration characteristics of the ultrasonic transducer 50 in the machine tool 12 and the operating conditions of the machine tool 12 is provided in the server 130, and the database 132 of the server 130 is accessed from the machine tool 12 for driving. The conditions may be determined, or the database 128 may be accessed from the client 128 to control the operation of the machine tool 12 according to the obtained vibration characteristics and the operating conditions. Furthermore, the control program stored in the control device 106 of the machine tool 12 can be updated remotely from the client 128 or the server 130 via the computer network 124. Incidentally, as shown in an arrow R ₃ in FIG. 19, for example, itself to the controller 106 of the machine tool 12 by providing a server function, without passing through the server 130, etc. that connect directly to the client 128 to the machine tool 12 You may.

As mentioned above, although one embodiment of the present invention was explained in full detail, a specific embodiment of the present invention is not limited to the above-mentioned embodiment. Hereinafter, although several different embodiments of the present invention are shown, these are merely illustrations and do not show that the present invention is limited to the following specific embodiments. Moreover, in the following embodiment, the description is abbreviate | omitted by attaching the code | symbol same as said 1st embodiment to the member and site | part corresponded to said 1st embodiment by the figure.

First, FIG. 20 schematically shows detection means constituting the non-contact type power supply device according to the second embodiment of the present invention. The resonance circuit of this embodiment is an ultrasonic transducer 50 substantially the same as that of the first embodiment. Further, in the present embodiment, a piezoelectric element 140 as a detection unit is provided together with the plurality of piezoelectric elements 52 constituting the ultrasonic transducer 50. The piezoelectric element 140 as a detection means is sandwiched between the electrodes 142 and 144, and the electrodes 142 and 144 are connected to the amplifier circuit 110 (see FIG. 8). Similar to the plurality of piezoelectric elements 52 constituting the ultrasonic transducer 50, the piezoelectric element 140 as such detecting means is externally inserted into the bolt 57, and a metal block 58 screwed to both ends of the bolt 57 By being tightened by the horn 60, they are laminated together with the piezoelectric element 52 constituting the ultrasonic transducer 50. An insulating material 146 is interposed between the electrode 56 of the adjacent piezoelectric element 52 and the electrode 142 of the piezoelectric element 140 as a detection means, and they are mutually insulated.

According to such a structure, when the ultrasonic transducer 50 is driven, the vibration of the ultrasonic transducer 50 is exerted on the piezoelectric element 140 as the detection means, and a voltage is generated in the piezoelectric element 140. The voltage generated in the piezoelectric element 140 is supplied from the electrodes 142 and 144 to the load signal coil 68b through the amplifier circuit 110 and transmitted to the main signal coil 68a. The vibration state of the sound transducer 50 can be detected as a change in voltage. And according to this embodiment, the detection means can be realized with a simple structure. At the same time, since the detection means can be coaxially arranged in the ultrasonic transducer 50, the detection means can be arranged efficiently with space, and the balance of weight balance on the load side can be suppressed, and rotation on the load side can be achieved. Driving can be performed more stably.

Next, in FIG. 21, the main body side coil head 152 provided with the primary side power coil 66a and the signal coil 150, which constitutes the non-contact type power supply device as the third embodiment of the present invention, is disassembled. Show. In the signal coil 150, after the lead wire 76 is circularly wound to form the first winding portion 78, the lead wire 76 is extended from the first winding portion 78 to form the first winding. The second winding portion 80 is formed by being wound around the wire portion 78 in the opposite direction. Then, the first winding portion 78 is accommodated in the circumferential groove 90 of the pot core 70, and then the primary power coil 66a and the second winding portion 80 are accommodated in order. As a result, the first winding portion 78 and the second winding portion 80 are disposed on both sides sandwiching the primary power coil 66a in the axial direction.

As in the present embodiment, it is also possible to form the first winding portion 78 and the second winding portion 80 in the signal coil 150 on different planes. In this way, the formation space of the first winding portion 78 and the formation space of the second winding portion 80 can be largely secured, respectively. Therefore, the first winding portion 78 and the second winding portion 80 can be provided. The degree of freedom in setting the number of turns can be improved. In addition, it is also possible to apply this structure to the load side coil head 64 (refer FIG. 4 etc.), and in such a case, the secondary side electric power coil 66b is sandwiched without using the pot type core 70. The first winding portion 78 and the second winding portion 80 of the signal coil 150 may be disposed on both sides. In addition, the signal coil 150 of the present embodiment may be used for both the main body side and the load side, or may be used for only one of them, and the other is different in the shape described in the first embodiment, etc. The shape may be adopted.

Next, FIG. 22 shows a signal coil 160 that constitutes a non-contact power supply according to a fourth embodiment of the present invention. The signal coil 160 is provided on the main body side coil head 62, and the lead wire 76 accommodated in the circumferential groove 90 of the pot core 70 is extended to the outside of the pot core 70, and the outer periphery of the pot core 70. It is wound around surface 162. An outer peripheral winding portion 164 is formed by the lead wire 76 wound around the outer peripheral surface 162. The winding direction of the outer peripheral winding portion 164 is set to be equal to one of the first winding portion 78 and the second winding portion 80.

In the present embodiment, the first winding portion 78, the second winding portion 80, and the outer peripheral winding portion 164 form coil winding paths that generate electromotive forces in opposite directions. In this way, the noise reduction effect can be adjusted more accurately. In addition, it is also possible to form a coil winding path which generates electromotive force opposite to each other by only one of the first winding portion 78 and the second winding portion 80 and the outer peripheral winding portion 164. It is. Further, the signal coil 166 of the load-side coil head 64 in the present embodiment is in the form of a ring which is wound widely only in one direction and which has been widely used conventionally. As described above, the coil winding path that generates electromotive forces in opposite directions may be formed in at least one of the signal coil on the main body side and the load side.

Further, FIG. 23 schematically shows a signal coil 170 which constitutes the non-contact type transmission apparatus as the fifth embodiment of the present invention. The outer coil portion 172 is formed by the signal coil 170 being extended in the circumferential direction (approximately 1/6 in the present embodiment) in which the lead wire 76 does not reach one round on the outer side in the radial direction. It is folded back from the outer winding portion 172, and is extended in the radial inner direction by a circumferential direction (approximately 1/6 in this embodiment) substantially equal to the outer winding portion 172 in the opposite direction to the outer winding portion 172. Thus, an inner winding portion 174 is formed, and a small loop portion 176 is formed by the outer winding portion 172 and the inner winding portion 174. Such small loop portions 176 are continuously formed, and a plurality of small loop portions 176 are formed side by side in the circumferential direction. The number of turns in each small loop portion 176 can be set arbitrarily. Thus, the outer winding portions 172 of each small loop portion 176 are formed on substantially the same circumference, and the plurality of outer winding portions 172 form the first winding portion 178, and An inner winding portion 174 of the small loop portion 176 is formed on substantially the same circumference inside the outer winding portion 172, and a plurality of inner winding portions 174 form a second winding portion 180. .

Also by such winding path, the outer winding portion 172 and the inner winding portion 174 are disposed on the main body side and the load side together with the signal coil 170, not shown for the primary side power coil and the secondary side power. A plurality of outer winding portions 172 are wound in opposite directions to each other (o in FIG. 23, the outer winding portion 172 is clockwise and the inner winding portion 174 is counterclockwise) around the center of the coil: o The plurality of inner winding portions 174 can form the first winding portion 178 and the second winding portion 180 which are wound in opposite directions to each other. Further, according to the present embodiment, since the number of turns can be adjusted for each small loop portion 176, the noise electromotive force can be reduced according to, for example, the variation in the local magnetic flux change amount in the circumferential direction of the signal coil 170. The effect can be adjusted more precisely. The shape stability of the signal coil 170 can also be enhanced by forming a plurality of annular small loop portions 176 extending partially in the circumferential direction.

As mentioned above, although the embodiment of the present invention has been described in detail, these are merely examples, and the present invention is not construed as being limited in any way by the specific description in the embodiment.

For example, although the resonant circuit in the above embodiment is configured to include an ultrasonic transducer that can be considered equivalent to an electric circuit including an LCR circuit, any resonant circuit may be used as long as it has an electrical resonant frequency. For example, the present invention is not limited to this, and may be, for example, a circuit in which electric components such as a motor or a sensor or various electric circuits are connected to a resonance circuit formed of a coil and a capacitor. Therefore, the non-contact type power supply device of the present invention is not limited to the machine tool as described in the above embodiment, and is capable of relative displacement on the main body side, including separation. Can be applied to various machines in which a resonant circuit is formed.

Furthermore, specific means for controlling the feeding frequency to the primary side power coil in response to changes in the resonant frequency of the resonant circuit are not limited to arithmetic processing by the CPU, for example, phase synchronization Various aspects such as feedback means using a circuit (PLL: Phase Locked Loop) can be adopted appropriately. Further, the detection target for detecting the change of the resonance frequency of the resonance circuit is not limited to the voltage or current as in the above embodiment, and may be, for example, the ambient temperature of the environment. In the case of a vibrator or the like, mechanical amplitude or distortion of the ultrasonic vibrator may be employed. Therefore, it is also possible to use a temperature sensor, an acceleration sensor or the like as a detection means for detecting a change in the resonant frequency of the resonant circuit.

Furthermore, in each of the above embodiments, the core member is provided only on the main body side, but it is desirable to increase the gap between the main body side and the load side to increase the relative displacement amount. When adjustment is desired, the core member may be attached to the load-side signal coil. In such a case, the core member is disposed so as not to surround the secondary power coil on the load side, thereby avoiding an increase in the inductance of the secondary power coil, and a signal on the load side Preferably, the core coil is assembled to the core member.

Further, the number of the primary side power coil, the secondary side power coil, and the number of the pair of signal coils are not limited to only one each, and a plurality of pairs may be provided, and transmission of a plurality of powers is possible. A path and a transmission path of a plurality of electrical signals may be configured. Furthermore, in the case of providing the signal coil, the arrangement position of the signal coil is not limited to the position where the power coil and the winding overlap, and for example, the proximity position which can be affected by the magnetic flux by the power coil. The signal coil may be disposed adjacent to the power coil. Therefore, even when the power coil and the signal coil are arranged in an overlapping manner, they need not necessarily be arranged concentrically, and the signal coil may be eccentrically arranged with respect to the power coil. good.

Further, the winding shape of the signal coil is not limited to a circular shape, and may be, for example, a rectangular shape or an elliptical shape. Furthermore, the specific shape of the coil winding path that generates electromotive forces in opposite directions in the signal coil is not limited to the shape of the above embodiment.

Furthermore, in the first embodiment, an electric signal is transmitted from the signal coil on the load side to the signal coil on the main body side, but using these signal coils, from the main body side Of course, it is also possible to transmit an electrical signal to the load side. For example, a plurality of detection means for detecting the vibration state of the resonance circuit is provided on the load side, and an electric signal specifying which one of the plurality of detection means is used from the main body side is transmitted to the load side The detection result of the means may be transmitted as an electrical signal from the load side to the main body side. In such a case, for example, the switching timing of the inverter that transmits power from the primary power coil to the secondary power coil is detected, and the transmission timing of the electrical signal in accordance with the timing, ie, for signals The application timing of the voltage to the coil may be controlled. Also, by using half duplex serial communication, transmission of an electrical signal from the main body side to the load side, and an electrical signal from the load side to the main body side, using a pair of signal coils on the main body side and the load side It is also possible to perform both of

In addition, the modulation method used to transmit an electrical signal using a pair of signal coils is not limited at all, and for example, amplitude modulation (AM), frequency modulation (FM), phase modulation (PM), etc. Analog modulation, phase shift keying (PSK), binary phase shift keying (Manchester coding, BPSK), digital modulation such as frequency shift keying (FSK), pulse modulation such as pulse width modulation (PWM), etc. Various modulation schemes may be adopted.

In addition, although not listed one by one, the present invention can be implemented in an embodiment to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art, and such embodiments are the present invention. It is needless to say that all are included within the scope of the present invention unless they depart from the spirit of the present invention.

10: non-contact type power supply device, 12: machine tool, 14: machine body, 16: spindle head (body side), 22: tool unit (load side), 26: work, 38: labyrinth seal, 42: pull chuck , 44: tool holder, 48: pull stud, 50: ultrasonic transducer (resonance circuit), 52: piezoelectric element, 57: bolt, 58: metal block, 60: horn, 61: insulating layer, 62: body side coil Head, 64: Load side coil head, 66a: Primary side power coil, 66b: Secondary side power coil, 68a: Body side signal coil (signal coil), 68b: Load side signal coil (signal coil ), 70: pot type core (core member), 72: lead wire (power coil), 74: bobbin, 76: lead wire (signal coil), 78: first winding portion, 80: second roll Part 86: Holding plate 96: Shield member 126: Network interface 128: Client 130: Server 140: Piezoelectric element (detection means) 142: Electrode 144: Electrode 164: Outer peripheral winding portion 176 : Small loop part

Claims

A pair of primary side power coils and two that make up a pair between a main body side provided with a feeding device that outputs an alternating voltage and a load side that is relatively displaceable with respect to the main body side and provided with a resonant circuit In a non-contact type power supply device provided with a secondary power coil, wherein drive power can be supplied from the power feeding device on the main body side to the resonant circuit on the load side through the power coils.
On the main body side, a core member made of a magnetically permeable material is provided so as to surround the primary side power coil, and on the load side, the core member is provided so as to surround the secondary side power coil. The contactless power supply device characterized by not being.
A pair of signal coils are provided between the main body side and the load side, and the load side includes detection means for detecting the vibration state of the resonant circuit, and the detection means Detection signals from the load side can be transmitted from the load side to the main body side using the signal coil, and a feed frequency adjustment mechanism for the primary side power coil is provided on the main body side, Based on the detection signal transmitted from the load side to the main body side through the signal coil, the feeding frequency to the primary side power coil corresponds to the change of the resonance frequency in the resonance circuit in accordance with the change of the resonance frequency. 2. A contactless power supply as claimed in claim 1 which is adapted to be controlled.
In at least one of the main body side and the load side, the signal coils are wound in opposite directions so as to cancel the electromotive force generated in the signal coils under the influence of the magnetic flux generated by the power coils. 3. A contactless power supply according to claim 2, wherein the first and second winding sections are formed.
The non-contact type power supply device according to claim 3, wherein a coil winding of the power coil and a coil winding of the signal coil are disposed in an overlapping manner.
The contactless power supply device according to claim 3 or 4, wherein the power coil and the signal coil are coaxially disposed.
A plurality of the secondary power coil or the secondary power coil and the signal coil on the load side are prepared for the primary power coil on the main body side and the signal coil. The contactless power supply device according to any one of claims 2 to 5, wherein the primary side power coil and the signal coil on the main body side can be selectively combined.
The contactless power supply device according to any one of claims 1 to 6, wherein the resonance circuit on the load side includes an ultrasonic transducer.
The ultrasonic transducer is a Langevin-type transducer in which a plurality of piezoelectric elements are stacked, and the detection means is configured by the piezoelectric elements stacked together with the plurality of piezoelectric elements. Contact-type power supply device.