JP3394066B2 - Electrode feeder for electric discharge machining - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode-feeding device for electric discharge machining, and more particularly to an electrode-feeding device having a function of feeding only electrodes.

[0002]

2. Description of the Related Art Conventionally, as an electrode feeding device for an electric discharge machine, there has been known a device for moving an electrode by utilizing expansion and contraction of a piezoelectric element to bring the electrode close to a work for electric discharge machining.

[0003]

However, in such an electric discharge machine, when a soft material such as copper or a cylindrical electrode having low rigidity is clamped, the electrode is deformed by the clamping pressure, and this deformation causes the electrode to be fed. The return becomes unstable and the accuracy of electrical discharge machining deteriorates. Furthermore, when the applied voltage to the piezoelectric element is fixed and the vibration frequency of the piezoelectric element is changed, the amplitude of the piezoelectric element decreases at high frequencies, the clamping pressure decreases, and the electrode return is unstable. There's a problem.

The present invention has been made in order to solve such a problem, and the clamping pressure of the electrode by the piezoelectric element is maintained at a predetermined value, and the electrode can be stably fed back over the entire frequency range. An object is to provide an electrode feeding device for electric discharge machining.

[0005]

According to a first aspect of the present invention for solving the above-mentioned problems, an electric-discharge machining electrode feeder is provided.
A stacked first axial piezoelectric element housed in a housing and provided so as to expand and contract in parallel with the axial direction of the electrode;
A case fixed to the free end of the axial piezoelectric element and movable in the axial direction of the electrode with respect to the housing; and a laminated second radial piezoelectric element housed in the case and expandable / contractible in the radial direction of the electrode. A first electrical insulator that abuts on a free end of the second radial piezoelectric element and crimps and separates an electrode in accordance with expansion and contraction operations of the second radial piezoelectric element,
First pressure detecting means for measuring a pressure at which the first electrical insulator crimps and separates the electrode in accordance with an expanding operation and a contracting operation of the second radial piezoelectric element, and converting the electric pressure into an electric signal and outputting the electric signal. First voltage feedback means for feeding back the electric signal output from the first pressure detection means to the voltage applied to the second radial direction piezoelectric element, and the first voltage feedback means housed in the housing and expandable / contractible in the radial direction of the electrode. A second laminated piezoelectric element and a second radial piezoelectric element that is in contact with a free end of the third radial piezoelectric element and crimps and separates electrodes in accordance with expansion and contraction operations of the third radial piezoelectric element.
A second electrical insulation and a second electrical insulation that measures the pressure at which the second electrical insulation presses and releases the electrode in response to the expansion and contraction operations of the third radial piezoelectric element, converts the pressure into an electric signal, and outputs the electric signal. Pressure detecting means, second voltage feedback means for feeding back the electric signal output from the second pressure detecting means to the voltage applied to the third radial piezoelectric element, and the step of sending the electrode in the processing direction. At
When the first axial piezoelectric element extends in the processing direction, the first electrical insulator crimps the electrode and the second electrical insulator separates from the electrode. , The first electrical insulator separates from the electrode, the second electrical insulator crimps the electrode, and the first axial piezoelectric element is machined in the step of returning the electrode from the machining direction. The first electrical insulator separates from the electrode when extending in the direction, and the second electrical insulator crimps the electrode, and the first electrical insulator contracts when the first axial piezoelectric element contracts. The insulator is pressure-bonded to the electrode, and the second
The electric insulator is provided with a control means for controlling a voltage applied to each piezoelectric element so as to separate the electrode. Electrode machining electrode feeder according to claim 2 of the present invention
Is housed in the housing and expands and contracts parallel to the axial direction of the electrode.
A stackable first axial direction piezoelectric element, and
The housing is fixed to the free end of the first piezoelectric element,
The case that can move in the axial direction of the electrode with respect to the
The second stackable type that is housed in
The radial piezoelectric element and the free end of the second radial piezoelectric element
Abutting and extending movement and contraction of the second radial piezoelectric element
A first electrical insulator that crimps and separates electrodes according to operation
And an extension operation and a contraction operation of the second radial piezoelectric element
The first electrical insulator crimps and releases the electrodes in response to
The first pressure to measure the pressure, convert it to an electric signal and output it.
Output from the force detecting means and the first pressure detecting means
An electric signal is applied to the voltage applied to the second radial piezoelectric element.
First voltage feedback means for feedback
It is housed in the housing and can expand and contract in the radial direction of the electrode.
Capable laminated type third radial piezoelectric element, and the third radial pressure element.
The free end of the electric element, and the extension of the third radial direction piezoelectric element.
Crimping and releasing the electrode according to long operation and contraction operation
A second electrical insulator and an extension motion of the third radial piezoelectric element.
The second electrical insulator causes the electrodes to
The pressure to crimp and release is measured and converted into an electrical signal
Second pressure detecting means for outputting and this second pressure detecting hand
A second voltage feedback means for feeding back the electric signal output from the stage to a voltage applied to the third radial piezoelectric element, the step of sending the electrode in the machining direction Contact
The first axial piezoelectric element in the opposite direction to the processing direction.
When stretched, the first electrical insulator leaves the electrode
The second electrical insulator is pressure bonded to the electrode,
Note that when the first axial piezoelectric element contracts, the first electrical disconnection occurs.
The rim body crimps the electrode, and the second electric insulator is the electric electrode.
In the process of separating the electrode and returning the electrode from the processing direction.
The first piezoelectric element in the direction opposite to the machining direction.
When extended, the first electrical insulator crimps the electrodes,
The second electrical insulator separates from the electrode,
When the uniaxial piezoelectric element contracts, the first electrical insulator
Disengages the electrode and the second electrical insulator disengages the electrode.
Control that controls the voltage applied to each piezoelectric element so that it is crimped
And means.

[0006]

According to the electrode-feeding device for electric discharge machining of the present invention, the second radial piezoelectric element and the third piezoelectric element which can expand and contract in the radial direction of the electrode.
By providing pressure detection means for measuring the pressure at which the radial piezoelectric element clamps the electrode, and feeding back the signal from this pressure detection means to the pulse signal applied to the second radial piezoelectric element and the third radial piezoelectric element. , Hold the electrode clamping pressure at a predetermined value.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 of a first embodiment in which the electrode feeder for electric discharge machining of the present invention is applied to the electrode feeder for a hole-cutting electric discharge machine.
Shown in. As shown in FIG. 2, in the electrode feeding device 1, the electrode 4 is inserted into the electrode insertion hole 3 of the housing 2.
In FIG. 2, the hole 3 is symmetrical with respect to the center, so for convenience of description, the structure of the right half of the hole 3 will be described first.

A cylindrical piezoelectric element mounting hole 5 is formed in the housing 2 in parallel to the axial direction of the electrode 4. One end 7a of the first axial piezoelectric element 7 is fixed to the hole bottom 5a, and the inner peripheral wall is formed. The first axial piezoelectric element 7 is accommodated in 5b slidably in the axial direction of the electrode 4, and the other end 7b is fixed to the case 8. The first axial piezoelectric element 7 is formed by stacking disk-shaped piezoelectric elements in the plate thickness direction.

The case 8 is accommodated so that the top surface 8a and the bottom surface 8b are slidable with respect to the housing 2 in the axial direction of the electrode 4. As shown in FIG. 3, in the cylindrical hole 10 of the case 8, a pressure sensor 50 is fixed to the hole bottom 10a. The pressure sensor 50 is formed by stacking piezoelectric elements, detects pressure using the piezoelectric effect of the piezoelectric elements, and outputs an electric signal according to the pressure change. An electric insulating plate 51 is fixed on the pressure sensor 50, and one end 12a of the second radial piezoelectric element 12 is fixed on the electric insulating plate 51. The other end 12b of the second radial piezoelectric element 12 is fixed to the electrical insulator 14.

A pair of electrical insulators 1 housed in the case 8.
The electrodes 4 and 15 and the feeding electrode 43 are provided above and below the electrode 4 in between. The power supply electrode 43 is the upper electrical insulator 15
Is fitted in a recess on the bottom surface of the. Lower electrical insulator 14
Bottom surface 14a is fixed to the other end 12b of the second radial piezoelectric element 12. The top surface 15 a of the upper electric insulator 15 is fixed to the case 8. Arc-shaped recesses 14b and recesses 43b are formed on the top surface of the electrical insulator 14 and the bottom surface of the power supply electrode 43 so that the electrode 4 can be sandwiched therebetween.

As shown in FIG. 2, the end surface 2 of the housing 2
The housing 18 fixed to a has a cylindrical hole 21 formed in the radial direction of the electrode 4. As shown in FIG. 4, a pressure sensor 52 is fixed to the hole bottom 21 a of the cylindrical hole 21. The pressure sensor 52 is a stack of piezoelectric elements,
The pressure is detected by utilizing the piezoelectric effect of the piezoelectric element, and an electric signal corresponding to the pressure change is output. An electric insulator 53 is fixed on the pressure sensor 52, and one end 20a of the third radial piezoelectric element 20 is fixed on the electric insulator 53. The other end 20b of the third radial piezoelectric element 20 is fixed to the electrical insulator 22.

The electrical insulator 22 and the power feeding electrode 44 have the same structure as the electrical insulator 14 and the power feeding electrode 43 described above, and the arc-shaped concave portion 22b and concave portion capable of gripping the electrode 4 on the top surface and the bottom surface thereof, respectively. 44b. Further, as shown in FIG. 2, an electrode guide 25 having a guide hole 25a through which the electrode 4 can be inserted is fixed to the end surface of the housing 18.

The second radial direction piezoelectric element 12 and the third radial direction piezoelectric element 20 are laminated, respectively, and extend in the laminating direction when energized, and the electric insulator 14 and the electric insulator 22 are respectively raised to feed power. The electrode 4 is sandwiched between the electrode 43 and the feeding electrode 44. Electrical insulator 14, electrical insulator 22
Has a groove portion into which the electrode 4 is fitted, and the groove portion is
Both ends are widened so that the electrode 4 can be easily inserted.

The system shown in FIG. 1, which controls the pressure at which the electrode 4 is clamped by the expansion and contraction operation of the piezoelectric element group shown in the right half of FIG. 2, is a clamp voltage generation circuit 101, a clamp pressure detection circuit 102, and a clamp voltage feedback circuit. It is composed of 103. Clamp voltage generation circuit 101
Is a pulse signal generation circuit 61 that generates a pulse signal, a phase conversion circuit 62 that follows the pulse signal generation circuit 61 and converts the phase of this pulse signal, and a voltage of the phase-converted pulse signal that follows the phase conversion circuit 62. Amplifying circuit 6 for amplification
It is composed of 3, 64 and 65. Amplifier circuit 63, 64
The pulse signals amplified by and 65 are applied to the first axial piezoelectric element 7, the second radial piezoelectric element 12, and the third radial piezoelectric element 20, respectively.

Clamp pressure sensing circuit 102 is comprised of pressure sensors 50 and 52 which convert pressure into electrical signals. The clamp voltage feedback circuit 103 includes amplifier circuits 71 and 8 that follow the pressure sensors 50 and 52.
1, low pass filters 72 and 82 following the amplifier circuits 71 and 81, and reference voltage generation circuits 73 and 83.

The structure of the electrode feeding device for the right half of the hole 3 in FIG. 2 has been described above. However, the structure of the left half is similar to that of the right half, and therefore substantially the same components are designated by the same reference numerals. However, the description is omitted. The system for controlling the pressure at which the electrode 4 is clamped by the piezoelectric element group on the left half has the same configuration as the system on the right half, and is not shown. The first axial piezoelectric element 27, the second radial piezoelectric element 32, the third radial piezoelectric element 40, and the feeding electrodes 41 and 42 shown in the left half configuration are respectively the first
It corresponds to the axial piezoelectric element 7, the second radial piezoelectric element 12, the third radial piezoelectric element 20, and the feeding electrodes 44 and 43.

In the first embodiment, the first axial piezoelectric elements 7 and 27, the second radial piezoelectric elements 12 and 32, and the third radial piezoelectric elements 20 and 40 are paired on the right side and the left side, for a total of two sets. This piezoelectric element group is provided so that the first set of piezoelectric element groups on the right side performs the feeding operation and the second set of piezoelectric element groups on the left side performs the returning operation to share the feeding function and the returning function. Is. This is because by applying a tensile force only to the electrode 4 when the electrode is fed and returned.
This is to prevent sagging and to perform fixed-quantity feeding accurately. Also, the first set and the second set are each only in one direction,
That is, by having only the feed function or the return function only in one direction which is opposite to each other, the accuracy of the electrode fixed amount feed is improved when the piezoelectric element is energized.

Although two sets of piezoelectric element groups are provided in the first embodiment, it is a matter of course that the present invention can achieve the above-mentioned object even with one set of piezoelectric element groups. Next, the electric discharge machining operation according to the first embodiment will be described. As shown in FIG. 5, in the initial state of the electrode feeding device 1, all of the first axial piezoelectric elements 7, 27, the second radial piezoelectric elements 12, 32 and the third radial piezoelectric elements 20, 40 are turned off. is there. Next, the second radial direction piezoelectric element 12 is turned on, and the electric insulator 14 and the power feeding electrode 43 shown in FIG. 2 are closed at (a) shown in FIG. Then, the first axial piezoelectric element 7 is turned on in (b) shown in FIG. Then, the case 8 shown in FIG. 2 moves rightward in FIG. 2 due to the extension of the first axial piezoelectric element 7, and the electrode 4 moves in the feeding direction (rightward) together with the electrical insulator 14 and the feeding electrode 43. Then the third
The radial piezoelectric element 20 is turned on in (c) of FIG.
The radial piezoelectric element 12 is turned off in (d) shown in FIG.
Next, the first piezoelectric element 7 is turned off in (e) shown in FIG. Then, with the electrode 4 held at that position,
The electrical insulator 14 and the power supply electrode 43 are opened, and the case 8 returns to the initial state shown in FIG. 2 due to the contraction of the first axial piezoelectric element 7. By repeating a series of operations (a) to (e) shown in FIG. 5, the required amount of the electrode 4 is sent out.

The fine adjustment of the feed amount of the electrode 4 is performed by turning on the second radial direction piezoelectric element 12 from the initial state and then turning on the analog voltage to the first axial direction piezoelectric element 7 by this voltage adjustment. The extension amount of the piezoelectric element 7 is finely adjusted, and accordingly, the feed amount of the electrode 4 is finally finely adjusted. Further, the discharge voltage is applied to the electrode 4 in order to perform the electric discharge between the electrode 4 and the work (not shown) to perform the drilling by the electric discharge machining, when the second radial direction piezoelectric element 12 or the third radial direction piezoelectric element 20 is turned on. Done. The supply voltage generated by the original power supply (not shown) is
It is applied to the electrode 4 via the power supply electrodes 43 and 44. Further, as shown in FIG. 5, the application of voltage from the switching circuit to the power supply electrodes 43 and 44 is turned on and off when the power supply electrode 43 or the power supply electrode 44 is surely in contact with the electrode 4, and Alternatively, the electrical conduction failure that causes discharge between the power feeding electrode 44 and the electrode 4 is suppressed.

As shown in FIG. 2, after the boring process is completed, the electrode 4 is returned by the expansion and contraction operation of the second set of the first axial piezoelectric element 27, the second radial piezoelectric element 32, and the third radial piezoelectric element 40. Take action. When the electrode 4 is returned, the first set of the first axial piezoelectric element 7, the second radial piezoelectric element 12 and the third radial piezoelectric element 20 in the right half shown in FIG. 2 are turned off. The return operation by the second set of the left half shown in FIG. 2 is performed from the initial state shown in FIG.
The second set of piezoelectric elements 2 shown in FIG.
By repeating steps 7, 32 and 40, these series of operations are repeated by the required return amount. This completes the one-hole machining on the work.

Next, the operation of making the clamping pressure of the electrode 4 into an electric signal and feeding this electric signal back to the pulse signals applied to the second radial direction piezoelectric elements 12 and 32 and the third radial direction piezoelectric elements 20 and 40 will be described. , As described below. As shown in FIG. 2, the electrode feeding device 1 has a bilaterally symmetric configuration with the hole 3 as the center, and the operation is the same on the left and right except for the direction in which the electrode 4 is fed back. Further, the clamping operation of the electrode 4 by the second radial direction piezoelectric element 12 and the third radial direction piezoelectric element 20 in the right half is different only in the timing of clamping, and therefore, for convenience of description, first, in the right half of the hole 3, The feedback operation to the second radial piezoelectric element 12 will be described.

The pulse signal generated by the pulse signal generation circuit 61 shown in FIG. 1 is supplied to the phase conversion circuit 62.
In the phase conversion circuit 62, the pulse signal generation circuit 61 generates pulse signals having different phases to be applied to the first axial piezoelectric element 7, the second radial piezoelectric element 12 and the third radial piezoelectric element 20 shown in FIG. Convert the pulse signal. The pulse signals having different phases are amplified by the amplifier circuits 63 and 64 shown in FIG.
And 65 to be amplified to a voltage necessary for the expansion and contraction operation of the first axial piezoelectric element 7, the second radial piezoelectric element 12 and the third radial piezoelectric element 20, and the first axial piezoelectric element 7, It is applied to the second radial piezoelectric element 12 and the third radial piezoelectric element 20.

The second radial piezoelectric element 12 repeats expansion and contraction in response to the pulse signal 201 shown in FIG. Second shown in FIG.
The expansion / contraction speed of the radial piezoelectric element 12 is determined by the frequency of the pulse signal 201 shown in FIG. 6, and the strength of the pressure for clamping the electrode 4 shown in FIG. 1 is determined by the voltage of the pulse signal 201. Next, the pressure at which the electrode 4 is clamped according to the expansion / contraction of the second radial piezoelectric element 12 is detected by the pressure sensor 50, and is output as a pressure sensor output signal 202 of an electric signal, as shown in FIG. The pressure sensor output signal 202 is amplified to a predetermined voltage by the amplifier 71 shown in FIG. 1, averaged by the low pass filter 72, and output as an average pressure signal 203 shown in FIG. The difference between this average pressure signal 203 and the reference voltage value indicating the predetermined clamp pressure of the electrode 4 supplied from the reference voltage generating circuit 73 shown in FIG. 1 is taken, and this difference voltage is fed from the phase converting circuit 62 to the amplifying circuit 65. Is fed back to the pulse signal supplied to. In the amplifier circuit 65, the voltage of the pulse signal applied to the second radial direction piezoelectric element 12 is controlled according to the differential voltage so that the electrode 4 can be clamped at a predetermined pressure.

As a result, the predetermined clamping pressure of the electrode 4 corresponding to the reference voltage value set by the reference voltage generating circuit 73 can be held, and the reference voltage value can be changed by the reference voltage generating circuit 73 to obtain a desired pressure. The electrode 4 can be clamped with. The feedback operation to the third radial piezoelectric element 20 is the same as the second radial piezoelectric element 12 except that a pulse signal having a phase different from that of the second radial piezoelectric element 12 is applied.
Is the same as the feedback operation to. The operations of the third radial piezoelectric element 20, the pressure sensor 52, the amplifier circuit 81, the low-pass filter 82, and the reference voltage circuit 83 are the same as those of the second radial piezoelectric element 12, the pressure sensor 50, and the amplifier circuit 7, respectively.
1 corresponds to the operation of the low pass filter 72 and the reference voltage circuit 73. Also, the feedback operation of the right half of the hole 3 has been described, but the feedback operation of the left half is the same as the feedback operation of the right half.

According to the first embodiment, it is possible to feed the piezoelectric element 7 in the right direction in FIG. 2 by the extension amount of the piezoelectric element 7 by the on / off combination operation of the three piezoelectric elements 7, 12, 20.
The required amount can be sent out by repeating this. The precision of the position adjustment of the electrode 4 can be improved by analogly controlling the voltage applied to the piezoelectric element 7 during the energization processing.

When the electrode is attached or detached, the electrode 4 is pressed or released by the axial expansion or contraction of the piezoelectric element instead of the radial expansion or contraction of the piezoelectric element, so that a large amount of expansion or contraction can be secured in the axial direction, so that an electrode having a small diameter can be accurately applied. You can grab and release. Moreover, since the electrodes are pressure-bonded or separated by the axial expansion / contraction operation of the laminated piezoelectric elements, it is possible to accurately grasp and separate the electrodes having a small diameter.

Since a large amount of expansion or contraction can be secured in the axial direction of the laminated piezoelectric elements when the electrodes are fed, the electrodes can be fed accurately. By repeating the feeding operation, the feeding amount of the electrode can be adjusted appropriately. In addition, the piezoelectric element groups 7, 12, 20 and 27, 32, 4 which are separate at the time of feeding and at the time of returning
With 0, individual control at the time of feeding and returning is possible, and precise control of the feeding amount and the returning amount is possible. Further, during analog control of the piezoelectric element in the axial direction, it is not necessary to re-hold the electrodes by the two radial piezoelectric elements, so that dead time can be reduced and the responsiveness of the electrode can be improved.

Further, as an electrode feed drive system using this apparatus, the drive frequency is in a region other than a general control region, in which the drive frequency is matched with a higher-order resonance frequency exceeding the break point frequency (cutoff frequency) of the system. It is possible to control the feed of the electrodes with. Therefore, when the resonance frequency of the first piezoelectric element is used, the amount of displacement per electrode step increases, and it is possible to apply high-frequency vibration to the electrode. At the resonance frequency, control has generally been impossible because a phase delay occurs with respect to the control signal. However, in the case of this device, since the response delay (-90 °) of the piezoelectric element is added to the delay of the secondary system (-90 °) at the resonance frequency, the system delay is delayed by -180 ° as a whole. Therefore, the phase of the control signal with respect to the fluctuation of the gap voltage between the electrode and the work is set to −18.
By reversing it by 0 °, the same control as the conventional one is possible.

Further, since the electrode 4 is linear, the electrode is continuously replenished and fed even if the electrode is worn, so that the frequency of replacement work at the time of electrode wear can be reduced, and frequent electrode replacement work can be performed. Is unnecessary, and maintenance and inspection work is easy. Next, a second embodiment of the electric-discharge machining electrode feeding device of the present invention is shown in FIG. In the second embodiment, the output signals output from the low-pass filters 72 and 82 are output to the arithmetic circuit 7.
4 and 84, and the difference from the reference voltage value set in the program stored in the arithmetic circuits 74 and 84 is taken, and the difference voltage passes through the amplifier circuits 75 and 85 and the amplifier circuit 65,
It is fed back to the pulse signal supplied to 64.
Thereby, the clamp pressure of the electrode 4 corresponding to the reference voltage value set by the arithmetic circuits 74 and 84 can be held. The reference voltage value can be changed by a program in the arithmetic circuits 74 and 84.

The rest of the configuration and operation are the same as in the first embodiment, so description will be omitted. In the above-described first and second embodiments, an example using two sets of piezoelectric element groups has been shown, but it goes without saying that the present invention can be realized with only one set of piezoelectric element groups.

[0031]

As described above, according to the electric-discharge machining electrode feeding apparatus of the present invention, the pressure detecting means for measuring the pressure at which the piezoelectric element clamps the electrode by the expansion and contraction operation is provided.
By feeding back the pressure signal from the pressure detecting means to the pulse signal applied to the piezoelectric element, it is possible to hold the clamping of the electrode at a predetermined pressure over the entire frequency range.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a control system of an electric-discharge machining electrode feeder according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a first embodiment in which the electric-discharge machining electrode feed device of the present invention is applied to an electrode-feed device for a hole-cutting electric discharge machine.

FIG. 3 is a view on arrow III in FIG.

FIG. 4 is a view on arrow IV in FIG.

FIG. 5 is an explanatory diagram showing an electrode feeding operation and an on / off state of each piezoelectric element according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an output signal output from the pressure sensor with respect to a pulse signal input to the radial direction piezoelectric element according to the first embodiment of the present invention and an average value of the output signals.

FIG. 7 is a sectional view showing an electrode-feeding device for electric discharge machining according to a second embodiment of the present invention.

[Explanation of symbols]

2 Housing 4 Electrode 7 First Axial Piezoelectric Element 8 Case 12 Second Radial Piezoelectric Element 14, 15 Electrical Insulator (First Electrical Insulator) 18 Housing 20 Third Radial Piezoelectric Element 22, 23 Electrical Insulator ( 2 electrical insulator) 27 first axial piezoelectric element 32 second radial piezoelectric element 40 third radial piezoelectric element 42, 43 feeding electrode (first feeding electrode) 41, 44 feeding electrode (second feeding electrode) 50 pressure Sensor (first pressure detection means) 52 Pressure sensor (second pressure detection means) 71 Amplifier (first voltage feedback means) 72 Low-pass filter (first voltage feedback means) 73 Reference voltage generation circuit (first Voltage feedback means) 81 amplifier (second voltage feedback means) 82 low-pass filter (second voltage feedback means) 83 reference voltage generation times (Second voltage feedback means)

Front Page Continuation (72) Inventor Naotake Mori 2-12-1, Kukata, Tenpaku-ku, Nagoya-shi, Aichi Prefecture Toyota Institute of Technology (56) Reference JP-A-3-187144 (JP, A) JP-A 1-225380 (JP, A) JP-A-2-297003 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B23H 7/10 B23H 7/02

Claims (2)

(57) [Claims] 1. A laminated first axial-direction piezoelectric element housed in a housing and provided so as to be capable of expanding and contracting in parallel with an axial direction of an electrode, and fixed to a free end of the first axial-direction piezoelectric element, and attached to the housing. On the other hand, a case that is movable in the axial direction of the electrode, a laminated second radial piezoelectric element that is housed in the case and that can expand and contract in the radial direction of the electrode, and abuts on the free end of the second radial piezoelectric element. A first electrical insulator that crimps and separates electrodes in response to expansion and contraction operations of the second radial piezoelectric element, and the first electrical insulator in response to expansion and contraction operations of the second radial piezoelectric element The first pressure detecting means for measuring the pressure at which the insulator crimps and separates the electrode, converting the pressure into an electric signal and outputting the electric signal, and the electric signal output from the first pressure detecting means for the second radial piezoelectric element. The voltage applied to the device A first voltage feedback means for feedback, a stacked third radial piezoelectric element housed in the housing and capable of expanding and contracting in the radial direction of the electrode, and contacting a free end of the third radial piezoelectric element, A second electrical insulator that crimps and separates electrodes in response to expansion and contraction operations of the third radial piezoelectric element; and the second electrical insulator in response to expansion and contraction operations of the third radial piezoelectric element Measures pressure for pressing and releasing the electrode, converts the pressure into an electric signal and outputs the electric signal, and an electric signal output from the second pressure detecting means to the third radial piezoelectric element. Second voltage feedback means for feeding back the applied voltage; and the step of sending the electrode in the processing direction, the first axial direction
When the piezoelectric element extends in the processing direction, the first electrical insulation
The rim body crimps the electrode, and the second electric insulator is the electric electrode.
The pole is separated and the first axial piezoelectric element contracts.
When the first electrical insulator leaves the electrode,
2 The electrical insulator is pressure-bonded to the electrode,
In the step of returning from the
The first electrical insulator extends over the electrode when elongated in a direction.
Withdrawal, and the second electrical insulator contact and pressed the pre-Symbol electrode
When the first axial piezoelectric element contracts,
The electrical insulator crimps the electrode and the second electrical insulator
A voltage is applied to each piezoelectric element so as to separate from the electrode.
An electrode-feeding device for electric discharge machining, comprising: an applying unit . 2. The housing is housed in the axial direction of the electrode.
Laminated first axial direction piezoelectric element provided so as to be capable of expanding and contracting in parallel
Is fixed to the free end of the first piezoelectric element and the housing.
A case that is movable in the axial direction of the electrode with respect to the ging, and a stack that is housed in the case and that can expand and contract in the radial direction of the electrode
The second radial piezoelectric element of the mold and the free end of the second radial piezoelectric element,
The electrodes according to the expansion and contraction of the directional piezoelectric element
The first electrical insulator that is crimped and released and the second radial piezoelectric element that responds to the expansion and contraction operations.
The pressure at which the first electrical insulator presses and releases the electrode.
The first pressure detector that measures the force, converts it into an electrical signal and outputs it.
The electric signal output from the knowing means and the first pressure detecting means is
Feedback to the voltage applied to the second radial piezoelectric element
And a first voltage feedback means for allowing the voltage to be accommodated in the housing and expandable / contractible in the radial direction of the electrode.
The third radial piezoelectric element of the laminated type and the third radial piezoelectric element are in contact with the free end of the third radial piezoelectric element,
The electrodes according to the expansion and contraction of the directional piezoelectric element
A second electrical insulator that is crimped and released and a device that responds to the expansion and contraction operations of the third radial piezoelectric element.
The second electrical insulator then presses and releases the electrode.
A second pressure sensor that measures force, converts it into an electrical signal and outputs it.
And an electric signal output from the second pressure detection means
Feedback to the voltage applied to the third radial piezoelectric element
In the step of sending the electrode in the machining direction , the second voltage feedback means for causing the first axial direction
When the piezoelectric element extends in the direction opposite to the processing direction,
The first electrical insulator separates from the electrode and the second electrical insulator
The body is pressure-bonded to the electrodes, and the first axial piezoelectric element
Crimping but when contracted, the first electrical insulator and the electrodes
The second electrical insulator separates from the electrode,
In the step of returning the
When the element extends in the direction opposite to the processing direction, the first electric current is applied.
The gas insulator is pressure-bonded to the electrode, and the second electrical insulator is
The electrode is separated and the first axial piezoelectric element contracts.
When the first electrical insulator separates from the electrode,
Note that the second electric insulator is formed by pressing each piezoelectric element so as to press the electrodes.
And a means for applying a voltage to the child.
Electrode feed device for electrical discharge machining.