JPH06339782A - Nozzle for precise manufacture - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is a nozzle that measures the distance between a tool part and a work piece for precision machining of a non-metallic component, does not require a contact formation attachment, and is a sturdy mechanical structure. It is to provide a nozzle having a structure. [Structure] The nozzle 1 is composed of a nozzle body 2 and a center electrode 27 arranged at the tip of the nozzle body 2. The central electrode 27 is in a plane perpendicular to the longitudinal axis A of the nozzle body 2 and is electrically insulated from the central electrode 27 and at least two electrodes 38, 36 electrically insulated from each other.
It is surrounded by. The capacitance between the center electrode 27 and the outer electrode 36 allows the distance between the nozzle and the part made of electrically non-conductive material to be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precision machining nozzle which is attached to a tool and measures the distance between the work and the tool so that the distance between the work and the tool is kept constant.

[0002]

2. Description of the Related Art In recent years, high precision processing of products has been demanded in all industrial fields. In order to respond to this demand, the development of processing technology is remarkable, and one of the high-precision processing technologies is, for example, laser processing. This laser processing is performed by irradiating a cutting portion of a work with a laser beam, and high energy can be concentrated in a very narrow range. Therefore, high-precision processing is possible.

By using this laser cutting technique, both metal and non-metal parts can be precision processed. In addition, the distance between the tool portion, which is the laser beam transmitter, and the workpiece must be controlled to a predetermined value in consideration of the convergence of the laser beam. In order to manage this distance, a device for measuring the capacitance between the center electrode provided on the tool part and the work has been developed. The center electrode may be provided on a nozzle that is removably attached to the tool. When the work is made of metal, the work itself can be used as a counter electrode and the capacitance between the work and the center electrode can be measured. On the other hand, when the work is a non-metal component, the component itself cannot be used as a counter-electrode when the distance between the component and the center electrode is measured from the capacitance. Therefore, until now, in order to perform precision machining of non-metallic parts, a contact forming attachment has been prepared. The contact forming attachment is arranged on a tool part or a nozzle,
It moves with this structural unit. When the contact forming attachment, for example, a metal ring is continuously pressed against the surface of the non-metal component and placed under the center electrode to change the shape of the surface of the non-metal component. It is possible to measure the change in the distance between the attachment and the tool from the capacitance.

[0004]

However, in particular,
If the surface of the component is easily scratched, there is a risk that the surface of the component will be scratched by the contact forming attachment.
In addition, rubbing the surface of the component can build up debris on the component surface, which can adversely affect the laser cutting process. Moreover, the contact-forming attachments need to be mechanically adjusted, which can be quite time consuming. Moreover, the attachment is very vulnerable to lateral mechanical loads and is susceptible to damage.

It is an object of the present invention to provide a robust mechanical tool or nozzle of the type described above for precision machining non-metallic parts, without the need for contact forming attachments. To do.

[0006]

In the nozzle according to the present invention, the center electrode is electrically insulated from the center electrode, and at least two outer electrodes electrically insulated from each other are provided, Characterized by being enclosed in a plane perpendicular to the longitudinal axis of the nozzle body.

When an appropriate electric potential is applied to the center electrode and the outer electrode, for example, from the center electrode to the next electrode with one center electrode among the outer electrodes and the next electrode, a line of electric force is applied. In particular, the morphology of this line of electric force changes as the nozzle approaches the component, resulting in a corresponding change in capacitance between the center electrode and the outer electrode. This change in capacitance can be measured metrologically by a conventional method to infer the distance between the center electrode and the component.
A center electrode and one outer electrode next to the center electrode,
A shielding potential is applied to the electrode located between the outer electrode and the center electrode in order to maximize the morphology of the electric field lines between. In order to change the electric field, it is possible to leave one from the central electrode and further surround the next outer electrode with a shielding potential.

The entire electrode arrangement has a relatively compact structure, and is therefore resistant to mechanical loads. Since the capacitance measurement is performed in a non-contact manner, there is no risk of scratching the surface of the material.

As an advantageous refinement of the invention, the outer electrode concentrically surrounds the central electrode. The central electrode is formed in radial symmetry and has a central conduit through which the laser beam passes. Therefore, since the outer electrodes are arranged concentrically, a reaction having radial symmetry is obtained. Further, the open end faces of the center electrode and the outer electrode are preferably on the same plane.

As a very advantageous refinement of the invention, the center electrode is inserted in the open end face of the carrier. The carrier is one of the outer electrodes.

The center electrode is attached to the carrier on the nozzle body. The carrier itself has a central conduit in the hollow, for example a conical hollow, through which the laser beam passes. The carrier is made of a conductor and is electrically insulated from at least the center electrode and the outer electrode or the annular electrode. The carrier receives a screening potential, but may also have a conductive connection with the nozzle body. In this way, a reliable shield is obtained behind the center electrode, so that no parasitic capacitance occurs between the center electrode and the outer electrode.

The free end surface of the carrier is preferably provided with a circumferential step for receiving at least one outer electrode, in other words an annular electrode. The outer electrode, in other words the annular electrode, can be fitted axially in the carrier until the free end faces of the electrode and the element are coplanar.

In order to electrically insulate the center electrode from the carrier and further the carrier from the outer electrode, a surface coating for insulation is provided on at least one side of each contact. Such a surface coating may be applied to the carrier, for example. Examples of surface coatings for insulation include ceramic layers or anodized aluminum layers, provided the parts to be coated are made of a suitable material. Alternatively, plasma CVD coating may be used, which uses plasma enhanced chemical (vapor) deposition. A surface coating for insulation may be applied to a portion of the carrier other than the above-mentioned contact portion,
This surface coating must not be applied to the part that contacts the nozzle body. This is because the shield potential is transmitted from the nozzle body to the carrier at this portion. A Teflon coating may be used as a surface coating for insulation.

Further, the center electrode and the outer electrode may be coated as described above so that a short circuit does not occur between components of different potentials when a conductor accidentally contacts the sensor. For example, the electrodes (center electrode, outer electrode) may be completely covered with a surface coating for insulation. According to this method, the end surface of the electrode can be protected as a matter of course.

According to another advantageous refinement of the invention, a conduit is provided in the carrier for making an electrically conductive connection with the central electrode. Insert the center electrode firmly into the carrier,
It can be connected to a lead wire running through the conduit. In principle, one lead is sufficient. The leads are electrically isolated from the carrier so that there is no short circuit between them and the carrier. The ends of the lead wires, which appear on the rear end face of the carrier, extend further to form a contact surface.
The contact surface is a portion where a spring contact attached to the nozzle body abuts when the carrier is attached to the nozzle body. On the outside of the carrier, an annular flange may be provided for pressing the carrier onto the nozzle body by means of a coupling part, for example a coupling nut. A conduit for the lead wire as described above may be connected to the carrier to make a conductive connection with another electrode or the outer electrode.

Thus, various electrode arrangements supported on the carrier can be attached to the nozzle body. For precision machining of metal parts, rather than non-metal parts, the nozzle can be easily replaced by replacing the carrier with another carrier with a modified electrode arrangement.
This is one of the types described, for example, in German Patent Application No. P4201640. In other words, the standardized nozzle body can be connected to a combination of various carriers and electrodes, which allows an economical use of the nozzle.

If the center electrode is surrounded by only two outer electrodes, the outermost one of these electrodes may be provided with radial through holes. A screw for fixing a lead wire for applying a desired electric potential to the electrode can be screwed into the radial through hole. However, a method of transmitting a potential to the electrodes by using a spring contact bracket is also conceivable. The spring contact bracket is supported on the one hand on the nozzle body with suitable resilience and the other free end is pressed against the outer rim of the outer electrode, for example. When the carrier is attached to the nozzle body, this spring contact bracket automatically contacts the outermost electrode located at the tip of the carrier. Therefore, the carrier to which the electrodes are attached can be easily attached to the nozzle body. It is also possible to transfer the electric potential to the outermost electrodes via leads through a conduit inside the carrier.

According to another very advantageous refinement of the invention, it is possible to mount the mutually insulated outer electrodes on the central electrode as one piece. The outer electrodes used include, for example, two or three annular electrodes located concentrically and firmly connected to each other. If this part is mounted on a sensor for an existing metal, the sensor can be replaced very easily for use on non-metals.

Even a cutting head which is not equipped with a normal sensor can be easily mounted and replaced according to its purpose. For example, as described above, the integral part may be attached to the tip of the metal nozzle body used for cutting. In this case, the tip of the metal nozzle body can be regarded as the center electrode. If the metallic nozzle body is already at chassis or ground potential, the required measuring signal and shielding potential can be utilized by the integral part.

Generally, the capacitance measurement is made between the center electrode and the outer electrode which is not adjacent to the center electrode in the case of the sensor according to the invention. Another electrode that can be used as a shield electrode may be installed between these outer electrode and center electrode. Further, the outside of the above-mentioned outer electrode may be surrounded by another shield electrode.
The shield electrode serves to shape the desired use for capacitance measurement or to focus in the form of lines of electric force. An active shield potential may be applied to the shield electrode for this purpose. The active shield potential is obtained by applying a measurement signal prepared for capacitance measurement to the shield electrode via an amplifier having a desired gain factor. The gain factor of the amplifier may be, for example, 1 or greater than 1.

According to another particularly advantageous refinement of the invention, in the case of the group consisting of the central electrode and of the outer electrodes one electrode from the central electrode and the next electrode (counter electrode), these electrodes One is the measurement signal (measurement potential)
To the other electrodes, a ground potential or a phase-shifted measurement signal can be applied. The phase shift is
It may be adjusted as desired, but may be 180 degrees, for example. The phase-shifted measurement signal is obtained by passing the actual measurement signal through an inverter circuit. Of course, the potential applied to the center electrode and the counter electrode is
Can be exchanged. The advantage of applying the measurement signal to the counter electrode and shifting or inverting the phase significantly reduces the effect of the metal being cut or underneath and located near the material. That is. Therefore, for example, an inverting amplifier (180
It will be readily accepted that costs such as (degrees of phase shift) are added.

The reason for reducing the influence of metal on the measurement result is understood from the fact that "the difference between the measurement signal and the measurement signal whose phase is shifted or inverted is larger than the difference between the measurement signal and the chassis potential". Will be done.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross section of the first embodiment of the nozzle according to the present invention in a plane including the axis. The nozzle 1
Is mainly composed of a nozzle body 2 and a carrier / electrode assembly 3 connected in a separable manner to it.

The nozzle body 2 is mainly composed of a conical nozzle portion 4 made of a conductor such as steel. A fixing sleeve 5 is located on the outer circumference of the thick end of the nozzle portion 4. The fixing sleeve 5 is formed in a cylindrical shape on the outer side and has a thread 6 on the outer circumference. Nozzle part 4
Since the fixing sleeve 5 and the fixing sleeve 5 are firmly connected to each other by, for example, a method such as bonding with an adhesive, the size of the support plate (not shown) is matched to the entire nozzle 1 by the screw thread on the outer surface. Can be inserted into the open hole. In that case, the stopper 7 of the fixing sleeve 5 comes into contact with the end of the opening from below. The nozzle 1 can be fixed to the support plate by screwing the threaded ring 8 into the external threads 6 and tightening the support plate with the fasteners 7 and the threaded ring 8. The fixing sleeve 5 may be made of, for example, an insulator, in which case the nozzle portion 4 is electrically insulated from the support plate.

Around the sharp end of the nozzle section 4 is an annular conduit 9 for receiving the lead wire. A coaxial socket (not shown) is inserted into the outer wall 10 of the annular conduit 9. On the outside, the coaxial socket can be connected to a coaxial cable. Since the annular conduit 9 is also made of a conductive material, the connecting portion of the shield conductor of the coaxial socket is directly electrically connected to the outer wall 10 of the annular conduit 9. In this way, the shielding potential is applied to the annular conduit 9 and further to the nozzle part 4 via the annular conduit 9. The nozzle part 4 and the annular conduit 9 are electrically conductively connected, for example, via a thread 11 on the outside of the nozzle part 4 into which the annular conduit 9 is screwed.

In the bottom surface 12 of the annular conduit 9, the contact 1
3 and 14 are inserted at a downward angle so as to point to the tip of the nozzle 1. The contacts 13 and 14 are, in particular,
The contacts 13 and 14 are electrically insulated from the annular conduit 9, in other words the bottom surface 12, by insulating sleeves 15 and 16 disposed therein. The contacts 13 and 14 each have spring contacts 17 and 18 on their distal faces facing the tip of the nozzle. The spring contacts 17 and 18 can move in the axial direction of the contacts 13 and 14. The lead wires 19 and 20 are the contacts 13.
And 14 connected to the end face on the side of the annular conduit 9. The lead wires 19 and 20 are in this case connected to the signal lead wire connection of the coaxial socket. The measurement voltage transmitted from the outside to the signal lead wire connecting portion is then applied to the lead wires 19 and 20 and the contacts 13 and 14.
Is transmitted to the spring contacts 17 and 18 via.

As already mentioned, the carrier-electrode combination 3 is located at the tip of the nozzle body 2. The carrier / electrode combination 3 comprises a carrier 21 made of a conductor. The carrier 21 has a cylindrical outer shape, and the nozzle body 2 side is cylindrical and has a central conduit 22 that tapers conically toward the opposite side. Carrier 2
1 is a shoulder 23 on the tip side of the nozzle body 2 or the nozzle portion 4.
Is attached to the nozzle body 2 by protruding into the cylindrical portion of the central conduit 22. Tip shoulder 2
3 also has a cylindrical profile and fits snugly into the cylindrical portion of the central conduit 22.

In order to press the carrier 21 against the nozzle body 2, in other words the nozzle part 4, an annular flange 24 is provided on the outer circumferential edge of the carrier 21, especially on the end face facing the nozzle part 4 side. ing. The coupling nut 25 is adapted to screw its inner thread onto the corresponding thread 26 on the outer peripheral surface of the nozzle body 2, and fits snugly on the circumferential flange 24. When the coupling nut 25 is tightened, the coupling nut 25 presses the carrier 21 against the nozzle body 2, so that the two parts are firmly connected.

The center electrode 27 is inserted into the end face (release face) of the carrier 21 having a cylindrical outer shape, which face does not face the nozzle body. The center electrode 27 has a cylindrical outer shape,
It has a central conduit 28. This central conduit 28
Continuing from the central conduit 22 of the carrier 21, it tapers conically towards the tip of the nozzle. The center electrode 27 is inserted into the carrier 21 such that its release surface is flush with the open end face 21 a of the carrier 21. The center electrode 27 is made of a conductor such as copper and is electrically insulated from the carrier 21. For this purpose, a thin insulating layer, for example a surface coating, may be applied to one of the contact parts of these two parts. Carrier 2
If 1 is made of aluminum, the surface may be coated with an anodized aluminum layer as the insulating layer. To ensure a firm support of the center electrode 27 in the carrier 21, both parts can be glued together, for example with an adhesive.

In order to make it possible to apply a measuring voltage to the central electrode 27, the central electrode 27 is lead 29 through conduits 31 and 32 located in the carrier 21.
And 30 are connected. The leads 29 and 30 are electrically insulated so that no short circuit occurs between them and the carrier 21. The free ends of the leads 29 and 30 extend to form a contact surface on the end face of the carrier 21 facing the nozzle body 2. These contact surfaces may be, for example, metallic disks 33 and 34. The lead wires 29 and 30 are respectively the metal disc 33.
And 34 mechanically and rigidly and electrically conductively connected.

The metal disks 33 and 34 are used for the carrier 2
1 is electrically insulated, again a surface coating for insulation is arranged between the respective parts, for example on the carrier 21. Metal disc 33
The positions of 34 and 34 are determined by the coupling nut 25 and the carrier 21.
Is selected so that when it is pressed against the nozzle body 2, it comes to the part where the spring contacts 17 and 18 are located. In this case, the spring contacts 17 and 18 press the metal disks 33 and 34, so that a conductive connection with the central electrode 27 is complete.

The release end surface 21a of the carrier 21 is further provided with a stepped portion 35 circumferentially. The circumferential step 35 has a circumferential lip and serves to receive the annular electrode 36. The annular electrode 36 has, for example, a rectangular cross section, and its axial and radial dimensions are such that the outer wall corresponds to the wall surface around the carrier 21 and the bottom surface corresponds to the free end face 21 a of the carrier 21, respectively. Stipulated in.

The annular electrode 36 is also electrically insulated from the carrier 21, again with a surface coating for insulation between the two parts, for example on the carrier 21. In order to insulate the annular electrode 36 from the outside,
A surface coating for insulation may be applied to the entire surface of the annular electrode 36. It is desirable to bond the annular electrode 36 and the carrier 21 to each other with an adhesive. In particular, it is desirable to use a heat resistant adhesive that is also used to bond the center electrode 27. In order to apply an appropriate electric potential to the annular electrode 36,
Radial through holes 37 are provided in the annular electrode 36. Screws can be screwed into the radial through holes 37 to secure a lead wire (not shown) to the annular electrode 36.

As can be deduced from the above description, the electrodes are arranged at the open end of the carrier 21, firstly the center electrode 27. The center electrode 27 is surrounded by two electrodes in a plane perpendicular to the vertical axis A of the nozzle body 2. These two electrodes are electrically insulated from the center electrode 27 and also electrically insulated from each other. Of the two electrodes, the first electrode is a portion adjacent to the center electrode 27 and indicated by reference numeral 38. Also, this first
The electrode of is also the remaining portion in which a concave portion for inserting the center electrode 27 and the annular electrode 36 into the open end surface 21a of the carrier 21 is formed. The annular electrode 36 is the above-mentioned second electrode.

For example, a chassis potential is applied to the annular electrode 36, while a shielding potential is applied, in particular the nozzle section 4 and the annular conduit 9.
May be applied to the carrier 21 and thus also to the outer electrode 38 via. The sensor potential is the lead wire 29.
And 30, the spring contacts 17 and 18, the contacts 13 and 14, and the leads 19 and 20 through the center electrode 2
Added to 7. However, the annular electrode 36 may be applied with a potential whose phase is shifted or inverted with respect to the sensor potential. This phase shifted or inverted potential is obtained by passing the sensor potential through a phase shift amplifier or a phase inverting amplifier. of course,
The potential of the center electrode 27 and the potential of the annular electrode 36 can be exchanged.

2 and 3 are enlarged views of the carrier 21 and the annular electrode 36, respectively. In both figures, each component is designated by the same reference numeral as in FIG.

According to FIG. 2, the carrier 21 has two cylindrical recesses 39 and 40 on its end face 21b facing the nozzle body 2 for receiving the metal disks 33 and 34 shown in FIG. And have. The conduits 31 and 32 start from the cylindrical recesses 39 and 40 and extend downwards to a cylindrical recess 41 on the other end face of the carrier 21. The cylindrical recess 41 is for properly receiving the cylindrical center electrode 27. The cylindrical center electrode 27 has dead-end holes 42 and 43. The dead end holes 42 and 43 are located on opposite sides of the conduits 31 and 32 and are for fixing lead wires (not shown in FIG. 2) passing through the conduits 31 and 32.

The carrier 21 shown in FIG. 2 may be provided with a surface coating for insulation. For example, if the carrier 21 is made of aluminum, an anodized aluminum layer, a ceramic layer, a Teflon layer, or a layer of the same kind may be applied to the entire surface. In order to make an electrical contact between the carrier 21 and the portion of the shoulder 23 on the tip side of the nozzle portion 4,
Only in the cylindrical portion of the central conduit 22 is this insulating layer removed. In this way, the shielding potential can be conducted to the outer electrode 38 via the carrier 21. on the other hand,
The surface coating of the carrier 21 described above also achieves insulation from the metal disks 33 and 34 and from the center electrode 27.

As further shown in FIG. 2, the carrier 2
Finally, the outer electrode 38 has the shape of a cylindrical ridge because there is an annular stepped portion 35 on the circumferential edge of the open end face 21a of No. 1. The outer diameter of the outer electrode 38 matches the inner diameter of the annular electrode 36. The annular electrode 36 is pushed over the outer electrode 38 until it faces the circumferential step 35. Like the center electrode 27, the annular electrode 36 may be made of copper.

FIG. 4 shows a second preferred embodiment of the nozzle according to the present invention.
The example of is shown. Here, the center electrode 27 is 3
It is surrounded by outer electrodes 38, 44 and 45 having the same center. Otherwise, the nozzle structure is the same as already described with reference to FIG. Therefore, the same parts as in FIG. 1 are designated by the same reference numerals and will not be described repeatedly here.

In the second embodiment shown in FIG. 4, the outer electrodes 44 and 45 are electrically isolated from each other, and in particular each electrode is provided with a suitable surface coating. The electrodes 44 and 45 may be glued together, for example to form one structural unit. Leads 44a and 45a for corresponding connections are attached to apply the appropriate electrical potentials to the electrodes 44 and 45.

An example of wiring of potentials to these electrodes will be given below. The sensor potential is applied to the center electrode 27. To the outer electrode 38, a shield signal obtained by passing the sensor signal through an amplifier having a desired gain factor is applied. The gain factor of the amplifier may be, for example, 1 or greater than 1. The chassis potential or the shield potential with the phase reversed is applied to the counter electrode 44.
Added to. This is obtained by applying the sensor signal to electrode 44 via a phase inverting amplifier. Further, for the sensor signal, for example, the shield signal amplified twice is further applied to the electrode 45. In this case, the capacitance measurement is performed between the center electrode 27 and the electrode 44. The potentials applied to these electrodes can be exchanged.

A preferred third embodiment of the nozzle according to the present invention is shown in FIG. In this example, a nozzle body 46 made of metal, for example, copper is shown. Tip portion 47 of nozzle body 46
The outer shape of is cylindrical. On the tip 47 which can function as a center electrode, two or three annular electrodes 48 and 49 or 48 and 49 or 50 having the same center in the axial direction of the nozzle are formed. The structural unit is installed. When the nozzle body 46 and the center electrode 47 are already at the chassis potential, the measurement signal is sent to the lead wire 49.
It can be added to the electrode 49 via a. At this time, the shield potential is applied to the annular electrode 48 via the lead wire 48a, but may be optionally applied to the electrode 50 via the lead wire 50a.

A fourth preferred embodiment of the nozzle according to the present invention will be described in detail below with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals and will not be described repeatedly here.

Unlike the first embodiment shown in FIG. 1, the nozzle portion 4 has a flat flange 4a at the upper portion or the inlet portion. Around the flange 4a, a screw thread 4b for screwing the nozzle into a holder (not shown) is cut. The flange 4a has a conductive contact bridge therein and supports a lead wire connector 51 made of an insulator at one point. A spring contact 52 is attached to the upwardly projecting end of the contact bridge, while the downwardly projecting end of the contact bridge is connected to the lead wire 19. This ensures that this electrically conductive connection is insulated from the nozzle part 4. The spring contacts 52 make contact with the chassis connection when the nozzle body 2 is inserted into a holder (not shown).

As already mentioned, the spring contact 17 is electrically conductively connected to the lead wire 19 or the spring contact 52 and also to the lead wire 29. In this example, the lead wire 29 is in contact with the annular electrode 36 in order to apply a chassis potential, which is connected via the spring contact 52, to the annular electrode 36. Therefore, the lead wire 29 is
It passes through a conduit 31a in the carrier 21. In this example, the conduit 31
a extends parallel to the outer wall of the carrier 21 or the central axis A. The measurement signal is further applied to the center electrode 27 via the lead wire 30. The lead wire 30 is similar to the other examples.
Extends through conduit 32.

[0048]

As described above, according to the present invention, the distance between the work and the tool can be measured in a non-contact manner even when the work is a non-metal. This prevents the surface of the non-metallic work piece from being damaged by the contact of the attachment for contact formation. Further, it is possible to prevent the attachment for contact formation from receiving a thrust force from the surface of the work and thereby damaging the attachment. Further, the nozzle for measuring the distance between the work and the tool can be easily attached and detached. As a result, it is possible to prepare the non-metal working one and the metal working one in advance, and select and use the nozzle suitable for the target work.

[Brief description of drawings]

FIG. 1 is a diagram showing a first preferred embodiment of a nozzle according to the present invention and is a cross-sectional view taken along a plane including an axis of the nozzle.

FIG. 2 is a cross-sectional view of a surface including a shaft of a carrier inserted into the nozzle portion of the first embodiment.

FIG. 3 is a cross-sectional view of a surface including an axis of an outer annular electrode of the first embodiment.

FIG. 4 is a view showing a second preferred embodiment of the nozzle according to the present invention and is a sectional view taken along a plane including the axis of the nozzle.

FIG. 5 is a view showing a third preferred embodiment of the nozzle according to the present invention and is a sectional view taken along a plane including the axis of the nozzle.

FIG. 6 is a view showing a fourth preferred embodiment of the nozzle according to the present invention and is a sectional view taken along a plane including the axis of the nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Nozzle body 3 Coupling body of carrier and electrode 4 Nozzle part 9 Annular conduit 13, 14 Contact 17, 17 Spring contact 21 Carrier 22 Central conduit 27 Central electrode 28 Central conduit 36 Annular electrode 38 Outer electrode 44 , 45 outer electrode

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location G01B 7/14 Z 9106-2F

Claims (19)

[Claims] 1. A nozzle for precision machining of a component, comprising: a nozzle body; and a center electrode arranged at the tip of the nozzle body, wherein the center electrode is electrically insulated from the center electrode. A nozzle that is enclosed in a plane perpendicular to the longitudinal axis of the nozzle body by at least two outer electrodes that are open and electrically insulated from each other. 2. The nozzle according to claim 1, wherein the outer electrode surrounds the center electrode in a concentric circle. 3. The nozzle according to claim 1, wherein the open end faces of the center electrode and the outer electrode are on the same plane. 4. Nozzle according to claim 2 or 3, characterized in that the central electrode is inserted inside the open end face of the carrier forming one of the outer electrodes. . 5. The nozzle according to claim 4, wherein the carrier has an annular step on its open end for receiving at least another outer electrode. 6. Nozzle according to claim 4 or 5, characterized in that there is a conduit in the carrier for electrically conductive connection with one of the central electrode or the outer electrode. . 7. The nozzle according to claim 4, wherein:
Nozzle characterized in that an annular flange is provided on the outside of the carrier in order to press the carrier against the nozzle body by a coupling member. 8. The nozzle according to claim 7, wherein a spring contact is attached to the nozzle body, and the spring contact is provided when the carrier is pressed against the nozzle body.
A nozzle connected to a lead wire extending in the carrier. 9. The nozzle according to claim 8, wherein the lead wire in the carrier extends to the spring contact side to form a contact surface. 10. The nozzle according to claim 1, wherein the mutually insulated outer electrodes can be attached to the center electrode as an integral part. 11. The nozzle according to claim 10, wherein the center electrode is formed at a tip of a metal nozzle body. 12. The nozzle according to claim 1, wherein at least an outer electrode is provided with a surface coating for insulation. 13. The nozzle according to claim 12, wherein the surface coating for insulation is a ceramic layer. 14. The nozzle according to claim 12, wherein the insulating surface coating is an anodized aluminum layer. 15. The nozzle according to claim 12, wherein the surface coating for insulation is plasma CVD coating. 16. The nozzle according to any one of claims 1 to 15, wherein in the case of a group consisting of the center electrode and one of the outer electrodes, one electrode from the center electrode and the next electrode, one of these electrodes is provided. Nozzle characterized in that a measurement potential can be applied to the other electrodes such as a ground potential or a phase-shifted measurement potential. 17. The nozzle according to claim 16, wherein the phase shift is 180 degrees. 18. The nozzle according to claim 1, wherein an active shield potential obtained from a measurement signal can be applied to an electrode of the outer electrodes that is connected as a shield electrode. Characteristic nozzle. 19. The nozzle according to claim 18, wherein the shield potential is amplified with respect to the measurement signal.