KR101465200B1 - Receiving device, especially for a nozzle element of a laser processing head - Google Patents

Abstract

The present invention relates to a storage device (52), particularly a nozzle member storage device of a laser machining head, characterized by comprising an annular insulator member (18) and a material having a thermal expansion coefficient different from that of the material of the insulator member And an insert (20) disposed in a central recess portion (26) of the insulator member (18) for removably receiving the nozzle member (38). (20) between the inner wall surface of the insulator member (18) and the outer wall surface of the insert (20) inside the central recess portion (26) in order to maintain the electrical characteristics of the accommodating device (52) A composite material is provided. This composite material compensates for the difference between the expansion of the insert 20, particularly in the radial direction, and the expansion of the insulator member.

Laser machining heads, nozzle holders, insulation, thermal expansion, composites

Description

TECHNICAL FIELD [0001] The present invention relates to a nozzle holding member for a nozzle member of a laser machining head,

The present invention relates to a receiving apparatus, and more particularly, to a receiving apparatus for a nozzle member of a laser machining head.

Using a laser machining head, the workpiece is machined by a laser beam in such a way that, for example, a welding or cutting operation is carried out. For this purpose, the laser machining head is positioned in a manner which is relatively suitable for the workpiece. The positioning is made through a spacing device, wherein the distance between the nozzle member and the workpiece can be measured, for example, on a capacitive path, and a nozzle member forming a capacitor with a workpiece functioning as a capacitor electrode for this, Voltage is applied. In this case, the nozzle member mounted on the housing of the laser processing head must be insulated from the housing.

An insulating member for fixing the nozzle member to the laser machining head is often used and its function is generally well known.

For example, DE 90 04 335 U1 discloses a storage device with a ceramic insulator. The insulator includes a recess portion for receiving a metal insert having a female screw for screwing a metal nozzle member for a laser machining head. At this time, the insert is press-fitted in a shape-locked manner in a threadless recess in the insulator. The nozzle member can be replaced by tightening or loosening the screw in the laser machining head by using the accommodating device provided with the insert.

US 6,025,571 discloses a storage device having an annular insulation portion of a ceramic material and a metal insert mounted in the central recess portion. In which case the insert is releasably secured by screws extending through holes provided axially within the insulator. This not only eliminates the drop of the insert caused by the thermal or mechanical load, but also facilitates easy replacement of the insert. The nozzle member can again be screwed into the metal insert.

A typical feature of the above insulation is in a metal insert that penetrates into the ceramic insulator and is centered in a shape-locked fashion. However, this type of shape locking is problematic in situations where the metal insert is strongly heated. This is particularly true when processing a reflecting material with high laser power and when plunge cutting for cutting. When the metal insert is strongly heated, the metal insert expands, which causes a tensile load on the ceramic insulation, and the insulation can be broken as a result of overloading.

Ceramic materials generally have a relatively low tensile strength and because only the materials available for electrical properties and the cost of ceramic materials are very limited, only the proper thermal load capacity of the structure can be provided using conventional means .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new accommodating apparatus in which load accommodation capacity is increased while maintaining electrical characteristics.

This object is achieved by a storage apparatus according to claim 1. Preferred embodiments and improved embodiments of the present invention are described below.

According to the present invention, there is provided an insulator comprising an annular insulator member, an insert mounted in a central recess portion of the insulator member for removably accommodating a nozzle member made of a material having a thermal expansion coefficient different from that of the insulator member, There is provided a receiving apparatus including a composite material provided between an inner wall surface of an insulator member and an outer wall surface of an insert in the insert. The composite material described above compensates for the difference between the expansion of the insert, especially in the radial direction, and the expansion of the insulator member.

In other words, the accommodating device for accommodating the nozzle member includes a ring-shaped insulator member as well as a metal insert which is mounted in the central recess portion of the insulator member, and between the outer wall surface of the metal insert and the inner wall surface of the insulator member There is provided a receiving apparatus in which, for example, an intermediate space for accommodating a hard solder or an adhesive is present. In this connection, the insert can be screwed into the insulator member. By doing so, the forces acting in the radial direction towards the outside, i.e. the shear forces in the circumferential direction of the insert, which can be caused by the different expansion of the insert and the insulator member upon heating, are compensated or absorbed by the composite material, The possibility that the manufactured insulator member can be destroyed is minimized.

In this regard, the composite material is preferably a high temperature adhesive such as an epoxy resin adhesive or a ceramic adhesive in view of the high temperature that occurs.

And, for good ceramic-metal bonding, the high temperature adhesive preferably contains an inorganic filler consisting of aluminum oxide, silicon oxide or magnesium oxide. In addition, for good thermal conductivity, a filler made of aluminum nitride may be added.

According to another preferred embodiment, the composite material may be a hard solder.

A thread is provided for receiving an insert with a counter thread, preferably in the central recess of the insulator member, in particular in order to achieve a high stability of the engagement of the insert with the insulator member in the axial direction.

On the basis of good electrical insulation properties, preferably the insulator member is made of ceramic, in which case the insulator member is preferably made of a glass ceramic, which is preferably machinable to provide threads.

The insert is preferably made of a metal or a metal alloy, in particular in this case copper, bronze or brass, taking into account the necessary electrical conductivity and good thermal conductivity.

For practical use in a laser machining system, preferably, the insulator member includes a flange extending radially outwardly at its self-axial end which is directed in the opposite direction from the insert, through which the housing receives a union nut And is detachably fixed to the housing of the laser processing head.

According to another embodiment of the present invention, a receiving device is used in a laser machining head having a housing, through which a machining laser beam path is guided. The machined laser beam path passes through the nozzle and flows out toward the object to be fixed to detachably fix the nozzle to the housing.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a receiving apparatus having an increased load carrying capacity while maintaining electrical characteristics.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic view showing a nozzle region of a laser machining head according to the present invention including a partial sectional view.

Fig. 2 is a schematic cross-sectional view showing a cutting-off device for a nozzle member of a laser machining head according to the present invention.

Structural members corresponding to each other in the drawings are indicated by the same reference numerals.

1 shows a portion of a laser machining head 10 used with a laser machining apparatus or system. In this case, the machining laser beam provided from the laser machining apparatus passes through the laser machining head 10 and is irradiated onto the workpiece 12. This is illustrated by the optical axis L.

An annular insulator member (18) is detachably fixed to the housing (14) of the laser processing head (10) using a union nut (16). The insert 20 is inserted into the center of the recessed portion 26 of the annular insulator member 18 using the bush 22 to which the radial flange 24 is connected and is described in more detail below May be coupled to the insulator member 18 in a variety of ways. For example, as can be seen in FIG. 1, the insert 20 may be screwed into a thread 28 located within the central recess 26. A bore 32 is located in the annular insulator member 18. A pin (34) is inserted into the bore (32). The pin 34 engages into the bore 36 of the insert 20 and is secured to the insert 20 by soldering, for example, to allow the insert 20 to be electrically connected to the nozzle member 38, , Fixed in the bore portion 36 through welding, screws, press fitting, or the like. In this case, soldering or welding is particularly preferable in consideration of excellent contact between the insert 20 and the pin 34. [

The nozzle member 38 includes a nozzle bore 40 and a radial flange 42 with an edge 44. The nozzle member 38 is screwed to the female screw 48 of the insert 20 using the male screw 46. The edge portion 44 may be provided with a small knurl in order to easily tighten and unscrew the threaded portion of the metal insert 20 and the nozzle member 38. [ The central member 50 is, for example, a conical centering surface between the nozzle member 38 and the insert 20.

Fig. 2 essentially shows only the storage device 52 according to the invention, and the removably fixed nozzle member 38 is shown schematically. The machining laser beam supplied from the laser machining apparatus passes through the accommodating device 52 along the optical axis L shown in the figure.

The accommodating device 52 includes the annular insulator member 18 and the insert 20 described above.

The annular insulator member 18 includes a flange 54 extending radially outwardly at its self-axial end towards the opposite direction of the insert 20. The annular insulator member 18 can be detachably fixed to the housing 14 shown in Fig. 1 of the laser processing head 10 by using the union nut 16 through the flange 54. Fig. The diameter of the annular insulator member 18 is typically 25 mm, and its height is usually 12 mm, but it may have another suitable dimension depending on each use region of the laser processing head 10. The annular insulator member 18 is made of an electrically insulating material, particularly ceramic.

2, a thread 28 is provided on the inner wall surface of the central recessed portion 26 of the insulator member 18 through which the insert 20 is inserted into the central recessed portion 26, As shown in Fig. For this purpose, glass ceramics capable of being cut, such as glass ceramic Macor of Corning Incorporated, are used particularly preferably. The above-described glass ceramics can be used under continuous operating conditions of an operating temperature of about 800 DEG C, but can also be used under short-term peak temperature conditions of about 1000 DEG C. Moreover, the above materials are excellent electrical insulators and have low thermal conductivity. In addition, the above-mentioned materials have an advantage that not only bonding but also hard soldering is possible.

The insert 20 is made of an electrically conductive material, particularly a metal or metal alloy. In this case, it is important that the material used to avoid material breakdown at the time of high temperature has a high melting point.

Thus, for example, when the plunge cutting process is performed in the workpiece during laser cutting, a local peak temperature of 1000 DEG C or higher may occur. To this end, the material used must have good thermal conductivity in order to allow a good induction and distribution of the local peak temperature. Particularly suitable materials are copper, bronze or brass, for example.

The insert 20 may be secured in various ways within the central recess 26 of the insulator member 18, as described below. There is a gap or intermediate space between the inner wall surface of the central recess portion 26 and the outer wall surface of the bushing 22 of the insert 20, The direct force transmission, which is achieved by direct axial contact with the insulator member 18 of the motor, is avoided.

The inner wall surface of the central recess portion 26 of the insulator member 18 and the outer surface of the bush 22 of the insert 20 can be easily fixed to the center recess portion 26, The walls may each have a thread and a counter thread. However, the inner wall surface of the central recess portion 26 and / or the outer wall surface of the bushing 22 of the insert 20 may be roughened to provide a good fixability to the composite material described below.

The composite material is inserted into the intermediate space between the inner wall surface of the central recess portion 26 and the outer wall surface of the bushing 22 of the insert 20 so as to secure the insulator member 18 and the insert 20 firmly On the one hand, and on the other hand accommodates the expansion or expansion of the insert 20, and in particular the bush 22, during heating, by means of self-resilient forces, while mitigating or buffering forces acting in the radial direction. Therefore, the direct force transmission toward the insulator member 18 is suppressed on the basis of various thermal expansion coefficients, and the possibility of breakage of the insulator member 18 associated therewith is minimized. A composite material may also be inserted between the radial flange 24 of the insert 20 and the bottom surface of the insulator member 18 to more securely secure the insert 20 to the insulator member 18.

As the composite material, an adhesive or solder may be used. In the case of an adhesive, a high temperature adhesive such as an epoxy resin is particularly suitable. However, special ceramic adhesives mixed with inorganic filler materials can also be used. In this regard, the filler material can meet a variety of challenges, for example ceramic-metal bonds can be strengthened or the thermal conductivity of the adhesive can be increased. In this case, possible filling materials are composed of aluminum oxide, silicon oxide, aluminum nitride, magnesium oxide or zirconium oxide, and in order to bond copper or brass with ceramics, a mixture of magnesium oxide or aluminum oxide and silicon oxide is particularly suitable Do.

In the case of solder, hard solder is particularly suitable considering the high temperature that occurs. In this regard, the above-described glass ceramics are particularly suitable, because this glass ceramic is capable of being hard soldered, whereby the liquid solder is provided between the bush 22 and the insulator member 18 based on the capillary phenomenon, Because it can flow into the space.

In other words, by using a composite material, the insert can be sufficiently rigidly secured within the insulator member 18, and when the metal insert 20 is heated between the insert and the insulator member and expands accordingly, The force acting on the annular insulator member 18 surrounding the insulator member 20 can be absorbed by the composite material described above. This embodiment has the advantage that the possibility that the material, which is preferably ceramic, of the insulator member 18 is destroyed by an internal tensile load is minimized. Therefore, not only the high load capacity of the storage device 52 of the present invention, but also a long life is guaranteed. Other damages that may be caused in the workpiece 12 or in the laser machining head 10 are also avoided by the destruction of the insulator member 18 during operation of the laser machining head 10.

1 is a schematic view showing a nozzle region of a laser machining head according to the present invention including a partial sectional view.

Fig. 2 is a schematic cross-sectional view showing a cutting-off device for a nozzle member of a laser machining head according to the present invention.

Claims (12)

An annular insulator member (18) having a central recess (26) in which a thread (28) is formed in an inner wall surface; A counterpart thread disposed on the central recess portion 26 and made of a material having a thermal expansion coefficient different from that of the material of the insulator member 18 and capable of engaging with the thread 28 is formed on the outer wall surface, An insert 20 for receiving the nozzle member 38; And And a composite material provided between the inner wall surface of the insulator member (18) and the outer wall surface of the insert (20) to compensate for the difference between the radial expansion of the insert (20) and the radial expansion of the insulator member Wherein the storage device is a storage device. The storage device according to claim 1, wherein the composite material is a high-temperature adhesive. The storage device according to claim 2, wherein the high temperature adhesive is an epoxy resin or a ceramic adhesive. The storage device according to claim 2, wherein the high temperature adhesive contains an inorganic filler composed of aluminum oxide, silicon oxide or magnesium oxide. The accommodating apparatus according to claim 1, wherein the composite material is a hard solder. delete The storage device according to claim 1, wherein the insulator member (18) is made of ceramic. 6. The accommodating apparatus according to claim 5, wherein the insulator member (18) is made of glass ceramic capable of being cut. The storage device according to claim 1, wherein the insert (20) is made of a metal or a metal alloy. 10. A storage device according to claim 9, characterized in that the insert (20) is made of copper, bronze or brass. 7. The insert of claim 1, wherein the insulator member (18) includes a flange (54) radially extending in an outward direction at a self-axial end of the insert (20) Wherein the accommodating device can be detachably fixed to the housing (14) of the laser processing head (10) by means of a union nut (16) through the flange (54). A laser machining head comprising a housing (14) for guiding a machining laser beam path, The machining laser beam passage flows out to the object side through the nozzle 38, Characterized in that the nozzle (38) is detachably secured to the housing (14) by means of a storage device according to any one of claims 1 to 5 or 7 to 11 Laser machining heads.

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