DE102022115454A1 - Device and method for texturing and/or coating a surface of a component - Google Patents

Abstract

The invention relates to a device and a method for texturing and/or coating a surface of a component which is located at least partially in a container filled with dielectric, the component being arranged at a distance opposite at least one electrode, and the device having a device for the relative movement of Component and electrode to each other and each electrode is preceded by a device for supplying electrical energy. The object of the invention is to create a new device for texturing and / or coating a surface of a component, which has a smaller size, at the same time an improvement in energy efficiency and an increase in spark yield is to be achieved. The task is solved by forming the device from at least one current source and one voltage source, which are arranged in parallel and alternately connected to the electrode, the voltage source initially having a constant high voltage for ionization of the dielectric and the power source then provides the desired current intensity for material removal and / or material application on the component.

Description

The invention initially relates to a device for texturing and/or coating a surface of a component which is at least partially located in a container filled with dielectric, the component being arranged at a distance opposite at least one electrode, and the device having a device for the relative movement of the component and electrode to each other and each electrode is preceded by a device for supplying electrical energy.

With such devices according to the prior art, methods for texturing surfaces of the components to be machined or methods for applying material to a surface of a component by spark erosion are carried out.

In this context, the texturing (roughening) of component surfaces by spark erosion is referred to as the so-called EDT process, which is derived from the English term “electrical discharge texturing”.

In addition, such devices are also used in connection with the EDC process (electrical discharge coating), in which electrode material is introduced into the surface of a component (coating).

From the prior art, which cannot be proven in print, there are basically two devices according to 1 and 2 or the 3 and 4 known from the description of the figures.

The device according to 1 and 2 has a capacitor, a resistor (discrete resistance levels adjustable), a switch element and an electrode arranged in the dielectric at a distance from the surface of the component to be texturized. The so-called backup capacitor is continuously charged to a constant voltage, with the current being adjusted via the downstream variable resistor. If the switch is closed, the spark ignites across the spark gap after a certain delay time and material is removed from the surface of the component.

Disadvantageously, the majority of the energy must be dissipated as heat via the resistance as soon as ignition has occurred. As a result, the resistors have a large volume and, disadvantageously, dissipating the heat is very complex. The current intensity can also only be adjusted in combination with discrete resistors.

Furthermore, a device is also known from the prior art, which cannot be proven in print, which is formed from a coil, a current control, two switch elements and in turn an electrode arranged in the dielectric (see 3 and 4 ). In this device, a defined current is impressed into a coil via a two-point control. If switch S1 is closed and switch S2 is opened, the spark gap ignites after an indefinite delay time.

Unfortunately, because of the indefinite delay time, the inductance of the coil must be sufficiently large to maintain the power (current) until ignition. The coil is also disadvantageously heavy. In addition, with this type of device, external influences such as inhomogeneities in the dielectric and changes in the distance between the electrode and the surface of the component to be processed can lead to ignition failures, which can have a negative impact on the spark yield.

Based on the prior art set out above, the object of the invention is to create a new device for texturing and/or coating a surface of a component, which has a smaller size, while at the same time improving the energy efficiency and increasing the spark yield shall be.

• Vorrichtung zur Texturierung und/oder Beschichtung einer Oberfläche eines Bauteils, welches zumindest partiell sich in einem mit Dielektrikum gefüllten Behälter befindet, wobei das Bauteil beabstandet gegenüberliegend mindestens einer Elektrode angeordnet ist, und wobei die Vorrichtung eine Einrichtung zur Relativbewegung von Bauteil und Elektrode zueinander aufweist und wobei jeder Elektrode eine Einrichtung zur Versorgung mit elektrischer Energie vorgeordnet ist, dadurch gekennzeichnet, dass die Einrichtung aus mindestens einer Stromquelle und einer Spannungsquelle gebildet wird, die parallel angeordnet und abwechselnd mit der Elektrode verbunden sind, wobei die Spannungsquelle zunächst eine konstant hohe Spannung zur Ionisation des Dielektrikums und die Stromquelle dann die gewünschte Stromstärke zum Materialabtrag und/oder Materialauftrag an dem Bauteil zur Verfügung stellt.

The solution to the problem results from a device for texturing and/or coating a surface of a component according to the features of the following claim 1:

• Device for texturing and/or coating a surface of a component which is at least partially located in a container filled with dielectric, wherein the component is arranged at a distance opposite at least one electrode, and wherein the device has a device for the relative movement of the component and electrode to one another and wherein each electrode is preceded by a device for supplying electrical energy, characterized in that the device is formed from at least one current source and a voltage source, which are arranged in parallel and alternately connected to the electrode, the voltage source initially providing a constant high voltage for ionization of the dielectric and the power source then provides the desired current strength for material removal and/or material application to the component.

The device according to the invention initially has the essential advantage that Parallel arrangement of a current source and a voltage source, which are alternately connected to the electrode, the overall size of the device is significantly reduced, since the current source as well as the voltage source in the device according to the invention each have a significantly smaller size.

In addition, the device according to the invention has improved energy efficiency and is characterized by less effort for heat dissipation.

Ultimately, the device according to the invention has an increased number of sparks and a largely constant spark yield.

In an advantageous embodiment of the device, the component is a roll for a cold rolling mill, which is fastened in a device for the rotating arrangement.

In further embodiments, either the current source is designed as a coil and/or the voltage source is designed as a capacitor.

In principle, it is also possible for the current source to be an operational amplifier (as a constant current source), an operational amplifier with a downstream MOSFET or a fixed voltage regulator as a constant current source or as a voltage source a battery, two fixed voltage regulators (integrated circuit/IC), a regulated (switching) power supply or a (power) operational amplifier is used.

In a particularly preferred embodiment of the invention, the capacitor is followed by a further coil to limit the increase in current.

In a further embodiment, it is also possible for a voltmeter to be additionally assigned to the capacitor.

Further advantages of the invention result from the following subclaims 7 and 8.

The invention further relates to a method for texturing and/or coating a surface of a component.

• Verfahren zur Texturierung und/oder Beschichtung einer Oberfläche eines Bauteils, welches zumindest partiell sich in einem mit Dielektrikum gefüllten Behälter befindet, wobei das Bauteil beabstandet gegenüberliegend mindestens einer Elektrode angeordnet ist, und wobei die Vorrichtung eine Einrichtung zur Relativbewegung von Bauteil und Elektrode zueinander aufweist und wobei jeder Elektrode eine Einrichtung zur Versorgung mit elektrischer Energie vorgeordnet ist, wobei die Einrichtung aus mindestens einer Stromquelle und einer Spannungsquelle gebildet wird, die parallel angeordnet und abwechselnd mit der Elektrode verbunden sind, wobei die Spannungsquelle zunächst eine konstant hohe Spannung zur Ionisation des Dielektrikums und die Stromquelle dann die gewünschte Stromstärke zum Materialabtrag und/oder Materialauftrag an dem Bauteil zur Verfügung stellt, gekennzeichnet durch nachfolgende Verfahrensschritte:
  • - Aufladung einer am elektrischen Netz angeordneten Spannungsquelle
  • - Entkoppelung der Spannungsquelle von der elektrischen Versorgung
  • - Zündvorgang durch Schaffung der elektrischen Verbindung zwischen Spannungsquelle und Elektrode mit der Folge einer hohen Potentialdifferenz zwischen der Elektrode und der Bauteiloberfläche sowie Ionisierung des Dielektrikums zwischen Elektrode und Bauteiloberfläche
  • - Beginn eines Stromflusses, der von der durch die Spannungsquelle hervorgerufenen Potentialdifferenz ausgeht, bei gleichzeitigem Spannungsabfall an der Spannungsquelle
  • - Zuschaltung der parallelen Stromquelle und Materialabtrag und/oder Materialauftrag an der Oberfläche des Bauteils im Zeitraum T 1 durch Funkenerosion
  • - Unterbrechung der Verbindung der Spannungsquelle zur Elektrode sowie anschließende Aufladung der Spannungsquelle
  • - Unterbrechung der elektrischen Verbindung zwischen der parallelen Stromquelle und der Elektrode sowie Unterbrechung des Materialabtrags und/oder Materialauftrag (Pause) im Zeitraum T2
  • - Entkopplung der Spannungsquelle von der elektrischen Versorgung
  • - Neuer Zündvorgang

Based on the state of the art already set out above and the task also defined, the solution results from the following features of method claim 9:

• Method for texturing and/or coating a surface of a component which is at least partially located in a container filled with dielectric, wherein the component is arranged at a distance opposite at least one electrode, and wherein the device has a device for the relative movement of the component and electrode to one another and wherein each electrode is preceded by a device for supplying electrical energy, the device being formed from at least one current source and one voltage source, which are arranged in parallel and alternately connected to the electrode, the voltage source initially having a constant high voltage for ionization of the dielectric and the power source then provides the desired current intensity for material removal and/or material application to the component, characterized by the following process steps:
  • - Charging a voltage source located on the electrical network
  • - Decoupling the voltage source from the electrical supply
  • - Ignition process by creating the electrical connection between the voltage source and the electrode, resulting in a high potential difference between the electrode and the component surface and ionization of the dielectric between the electrode and the component surface
  • - Beginning of a current flow that starts from the potential difference caused by the voltage source, with a simultaneous voltage drop at the voltage source
  • - Switching on the parallel power source and material removal and/or material deposition on the surface of the component in the period T 1 by spark erosion
  • - Interruption of the connection between the voltage source and the electrode and subsequent charging of the voltage source
  • - Interruption of the electrical connection between the parallel power source and the electrode and interruption of material removal and/or material application (pause) in the period T2
  • - Decoupling the voltage source from the electrical supply
  • - New ignition process

The method according to the invention also has the advantages already mentioned above for the device according to the invention, in particular with regard to smaller size, increased energy efficiency and high and stable spark yield.

In an advantageous embodiment of the method, it is possible that the construction part is a roll for a cold rolling mill, which is mounted in a device for rotating arrangement.

• 1 und 2 eine erste Vorrichtung zur Texturierung und/oder Beschichtung einer Oberfläche einer Walze nach dem Stand der Technik,
• 3 und 4 eine zweite Vorrichtung zur Texturierung und/oder Beschichtung einer Oberfläche einer Walze nach dem Stand der Technik und
• 5 - 8 eine erfindungsgemäße Vorrichtung zur Texturierung und/oder Beschichtung einer Oberfläche einer Walze mit ihren verschiedenen Verfahrensschritten.

Further advantages of the invention result from the following patent claims and from the description of an exemplary embodiment. Show it:

• 1 and 2 a first device for texturing and/or coating a surface of a roller according to the prior art,
• 3 and 4 a second device for texturing and/or coating a surface of a roller according to the prior art and
• 5 - 8th a device according to the invention for texturing and/or coating a surface of a roller with its various process steps.

In the 1 and 2 a device A for texturing and/or coating a surface B of a roll C of a cold rolling mill, not shown, can be seen in different process states according to the prior art, the roll C being arranged opposite an electrode D in a trough F filled with dielectric E . The device A initially has a capacitor K arranged on the electrical network N, which is connected via a controllable resistor W and a switch S to the electrode D arranged in the trough F in the dielectric E, the distance between the electrode D and the roller C being determined by means of can be changed using a motor adjustment G.

As in 1 shown, the capacitor K is first continuously charged to a constant voltage via the network N with the switch S open. When the switch S is closed, the spark gap ignites after a delay time, since the voltage must first form an ion channel in the dielectric E, which significantly reduces the resistance of the dielectric E, so that a current can then flow, which is the basis for represents the necessary spark FS. The strength of this current is adjusted via the resistance W. This last situation described arises according to 2 after closing switch S.

In the embodiment according to the prior art according to 3 and 4 Parts of the device A are identical to the prior art according to 1 and 2 . The device A in turn has a trough F which is filled with dielectric E, in which a roller C is arranged to rotate, an electrode D being attached opposite the rotating roller C. Here too, a motorized adjustment G of the distance between the electrode D and the roller C is provided.

In this prior art, however, the electrode D is preceded by a coil P arranged on the network N, which is connected to the electrode D via a current control SR and two switches S1 and S2. A defined current intensity is impressed into the coil P via a two-point control.

Unless, as in 4 shown, the switch S1 is closed and the switch S2 is opened, the spark gap ignites after a delay time.

In the 5 - 8th a device 10 according to the invention for texturing and/or coating a surface 11 of a roll 12 of a cold rolling tool is designated by the reference number 10.

The roller 12 is arranged to rotate in a manner not shown in a trough 14 filled with dielectric 13. In the trough 14 or on the trough 14, an electrode 15 is fastened in the dielectric 13 at a certain distance from the surface 11 of the roller 12.

The distance between the electrode 15 and the surface 11 of the roller 12 is actively regulated during texturing by a motorized adjustment of the electrode 15 marked with the designation 25. The controlled variable is the so-called “gap voltage”, i.e. the voltage that is measured at the electrode 15 during the spark flashover. If the current is known, one can draw conclusions about the resistance of the ion gap and thus about the distance between the electrode 15 and the roller 12. The “gap voltage” is measured and forwarded to the control of the device 10. Basically, the aim is to have the largest possible electron distance, as this reduces the probability of a collision with the roller 12. The larger the electrode gap, the higher the ignition voltage required.

This arrangement described above is preceded by a device described below for supplying electrical energy.

Basically, according to the invention, a coil 17 (inductance 200 µH) with a current control 18 and a switch 19 is arranged in parallel on the electrical network 16 on the one hand and, on the other hand, a switch 20, a voltage measuring device 21, a capacitor 22 (capacity approx. 20 nF) in parallel with it. and a coil 23 and a switch 24 are arranged.

From the 5 It can be seen that, in a first step, the capacitor 22 connected to the electrical network 16 via the closed switch 20 is charged while the switch 24 is simultaneously opened towards the electrode 15, with the parallel switch 19 being opened at the same time.

After the capacitor 22 has been charged, the switch 20 is first opened (see Fig. 6 ), so that the capacitor 22 is decoupled from the electrical network 16. The ignition process is then established by closing the switch 24, i.e. by creating an electrical connection between the capacitor 22 and the electrode 15. This leads to a high potential difference between the electrode 15 and the surface 11 of the roller 12 and to ionization of the dielectric 13 between the electrode 15 and the surface 11 of the roller 12.

The beginning of a current flow, which starts from the potential difference caused by the capacitor 22 with a simultaneous voltage drop across the capacitor 22, can be seen in 6 by the spark symbol FS between the electrode 15 and the surface 11 of the roller 12.

The voltage drop determined by the voltage measuring device 21 is the signal for switching on the parallel power source (coil 17), whereby material is removed from the surface 11 of the roller 12 by spark erosion in a period of time T1 (see Fig. 7 ).

At the same time, by opening the switch 24, the connection of the capacitor 22 to the electrode 15 is interrupted, and by closing the switch 20, a parallel charging of the capacitor 22 takes place again (see 8th ).

After the period T1 (pulse duration) has elapsed, in the next step the electrical connection between the parallel power source (coil 17) and the electrode 15 is interrupted, which means that the material removal on the surface of the roller 12 is also interrupted in a “break” during the period T2.

Ultimately, after the capacitor 22 has completed charging, which is determined by the voltmeter 21, the capacitor 22 is again decoupled from the electrical supply 16 and a new ignition process begins.

Reference symbol list

10

Vorrichtung

11

Oberfläche von 12

12

Walze

13

Dielektrikum

14

Wanne

15

Elektrode

16

elektrisches Netz

17

Spule

18

Stromregelung

19

Schalter

20

Schalter

21

Spannungsmessgerät

22

Kondensator

23

Spule

24

Schalter

25

motorische Verstellung (Doppelpfeil)

FS

Funkenschlag

Stand der Technik

A

Vorrichtung

B

Oberfläche von C

C

Walze

D

Elektrode

E

Dielektrikum

F

Wanne

P

Spule

S

Schalter (1/2)

W

diskreter Widerstand

K

Kondensator

S1/S2

Schalter (Fig. ¾)

N

Netz

SR

Stromregelung

G

motorische Verstellung (Doppelpfeil)

10

contraption

11

Surface of 12

12

roller

13

dielectric

14

tub

15

electrode

16

Electrical network

17

Kitchen sink

18

Current regulation

19

Switch

20

Switch

21

Voltmeter

22

capacitor

23

Kitchen sink

24

Switch

25

motorized adjustment (double arrow)

FS

Sparks

State of the art

A

contraption

b

Surface of C

C

roller

D

electrode

E

dielectric

F

tub

P

Kitchen sink

S

Switch ( 1 /2)

W

discrete resistance

K

capacitor

S1/S2

Switch (Fig. ¾)

N

network

S.R

Current regulation

G

motorized adjustment (double arrow)

Claims (12)

Device (10) for texturing and/or coating a surface (11) of a component (12), which is located at least partially in a container (14) filled with dielectric (13), the component (12) being spaced apart opposite at least one electrode (15) is arranged, and wherein the device (10) has a device for the relative movement of the component and electrode to one another and wherein each electrode (15) is preceded by a device for supplying electrical energy, characterized in that the device consists of at least one power source (17) and a voltage source (22) is formed, which is arranged in parallel and alternately connected to the electrode (15). are, wherein the voltage source (22) initially provides a constantly high voltage for ionization of the dielectric (13) and the current source (17) then provides the desired current intensity for material removal and / or material application on the component (12). Device according to Claim 1 , characterized in that the component (12) is a roll for a cold rolling mill, which is mounted in a device for rotating arrangement. Device according to Claim 1 or 2 , characterized in that the power source (17) is designed as a coil. Device according to one of the preceding claims, characterized in that the voltage source (22) is designed as a capacitor. Device according to one of the preceding claims, characterized in that the capacitor (22) is followed by a further coil (23) to limit the increase in current. Device according to one of the preceding claims, characterized in that a voltage measuring device (21) is assigned to the capacitor (22). Device according to one of the preceding claims, characterized in that the inductance of the coils (17, 23) is approximately 200 µH each. Device according to one of the preceding claims, characterized in that the electrical capacity of the capacitor (22) is approximately 20 nF. Method for texturing and/or coating a surface of a component which is at least partially located in a container filled with dielectric, wherein the component is arranged at a distance opposite at least one electrode, and wherein the device has a device for the relative movement of the component and electrode to one another and wherein each electrode is preceded by a device for supplying electrical energy, the device being formed from at least one current source and one voltage source, which are arranged in parallel and alternately connected to the electrode, the voltage source initially having a constant high voltage for ionization of the dielectric and the power source then provides the desired current intensity for material removal and/or material application on the component, characterized by the following process steps: - charging a voltage source arranged on the electrical network - decoupling the voltage source from the electrical supply - ignition process by creating the electrical connection between the voltage source and Electrode with the result of a high potential difference between the electrode and the roller surface and ionization of the dielectric between the electrode and the roller surface - beginning of a current flow that starts from the potential difference caused by the voltage source, with a simultaneous voltage drop at the voltage source - switching on the parallel current source and material removal and /or material application to the surface of the roller in the period T 1 by spark erosion - interruption of the connection between the voltage source and the electrode and subsequent charging of the voltage source - interruption of the electrical connection between the parallel current source and the electrode and interruption of the material removal and/or material application (break) in the period T 2 - decoupling of the voltage source from the electrical supply - new ignition process Procedure according to Claim 9 , characterized in that the component is a roll for a cold rolling mill, which is mounted in a device for rotating arrangement. Method according to one of the preceding Claims 9 and 10 , characterized by voltages on the electrode between 50 and 400 V and electrical currents from 1 to 36 A. Method according to one of the preceding Claims 9 until 11 , characterized by a pulse duration of 500 ns to 1000 µs and a pause between the pulses of 1 to 1000 µs.

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