JPH0790536A - Detection of arc shortage of arc thermal spraying machine and control system for apparatus for producing clad material - Google Patents

Abstract

PURPOSE:To provide the method for detecting arc shortage capable of exactly detecting the arc shortage and to exactly detect the arc shortage and surely control an apparatus for producing a clad material by this detection. CONSTITUTION:This method for detection comprises detecting a fluctuation in an arc current during arc thermal spraying and decides the arc shortage when this fluctuation width is off a prescribed range. This control system is provided with a detecting means 3 for detecting the fluctuation in the arc current during the arc thermal spraying and a control means 6 for controlling the operation of an arc thermal spraying machine 2 and an extruder 1 in accordance with the value detected by this detecting means 3. The control system has an input means to this control means 6. An analog voltage converter is preferably used for the detecting means 3 to digitalize the detected voltage by boosting the voltage and subjecting the voltage to signal processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting arc breakage in an arc sprayer which forms a sprayed coating of another metal on the surface of a metal material, and an extruder on the surface of a metal extruded material after extrusion. The present invention relates to a control system for a clad material manufacturing apparatus that sprays another metal to form a sprayed coating by a spraying gun of an arc sprayer installed on the outlet side of.

[0002]

2. Description of the Related Art For example, aluminum capacitor tubes and other aluminum products are coated with a metal having a low potential, for example, Zn or a Zn alloy, on the surface of the product in order to provide cathodic protection and brazing properties. As one means of forming this film, while supplying two thermal spray wires (metal wires) to the thermal spray gun, an arc is generated between the thermal spray wires, and the portion melted by the heat is finely divided by a jet of compressed gas. An arc spraying machine is used which sprays this on the product surface.

In such an arc spraying machine, an arc break (interruption of the arc) often occurs. This arc break includes a complete arc break in which the arc breaks and the thermal spray continues and stops, and a moment arc break in which the arc breaks momentarily and recovers immediately thereafter. In the former case, the noise can be easily confirmed by stopping the sound of the spray gun, and the arc sprayer or the extruder can be stopped to perform a predetermined treatment.
Regarding the instantaneous arc break, there has been no suitable detection method in the past, and the change in the sound of the spray gun was confirmed by the ear and the change in the arc light was confirmed by the eye.

[0004]

However, in order to completely confirm the instantaneous arc breakage with eyes and ears, it is instantaneous (for example, about 0.1 sec) and continuous monitoring by humans is necessary. It is extremely uneconomical and practically impossible.If the thermal spraying is continued without being noticed, the formation of the thermal spray coating on the surface of the metal extruded material is insufficient at the part where the arc is broken The product becomes defective because it becomes thinner than the area of (1) or the adhesion of particles becomes mottled). Therefore, the product surface must be inspected visually or by other means in a later step, but even if the film on the product surface is completely interrupted, it is easy to detect, but the film formation is insufficient. In this case, it was difficult to detect, and there was a risk of detection error. The inventors completed the present invention by finding that in the process of investigating the phenomenon of arc breakage, the arc current changes more greatly than the fluctuation during normal operation (it fluctuates up and down) at the moment the arc is interrupted However, the purpose of the method is to detect an arc break that can accurately detect an arc break, and to accurately detect an arc break, and to appropriately control the clad material manufacturing apparatus by this detection. To provide a control system.

[0005]

The arc-break detection method according to the present invention detects fluctuations in the arc current during arc spraying, and determines that the arc breaks when the fluctuation range is outside a predetermined range. It is characterized by doing.

In the above-described arc breakage detecting method, the fluctuation of the arc current can be detected by an ammeter, a voltmeter, or other means. However, the fluctuation of the arc current is converted into an analog voltage and detected, and the detected voltage is detected. For example, it is preferable that the voltage is boosted by a transducer or the like and digitized by a sequencer or the like.

The first means for solving the problems of the control system for the clad material manufacturing apparatus according to the present invention is to use a spray gun of an arc sprayer installed on the exit side of an extruder on the surface of a metal extruded material after extrusion. In a clad material manufacturing apparatus for spraying a metal of the above to form a sprayed coating, a detection means for detecting a variation in arc current during arc spraying, and an operation of the arc sprayer and the extruder based on the detection value of the detection means. Is provided with a control means for controlling the control means and an input means for the control means.

A second means for solving the problem of the control system for the clad material manufacturing apparatus according to the present invention is to detect the fluctuation of the arc current during arc spraying by converting it into an analog voltage in the clad material manufacturing apparatus as described above. Means, computing means for digitizing the detection value of the detecting means, control means for controlling the operations of the arc sprayer and the extruder based on the values calculated by the computing means, and input means for the controlling means It is characterized by having and.

In each of the control systems described above, it is preferable that the detecting means for detecting the fluctuation of the current is composed of an analog voltage converter, and the detected voltage of the analog voltage converter is boosted by the transducer and input to the calculating means. .

Further, in each of the control systems described above,
Marking means is installed behind the thermal spray gun of the thermal spray machine, and in synchronization with the control means controlling the arc thermal spray machine and the extruder, by the control means, the metal extruded material immediately after the thermal spray coating is formed. It is preferably arranged to control the marking means in order to effect marking on the surface.

[0011]

[Function] The fluctuation range of the arc current at the time of arc break is obviously larger than the fluctuation range due to other causes, and the extent to which the fluctuation range is caused by the arc break is It can be accurately set experimentally according to the specifications and history of the thermal spraying machine. Therefore, in the arc breakage detection method according to the present invention, the fluctuation of the actual arc current is detected, and the arc breakage judgment is performed depending on whether or not the fluctuation width is larger than the width set as described above. A break can be detected.

If the fluctuation of the arc current is detected by converting it into an analog voltage, the detected voltage is boosted by, for example, a transducer, and digitized by a sequencer or the like, a near-immediate response of the fluctuation detection of the arc current is realized. be able to.

In the control system of the clad material manufacturing apparatus according to the present invention, when the detected value of the arc current detected by the detecting means is out of the predetermined setting range input by the input means, the control means causes the arc spraying. By controlling the machine and the extruder to stop its operation, appropriate measures can be taken, such as replacing the contact block at the tip of the spray gun. Further, since the defective portion for thermal spraying on the metal extruded material can be easily confirmed by stopping the operation of the extruder and the thermal spraying machine, the defective portion can be removed and only good quality products can be provided to the market. In the control system provided with the marking means, it becomes easier to detect the defective portion for thermal spraying on the metal extruded material.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, a preferred embodiment of an arc breakage detection method for an arc sprayer according to the present invention, and
A preferred embodiment of the control system in the clad material manufacturing apparatus will be described. 1 is a side view of a clad material manufacturing apparatus including a block diagram for explaining an embodiment of the arc breakage detection method and control system of the present invention, and FIG. 2 is a position of a metal extruded material and a spray gun in the apparatus of FIG. It is a schematic front view which shows a relationship.

In FIG. 1, 1 is an extruder and a is an extruder 1.
A metal extruded material of an aluminum alloy that is continuously extruded by, 2 is an arc sprayer, 20 is an arc sprayer main body,
Reference numeral 21 is a spray gun. Sprayed wire b, b which is zinc wire
Is housed in a pail can (not shown) in a wound state, is drawn by each pinch roll (not shown) in the thermal sprayer main body 20 and the thermal spray gun 21, and has guide grooves 23, 23 having grooves in the circumferential direction, and thermal spraying. It is continuously supplied to the thermal spray gun 21 via the machine body 20 and the guide tube 24. The sprayed wire rods b, b, which are continuously supplied to the spray gun 21, are melted by the heat of the arc generated at the tip portion 22, atomized by a jet of compressed gas, and continuously extruded by the extruder 1. The material a is sprayed onto the surface to form a film.

In this embodiment, as shown in FIG. 2, four metal extruded materials a are simultaneously extruded by a total of four spray guns 21 installed above and below the exit side of the extruder. Arc sprayed onto the surface of the.

During the arc spraying, fluctuations in the arc current (direct current) of the arc spraying machine 2 are detected by the detecting means 3 comprising an analog voltage converter. The detection voltage of the detection means 3 is boosted by the socket type transducer 4 which is a DC insulation converter, and digitized by the signal processing of the arithmetic means 5 which is a sequencer, and the digital signal is input to the control means 6. In this embodiment, the maximum compatible arc current of the arc sprayer 2 is 300 A, the maximum value converted by the detecting means 3 is 100 mV, and the maximum value converted by the transducer 4 is 10 V. However, the practical maximum values are about 150 A, 50 mV, and 2.5 V, respectively. In this embodiment, the relationship between the voltage of the arc current detected by the detecting means 3, the voltage after boosted by the transducer 4, and the digital value signal-processed by the calculating means 5 is as shown in the conversion value comparison table illustrated in Table 1. Is.

[0018]

[Table 1]

Reference numeral 7 is an input means for the control means 6,
The upper limit value and the lower limit value of the fluctuation range of the arc current during the normal operation of the arc sprayer 2 without arc break, and other necessary information are input to the control means 6 by the input means 7.

In the arc spraying machine 2 of this embodiment, the fluctuation range of the arc current not caused by the arc break is 50 to 150 A, and in the case of the arc break, the arc current fluctuates outside this range and fluctuates up and down. The control means 6 has a lower limit value 700 and an upper limit value 2000 of the digital values after the signal processing shown in Table 1.
Has been set.

The control means 6 judges that the arc is broken when the digital value corresponding to the detected value of the arc current detected by the detection means 3 deviates from the lower limit value and the upper limit value, and the arc sprayer 2 and While controlling the operation of the extruder 1 to stop its operation, the marking means 9 installed immediately after each spray gun 21 is controlled to mark the metal extruded material a. When the arc sprayer 2 and the extruder 1 are stopped by the above control, appropriate measures are taken such as replacing a contact block (not shown) at the tip 22 of the spray gun 21 of the arc sprayer 2. Restart these operations.

In this embodiment, when it is judged that the arc is broken, the display device 80 and the recording device 8 are operated in addition to the above-mentioned control.
It is configured to be output to the output means 8 such as 1.
The display device 80 of this embodiment displays a count number that counts the determination of arc break. Further, the recording device 81 records the upper and lower limit values and the time when the arc current fluctuates due to the arc break.

A metal having a width of 22 mm, a height of 3.6 mm, nine holes (not shown) arranged in the width direction and continuous in the length direction, and made of a flat multi-hole heat transfer tube made of aluminum for capacitors. Extruded material a with a line speed of approximately 43 m / mi
While continuously extruding with n, the amount of zinc sprayed by the spray gun 21 is set to about 10 g / m ^2, and a zinc film of about 50 μm on average is formed on the surface of each metal extruded material a.
Test operation was performed for one week.

During the above-mentioned test operation, when the extruder 1 and the arc sprayer 2 are stopped by the control as described above, the metal extruded by the extruder 1 and the zinc film is formed on the arc sprayer 2 is extruded. In the marking part of the extruded material a (cladding material) or in the vicinity thereof, a part where the zinc film was not sufficiently formed (a part where the zinc film was thin or a part where zinc particles were not adhered) was confirmed. Also, the clad material produced in the test run was carefully inspected visually (the color of the part where the zinc film is not sufficiently formed due to arc breakage is slightly different from that of the part where the zinc film is normally formed. However, no zinc film formation failure part was detected except in the marking part or its vicinity.

As described above, according to the arc breakage detecting method of this embodiment, the arc breakage can be accurately detected. Further, according to the control system for the clad material manufacturing apparatus of this embodiment, the apparatus can be reliably stopped when the arc is broken, and the measures for the arc break can be taken. Instantaneous arc breakage does not usually occur often, and once a day or a few times a day or less. By visually inspecting the clad material, which is a product, defective film formation can be detected without error. It is very difficult to do so, but the control system of the above-described embodiment could accurately pick up the defective portion of the film formation due to the arc break.

In the above-described embodiment, in order to shorten the response time for detecting the arc current and bring it into a state close to an immediate response, the fluctuation of the arc current is converted and detected by the analog voltage converter. However, other ammeters or voltmeters can be used. Further, in the above-mentioned embodiment, the detection voltage by the analog voltage converter is boosted so that the upper limit value and the lower limit value at the time of the arc break determination due to the fluctuation of the arc current can be finely set, and this is increased by the signal of the sequencer. Although digitized by the processing, the signal processing can be performed by other means.

Although the arcing means 9 is installed in the above-mentioned embodiment, the defective portion of the sprayed coating of the clad material due to the arc break can be easily confirmed by stopping the arc sprayer 2 or the extruder 1. The marking means 9 may be omitted.

[0028]

According to the arc break detecting method of the present invention, the arc break can be accurately detected. Also,
According to the control system of the clad material manufacturing apparatus of the present invention, the apparatus can be reliably stopped when the arc is cut off, and it is possible to respond to the arc breakage in a timely manner. You can surely pick up.

[Brief description of drawings]

FIG. 1 is a side view of a clad material manufacturing apparatus including a block diagram for explaining an embodiment of an arc breakage detection method and a control system of the present invention.

FIG. 2 is a schematic front view showing the positional relationship between the metal extruded material and the thermal spray gun of the embodiment shown in FIG. a metal extruded material b sprayed wire 1 extruder 2 arc sprayer 20 arc sprayer main body 21 spray gun 22 tip part 23 guide roller 24 guide tube 3 detection means 4 transducer 5 control means 6 input means 8 output means 80 display Device 81 Recording device 9 Marking means

Claims (6)

[Claims] 1. A method for detecting an arc break in an arc sprayer, which comprises detecting a fluctuation in an arc current during arc spraying and determining that the arc breaks when the fluctuation range is outside a predetermined range. 2. The arc break detection of the arc sprayer according to claim 1, wherein the fluctuation of the arc current is converted into an analog voltage for detection, the detected voltage is boosted and digitized. Method. 3. A clad material manufacturing apparatus for spraying another metal to form a sprayed coating on the surface of a metal extruded material after extrusion by a spray gun of an arc sprayer installed on the exit side of the extruder, A detection means for detecting fluctuations in the arc current during arc spraying, a control means for controlling the operation of the arc sprayer and the extruder based on the detection value of the detection means, and an input means for the control means are provided. A control system for a clad material manufacturing apparatus, which is characterized in that 4. A clad material manufacturing apparatus for spraying another metal to form a sprayed coating on the surface of a metal extruded material after extrusion by a spray gun of an arc sprayer installed on the exit side of the extruder, Detecting means for converting the variation of the arc current during arc spraying into an analog voltage for detection, computing means for digitizing the detection value of this detecting means, arc spraying machine based on the value computed by this computing means, and A control system for a clad material manufacturing apparatus, comprising: control means for controlling the operation of the extruder; and input means for the control means. 5. The control of the clad material manufacturing apparatus according to claim 4, wherein the detection means is an analog voltage converter, and the detection voltage of the analog voltage converter is boosted by a transducer and input to the calculation means. system. 6. A marking means for marking the surface of the metal extruded material immediately after the formation of the sprayed coating by being controlled by the control means together with the arc spraying machine and the extruder. Claim 3 ~
5. The control system for the clad material manufacturing apparatus according to any one of 5 above.