GB1567092A - Consumption rate measurement for consumable electrode welding - Google Patents

Abstract

A device is provided for governing the wire feed or the wire feed rate during welding with a melting electrode, which device has a light barrier (1) which contains a slotted wheel (2) which interrupts the light path periodically, a light source (3), and a light-recording receiver (4). Attached to the slotted wheel (2) is a measuring cylinder (5) over which the wire electrode (6) which is to be measured runs. The receiver (4) is connected to a pulse counter (10). <IMAGE>

Description

(54) CONSUMPTION RATE MEASUREMENT FOR CONSUMABLE ELECTRODE WELDING (71) We, LINDE AKTIENGESELL SCHAFT, a German Company of Abraham Lincoln-Strasse 21, D--6200 Wiesbaden, German Federal Republic, do hereby, declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a welding gun for consumable electrode welding and particularly to the measurement of electrode comsumption rate therein.

To ascertain the consumption rate when welding with a consumable electrode it is important to establish the speed of the wire electrode. A wire feed unit is known from German Gebrauchmuster specification U 1908/49h with the aid of which the wire electrode can be fed at a specific speed, the electrode advance speed. The electrode advance speed can also be indicated with this unit. However, the use of such a unit merely to determine the consumption rate would not be economically viable because of the high acquisition cost and the awkward handling.

According to the present invention there is provided a welding gun for consumable electrode welding, and including measurement means for measuring the rate of electrode wire consumption, the measurement means comprising a wire-engaging roller over which, in use, the electrode passes, a wheel secured for rotation with the roller and disposed between a light source and a photo-detector, the wheel having transparent and non-transparent portions whereby rotation thereof repeatedly interrupts the passage of light from the source to the photo-detector, whereby an indication of the consumption rate may be obtained by counting, by means of an impulse counter, electrical impulses obtained from the photo-detector.

By means of the wheel - e.g. a slotted wheel - the light emitted by the light source is broken up into individual light impulses. The number of light impulses corresponds with a specific length of unwound wire. An impulse counter may then add up to impulses received during welding, and thus the total material consumption at the wire electrode can be indicated.

It is also possible to arrange the impulse counter to indicate the number of impulses for a given unit of time. The indication obtained then corresponds to the wire advance speed from which the consumption rate can then be ascertained.

Such a, simple arrangement with a roller and a slotted wheel constituting the mechanically moved parts can enable the unit to have a long service life. By using opto-electronic measuring devices, an almost undelayed indication of the speed of the wire electrode is obtainable with satisfactory accuracy.

Since the light impulses are transmitted by electrical means, the impulse counter can be set up spatially separated from the apparatus. Since in addition the welding operation itself does not have to be interrupted to measure the electrode advance speed, the measuring devices in accordance with the invention can be used without causing any hold-ups in the working area.

If desired the photo-detector may also be linked to a clock that can be switched on and off with the aid of the light impulses recorded by the receiver. Through this the time required for the complete welding operation can be indicated.

Preferably the wire electrode runs between the wire-engaging roller and a pressure roller. This particularly reduces the possibility of slip between the wire electrode and the wire-engaging roller during the measuring operation and the measurement result being falsified.

In the following one embodiment of the invention is explained, by way of example with reference to the accompanying drawing which shows schematically one form of a device in accordance with the invention for determining the consumption rate when welding with a consumable electrode.

A wire electrode 6 runs between a wire-engaging roller 5 and a pressure roller 12 which is urged in the direction of the arrow so that, as the wire passes through, the rollers rotate. The wire-engaging roller is connected to a slotted wheel 2. As the slotted wheel 2 turns, it interrupts the light beam that is sent out from a light source 3 to a photo-detector 4, both of which are mounted in a mounting 1. The light impulses are converted by the photo-detector 4 into electrical impulses which are then fed via a line 7 to an impulse converter 8. In this impulse converter 8 the incoming impulses are converted for digital or analogue processing. An impulse counter 10 which ascertains the overall number of impulses for a given unit of time is connected to the impulse converter 8 by means of a line 9. In addition the impulse convertor 8 is connected to a clock 11 which switches on when wire electrode 6 begins to run over the wire-engaging roller 5 and switches off when the wire electrode stops moving.

The items 1 to 5 and 12 above are incorporated in a welding gun (not shown).

There is thus provided a device with the aid of which the comsumption rate can be ascertained rapidly and which is also relatively economic to produce.

WHAT WE CLAIM IS: 1. A welding gun for consumable electrode welding, and including measuremment means for measuring the rate of electrode wire consumption, the measurement means comprising a wire-engage roller over which, in use, the electrode passes. a wheel secured for rotation with the roller and disposed between a light source and a photo-detector, the wheel having transparent portions whereby rotation thereof repeatedly interrupts the passage of light from the source to the photo-detector, whereby an indication of the consumption rate may be obtained by counting, by means of an impulse counter, electrical impulses obtained from the photo-detector.

2. A welding gun as claimed in claim 1.

wherein the wheel is of opaque material and the transparent portions are in the form of slots.

3. A welding gun as claimed in claim 1 or ', further including a pressure roller for, in use, urging the electrode wire into engagement with the wire-engaging roller.

-1. A welding gun as claimed in claim 1, 2 or 3. including an impulse counter connected to receive, in use, electrical impulses from the photo-detector.

5. A welding gun as claimed in claim 4.

further including a clock arranged to switch on upon receipt of impulses from the photodetector and switch off when no pulses are received, whereby the welding time may be measured.

6. A welding gun for consumable electrode welding and including measurement means for measuring the rate of electrode wire consumption, substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. with reference to the accompanying drawing which shows schematically one form of a device in accordance with the invention for determining the consumption rate when welding with a consumable electrode. A wire electrode 6 runs between a wire-engaging roller 5 and a pressure roller 12 which is urged in the direction of the arrow so that, as the wire passes through, the rollers rotate. The wire-engaging roller is connected to a slotted wheel 2. As the slotted wheel 2 turns, it interrupts the light beam that is sent out from a light source 3 to a photo-detector 4, both of which are mounted in a mounting 1. The light impulses are converted by the photo-detector 4 into electrical impulses which are then fed via a line 7 to an impulse converter 8. In this impulse converter 8 the incoming impulses are converted for digital or analogue processing. An impulse counter 10 which ascertains the overall number of impulses for a given unit of time is connected to the impulse converter 8 by means of a line 9. In addition the impulse convertor 8 is connected to a clock 11 which switches on when wire electrode 6 begins to run over the wire-engaging roller 5 and switches off when the wire electrode stops moving. The items 1 to 5 and 12 above are incorporated in a welding gun (not shown). There is thus provided a device with the aid of which the comsumption rate can be ascertained rapidly and which is also relatively economic to produce. WHAT WE CLAIM IS:

1. A welding gun for consumable electrode welding, and including measuremment means for measuring the rate of electrode wire consumption, the measurement means comprising a wire-engage roller over which, in use, the electrode passes. a wheel secured for rotation with the roller and disposed between a light source and a photo-detector, the wheel having transparent portions whereby rotation thereof repeatedly interrupts the passage of light from the source to the photo-detector, whereby an indication of the consumption rate may be obtained by counting, by means of an impulse counter, electrical impulses obtained from the photo-detector.

2. A welding gun as claimed in claim 1.

wherein the wheel is of opaque material and the transparent portions are in the form of slots.

3. A welding gun as claimed in claim 1 or ', further including a pressure roller for, in use, urging the electrode wire into engagement with the wire-engaging roller.

-1. A welding gun as claimed in claim 1, 2 or 3. including an impulse counter connected to receive, in use, electrical impulses from the photo-detector.

5. A welding gun as claimed in claim 4.

further including a clock arranged to switch on upon receipt of impulses from the photodetector and switch off when no pulses are received, whereby the welding time may be measured.

6. A welding gun for consumable electrode welding and including measurement means for measuring the rate of electrode wire consumption, substantially as herein described with reference to the accompanying drawing.