JPS59171548A - Shield opening and closing device of welding helmet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for
The present invention relates to a welding shield opening/closing device equipped with an automatic 1 m tA shield that closes and opens when the shield ends.

BACKGROUND OF THE INVENTION Conventionally, welding helmets have been used in welding operations to protect the eyes of workers from welding sparks and other harmful rays emitted during welding operations. This shield uses a shielding plate made of glass or other material that has a high absorption rate of light in order to block the intense light rays emitted during welding, but its transparency is extremely low, so it is difficult to check objects in the pond except during welding work. If it's too dark.

Therefore, each time welding work is performed, the shield must be opened and closed. Therefore, one hand is required to open and close the shield, and the welding work must be performed with only the other hand. It becomes extremely difficult to install, attach, and maintain welded objects.

In view of this, the present invention is designed to be electrically driven based on the current excited by the current flowing through the anode cable of the welding machine, which is an open/close shield in which the shield of the welding helmet closes at the start of welding work and opens at the end of welding work. , the main purpose is to solve all the drawbacks of the conventional technology at once.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of the shield opening/closing device of the present invention. Reference numeral 1 indicates an arc bath welding machine body, and a detection coil 4 excited by a current flowing through a cable 3 communicating with an electrode holder 2 is connected to an input end of a fitting circuit 5. The control circuit 5 is connected to the amplifier section 7 through a sensitivity adjustment section 6 for making the excitation current of the detection coil 4 constant due to changes in welding/fusing current consumption due to plate thickness, and is connected to the amplifier section 7 at the output terminal of the amplifier section 7. The welding helmet 1 is connected to the relay part 8 by a drive relay that constitutes a drive part 9 that is interlocked with the relay part 8.
0 shield plate 10a is configured to be opened and closed.

The drive relay of the drive unit 9 is connected to a commercial power source (AC100V
or 200V).

In order to obtain a bias power source for the control circuit 5, the music power source end is connected to the control circuit 5 via a power source section 11 consisting of a transformer section and a rectifier section.

FIG. 2 is a circuit diagram showing a specific example of the control circuit.

The detection current from the detection coil 4 is supplied to the voltage adjustment relay at the transformer 22 via the diode 21 to adjust the ripple current, and then to the base of the first transistor 230 for further amplification in two stages. is supplied to the base of the second transistor 240 via a transformer,
A driving waveform of "detection 1-25" can now be obtained between the collector and emitter of the second transistor 24.

The detection relay 25 and the amplifier section 7 are connected to the transformer 26 of the power supply section 11.
and the power source processed by the rectifier circuit 27.

In this case, the detection relay 25 is of the spare contact type,
Its preliminary contact is switch 2 of the drive relay 28 of the drive unit 9.
8a is also used. Therefore, when the detection link 25 is turned on, the drive relay 28 is turned on, and when the detection relay 25 is turned off, the drive relay 28 is turned off. - Since the drive relay 28 is driven by commercial power, it is connected to and driven by the drive relay 28. The structure j1 of the shield plate 10a can be a simple sliding structure (see FIG. 1).

In FIG. 1, the shield plate 10a is the welding helmet 1.
A type that slides up and down on the front surface of 0 is adopted. At all times (when not welding), it is located above the @-face window 10b, and when it is driven (when in contact with the bath), it is configured to block light by the force of the drive relay 28 to ensure the safety of workers. Therefore, the position of the shield plate 10' is always held by the tension spring 32, and when driving, it is necessary to select a drive relay stronger than the spring force of the spring 32.

Referring again to FIG. 2, there is a connection between the transformer 22 and the first transistor 23 to prevent the detection relay 25 from malfunctioning due to variations in the detection current from the detection coil 4 due to variations in the thickness of the base material, etc. A first CiT resistor 33 is provided for this purpose. Furthermore, the shield plate LOa of the helmet 10
In order to test the opening/closing of the detection coil 4, a second variable low resistor 35 is connected to the base of the first transistor 230 via a test button 34 to one terminal of a low power supply (for example, 11). Even during operation, the shield plate 10a can be opened and closed, and the balanced state between the drive relay 28 and the spring 32 at the reference time can be confirmed.

Next, the operation of the device of the present invention will be explained. By turning on the power to the control circuit 5, the detection relay 25 is activated when the test button 34 is pressed and turned on. Therefore, the switch 28a of the drive relay 28 is turned on, and the one drive relay 28 is turned on.
The shield plate 10a is brought to the light shielding position by driving. still,
As shown in FIG. 3, the welding rod 2a supported by the electrode holder 2 is actually discharged from the base metal 2b when there is a gap between the welding rod 2a and the base metal 2b just before welding starts. Since a weak current flows through the cable 3, this weak current can be detected immediately and the shield plate 10a of the helmet 10 can be closed. That will no longer be the case.

In the above description, by employing a self-holding type for the detection relay 25, the current consumption during operation of the detection relay 25 can be minimized.

As described above, according to the present invention, there is provided a detection coil that detects energization during welding, an amplification section that amplifies the excitation current from the detection coil, and a preliminary contact that is operated by the detection current amplified by the amplification section. The preliminary J point is configured to double as a switch for the drive relay that drives the shield plate of the welding helmet, so the drive relay has a high voltage and the detection relay has a low voltage. Therefore, the excitation current of the detection coil directly causes -
” Larger power can be obtained compared to the configuration in which the shield plate is driven as described in 2 above. Therefore, an appropriate driving power source can be selected depending on the thickness and weight of the shield plate.

Further, according to the present invention, the amplifier section that processes the detection current from the detection coil is configured to adjust the detection current in order to prevent the detection relay from malfunctioning due to fluctuations in power consumption due to changes in the base material during welding. Since a variable resistor is installed, there is no malfunction of the detection coil due to fluctuations in power consumption due to changes in the material or thickness of the base material during welding, or high operation of the drive coil, which improves worker safety. be able to.

Furthermore, according to the present invention, a switch and a second variable resistor for adjusting the sensitivity are provided between the power supply section that drives the amplifying section 1i'W section and the amplifying section 7, so that when the detecting coil is not in operation, Since the opening/closing operation of the shield plate of the helmet can also be confirmed, the balance adjustment of the drive relay and tension spring that drive the inside of the shield plate can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the apparatus of the present invention, FIG. 2 is a circuit diagram showing an example of a control circuit, and FIG. 3 is a diagram for explaining the operation. 4... Detection coil, 5... Control circuit, 10a... Shield plate, 25... Detection relay, 28... Drive relay, 28a... Switch, 33... First variable resistor , 34--Test button, 35--Second variable resistor. Applicant's agent Patent attorney Akiyama, 28th year of high school

Claims (1)

[Scope of Claims] 1. A detection coil that detects energization during welding, an amplification section that amplifies the excitation current from the detection coil, and a preliminary contact detection that is activated by the detection current amplified by the amplification section. A shield opening/closing device for a welding helmet, comprising a relay, and the preliminary contact also serves as a switch for a drive relay for driving a shield plate of a welding helmet. 2. A variable resistor is provided in the amplification section that processes the detection current from the detection coil to adjust the detection current in order to prevent the detection relay from malfunctioning due to fluctuations in power consumption due to changes in the base material during welding. A shield opening/closing device for a welding helmet according to claim 1. 3. It consists of a detection coil that detects energization during welding, an amplification section that amplifies the excitation current from the detection coil, and a preliminary contact detection relay that is activated by the detection current amplified by the amplification section. A welding helmet characterized in that the spare contact also serves as a switch for a drive relay that drives the shield plate of the welding helmet, and a switch and a second variable resistor for adjusting sensitivity are provided between the power supply section and the amplifier section. shield switchgear.