JPS59105509A - Used amount detector for welding wire - Google Patents

Abstract

PURPOSE:To stabilize welding accurately and positively capturing residue by detecting used amount of a welding wire from revolutions of a winding frame. CONSTITUTION:A pulse generator 26 outputs a pulse signal each time a detector 24 detects a projection 22, where the cycle T1 is the time for one rotation of a winding frame 60. A timer circuit 28 starts to measure time by a synchronous signal of the generator 26 and completes the operation of a time piece after the set time T2 of a variable time setting device 30. A time comparator 32 compares the cycle T1 and the time T2 and a welding wire 12 is continuously pulled out when T1>T2. When the relation turns to T1<T2, a signal of the circuit 32 activates an alarm circuits 34 to forcibly stop a motor 16 and alarming or the like is performed with a buzzer. The time T2 can be adjusted freely with the setting device 30 while the residue of the wire 12 for actuating a circuit 34 can be set as desired thereby accurate and positive sensing of the residue and the used amount of the wire 12 can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the amount of welding wire used, particularly for detecting the amount of welding wire wound around a winding frame.

Generally, the welding wire used in automatic welding machines is M
As shown in Figures 1a and 1b, it is wound around a circular winding frame lO. During welding, the welding wire 1 wound around the winding frame 10
2 continuously. The welding wire 12 is pulled out from the outside of the winding frame IO while rotating the winding frame IO. When the welding wire 12 is running low as shown in FIG. 1C, the wire 12 must be replaced with a new winding frame 10 to replenish the wire 12'ft before it runs out. If the welding wire runs out during automatic welding, welding will be interrupted midway and a seam will occur in the welded area, resulting in a welding defect.

However, in the past, the remaining amount of welding wire 12 in the winding frame 10 could only be confirmed visually by the welding operator, and for this reason, the welding operator may misjudge the remaining amount or forget to check the remaining amount during welding. In the past, it has often been the case that the welding wire I2 runs out during the welding process and the welding has to be interrupted.

This invention was made in view of the conventional problems mentioned above, and its purpose is to reliably and accurately check the remaining amount of welding wire, which conventionally relied solely on the intuition and attentiveness of the welding operator. To provide a welding wire usage amount detecting device which can prevent welding from being forced to be interrupted due to running out of wire during welding.

In order to achieve the above object, the present invention provides an automatic welding machine that performs welding while continuously unwinding a welding wire wound around a winding frame, in which a number of pulse signals corresponding to the rotational speed of the winding frame is transmitted. a variable time setting means whose set time changes in proportion to the reciprocal of the unwinding speed of the wire; a period of the pulse signal from the pulse generating means; and a set time of the variable time setting means. and time comparison means for comparing the pulse signals, and the alarm means is activated when the period of the pulse signal becomes equal to or less than the set time.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

First, FIG. 2 is a diagram for explaining the basic principle of this invention.

In Fig. 2, ■1 is the drawing speed of the welding wire (隨/
), DI is the welding wire pull-out position at the start of use (ml
), D2 is the welding wire pull-out position (am) at the end of use.
, N indicate the rotational speed (rpm) of the winding frame, respectively.

The relational expression among these Vl, DI, and D2 is as follows.

■1=πXDIXNI ■1=πXD 2XN 2 N 2/N l =D 1/D 2 N2=(DI/D2)
represents the rotational speed (rpm) at D2, and π represents pi.

As shown in the above equation, even if the drawing speed is the same, the rotational speed of the winding frame 10 differs depending on the drawing position, that is, the remaining amount of welding wire 12. Furthermore, if the withdrawal speed is the same, the rotational speed of the winding frame 1O will be slower near the end of use than near the start of use by the diameter ratio (DI/D2). This means that the amount of welding wire 12 used can be determined by measuring the rotational speed of the winding frame 10.

However, in reality, the welding wire 12 is
is not always drawn out at a constant speed.

However, even if the speed vn is arbitrary, the rotational speed at the drawer positions D1 and D2 is always the diameter ratio (D t /n
2), there will be no problem if the measured value of the rotational speed (rotation speed) is corrected by the variation in the withdrawal speed.

FIG. 3 shows an embodiment of the device according to the invention.

The device shown in the figure includes a winding frame 10 around which a welding wire 12 is wound;
A drive roller 14 for pulling out the welding wire, an electric motor 16 for rotating this roller 14, a control circuit I8 for the electric motor 16, a speed setting device 20 for the electric motor I6, a protrusion (strike) 22 for detecting the rotation of the winding frame 10, and this A detector 24 operated by the protrusion 22, a pulse generator 26 operated by the detection signal of this detector 24, this pulse generator 2
A timer circuit 28 that measures time for each pulse signal in synchronization with the pulse signal from 6, a variable time setter 30 that sets the time measured by this timer circuit 28, and a comparison between the pulse period of the pulse signal and the measured time. time comparison circuit 32
, and an alarm circuit 34 activated by the output of this comparison circuit 32.

Next, the operation of the above device will be explained.

First, the speed setter 20 causes the control circuit wII8 to rotate the electric motor 16. This causes the drive roller 14 to rotate and pull out the welding wire 12 from the winding frame 10. When the welding wire t2 is drawn out, the winding frame lO rotates in response to the drawing speed, and the protrusion 22 also rotates. Detector 24
Every time the sensor detects the protrusion 22, the pulse generator 26 outputs a pulse signal as shown in FIG. 4a. In the period of this pulse signal, 1 is the time for one rotation of the protrusion 22, that is, the time for one rotation of the winding frame IO.

On the other hand, the timer circuit 30 starts measuring time in response to a synchronizing signal from the pulse generator 26, and ends the time measuring operation after a time T2 set by the variable time setting device 30. The fourth diagram shows the output signal of the timer circuit 28.

The pulse signal period Tl of the pulse generator 26 and the measured time T2 of the timer circuit 28 are compared by the time comparator 32, and if they are in a relationship of TI>T2 as shown in a and b of FIG. 4, the control circuit 18 drives the electric motor t6, and the wire 12 is continuously drawn out.

However, the welding wire 12 in the winding frame 10 is running low, and the drawer position is changed from DI to D2 as explained in FIG.
When the period shifts to , the rotational speed of the winding frame 10 becomes faster and the period Tl becomes shorter.

FIG. 4C shows the output waveform of the pulse generator 26 in this state. When the time T3 becomes shorter than the set time T2 of the timer circuit 28, the alarm circuit 34 is activated by the signal of the comparison circuit 32. be activated. In this case, either the electric motor 16 is forced to stop immediately by the alarm circuit 34, or
Alternatively, the operation mode can be arbitrarily selected, such as only warning the operator by a buzzer or the like, or forcing the motor 16 to stop after a certain period of time has elapsed after the warning by the buzzer. Since the measured time T2 of the timer circuit 28 can be freely adjusted by the variable time setting device 30, the remaining amount of welding wire 12 that activates the alarm circuit 34 can be set arbitrarily. This makes it possible to reliably and accurately perceive the remaining amount or used amount of welding wire 12.

Further, a signal proportional to the reciprocal of the drawing speed of the welding wire 12 by the speed setting device 20 is sent from the control circuit 18 to the timer circuit 28 . For example, when the drawing speed of the welding wire 12 is increased by the speed setting device 20, the period Tl in FIG. 4a becomes shorter, but this signal shortens the time T2 in FIG. 4 by the increased speed. It works like this. Conversely, if you decrease the speed, it will become longer and always T.
The relative relationship between l and T2 remains the same.

As described above, the welding wire usage amount detection device according to the present invention can easily detect the usage amount of welding wire based on the number of revolutions of the reel, and can also prevent the welding wire from being erroneously used when welding is insufficient. can be prevented from starting. Therefore, it is possible to reliably prevent welding defects from occurring due to interruption of welding midway. Furthermore, the remaining amount of welding wire can be determined reliably and accurately without relying on the operator's attentiveness or intuition, allowing for stable welding and reducing the burden on the operator. .

[Brief Description of the Drawings] Figure 1 is a front view and side view of a welding wire used in this invention, Figure 2 is a diagram for explaining the invention in detail,
FIG. 3 is a block diagram showing an embodiment of a welding wire usage amount detection device according to the present invention, and FIG. 4 is a timing chart diagram for explaining the operation of the device of the embodiment shown in FIG. Identical members in each figure are given the same reference numerals, lO is the winding frame, 12
is welding wire, 14ij drive roller, 16 is electric motor, 1
8 is a control circuit, 20 is a speed setting device, 22 is a protrusion (rotation detection striker), 24h detector, 26 is a pulse generator, 28 is a timer circuit, 30 is a variable time setting circuit, 3
2 is a time comparison circuit, 34 is an alarm circuit, 'rt and 'ra are rotation periods of the winding frame, and T2 is a time measured by a timer circuit. Agent Patent Attorney Shin Kuzuno (and others) Figure 1 (G) (b) (C) Figure 2 Figure 4 Mr. Commissioner of the Japan Patent Office 1. Indication of the case Patent Application No. 1987-216226 2. Invention Name of Welding Y V usage amount detection device 3,
Relationship with the person making the amendment Patent applicant address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Co., Ltd. Representative Katayuni Yabu 4, Agent address Marunouchi, Chiyoda-ku, Tokyo 2-2-3, Mitsubishi Electric Corporation, 5, Detailed explanation of the invention in the specification subject to amendment. (2) 51-

Claims (1)

[Claims] (1) In an automatic welding machine that performs welding while continuously unwinding a welding wire wound around a winding frame, a pulse generating means for generating a number of pulse signals corresponding to the rotational speed of the winding frame; It has variable time setting means for changing the set time in proportion to the reciprocal of the unwinding speed, and time comparison means for setting the period of the pulse signal from the pulse generating means and the set time of the variable time setting means. . A welding wire usage amount detecting device, wherein the welding wire usage amount detection device is configured to actuate an alarm means when the cycle of the pulse signal becomes equal to or less than the set time.