JPH0929457A - Spotting number monitoring device for manual spot welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent welding defect from lack of spot welding by informing a worker with an alarm that a number of spotting of spot welding is short by using a welding completion signal outputted from a welding control device. SOLUTION: An object to be welded clamped with a jig is held between electrode tips 6a, 6b of a welding gun 6 and a prescribed welding current is supplied between the electrode tips 6a, 6b and then spot welding is executed. By confirming this with a welding control device 3, a prescribed welding completion signal is inputted in a welding number counting part of a monitoring control part. A number of places to be spot welded is set/stored in the welding number counting setting part beforehand, this is compared to the counted number from the welding number counting part. When a worker pushes a working completion button, a comparing signal is outputted from a comparing part. In the case where the counted number of the welding number counting part is not reached to the set number of a welding setting part, an alarm signal is supplied from the comparing part to the alarm part and the alarm is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for monitoring the number of spot weldings, that is, the number of hit points when spot welding a workpiece by using a manual spot welding machine. The present invention relates to a number-of-spots monitoring device for a manual (hand-operated) spot welding machine having a function of preventing forgetting of spot welding (insufficient number of spots) in the spot welding process of a vehicle body.

[0002]

2. Description of the Related Art For example, when welding a vehicle body of a four-wheeled vehicle, a worker may manually perform a so-called hand-spot spot welding operation with a welding gun. In this work, it is necessary to surely perform spot welding one by one at all of the predetermined locations of the vehicle body, but conventionally, it is necessary to spot whether or not the predetermined number of spot weldings have been performed at all the predetermined locations. The actual condition is that the operator visually confirms after the welding work.

[0003]

However, when performing spot welding work using a manual spot welder (portable spot welder), there is a risk of forgetting to perform spot welding because the work is manual. In addition, since the operator checks whether the spot welding has been forgotten or not by visual inspection, there is a risk that the welding work may be completed without spot welding some of the prescribed spots to be spot welded. In such a case, a defective product is produced due to insufficient spot welding spots.

The present invention has been made to solve such a problem, and its purpose is to reliably prevent the generation of defective products due to insufficient spot welding spots by controlling the cost and the simple structure. An object of the present invention is to provide a device for monitoring the number of spots of a manual spot welding machine which is made possible.

[0005]

In order to achieve the above object, in the present invention, a welding gun for spot welding which is manually moved and operated, and a welding control device for controlling the operation of the welding gun are provided. Each has a manual start switch that outputs a welding command signal to the welding control device, and when the start switch is operated, the welding command signal is supplied to the welding control device to perform spot welding by the welding gun. In the manual spot welder configured as described above, based on the welding command signal output from the start switch and the welding number setting unit that presets the prescribed number of spot weldings of the workpiece to be spot-welded in advance. A welding number counter that counts a welding completion signal output from the welding control device when the welding control device operates and the predetermined welding control is normally completed. And isolation portion, and a comparator for comparing the outputs of the weld count setter and weld number count section from each other,
The spot welding work is operated after the completion of the spot welding work, and an alarm unit to which a comparison signal is input from the comparison unit in response to pressing the work completion button is provided. When the work completion button is pressed in the absence of the alarm, an alarm is issued from the alarm unit based on the output signal from the comparison unit.

Further, according to the present invention, a jig control device for automatically controlling a jig for clamping an object to be welded in accordance with a predetermined sequence is provided, and when the work completion button is pressed, the number of times of welding is counted. When the prescribed number of spot weldings is not reached, the jig control device is maintained in the clamped state based on the output signal from the comparison unit so that the jig control device is not set in the unclamped state. are doing.

[0007]

[Function] When the operator determines that the manual spot welding work has been completed and switches the work completion button to the ON state, and if all the prescribed spot welding points have been welded, an alarm is issued from the alarm section. Not emitted. In addition, if the spot welding is forgotten even in a part of the prescribed spot welding spots, the alarm unit gives an alarm so that the worker can recognize that the spot welding has been forgotten. By performing spot welding of the welded spots, it is possible to prevent defective products due to insufficient spotting.

Further, when spot welding is forgotten even at a part of the prescribed spot welding spot, the jig control device is configured so as not to be in an unclamped state, so that the workpiece to be welded is left as spot forgotten. Is not removed from the jig, and a part having the prescribed number of welding points can be obtained by spot welding again.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a manual spot welder (portable spot welder) 1 equipped with a spot number monitoring device according to the present invention. In FIG. 1, 2 is a welding power source circuit breaker and 3 is a welding power source circuit breaker. Is a welding control device (a controller of a welding machine), 4 is a welding transformer having a gun pressurizing valve 5 and the like, and 6 is a pressurizing cylinder 7 operated by the valve 5.
Welding gun equipped with, 8 is a welding transformer 4 and a welding gun 6
It is a rail frame that holds these in a suspended state and slidably supports them. The above-described welding gun 6 is of a type that is manually operated by an operator, and a starting switch 9 for starting the operation of the welding gun 6 is provided at an appropriate position of the welding gun 6.

The manual spot welding machine 1 of this embodiment is
A dot number monitoring device 10 having a configuration as shown in FIG. 2 is provided. The number-of-spots monitoring device 10 includes a monitoring control unit 11 to which a welding completion signal from the welding control device 3 is input, and an alarm including a buzzer, a lamp, and the like that are activated based on the output signal from the monitoring control unit 11. And a part 12. Then, as shown in FIG. 3, the monitoring control unit 11 outputs from the welding number setting unit 13 that presets the prescribed number of spot welding times of the workpiece to be spot-welded and the start switch 9 described above. A welding number counting unit 14 that counts a welding completion signal output from the welding control unit when the welding control device 3 operates based on the welding command signal and the predetermined welding control is normally completed; Number of times setting section 1
3 and a comparison unit 15 that compares the outputs of the welding number counting unit 14 with each other.

Further, the number-of-spots monitoring device 10 is equipped with a work completion button 16 (see FIG. 2). When the work completion button 16 is pressed after the completion of the spot welding work, the comparison signal from the comparison section 15 is sent. It is adapted to be input to the alarm unit 12. Further, the number-of-spots monitoring device 10 is provided with an alarm release button 17 (see FIG. 2), and a predetermined alarm release signal is supplied to the monitoring control unit 11 when the alarm release button 18 is pressed. Is configured.

Further, the manual spot welding machine 1 of this embodiment is
A jig control device 19 for automatically controlling a jig for clamping a workpiece is provided according to a predetermined sequence (see FIG. 2), and when the work completion button 16 is pressed, the welding operation count number is specified. When the number of spot weldings is less than the number of times, the monitor control unit 11 supplies an operation prohibition signal to the jig control device 19.

Next, referring to the flow charts of FIGS. 2, 3 and 4, for the operation procedure and the function at that time when spot welding is performed using the manual spot welder 1 of the present example having such a configuration. The explanation is as follows. First, an operator manually moves the welding gun 7 to place the welding gun 7 at a predetermined spot welding position, and then turns on the starting switch 9. Along with this, the gun pressurizing valve 5 and the gun pressurizing cylinder 7 are operated based on a predetermined sequence pre-installed in the welding control device 3, and the workpiece clamped by the jig is the electrode of the welding gun 6. While being sandwiched between the tips 6a and 6b (see FIG. 1), a predetermined welding current is supplied between these electrode tips 6a and 6b to perform spot welding at the first one place (one step).

When the welding control device 3 operates normally and one spot welding is completed, the welding control device 3 confirms this and a predetermined welding completion signal is sent from the welding control device 3 to the monitoring control unit 11. Is input to the welding frequency counting unit 14. Then, each time the spot welding operation is performed, the number of times is counted by the welding number counting unit 14, and the information signal about the count number counted by the welding number counting unit 14, that is, the number of spot welding performed actually is compared with the comparison unit. 15 is input. Thus, such a process is repeated for one object to be welded a prescribed number of times.

On the other hand, the welding number setting unit 1 of the monitoring control unit 11
The number of spots to be spot-welded, that is, a prescribed number of spots is preset and stored in 3, and the predetermined set number (set value) is the count number from the welding number counting unit 14 in the comparison unit 15 described above. Compared to.

When the worker presses the work completion button 16 at the time when the worker recognizes that a series of spot welding work has been completed, the comparison section 15 outputs a comparison signal accordingly. At this time, if the count number of the welding number counting unit 14 has reached the setting number of the welding number setting unit 13, the comparison unit 15
The count number in the welding number counting unit 14 is reset to zero on the basis of the control signal from, and a series of spot welding operations are completed in a normal state. At this time, the alarm unit 12 is not activated, the jig control device 19 is unclamped in synchronization with the completion of the welding operation, and the workpiece is sent to the next step.

On the other hand, when the count number of the welding number counting unit 14 does not reach the setting number of the welding number setting unit 13, that is, when it does not reach the prescribed spot welding number, the comparison unit 15 notifies the alarm unit 12 of a predetermined number. An alarm signal is supplied, and an alarm sound by a buzzer or an alarm display by a lamp is made, thereby issuing an alarm to the operator that the number of spot welding spots is insufficient. At this time, the welding count value is held in the welding count section 14 at the time when the spot welding operation is finally completed (when the work completion button 16 is pressed). Also, work completion button 1
When the number of welding operation counts is smaller than the prescribed number of spot weldings when 6 is pressed, the jig control device 19 maintains the clamped state of the workpiece based on the output signal from the comparison unit 15, The controller 19 is not set to the unclamped state. For this reason, the object to be welded, which is defective in welding, is held without being removed from the jig.

In such a case, the worker first releases the alarm state by pressing the alarm release button 17, confirms the spot where the spot welding operation has been forgotten, and performs spot welding at the spot. And again, work completion button 1
6 is pressed, and by confirming that no alarm is issued at this time, it is confirmed that spot welding has been performed on all the prescribed portions, and the spot welding operation is completed.

When the spot welding work for one work piece is completed, the spot welding work for the following work piece is started again, and such a series of operations is performed for each one work piece. It is done sequentially.

A manual spot welder 1 having such a configuration
According to the number-of-spots monitoring device 10, the confirmation as to whether or not the spot welding is performed by the regular number of spots can be surely recognized by the alarm without visually confirming. Therefore, even an operator unfamiliar with the spot welding work can significantly reduce the occurrence of spot welding defects due to insufficient spotting. Further, since it is not necessary for the worker to be conscious of counting the number of hit points, it is possible to concentrate on the welding work. In addition, there is an advantage that the control system can be realized at a low cost and with a simple structure, while having such practical effects.

Further, according to this embodiment, since the control of the supervisory control unit 11 and the control of the jig control device 19 are used together as described above, when the welding point is insufficient, the unclamping (removal) of the workpiece is performed. Therefore, it is possible to prevent the generation of defective welding products.

The embodiment of the present invention has been described above.
The present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, the series of spot welding operations are not limited to the sequence shown in FIG. 4 and can be variously changed as necessary. Further, although the above-mentioned embodiment is intended for the portable spot welder, it can be applied to all other manual spot welders that are not sequence-controlled, such as a robot welder.

[0024]

As described above, according to the present invention, the number of spot welding spots is insufficient for the operator by effectively utilizing the welding completion signal output from the ordinary welding control device (forgetting spot welding). Since it is configured to notify by alarm instead of visual inspection, the operator can surely recognize the shortage of the number of spots at the spot welding by the control of the low cost and simple configuration. It is possible to prevent defective welding products. Therefore, even an operator unfamiliar with the spot welding can perform the spot welding easily and accurately, and since it is not necessary to manage the number of spots during the welding work, the worker can concentrate on the welding work.

Further, according to the present invention, in the case where the number of spot welding spots is insufficient, the jig control device is maintained in the clamped state and is not set in the unclamped state. It is possible to reliably prevent a defect such as sending a defective welding product that is forgotten to be spot-welded even in part to the next process.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of a manual spot welding machine provided with a hitting point monitoring device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a hitting point monitoring device according to the present invention.

FIG. 3 is a block diagram showing a configuration of a monitoring control unit in the hitting point monitoring device.

FIG. 4 is a flowchart showing an operation when performing a spot welding operation using the above-mentioned manual spot welding machine.

[Explanation of symbols]

 1 Manual Spot Welder 3 Welding Control Device 6 Welding Gun 9 Start Switch 10 Spotting Number Monitoring Device 11 Monitoring Control Unit 12 Alarm Unit 13 Welding Number Setting Unit 14 Welding Number Counting Unit 15 Comparison Unit 16 Work Complete Button 17 Alarm Release Button 19 Jig control device

Claims (2)

[Claims] 1. A welding gun for spot welding which is manually moved and operated, a welding control device which controls the operation of the welding gun, and a manual start switch which outputs a welding command signal to the welding control device. In a manual spot welding machine configured to perform spot welding by the welding gun by supplying the welding command signal to the welding control device at the time of operating the start switch, the welding target to be spot welded The welding number setting unit that presets the prescribed number of spot welding times of the object, and the welding control device operates based on the welding command signal output from the start switch, and the predetermined welding control is normally completed. At the time of welding, a welding number counting unit that counts a welding completion signal output from the welding control device and each of the welding number setting unit and the welding number counting unit are output. A comparison part for comparing forces with each other, a work completion button operated after completion of spot welding work,
When the work completion button is pressed under a condition where the comparison signal is input from the comparison unit in response to pressing the work completion button and the number of spot weldings is less than the specified number. In the above, the number-of-spots monitoring device for a manual spot welding machine is characterized in that an alarm is issued from the alarm unit based on an output signal from the comparison unit. 2. A jig control device for automatically controlling a jig for clamping an object to be welded in accordance with a predetermined sequence, wherein when the work completion button is pressed, the welding number count is the prescribed spot. When the number of times of welding is less than, the jig control device is maintained in a clamped state based on the output signal from the comparison part so that the jig control device is not set in the unclamped state. The spot number monitoring device for a manual spot welder according to claim 1.