JPH0767626B2 - Automatic butt welder - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an automatic butt welder, and more particularly to an automatic butt welder capable of automatically determining the quality of a welded product at the end of welding.

[Prior art]

A conventional automatic butt welding machine is generally a power source, a pair of electrodes that are respectively connected to the power source through a transformer, and that sandwich the respective members to be welded so that the opposite end surfaces of the pair of members to be welded face each other, and A pressurizing device such as a pneumatic cylinder for pressing the movable electrode of the pair of electrodes against the fixed electrode in order to press and contact the opposite end faces of the respective members to be welded held by the electrodes with each other. Further, the pressurizing device is adapted to be operated and controlled by a control device. In welding with this butt welder, if the amount of fusion from the opposite end faces of the pair of members to be welded is too small, the welding strength will be low and the welding quality will be poor. While high welding strength is obtained, the weld burr height becomes large and the welding quality deteriorates. Therefore,
It is preferable that the melting amount be moderate.

[Problems to be Solved by the Invention]

By the way, since the automatic butt welding machine is not provided with a mechanism for judging the quality of welding, conventionally, for example, the welding quality of a welded product is judged as follows. That is, an index is marked with a marking needle at a position separated from the facing end surface of each member to be welded by a predetermined distance, and the distance between both indexing members in a state where both facing end surfaces of the pair of members to be welded are in close contact with each other before welding. Is measured with a caliper, and after welding, the distance between both indexes is again measured with a caliper. Then, the quality of the welding quality is determined based on the difference in the distance between the two indexes before and after the welding, that is, the melting amount from the opposite end surfaces of the pair of members to be welded. However, such a welding quality determination method is very troublesome, and thus there is a problem that it cannot be performed for all welded products. The present invention has been made in view of the above problems and to solve these problems effectively. Therefore, its purpose is
An object of the present invention is to provide an automatic butt welder capable of automatically determining the quality of welding for all welded products at the end of welding.

[Means, actions, and effects for solving problems]

The automatic butt welding machine according to the present invention is operationally controlled by the control device, holds one member to be welded on the fixed electrode, while holding the other member to be welded on the movable electrode, and fixes the movable electrode by the pressure device. While pressing in the direction of the electrodes and conducting electricity between both electrodes, the opposite end faces of both members to be welded are butt welded. And, in order to solve the problems of the above-mentioned prior art, it is configured as follows. That is, a melting amount detecting device for detecting the melting amount at the time of welding as a moving amount of the movable electrode with reference to the contact end surfaces of both members before the start of energization, and the melting amount detected by the melting amount detecting device. By comparing the melting amount display device for displaying the amount, the melting amount at the end of melting detected by the melting amount detecting device, and a preset reference melting amount, the melting amount at the end of welding The control device performs zero setting of the display value of the melting amount display device almost in synchronization with the start of the energization, and substantially in synchronization with the end of the energization. The display value of the melting amount display device is latched. According to the butt welding machine having the above-described configuration, the amount of fusion from both facing surfaces of the pair of members to be welded is constantly measured by the fusion amount detection device during welding. Then, at the end of welding, the determination means determines the suitability of the melting amount by comparing the melting amount at that time with the reference melting amount. Therefore, according to the butt welder of the present invention, the welding quality of all welded products can be automatically determined at the end of welding.

【Example】

An embodiment according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram of a butt welding machine according to an embodiment of the present invention. The butt welding machine according to the present embodiment is operated and controlled by the control device 11 so that one member to be welded 7 is held by the fixed electrode 5 while the other member to be welded 8 is held by the movable electrode 6 and the pressurizing device. While pressing the movable electrode 6 in the direction of the fixed electrode 5 by the pneumatic cylinder 9 as
The opposing end faces 7a, 8a of 8 are butt welded. Each of the electrodes 5 and 6 is driven by the receiving portions 5a and 6a and a clamp device 10 such as a hydraulic cylinder and the receiving portions 5a and 6a.
And driving parts 5b and 6b for holding the members to be welded 7 and 8 therebetween. Therefore, the holding of each electrode 5, 6 with respect to each welded member 7, 8 is
By the clamp device 10, the electrodes 5 and 6 are firmly clamped on the members 7 and 8 to be welded. In addition, the pair of electrodes 5 and 6 are provided for the switch 2 and the transformer 3.
It is connected to the power source 1 via the, so that the pair of electrodes 5, 6 can be energized. The switch 2 is controlled by the control device 11 to control the power source 1 and the pair of electrodes 5, 6
The circuit that connects to and is opened and closed. The current flowing through this circuit is detected by the toroidal coil 19, and the detected value is displayed on the current display device 16. Further, the butt welding machine according to the present embodiment includes a melting amount detecting device 12, a melting amount displaying device 17, and a welding quality judging device 15 as a judging means. The melting amount detecting device 12 detects the moving stroke of the melting amount detecting arm 13 fixed to the movable electrode 6 at the time of welding, so that the melting amount from the opposite end faces 7a, 8a of the pair of members to be welded 7, 8 Is to detect. The melting amount display device 17 digitally displays the melting amount detected by the melting amount detection device 12. still,
The display value of the melting amount display device 17 is automatically set to zero or latched (held) by a signal from the control device 11. Further, the welding quality determination device 15, by comparing the melting amount at the end of welding detected by the melting amount detection device 12, by comparing the upper limit value and the lower limit value of the preset appropriate melting reference amount, The suitability of the melting amount at the end of welding is determined. When the amount of melting at the end of welding is outside the upper and lower limits, the result is notified to the operator by a warning means such as a buzzer or a lamp. The butt welding machine according to the present embodiment is a pair of members to be welded 7,8.
Of each electrode so that both facing end surfaces 7a, 8a of the
Each member to be welded between the receiving portions 5a, 6a of 5, 6 and the driving portions 5b, 6b
After positioning 7,8, for example, the timer is controlled by the controller 11 as shown in FIG. The pair of members to be welded 7,8 at the end of welding
The appropriate upper and lower limits of the amount of melting from the opposite end faces 7a, 8a are measured in advance by, for example, a tensile test or the like, and the upper and lower limits are set in the welding quality determination device 15. The operating procedure of the automatic butt welding machine having the above-mentioned configuration will be described below with reference to the flowchart of FIG. First, when the activation switch 18 starts the operation, in step S1, the control device 11 inputs a drive start signal to the clamp device 10 to drive the clamp device 10. As a result, the driving portions 5b and 6b of the electrodes 5 and 6 press the receiving portions 5a and 6a through the members to be welded 7 and 8 respectively, and as a result, the members to be welded 7 and 8 are firmly fixed by the electrodes 5 and 6. Tighten (clamp)
Be held. Next, a predetermined time after the clamp device 10 is started to be driven, in step S2, a drive start signal is input from the control device 11 to the pneumatic cylinder 9 to drive the pneumatic cylinder 9. As a result, the movable electrode 6 is pressed so as to approach the fixed electrode 5, and the pair of members to be welded 7, 8 are welded.
Both opposing end surfaces 7a, 8a of the are pressed against each other. Next, a predetermined time after the pneumatic cylinder 9 is started to be driven, in step S3, the control device 11 inputs the closing signal of the above circuit to the switch 2, and the pair of electrodes 5, 6
Energization is started in the meantime. In synchronization with this, in step S7, a zero set signal is input from the control device 11 to the melting amount display device 17, and the display value of the melting amount display device 17 is set to zero. After the energization is started, in step S8, the moving amount of the movable electrode 6, that is, the pair of members to be welded is detected by the melting amount detecting device 12.
The amount of melting from both opposing end faces 7a, 8a of 7, 8 is detected, and the value is displayed on the melting amount display device 17. The current passing through the circuit is detected by the toroidal coil 19 and the value is displayed on the current display device 16. Then, after a lapse of a predetermined time from the start of energization, in step S4, the opening signal of the circuit is input to the switch 2 from the control device 11, and the energization between the pair of electrodes 5 and 6 is terminated. This completes the welding of the pair of members 7 and 8 to be welded. Next, a predetermined time after the end of energization, a reverse drive start signal is input from the control device 11 to the pneumatic cylinder 9 to start the reverse drive of the pneumatic cylinder 9. As a result, the pressure of the movable electrode 6 on the fixed electrode 5 is released.
Further, in synchronization with this, the melting amount display device from the control device 11
When the signal of the display value latch is input to 17, the opposing end surfaces 7a of the pair of members to be welded 7, 8 after the end of energization, that is, after the end of welding,
The melting amount from 8a is latched by the melting amount display device 17. In addition, almost simultaneously with step S5, in step S6, a signal for starting reverse drive is input from the control device 11 to the clamp device 10, and the clamp device 10 is started to perform reverse drive. As a result, the fastening of the electrodes 5 and 6 to the members to be welded 7 and 8 is released. Further, in parallel with this, in step S10, the display value latched in step S9 from the melting amount display device 17 is input to the welding quality determination device 15, the latched value, and the melting amount at the end of welding. The welding quality is determined by comparing the reference upper limit value and the lower limit value of. If the latched display value is outside the upper and lower limits as a result, the operator is notified of this by a lamp or a buzzer. Therefore, when a defective welding product is produced, the operator can easily recognize it. This is the end of the operation of the automatic butt welding machine according to the present embodiment. Therefore, according to the automatic butt welding machine according to the present embodiment, it is possible to automatically and accurately determine the quality of welding quality of all welded products. Further, in the present embodiment, since the melting amount is latched by the melting amount display device 17, when a defective welding product is produced, the operator can easily know the cause of the defective product. Therefore, in consideration of the cause of this defect, the device can be easily adjusted so that the next defective product does not occur. Further, the automatic butt welder according to this embodiment is manufactured at low cost because various known devices are added to the conventional automatic butt welder. Incidentally, in the above-mentioned embodiment, after the end of energization, step S9
In the above, the value of the melting amount is latched in synchronization with the release of pressure in step S5, but it may be performed in synchronization with the release of clamp in step S6. Further, in the above-described embodiment, the series of operation steps of steps S7 to S10 are started in synchronization with the energization start of step S3, but the pneumatic cylinder 9 of step S2 is started.
It may be started at any time after the start of driving and immediately before or immediately after the start of energization in step S3. Further, in the above-described embodiment, in order to perform the zero setting of the melting amount display device 17 in step S7, a zero set signal is input from the control device 11 to the melting amount display device 17 in synchronization with the start of energization in step S4. However, when the toroidal coil 19 detects that a current starts flowing in the circuit and the value is displayed on the current display device 16, the current display device 16 displays zero on the melting amount display device 17. A set signal may be input.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an automatic butt welding machine according to an embodiment of the present invention, and FIG. 2 is a flowchart showing an example of control by a control device of the automatic butt welding machine. 1 ... Power supply, 2 ... Switch, 3 ... Transformer, 5 ... Fixed electrode, 6 ... Movable electrode, 7,8 ... Joined member, 7a, 8a ... Opposing end face, 9 ... Pressurization Device (pneumatic cylinder), 10 ... Clamping device, 11 ... Control device, 12 ... Melting amount detecting device, 13 ... Melting amount detecting arm, 15 ... Judging means (welding quality judging device), 16 ... Current Display device, 17 ... Melting amount display device, S1 to S10 ... Operating steps.

Claims (1)

[Claims] 1. A control device (11) controls the operation of holding one member to be welded (7) on a fixed electrode (5) while holding the other member to be welded (8) on a movable electrode (6). Then, the movable electrode (6) is pressed in the direction of the fixed electrode (5) by the pressurizing device (9), and the members to be welded (7, 8) are welded while energizing the electrodes (5, 6). Opposite end face of (7
In an automatic butt welding machine for butt welding a, 8a), the melting amount at the time of welding is determined by measuring both members (7,
Movable electrode (6) with reference to the contact end surfaces (7a, 8a) of 8)
Melt amount detection device (12) for detecting the amount of movement of the melt, a melt amount display device (17) for displaying the melt amount detected by the melt amount detection device (12), and the melt amount detection device (12) A determination means (15) for determining whether or not the melting amount at the end of welding is appropriate by comparing the above-mentioned melting amount at the end of melting detected by The control device (11) zero-sets the display value of the melting amount display device (17) almost in synchronization with the start of the energization, and the melting amount display device almost in synchronization with the end of the energization. An automatic butt welding machine characterized in that it latches the display value of (17).