JPS63230280A - Resistance welding machine - Google Patents

Abstract

PURPOSE:To improve the welding working efficiency without interrupting the welding work by automating a change and polishing of electrode chips with a resistance welding machine. CONSTITUTION:Motors 18 and 38 are operated and both dividing tables 10 and 30 are rotated by 90 deg. and each electrode chip is moved to a next station. The chip tip is polished on the welding station and the electrode chips LC4 with the proper height come thereto an these electrode chips are used to continue the resistance welding by a pressure device 50 and a welding current feeder 60. On the other hand, the deformed or soiled electrode chips come on polishing stations Sug and Slg and are polished with polishing devices 70 and 80. At this time, a control part 94 actuates air cylinders 76 and 86 and advances rotating brushes 74 and 84 to the polishing stations Sug and Slg respectively and actuates motors 72 and 82 to rotate the rotating brushes 74 and 84. Moreover, the control part 94 takes in height information from a position sensor of a chip height detecting station and sends an inspection result.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resistance welding machine using an electrode tip, and more particularly to improved maintenance and management of the electrode tip.

(Conventional technology) FIG. 2 shows the structure of a typical conventional resistance welding machine.

When compressed air is sent into the air cylinder 100 and the piston rod 102 is lowered, the pressurized slide rod 108.
Cross roller guide 108. The pressure holding plate 112 is lowered via the pressure guide 110, and the spring pressing member 114 presses the compression coil spring 116 downward. This allows upper arm 118 . to receive the lower end of spring 116 . The upper electrode holder 120 and the upper electrode tip 122 are lowered together, and the material to be welded 128 is placed between them and the lower electrode tip 124.
．． 130 and start applying pressure.

Then, when the pressurizing force reaches a predetermined value, the microswitch 134 is turned on, and in response, the welding control circuit (not shown) starts energizing, and the welding power supply circuit (not shown)
The welding current flows through the electrode tips 122, 124 to the welded materials 128, 130, and the welded part is heated and melted by Joule heat, and when the current is cut off, a nugget is generated after cooling for a predetermined period of time, and the welding is completed. finish.

Note that 140 is a stopper member for receiving and stopping the pressurized slide 106, and 142 and 144 are an upper feeder and a lower feeder for supplying welding current.

(Problems to be Solved by the Invention) As mentioned above, during resistance welding, the electrode tip 122.12
Since high pressure and high temperature are applied to 4, the tip end becomes crushed and deformed as the number of welding increases. If this happens, the pressurizing force and welding current will deviate from the set values,
This will cause welding defects. Furthermore, plating or oil from the material to be welded may adhere to the tip end of the tip, and in this case as well, the welding current fluctuates due to electrodeposit or dirt, resulting in defective welding.

Therefore, it is necessary to polish or dress the tips of the electrode tips 122 and 124 at an appropriate time, and conventionally, for this purpose, the welding operation is interrupted and the operator cuts the electrode tips 122 and 124.
124 is polished by hand with a brush or with a die.

However, interruption of welding work causes a decrease in work efficiency, and manual polishing work makes maintenance and management of electrode tips troublesome and costly.

The present invention has been made in view of these problems, and an object of the present invention is to provide a resistance welding machine that automates the maintenance and management of electrode tips and improves welding efficiency.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an index table in a resistance welding machine that performs welding by applying an electrode tip to a material to be welded and applying pressure while applying current. an indexing mechanism that rotates intermittently at a predetermined angle; chip support means disposed at predetermined intervals on the indexing table and supporting each electrode chip; a pressurizing means for applying pressure to the welded material through the welding material; a welding current supply means for supplying a welding current to the welded material through the electrode tip at the first station; The present invention is configured to include a tip polishing means for polishing the tip of the electrode tip at the station.

(Function) When the tip of the electrode tip previously used at the first station becomes deformed or dirty, the indexing table is rotated by a predetermined angle between resistance welding operations.

Then, another electrode tip whose tip end has been neatly polished or shaped by the tip polishing means comes to the first station, and this electrode tip is used for subsequent resistance welding. This tip replacement is automatic and does not require interruption of the welding operation.

On the other hand, the tip of the consumable electrode tip transferred from the first station to another station is polished by a chip polishing device. This polishing work is also performed automatically without affecting the welding work. The electrode tip whose tip end has been cleaned in this way is later sent to the first station again by rotation of the indexing table.

(Embodiment) FIG. 1 shows the main parts of a resistance welding machine according to an embodiment of the present invention. This resistance welding machine has a pair of electrode tips (upper,
This is a direct resistance welding machine that applies pressure and welding current while sandwiching the material to be welded (lower electrode tip).

In this embodiment, as shown, an upper index table 10
Four upper electrode chips UCI-UC4 are supported by four upper chip holders UHI to UH4 arranged at 90° intervals on the top, while 90' are supported on the lower indexing table 30. Four lower electrode chips LCI-LC4 are supported by four lower chip holders LHI #LH4 arranged at intervals of .

The bisecting ratio tables 10.30, each of which is arranged with its table surfaces orthogonal to each other, are arranged at four positions (stations) intermittently rotated at 90° intervals about an axis 20.40 by the drive of a motor 18.38. ) type configuration, and the positioning machine and the side are stored in the box 22.42 on the back side of the table.

I Stage The lower station of the upper index table 10 and the left station of the lower index table 30 are welding stations SW, where the upper and lower electrodes (UCI, LCI in the illustrated state) are used for resistance welding. It will be done. This welding/welding station 3w is provided with a pressure device 50 and a welding current supply device 60, and resistance welding is performed by the following operations.

The pressurizing device 50 includes an air cylinder 52. is the driving source, and when this actuates and the piston 54 descends, the spring presser member 56. Compression coil spring 58. The arm 62 descends, and the tip 62a of the arm 62 contacts the upper end surface 12 of the tip holder UHI and presses the tip holder UHI downward.

As a result, the tip holder UHI slides downward along the guide 16 against the tension coil spring 14, and the workpiece 24, 28 is finally sandwiched between the upper electrode tip UCI and the lower electrode tip LCI. It will be done. When the piston 54 further descends, the compression coil spring 58 is elastically deformed, and a pressurizing force is applied to the workpiece 24, 26 through both electrode tips U C1, LCt, and when a predetermined value is reached, a microswitch (not shown) is activated. is activated, and in response, welding current is applied from the welding current supply device 60 to the workpiece 24.
26.

The welding current supply device 60 includes a welding power supply circuit (not shown) and an arm 62 . It is composed of a power supply bar 64 and upper and lower chip holders UHI, LHL. In other words, when energizing, the welding power supply circuit → arm 62 →
Upper chip holder UHI→upper electrode chip UC1-4-
VL welding material 24, 2E3 Welding current flows through the lower electrode tip LCI → lower tip holder LHI → power supply bar 64 → closing of the welding power supply circuit. Note that the power supply bar 84 is brought into contact with the lower surface of the lower tip holder LHI by driving the air cylinder 66.

In this way, electricity is applied for a predetermined time, and then cooling is performed to complete one resistance welding, and the air cylinder 52.68
will return. Thereafter, the material to be welded 24, 26 or the welding point is replaced with a new one, and then resistance welding is repeated in the same manner as described above.

The upper station of the stage upper indexing table 10 and the right station of the lower indexing table 30 are polishing stations SUG and SLG, respectively, in which chip polishing devices 70 and 80 are respectively provided.

These chip polishing devices 70.80 are equipped with motors 72.8
Donut-shaped rotating brush 74.84 at the tip of the rotating shaft of 2
and rotate it to polish the tip of the electrode tip (UO3, LC3 in the illustrated state). The air cylinders 76.86 guide the supports 78.88 of the motors 72.82 along arrows C1, GO, DI, respectively, along 79.89.
, DO moves in the direction of the force, and in the forward movement state shown, the rotating brushes 74 and 84 are connected to the polishing stations SUG, S
It is expanding into LG.

In this way, in this embodiment, the polishing of the electrode tip is automatically (mechanically) performed at stations SUG and SLG, which are separate from the welding stage tongue SW, independently of the welding operation, so that the welding operation is not interrupted. There is no need, and there is no need to have workers for polishing.

- Stage As shown in the figure, a chip height detection station SL■ is provided between the polishing station SLG of the lower indexing table 30 and the welding station 3w. Here, the position sensor 90 detects the height of the electrode tip (LC4 in the illustrated state) whose tip end has been polished and has become lower, and sends height information to the control section 94. Control unit 94
When the chip height is lower than the reference value, it issues an alarm signal AR to prompt adjustment. Therefore, when the electrode tip LC4 is next transferred to the welding station SW, resistance welding will be performed with the appropriate tip height.

Although not shown, the upper index table 10 also has a chip height detection station SUH between the polishing station SUG and the welding station SW.
is provided.

System Control Control of each part of the apparatus described above is performed by the control section 94. This control section 94 operates each section of the apparatus under sequence control in response to a tip exchange instruction signal KG from a resistance welding control device (not shown).

That is, first, the motor 18.38 is operated to rotate the ratio table 10.30 by 90' to move each electrode tip to the next station.

As a result, the welding station SW has an electrode tip with a cleanly polished tip and an appropriate height (for example, UC4).
, LC4), and resistance welding is continued without interruption using these electrode tips by the pressurizing device 50 and the welding current supply device 60.

On the other hand, the polishing stations SUG and SLG receive electrode tips (such as UC2 and LC2) whose tips have been deformed or dirty due to multiple welding, and the chip polishing devices 70 and 80 polish these electrode tips. administer. At this time, the control unit 94 operates the air cylinders 76.86 to move the rotating brushes 74.84 to the respective polishing stations S.
In addition to expanding into UG and SLG, motor 72.
82 to rotate the rotating brushes 74 and 84, respectively.

The control unit 94 also controls the chip height detection station SU.
The height information is taken in from the position sensors 90 and 92 of H and SLH and the inspection results are output.

Note that the tip replacement instruction signal KG from the resistance welding control device
When a no-current accident occurs (in other words, it is determined that the tip tip is dirty and current no longer flows), or when a preset number of welding is reached (in other words, it is determined that the tip tip is crushed into a fairly round shape). is given to the control unit 94 when the

Although one embodiment of the present invention has been described above, it should be understood that the present invention is by no means limited thereto.

For example, the number of chip holders UHI and LH1 and the number of electrode chips U Ci and L Ci arranged on the upper and lower index tables 10 and 30, respectively, are not limited to four as in the above embodiment. , any number is possible.

In addition, various types of chip polishing devices are possible in addition to the rotating brush type described above, and a polishing device that not only polishes the tip of the chip but also shapes it is also suitable.

In addition, although the above embodiment relates to a direct type resistance welding machine, the present invention can also be applied to an indirect type resistance welding machine that uses only one electrode tip. It is possible to get away with just one index table.

(Effects of the Invention) As described above, according to the present invention, the replacement and polishing of the electrode tip are automated, so there is no need to interrupt welding work for maintenance of the electrode tip, and manual polishing work is no longer necessary. , a significant improvement in welding work efficiency is realized.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing the main structure of a resistance welding machine according to an embodiment of the present invention, and FIG. 2 is a side view showing the structure of a typical conventional resistance welding machine. In the drawings, 10... Upper index table, 30... Lower index table, 18.38... Motor, 50... Pressure device, 60... Welding current supply device. , 70.80...Chip polishing device, 94...Control unit, UCI~UC4...Upper electrode chip, LCI-LC
4...lower electrode tip, UHI-UH4...upper chip holder, LHI-LH4...lower tip holder. Patent applicant Miyaji Denshi Co., Ltd. Company agent
Patent Attorney Takashi SasakiFigure 1Figure 2

Claims (1)

[Scope of Claim] A resistance welding machine that performs resistance welding by applying an electrode tip to a material to be welded and applying pressure while applying current, comprising: an indexing mechanism that intermittently rotates an indexing table at a predetermined angle; chip support means disposed at predetermined intervals on an indexing table and supporting the electrode tips, respectively; applying pressure to the workpiece through the electrode tips at a first station of the indexing table; pressurizing means; welding current supply means for supplying welding current to the workpiece through the electrode tip at the first station; A resistance welding machine comprising: a tip polishing means for polishing the tip of an electrode tip;