JPS6110863Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a resistance welding machine in which a lower arm to which a lower electrode is attached can slide up and down.

In general, with resistance welding machines, if the interval between the upper and lower conductors on the secondary side (hereinafter referred to as the gap) is narrow, the secondary inductance will decrease and the welding current will increase, so it is recommended to weld even thick plates. However, it can only be applied to welding small objects. On the other hand, if the spacing between the bosoms is wide, the opposite is true. In other words, in order to perform more effective welding work, resistance welding machines have a structure in which the upper electrode or lower electrode can be slid up and down so that the gap between the welds can be adjusted, and the welding machine has to be designed so that the upper electrode or the lower electrode can be slid up and down. It is necessary to select the spacing.

Therefore, in the conventional resistance welding machine, as shown in FIG. 1, the lower arm 4 to which the lower electrode 3 is attached can be slid up and down with respect to the upper arm 2 to which the upper electrode 1 is attached. Note that the upper arm 2 rotates around an axis 6 by operating the foot pedal 5, and the lower arm 4
is guided by a slide portion 8 attached to the main body case 7 and slides up and down.

By the way, in a resistance welding machine, the object to be welded 9
is pressurized from above and below by upper electrode 1 and lower electrode 3,
Welding is carried out by passing a large current through this and melting it due to resistance heat generation in the welding part, and the upper arm 2 and lower arm 4 also function as secondary conductors.

Therefore, in a structure in which the lower arm 4 slides up and down as shown in FIG. 1, the following requirements are required.

That is, (1) the workpiece to be welded is pressurized at several hundred kilograms by the upper and lower arms, so mechanical strength is required to withstand this pressure. (2) Materials with good conductivity are required because large currents flow through them. (3) Even when the lower arm is slid up and down, it is necessary to guide the sliding movement so that the centers of the upper and lower electrodes can be easily aligned.

From this point of view, in conventional resistance welding machines, a T-shaped groove 8a is formed in a copper alloy casting or plate as the sliding part 8 of the lower arm 4, as shown in FIG.
A device with a

However, although such conventional resistance welding machines have good electrical conductivity, they have the disadvantage that they have weaker mechanical strength than iron-based materials and are more expensive.

Furthermore, machining is required to form the T-shaped groove 8a, resulting in an increase in cost.

The present invention eliminates these conventional drawbacks and provides a resistance welding machine with strong mechanical strength, good conductivity for supplying electricity to the lower electrode, and an inexpensive sliding mechanism. An embodiment of the present invention will be described below with reference to the drawings of FIGS. 3 and 4.

3 and 4, 10 is the upper electrode 11
12 is the upper arm to which the upper electrode 1 is attached;
The upper arm 10 is rotatably supported by the main body case 14. 15 is a slide mechanism for vertically sliding the lower arm 12, and this slide mechanism 15 is fitted into a slide guide section 16 having a T-shaped groove 16a, and into the T-shaped groove 16a of this slide guide section 16. By tightening or loosening the T-shaped nut 17 and the bolt 18 screwed into the T-shaped nut 17, a part of the slide guide portion 16 can be held between the T-shaped nut 17 and the bolt 18 screwed into the T-shaped nut 17. The slide guide part 16 is configured by an arm holder 19 whose state is released, and the slide guide part 16 has a first slide guide member 16b fixed to the main body case 14 by welding or bolts. A second slide guide member 16c forms a T-shaped groove 16a together with the first slide guide member 16b.
and its second slide guide member 16
It is constructed by attaching a conductive plate 16d made of copper or copper alloy to the surface of c that is in contact with the arm holder 19. Further, the conductive plate 16
One end of d is connected to one secondary terminal 20 of the welding transformer. Further, the upper arm 10 is connected to the other secondary terminal 21 of the welding transformer via a conductor 22.

In the resistance welding machine having such a configuration, the output obtained from the secondary terminal 21 of the welding transformer is supplied to the upper electrode 11 via the conductor 22 and the upper arm 10, and the output obtained from the secondary terminal 20 is supplied to the upper electrode 11 via the conductor 22 and the upper arm 10. is supplied to the lower electrode 13 via the conductive plate 16d, arm holder 19 and lower arm 12.

Also, by loosening the bolt 18 that fixes the arm holder 19 to the slide guide member 16, the arm holder 19 and the lower arm 12 can be removed.
can move up and down on the slide guide part 16, and in this state, slide the lower arm 12 up and down together with the arm holder 19 to adjust the gap between the arms, and then tighten the bolt 18 at that position. It can be adjusted to the optimal spacing.

As described above, according to the resistance welding machine of the present invention, the slide guide part of the slide mechanism for vertically sliding the lower arm is attached to the tip surface of the first slide guide member fixed to the main body case. A second groove forming a T-shaped groove together with the slide guide member.
It is constructed by attaching a second slide guide member and disposing a conductive plate with good electrical conductivity on the side in contact with the arm holder to which the lower arm of the second slide guide member is attached. Since the force is applied to the first slide guide member and the second slide guide member, and the welding current is supplied to the lower arm via the conductive plate, the force is applied to the first slide guide member and the second slide guide member. If it is made of a highly rigid iron-based material, the mechanical strength can be increased, and the amount of material such as copper or copper alloy, which has good conductivity, can be reduced to about 1/3 of that of conventional materials. Moreover, since the T-shaped groove into which the T-shaped nut is fitted is formed by the combination of the first slide guide member and the second slide guide member using flat steel plates, it is difficult to form the T-shaped groove. This eliminates the need for machining, resulting in the effect that the price can be reduced.

[Brief explanation of the drawing]

Figure 1 is a side view showing a conventional resistance welding machine, Figure 2 is a side view showing a conventional resistance welding machine.
The figure is a cross-sectional view taken along line A-A' in Figure 1.
4 is a plan view showing the main structure of a resistance welding machine according to an embodiment of the present invention, and FIG. 4 is a sectional view taken along line B-B' in FIG. 3. 12...Lower arm, 13...Lower electrode, 14...
...Body case, 15...Slide mechanism, 16...
Slide guide portion, 16a...T-shaped groove, 16b...
...First slide member, 16c...Second slide member, 16d...Conductive plate, 17...T-shaped nut, 18...Bolt, 19...Arm holder.

Claims (1)

[Scope of utility model registration request] A slide mechanism is provided to hold the lower arm to which the lower electrode is attached so that it can slide up and down, and the slide mechanism is fitted into the slide guide portion having a T-shaped groove and the T-shaped groove, and by tightening a bolt. A T-shaped nut that holds the slide guide part between an arm holder to which the lower arm is attached, and the slide guide part is attached to a first slide guide member attached to the main body case. A resistance welding machine comprising: a second slide guide member attached so as to form a T-shaped groove; and a conductive plate attached to the side of the second slide guide member that contacts the arm holder.