JPS6032550B2 - Method and device for controlling descent of welding electrode during chip dressing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for controlling the descent of a welding electrode during tip dressing, which is commonly used in spot welding machines, three-phase low frequency welding machines, and the like.

The electrodes used in the various welding processes mentioned above are, for example, 80k9
Most of the welding electrodes are quite heavy, and the welding electrodes must be reground (hereinafter referred to as tip dress).

), conventionally this was done by lowering the welding electrode under its own weight. That is, when tip dressing is performed by preparing an abrasive tool having an abrasive material such as sound paper on its surface at the lowering position of the welding electrode during tip dressing, and lowering the welding electrode by its own weight onto the abrasive tool. When the welding electrode, which is a considerable weight, is lowered by its own weight, it not only bounces on the abrasive odor and is easily scratched by sound paper, but also requires the abrasive tool to be rotated to dress the tip. The welding process must be carried out against the load of the welding electrode, so it is not only hard labor, but also has many problems, such as the need for good timing, the need for good heat-brining properties, and the danger. was. This invention was devised in view of the current situation, and its purpose is to prevent damage to the welding electrode by lowering the welding electrode at an extremely low speed through a rapid exhaust valve during tip dressing. Moreover, it is an object of the present invention to provide a method and device for controlling the descent of a welding electrode during tip dressing, which can simplify tip dressing work, is easy to handle, and is safe.

An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 in the drawings indicates a welding electrode of a spot welding machine or the like, which is connected to a diaphragm 4 of a diaphragm valve 3 via a piston rod 2.

In the diaphragm valve 3, the upper chamber 4a of the diaphragm 4 is provided with an electrode pressurizing side pressure guide pipe 5, and the lower chamber 4b of the diaphragm 4 is connected with an electrode rising side pressure guide pipe 6, respectively.

The electrode pressurizing side pressure conduit 5 has a valve 8 for opening and closing the conduit, a filter 9, a high pressure reducing valve 10, and a two-way valve 8 for opening and closing the conduit from the air source 7 side through which the base end is passed through, toward the diaphragm valve 4. An electromagnetic switching valve 11 and a flow rate control valve 12 are each incorporated.

The flow rate control valve 12 includes a throttle valve part 12a and a throttle valve part 1.
The check valve 12b is narrowed into a bypass passage 5a that bypasses the diaphragm upper chamber 4a and is controlled by air pressure from the diaphragm upper chamber 4a.

On the other hand, the electrode rising side impulse line 6 is a branched part between the filter 9 and the high pressure reducing valve 10 in the electrode pressurizing side impulse line 5, and the low pressure reducing valve 13, a two-way electromagnetic switching valve 14, and a quick exhaust valve 15, respectively.

This quick exhaust valve 15 is a check valve 1 of the flow rate control valve 12.
2b is provided with a check valve 15a facing oppositely to the check valve 15a, which functions as a relief valve when the welding electrode 1 is lowered.

Further, between the low pressure reducing valve 13 of the electrode rising side impulse pipe 6 and the Niman Mukai Kaji switching valve 14, there is a diaphragm lower chamber 4.
Toward the b side, an ultra-low pressure reducing valve 16, a rapid exhaust valve 17, and a two-way Kame-Shige switching valve 18 are connected to a tip-less lowering pressure conduit 19.
are incorporated in each.

This tip dressing pressure impulse tube 19 is branched from the electrode rising side pressure impulse tube 6.

Further, the ultra-low pressure reducing valve 16 is set to be extremely lower than the set pressure of the low pressure reducing valve 13, and the quick exhaust valve 17 is oriented in the opposite direction to the check valve 12b of the flow rate control valve 12, that is, the quick exhaust valve 15 is A check valve 17a is provided in the same direction as the check valve 15a, and the welding electrode 1 is lowered at a low speed during tip dressing of the welding electrode 1.

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

First, when moving the welding electrode 1 up and down in normal welding work, by energizing each of the two-way electromagnetic switching valves 11 and 14 with the welding electrode 1 locked and held in the raised position, The pressurizing side two-way electromagnetic switching valve 11 is switched to a position where the diaphragm side pipe line and the air source side pipe line communicate, and the rising side two-way electromagnetic switching valve 14 is switched to the position where the low pressure reducing valve 13 and the rapid exhaust valve 15 communicate. Switch to cutoff position. At this time, the two-way electromagnetic switching valve 18 is the two-way switching valve 1 on the rising side.
Since the pipe line is blocked at 4, no operation is involved. When the valve 8 is opened from this state, air pressure from the air source 7 passes through the filter 9, the high pressure reducing valve 10, the two-way electromagnetic switching valve 11, and the throttle valve part 2a of the flow rate control valve 12 into the diaphragm upper chamber 4a. As the pressure in the diaphragm chamber 4a is gradually increased, the rapid exhaust valve 15 operates as a relief valve. As the pressure is reduced, the welding electrode 1 gradually descends at a constant speed and pressurizes an object to be welded (not shown).

After welding, each two-way solenoid valve 11, 14
is switched to the illustrated position, and the other two-way electromagnetic switching valve 18 is energized and switched in the direction in which it communicates with the low pressure reducing valve 13, thereby causing the air pressure from the air source 7 to pass through the electrode rising side impulse pipe 6. This flows into the diaphragm lower chamber 4b, and the pressure inside the diaphragm lower chamber 4b is increased, so that the welding electrode 1 rises to the standby position, and the two-way electromagnetic switching valve 14 is switched at the raised standby position. As a result, the locked state is maintained. During tip dressing, the welding electrode 1 is locked and held in the raised position, and the two-way electromagnetic switching valve 11 on the pressurizing side is switched to a position where the diaphragm side pipe line and the air source side pipe line communicate with each other, and the welding electrode 1 is lifted up. The 20,000-way sliding door valve 14 on the side is connected to the quick exhaust valve 15.
At the same time, the other one-way electromagnetic switching valve 18 is switched to a position where it is cut off from the low pressure reducing valve 13, and the quick exhaust valve 17 is switched to a position where it is cut off. When the valve 8 is opened from this state, the air pressure from the air source 7 passes through the filter 9, the high pressure reducing valve 10, the 20,000-way electromagnetic switching valve 11, and the throttle valve part 12a of the flow rate control valve 12 to the diaphragm upper chamber 4a. As the pressure in the diaphragm upper chamber 4a gradually increases, the rapid exhaust valve 17 operates as a relief valve.
As the pressure in the diaphragm lower chamber 4b is gradually reduced as the pressure in the welding electrode 1 is increased, the welding electrode 1 is lowered very gently at a constant speed and comes into contact with a polishing tool (not shown).

That is, at the end of the welding work, there is only enough pressure in the diaphragm lower chamber 4b to support it from below, so the pressure on the diaphragm lower chamber 4b side does not drop immediately and the pressure set by the low pressure reducing valve 13 becomes extremely low. Since it takes time for the pressure to be released from the ultra-low pressure reducing valve 16 by an amount greater than the pressure set by the pressure reducing valve 16, the welding electrode 1 is made to descend immediately by simply switching the two-way electromagnetic switching valve 18. be. The descending speed of the welding electrode 1 during tip dressing can be adjusted by the ultra-low pressure reducing valve I6. As described above, this invention exhibits a relief valve function that lowers the welding electrode at an extremely low speed during tip dress in the electrode rising side impulse pipe that is fitted to the lower chamber of the diaphragm of the diaphragm valve that controls the vertical movement of the welding electrode. By interposing the rapid exhaust valve, unlike the conventional method in which the welding electrode is lowered by its own weight when dressing the tip of the welding electrode, the welding electrode is moved at an extremely low speed by the IJ leaf function of the rapid exhaust valve. can be lowered with
Therefore, there is no damage to the welding electrode due to the impact caused by the descending welding electrode, and the load on the welding electrode during tip dressing can be reduced by 4 mm, making tip dressing easier and safer. It has many beneficial effects.

[Brief explanation of the drawing]

The drawing is a welding electrode lowering control circuit diagram showing an embodiment of the present invention. 1...Welding electrode, 3...Diaphragm valve,
4a...Diaphragm upper chamber, 4b...Diaphragm lower chamber, 5...Electrode pressure side impulse pipe, 6...
... Electrode rising side impulse pipe, 16 ... Ultra-low pressure reducing valve, 17 ... Rapid exhaust valve, 18 ... Two-way electromagnetic switching valve.

Claims (1)

[Scope of Claims] 1. In a method of controlling the vertical movement of a welding electrode using a diaphragm valve, the welding electrode is moved at an extremely low speed by a rapid exhaust valve interposed in a pressure pipe on the electrode ascending side that communicates with the lower chamber of the diaphragm during chip dress. 1. A method for controlling the descent of a welding electrode during chip dressing, characterized in that the welding electrode is lowered by 2. A rapid exhaust valve that lowers the welding electrode at an extremely low speed during chip dressing is interposed in the impulse pipe on the electrode rising side leading to the lower chamber of the diaphragm of the diaphragm valve that controls the vertical movement of the welding electrode. Welding electrode drop control device.