General view of pneumohydraulic valve

Pneumohydraulic valve

Valve design and operation: During welding operations, parts of welding machine heads located in the arc thermal action zone are heavily cooled with water. Untimely disconnection of cooling water during interruptions in the welding process leads to its overflow. Pneumohydraulic valve is intended for automatic switching on and off of water supply at the beginning of o at the end of welding process. The valve is assembled in the following order. Nozzles 12 are inserted into hole with diameter 18 of housing 5 and welded by electric welding by seam of T4 type with spools of 5 mm. The rod 2, together with the valve 4 placed in the bore of the rod with the diameter of 35, is installed in the body 5 with the cut rod down so that the valve 4 closes the hole with the diameter of 22 in the body from above. Nut (6) and tip (7) are screwed onto rod (2). Nut (6) fixes position of tip on rod thread. Two washers 8 with membrane 10 between them are put on rod of tip 7 with convex surfaces to each other and tightened with nut 9 with washer 23.

Cover 1 with gasket 24 is attached to housing on side of rod 2 by screws 3. At the same time the ledge with a diameter of 8Х4 rods has to enter the corresponding nest on a cover.

The lower cover 13 is separately assembled and consists of a fitting 20, a gasket 18, a valve 21, a stem 22, a spring 19 and a cap 11. Connector 1.5 is screwed into hole of cover 20 22 * from outside. Gasket 18 is placed between connector and cover. Inside the cover the hole of the plug is closed with rod 22 with valve 21. Note here that ledge with rod lug 22 fits into pin hole while valve 21 is pressed against connector by rod bead. Spring 19 is put on rod and pressed by cap 11 until stop against cover 13 in assembled form, cover is fixed to body by screws 3, clamping membrane between flanges. The nozzle 14 is then screwed into the hole M10 of the cover 13 with a gasket 17 pre-fitted thereon. Opening of union with diameter 5 is covered with needle 16. Cap 15 is screwed onto connector until stop.

The valve operates as follows. At the beginning of the welding process, compressed air at a pressure of 5 kgf/cm2 is supplied to the welding apparatus to create a vacuum in the tube that sucks the unused flux from the welding site. Some of this air is supplied to connector (20). By pressing the valve 21 through the opening of the cap 11, air enters the cavity of the cover 13, presses the membrane 10 and opens the valve 4. Cooling fluid under pressure of 2 kgf/cm2 RH connector (12), open valve (4) and LH connector (12) rushes into welding unit. At the end of the welding process, the access of compressed air to the valve is stopped, and the air remaining in the cover 13 gradually leaves through the gap between the walls in the hole of the union 14 and the needle 16, after which the membrane 10 drops, and the valve 4 closes the water. This gap is adjusted so that during short-term interruptions of the welding process, water access to the unit does not stop .

Note: Details 3, 6, 9 and 23 are not shown. They must be found by GOST number in technical directories: det. 3 bolt of M6, GOST 780570; part 6-nut M8, GOST 592770; det. 9-nut M6, GOST 592770; det. 23Shib spring, GOST 640270. Missing dimensions of standard parts according to the tables of GOST, considering the purpose of these parts in the assembly unit; Set the required number of parts by itself. The standard part number in the assembly drawing schedule must comply with the legend used in GOST.