RU2455135C1 - Machine for contact butt welding of round articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to contact butt welding and may be used in drawing for enlargement of wire coils or in construction for jointing reinforcing bars. Two end clamps are arranged on stationary and moving beds with top and bottom current conducting electrodes provided with half-sleeves from wear-resistant material with sharp edges on opposite sides. Device for electrode clamp and moving bed displacement comprises time relay, switch of compressed air feed into electrode clamp hydraulic cylinders, distributor of feeding compressed air into upset pneumatic cylinder and those of electrode clamp, as well as additional distributors of compressed air into every clamp pneumatic cylinder lifting chamber. The latter are furnished with fast-release valves communicated with clamping chambers to lessen clamping of one of electrodes and remove flash. All distributors are equipped with pilot-operated valves.

EFFECT: higher efficiency and quality.

3 dwg

Description

The present invention relates to welding production, and in particular to devices for flash butt welding by fusion of rods or rods, performed on specialized welding machines installed in the drawing industry for enlarging wire riots or in construction when connecting reinforcing bars.

The periodic welding of hot-rolled wire riots, which are specified in the drawing units, not only ensures their continuous operation, but also allows to increase the weight of the finished wire riots, while the duration of joining the riots should not allow the unit to stop or slow down. High productivity of welding machines under these conditions is achieved due to automation of the welding process and acceleration of auxiliary operations, in particular, the operation of removal of weld from welded joints, which is necessary before drawing them. The removal of burr is also necessary when welding reinforcing bars, since the reinforcement at the junction is a concentrator of alternating load in reinforced concrete products, which often causes destruction of concrete at the joints of the reinforcement. Currently, due to the lack of shredders on the welding machines, the shreds are manually cleaned with grinding wheels. In addition, when installing round-section products for welding, due to the rapid wear of the electrodes made of copper alloys, difficulties arise in the axial alignment of the welded ends.

Known welding machine K-606, designed for welding round billets, including reinforcing bars (see. Operation manual. IEGV. 683260.001 RE, 1987). The machine provides automatic welding by continuous melting and welding with preheating of the ends of the welded products. The disadvantage of the machine is the lack of mechanisms for stripping the weld on it.

There is a method of removing grata on round products from heat-strengthened aluminum alloys D16T, D18 (see, for example, the book "Contact butt welding with resistance with the formation of the connection.” Collection of scientific papers of the Academy of Sciences of the Ukrainian SSR. / Edited by V. Lebedev - Kiev, EO Paton Electric Welding Institute, 1988, pp. 38 ... 39), in which the metal during extrusion is squeezed into grath between the working ends of the electrode forming devices and, at the final stage of precipitation, is cut off by their edges and separated.

The disadvantage of using this method of removal of burr in welding steel products is the low resistance of the forming devices of the electrodes caused by thermal softening of the edges when they come in contact with the heated metal of the ends of the products, as well as the melting of the edges by a passing current during upsetting.

We also know the closest device for removing the burr after welding the workpieces of a wrench tap with four semicircular knives with annular cutting edges covering the welded workpiece to the right and left of the burr in a separate filler (see the book "Resistance Butt Welding with the Formation of the Joint". Sat. Scientific. tr. Academy of Sciences of the Ukrainian SSR. / Under the editorship of Lebedev V.K. - Kiev, IEO named after E.O.Paton, 1988, pp. 80 ... 82).

The disadvantage of removing the burr in such a device is the inability to maintain the temperature of the weld heated during welding due to its rapid cooling when transferring the product to the burr, therefore, either reheating or the use of great efforts to trim and separate the burr are necessary. It should also be noted that when removing grata on cooled products from hardened steels, cold cracks may appear at the junction.

The technical result of the invention is to increase the productivity of joining products of circular cross section due to the combination of welding and removal of burrs after flash butt welding.

The technical result is achieved by the fact that in a machine for flash butt welding of products of circular cross section with stripping, containing a fixed and movable bed, on which there are two cantilever clamps with upper clamping and lower current-carrying electrodes equipped with half-sleeves of hard-wearing material, having on facing each other sharp edges to the other sides, and clamping drives in the form of pneumatic cylinders, mechanisms for moving the movable bed during reflow and draft, welding transformer and control system Lenia clamping electrode and slump, the control system is further provided with two pilot valves and feed valves pressure in the cavity lifting clamp cylinders time relay and switch the compressed air in the cavity cylinders clamp the fixed and movable yokes, and these cavities clamping cylinders are provided with quick exhaust valves.

The inventive machine for flash butt welding by fusion of products of circular cross section is shown in figure 1 ... 3, where

figure 1 schematically shows a machine for flash butt welding of products of circular cross section with stripping;

figure 2 schematically shows the position of the electrodes before stripping the burr with the edges of the half-sleeves of a fixed clamp;

figure 3 shows the control circuit of the machine for flash butt welding of products of circular cross section with stripping grata.

The inventive machine for flash butt welding of products of circular cross section with stripping (see Figs. 1 and 2) contains a fixed 1 and a movable 2 bed, on which are placed two cantilever clamps 3 and 4 with the upper 5 and lower 6 current-carrying electrodes equipped with hard wearing semi-bushings 7, having sharp edges 8 facing each other, and clamping drives in the form of pneumatic cylinders 9 and 10, drives for moving the movable bed 2 during reflow in the form of a power cam (not shown) and when upsetting, in the form of a pneumatic cylinder 11, the control system for clamping the electrodes 5 and 6 and moving the movable bed 2, the welding transformer 12 for heating the products by reflowing 13. The control system (see Fig. 3) consists of distributors 14 and 15 for clamping and lifting the electrodes 5 and 6 with pneumatic cylinders 9 and 10, included by pilot valves 16 and 17. The draft cylinder 11 is controlled by the distributor 18 and 19 from the pilot valves 20 and 21. The system is equipped with pressure reducing valves 22 and 23 with manometers 24 and 25 for adjusting the air pressure in the supply lines and silencers 26. Additionally, the system is equipped with two There are distributors 27 and 28 of air supply in the lifting cavity of the cylinders 9 and 10 and turned on by pilot valves 29 and 30, respectively, a time switch and a switch (not shown) for turning on the cylinders 9 and 10 of clamps 3 and 4, the clamping cavities of the cylinders 9 and 10 are also equipped with valves quick exhaust 31 and 32.

The inventive machine for flash butt welding of products of circular cross section with stripping works as follows:

- after trimming and feeding into the welding zone between the fixed 1 and movable 2 beds the ends of the products 13 install them on the lower current-carrying electrodes 6 and bring the ends of the products to contact, then turn on the pilot valves 16 and 17 and distributors 14 and 15 supply air to the cylinder clamping cavity 9 and 10, lower the upper electrodes 5 of the clamps 3 and 4 and clamp the ends of the products 13 in the electrodes 5 and 6, equipped with hard-wearing half-sleeves 7, fixed 1 and movable 2 beds, while the half-sleeves 7 not only clamp, but also center the ends of the product 13;

- turn on the welding transformer 12 and the drive of moving the movable bed 2, carry out the reflow, and then at the end of the reflow turn on the pilot valve 20, and the distributor 18 supplies air to the piston cavity of the pneumatic cylinder 11, upsetting and welding of products 13;

- after upsetting, without removing the upsetting force, the welding transformer 12 is turned off, after a predetermined period of time, the relay turns on the pilot valve 29 and compressed air from the distributor 27 enters the cavity of the cylinder 9, while the quick exhaust valve 31 from the cavity of the clamping cylinder 9 is turned on and decreases the clamping force of the product 13 in the electrodes 5 and 6 of the clamp 3 of the fixed frame 1 until the welded products 13 slip through them, while the edges 8 of the half-sleeves 7 of the electrodes 5 and 6 of the clamp 3 come close to the weld heated during welding and cut it off.

After wear of the edges 8 of the steel half-bushings 7 of the electrodes 5 and 6 of the clamp 3, half-bushings 7 of the clamp 4 of the movable bed 2 are put into operation.

For this:

- before welding, change the position of the handle of the switch to turn on the supply of compressed air, install in the welding machine products 13, clamp them in electrodes 5 and 6 and weld;

- after upsetting and turning off the welding transformer 12, without removing the upsetting force, the pilot valve 30 is turned on by means of a time relay 30 and compressed air from the distributor 28 enters the cavity of the cylinder 10, while the quick exhaust valve 32 from the cylinder clamping cavity 10 is turned on and the clamping force is reduced products 13 in the electrodes 5 and 6 of the clamp 4 of the movable bed 2 until the welded products 13 begin to slip in them, while the edges 8 of the half-sleeves 7 of the electrodes 5 and 6 of the clamp 4 come close to the weld heated during welding and cut it off.

After stripping the burr, the pilot valves 16, 17, 29 and 30 are turned off and the upper electrodes 5 are lifted to release the welded products 13, the pilot valve 21 is turned on and the distributor 19 supplies air to the piston cavity of the pneumatic cylinder 11, while the movable bed 2 is returned to the initial position before welding .

On the proposed machine, you can weld wire and reinforcing bars with a diameter of 10 ... 45 mm from various materials. The durability of the edges of half-sleeves during stripping is up to at least 100 joints to regrind the edges.

Thus, the proposed machine for flash butt welding of products of circular cross section with stripping by using the electrodes of the welding machine equipped with semi-bushings from hard-wearing materials and additional control system devices allows:

- significantly speed up the process of joining round products by combining welding and stripping operations;

- improve the quality of stripping of the burr by removing the deposited metal immediately after welding, while maintaining the temperature of the welding heat.

The proposed machine can be used not only for welding fittings, but also in continuous drawing units under the conditions of limiting the time allotted for docking riots before drawing.

Claims (1)

A machine for flash butt welding of circular products with stripping of a burr containing a fixed bed and a movable bed with a mechanism for moving it during reflow and a precipitation drive in the form of a pneumatic cylinder, on which two cantilever clamps with upper and lower current-carrying electrodes equipped with half-sleeves made of wear-resistant material are placed, having sharp edges on the sides facing each other, and clamping electrodes in the form of pneumatic cylinders, as well as a welding transformer and control device electrodes and moving the movable bed during welding, which includes a time switch and a switch for supplying compressed air to the cavity of the pneumatic cylinder clamping electrodes, a distributor for supplying compressed air to the cylinder of the precipitation cylinder, distributors for supplying compressed air to the cavity of each of the pneumatic cylinders for clamping electrodes, and additional distributors for supplying compressed air to the lifting cavity of each of the pneumatic clamping electrodes equipped with quick exhaust valves connected to the clamping cavities, to reduce I am trying to clamp one of the electrodes and ensure stripping of the burr, while all the compressed air distributors are equipped with pilot valves.

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