RU2599469C1 - Centralizer for assembling and welding of circular seams - Google Patents

Abstract

FIELD: metal processing.

SUBSTANCE: invention relates to automatic welding equipment for welding articles with inner cylindrical surfaces. Centralizer consists of rod 1, at the end of which three levers 2 are uniformly pivotally connected around the axis. Second end of levers 2 is connected to pressing element 4 and pusher 7 with one common axle 10. Pressing elements 4 are made in the form of double-arm levers with thrust ledges 5, 6. Second ends of pushers 7 are pivotally connected to pressure tube 9 fitted on rod 1 with possibility of movement and having two annular stops 11 and 12 between which flange 13 is arranged with capability of movement, flange is spring-loaded in relation to pressure tube 9 with spring 14. Pressing elements 4 are located at an acute angle β to the axis of rod1. Each pressing element 4 has torsion spring 16 and 17 limiting its free rotation around axis 10. Second end of rod 1 is connected to linear displacement drive 20, for example, air cylinder by means of bearing unit 21, 22. Bearing unit 21, 22 provides transfer of force from fixed linear actuators 20 onto rotating rod 1.

EFFECT: invention allows to increase tabour efficiency and enlarge the application range of the centralizer.

1 cl, 5 dwg

Description

The invention relates to the welding of rotary annular seams and can be used as part of automatic welding equipment, which is used in engineering, gas, oil and other industries for the manufacture of products welded from parts having inner cylindrical surfaces.

Known internal centralizer for assembly and vacuum welding of ring joints (patent for the invention of the Russian Federation No. 2169654, IPC ⁷ V23K 37/053, publ. 06/27/2001). The centralizer is made in the form of a central shaft with nuts on which flanges and annular elastic seals are concentrically mounted. In this case, the flanges are made in the form of fixed and movable glasses. The fixed cup is made with an annular side and is fixed at the end of the central rod. The elastic ring seals are made in the form of a stack of flat rings and are mounted on the outer surface of the fixed cup with the possibility of their deformation using one of the movable cups worn on the fixed cup, located on the central shaft of the tube and one of the nuts. A second movable cup and a second nut are mounted on the opposite end of the central shaft.

The disadvantage of this centralizer is a small range of diameters of fixed pipes on one type of centralizer. The diameter range is limited to a small (several millimeters) increase in the diameter of the pack of elastic rings when they are compressed. This leads to the need to manufacture for each pipe size a separate instance of the centralizer.

This disadvantage is eliminated in the design of the centralizer for connecting the ends of the pipes for welding (patent for the invention of the Russian Federation No. 2302933, IPC V23K 37/053 (2006.1), publ. 20.07.2007), selected as a prototype. The centralizer is made in the form of a rod, at one end of which there is a device for fixing the end of the rod in the pipe, that is, a device for fixing the end of the rod inside a cylindrical surface, made in the form of three hinged parallelograms, uniformly circumferentially mounted on one end of the rod. At the other end of the shaft there is a pressure tube which is moved by a nut, as well as a flange which is moved along the shaft by a second nut. Hinged parallelograms consist of two swinging links and a link moving parallel to the axis of the rod and in contact with the inner cylindrical surface of the pipe (pressure member). The joints of the articulated parallelograms parallel to the rod (push elements) are coated with an elastic material, for example, vacuum rubber. The elastic element eliminates the gap between the links moving strictly parallel to the axis of the rod and the actual position of the lines forming the inner cylindrical surface along which the contact occurs when the product is clamped. The actual position of the lines forming the inner cylindrical surface may differ from the theoretical, that is, parallel to the axis of the rod, by the tolerance for the manufacture of the welded product, for example, the permissible taper. Pushers are used to change the slope of the swinging links of the parallelograms, one ends of which are pivotally connected to the links of the hinged parallelogram, and the other ends are pivotally fixed to the end of the pressure tube. Due to the rotation of the first nut and the movement of the pressure tube, the diameter of the circle described around the links can be changed, which allows the centralizer to be inserted into the pipe and firmly fixed to it. To simplify folding parallelograms between the end of the pressure tube and the hinges closest to the pressure tube, a compression spring is installed on the rod. The second part of the welded assembly is pressed against the pipe by means of a flange and a second nut.

The disadvantage of this technical solution is the manual clamping of the welded product, which is performed by the rotation of two nuts. Manual clamping of the welded product reduces labor productivity and does not allow the design of this centralizer to be used in automatic welding installations, which narrows the range of its use. Another disadvantage of the prototype is the presence on the links of the centralizer in contact with the inner cylindrical surface of the welded product of an elastic element made, for example, of vacuum rubber, which does not allow to locate these links in the immediate vicinity of the weld. This disadvantage also narrows the range of use of this centralizer design.

The problem solved by the proposed invention is the creation of a centralizer design that automates the process of centering and clamping products of a wide range of shapes and sizes.

The technical result is to increase labor productivity and expand the range of use of the centralizer.

The specified technical effect is achieved by the fact that in the centralizer for assembling and welding annular seams containing a rod, on which a flange and a device for fixing the end of the rod inside the cylindrical surface are installed, consisting of three levers pivotally connected and evenly spaced around the circumference, mounted on the end of the rod, three push elements, three pushers pivotally connected to the push tube mounted on the rod with the possibility of movement, and the spring in contact with the pusher, according to the image For each lever, the pressure member and the pusher are interconnected by one common hinge axis; each pressing element is made in the form of a two-shouldered lever, equipped with support projections at the ends, mounted at an acute angle to the axis of the rod in the direction of the junction of the rod and the levers, and equipped with two torsion springs resting on one lever and the other on a pusher; the second end of the rod is connected to a linear displacement drive through a bearing assembly consisting of thrust and radial bearings; the flange is mounted on the pressure tube with the ability to move between two annular stops located on the pressure tube, and the spring is installed between the pressure tube and the flange.

Comparative analysis with the prototype allows us to conclude that the inventive centralizer differs in that instead of a manual screw-nut drive, the design uses a mechanized linear displacement drive connected to the rod using a bearing assembly consisting of thrust and radial bearings. Also, the inventive centralizer is characterized in that each of the three levers, push elements and pushers are connected by one common hinge axis, that is, form one hinge assembly, while the push elements are made in the form of two-arm levers, are provided at the ends with support protrusions and are installed at an acute angle to axis of the rod in the direction of the junction of the rod and levers. The arrangement of the pressure elements is carried out using two torsion springs mounted on the pressure element and resting one on the lever and the other on the pusher. The inventive centralizer is also characterized in that the pressure tube is provided with two annular stops, between which a flange spring-loaded relative to the pressure tube is located.

Thus, the claimed technical solution meets the criteria of the invention of "novelty."

To verify compliance of the invention with the condition "inventive step", the applicant conducted an additional search for known solutions to identify signs that match the distinctive features of the prototype of the features of the claimed device. The search results showed that the invention does not follow explicitly from the prior art for a specialist, namely, the claimed combination of essential features exhibits a new property - it increases labor productivity during welding due to quick automatic centering and clamping of the welded product and more convenient installation of the welded product on the centralizer. Also, the proposed combination of essential features allows you to expand the range of use of the centralizer due to the lack of elastic elements narrowing the temperature range of use and the availability of the possibility of using the proposed design in automatic installations for welding parts having different diameters of the inner cylindrical surfaces.

Thus, the claimed technical solution meets the criterion of "inventive step".

The invention is illustrated by drawings, where in FIG. 1 shows the censor in the initial position (the item to be welded is not shown). The levers, clamping elements and pushers located around the circumference at an angle of 120 ° (Fig. 2) are conventionally shown in the same plane.

In FIG. 2 shows a local view along arrow A in FIG. one.

In FIG. 3 shows a section BB in FIG. one.

In FIG. 4 and 5 show the centralizer in the working position (the centralizer is mounted on the welding rotator, the item to be welded is assembled and clamped).

The centralizer consists of a rod 1, on which a device for fixing the rod inside a cylindrical surface is installed, consisting of three levers 2 evenly spaced around the axis of the rod 1, mounted on the end of the rod 1 using hinges 3, three pressure elements 4 made in the form of two-arm levers, having ends at the ends of the support protrusions 5, 6, and three pushers 7 connected by hinges 8, with a pressure tube 9 mounted on the axis of the rod 1 with the possibility of linear movement. The levers 2, the pressure elements 4 and the pushers 7 are interconnected using one common for each group of links, the hinge axis 10. The pressure tube 9 is equipped with two annular stops 11 and 12, between which a flange 13 spring-loaded relative to the pressure flange 13 is mounted for linear movement the tube 9 by the spring 14. In the initial position, the flange 13 is in contact with the abutment 12 by the action of the spring 14. The pressure elements 4 are located at an acute angle β to the axis of the rod 1. On each pressure element 4, springs are mounted on the centering pins 15 16 and 17. One end of the spring 16 is fixed in the hole 18, which is located on the pressure element 4, and the second end is supported by a lever 2. One end of the spring 17 is fixed in the hole 19, which is also located on the pressure element 4, and the second end is supported to the pusher 7. The second end of the rod 1 is connected to a linear displacement drive 20, for example, a pneumatic cylinder, using a bearing assembly consisting of a thrust bearing 21 and radial bearings 22.

The centralizer works as follows.

Example 1. FIG. 4. Welded connection of the "body - flange" type. The parts to be welded are welded together using a bored seating surface.

The centralizer flange 13 is fixedly mounted on the faceplate 23 of the welding positioner (rotator) 24 having a through hole in the spindle. The linear actuator drive housing 20 is connected to the part of the welding manipulator 24 that is stationary at the time of welding, while the linear actuator drive stroke 20 determines the amount of movement of the pressure elements 4 in the direction perpendicular to the axis of the rod 1. This value is set as minimal from the condition of ensuring free installation and durable clamp welded parts 25, 26.

The parts to be welded 25 and 26 are mounted on the flange 13. The inclination of the three pressure elements 4 to the axis of the rod 1 forms a lead-in cone, which simplifies and speeds up the process of installing the parts to be welded 25, 26 on the centralizer.

The linear displacement drive 20 is turned on, the rod 1 moves down, the pressure tube 9 remains stationary under the action of the pre-compression of the spring 14. Due to the rotation of the levers 2 and pushers 7 around the hinge axes 3, 8, and 10, the pressure elements 4 are moved in the direction perpendicular to the axis the rod 1, until the abutment protrusion 6 touches the inner cylindrical surface of the welded part 25, while torsion springs 16 and 17 limit the free rotation of the pressing elements 4 relative to the axis 10. After touching the cylindrical the surface of the welded part 25 of the support ledges 6, the pressure elements 4, rotating around the axis 10 and twisting the springs 16 and 17, occupy a position in which the support ledges 5 are also in contact with the cylindrical surface of the welded part 25. Further movement of the rod 1 downward leads to the pressing of the supporting ledges 5 and 6 to the part to be welded 25 with the pre-compression force of the spring 14 and to the centering of the parts to be welded 25 and 26 around the axis of the rod 1, that is, the installation of the product in a position coaxial with the rod 1. Further small 1-3 mm The rod 1 is joined together with the pressure tube 9 until the stop 11 contacts the flange 13. In this case, the spring 14 is compressed, and the pressure elements 4 slide along the cylindrical surface of the part being welded 25, thereby providing a compressive force of the parts being welded 25 and 26. After the contact of the stop 11 with the flange 13, the pressure elements 4 are pressed against the cylindrical surface of the welded part 25 with the force provided by the linear displacement drive 20. There is a final centering and pressure of the welded parts 25, 26 to the flange 13. The supporting protrusions 5.6 about espechivayut guaranteed pressing the pressure member 4 to the cylindrical surface in two maximally spaced apart points. The electric motor 27 is turned on, the faceplate 23, together with the centralizer and the parts to be welded 25, 26, rotates. Welding of the annular seam is in progress. In this case, the bearings 21, 22 provide the transmission of clamping forces from the stationary linear drive 20 to the rotating rod 1 together with the faceplate 23.

Example 2. FIG. 5. Welded connection of the "body - pipe" type. The parts to be welded are welded together without ring boring. The welded parts have different diameters of the inner cylindrical surfaces. The weld is located in the immediate vicinity of the pressure elements.

The centralizer is mounted on the welding manipulator (rotator) 24 as in Example 1. The stroke value of the linear displacement drive 20 is increased to a value that provides clamping of the welded product along two cylindrical surfaces of different diameters. The diameter of the circle passing around the support protrusions 6 in a plane perpendicular to the axis of the rod 1 is set when adjusting the centralizer slightly larger than the diameter of the inner cylindrical surface of the part 28. Therefore, when installing the welded body 28 on the centralizer, the welded part 28 is centered relative to the axis of the rod 1 due to the displacement of the supporting the protrusions 6 in the direction of the axis of the rod 1 and the tightening of the springs 16, 17. After installing the welded part 29 include a linear actuator 20. Moving the rod 1 downward, under ystviem linear displacement drive 20 causes the support arms 5 contact with the surface of the cylindrical member 29. Further downward movement of the rod 1 provides centering and clamping the welded parts 28, 29 is similar to Example 1.

In both examples, the resetting of the centrator to products having a different shape and size is performed by changing the position of the linear displacement drive 20 relative to the flange 13, changing the stroke value of the linear displacement drive 20 or replacing the pressing elements 4 with pressure elements having a different distance from the axis 10 to the protrusions 5 , 6.

The centralizer was tested as part of a prototype of an automatic welding machine in a carbon dioxide medium with a consumable electrode, consisting of a welding manipulator and a device for automatically supplying the torch to the welding zone. The gas valve body was welded with a flange having an internal cylindrical hole corresponding to a nominal diameter of Dy-250 mm. The base surfaces of the product were turned, corresponding to accuracy mH according to GOST 30893.2. A pneumatic cylinder having a piston diameter of 63 mm was used as a linear displacement drive. The stroke of the pneumatic cylinder rod and the core of the centralizer is 25-30 mm. Welding was carried out in one pass. The weld time of the annular seam is 4-5 minutes. The time for clamping and expanding the product, that is, the time for turning the pneumocylinder on and off, as well as the time for the pneumatic cylinder to move down to center and clamp the item to be welded and the rod up to expand the product was 3-4% of the welding time (machine time). This has virtually no effect on the performance of the automatic welding process.

Also, the design of the proposed centrator was tested as part of a prototype installation of argon-arc welding of ring welds of products with an inner diameter of up to 63 mm. The base surfaces of the product were turned, corresponding to accuracy mH according to GOST 30893.2. A pneumatic cylinder having a piston diameter of 40 mm was used as a linear displacement drive. The stroke of the pneumatic cylinder rod and the core of the centralizer is 15-20 mm. Welding was carried out in one pass with the use of filler wire with a diameter of 1 mm. To compensate for the error in centering the product in the installation, an automatic arc gap adjustment system was used. The weld time of the circumferential seam is 3-4 minutes. The time for installation and removal of the product was 2-3% of the welding time (machine time).

Using the invention allows to increase the productivity of the welding process by replacing the manual clamp of the parts to be welded with an automatic clamp. The presence of the inlet cone formed by the inclination of the clamping elements reduces the installation time of the welded parts on the centralizer, which also increases productivity. Also, the productivity of the welding process is increased due to the possibility of quick changeover to products of various sizes, which is provided by changing the stroke of the linear displacement drive or replacing only three pressure elements.

The automatic clamp allows you to expand the range of use of the centralizer due to the possibility of using it as part of automatic welding devices. The range of use of the centralizer is also expanding due to the fact that the design of the centralizer allows welding products with different diameters of the inner cylindrical surfaces, as well as welding products with the location of the welded joint in the immediate vicinity of the clamping elements of the centralizer.

Thus, the claimed technical solution meets the criterion of "industrial applicability".

Claims (1)

A centralizer for assembling and welding annular seams, comprising a rod on which a flange and a device for securing the end of the rod inside the cylindrical surface are mounted, consisting of three levers pivotally connected and evenly spaced around the rod end, three push elements, three pushers, pivotally connected to the pressure tube mounted on the rod with the possibility of movement, and the spring in contact with the pusher, characterized in that each lever, pressure element and pusher soy are interconnected by one common hinge axis, each pushing element is made in the form of a two-shouldered lever, equipped with support projections at the ends, mounted at an acute angle to the axis of the rod in the direction of the junction of the rod and levers, and equipped with two torsion springs resting one on the lever and the other - on the plunger, the second end of the rod is connected to a linear displacement drive through a bearing assembly consisting of thrust and radial bearings, the flange is mounted on the pressure tube with the possibility of movement between two ring stops located on the pressure tube, and a spring is installed between the pressure tube and the flange.

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