RU2796904C1 - Method for soldering plates with a hole to tubular shaped parts and a device for its implementation - Google Patents

Abstract

FIELD: soldering.

SUBSTANCE: invention can be used for soldering by induction heating of flat plates with a hole to tubular parts. A tubular part is installed with an inner diameter with a gap on a mandrel fixed by thrusting in the lowering of the support, the depth of which is equal to the diameter of the solder wire. A soldered flat plate is mounted on the seating surface of the annular protrusion of the support. The gap between the parts is selected such as to obtain a brazed seam on both sides of the flat plate. During soldering, a flat plate is pressed against the support by a compression spring. The landing surface of the support of the soldering device is located perpendicular to the axis of the mandrel with a deviation not exceeding 0.01 mm. The compression spring acts through the bushing, which is configured to abut its lower end against the surface of the flat plate and has a cavity extending to the lower end from the side of its central hole. The technological weight is installed on the mandrel by fit with a gap and simultaneously performs the function of a stop for the compression spring.

EFFECT: ensuring a minimum deviation of the flat plate relative to the axis of the tubular part when performing a brazed seam on both sides of the flat plate under soldering conditions at an induction heating unit.

4 cl, 2 dwg

Description

The invention relates to the field of soldering parts made of alloys with different physical and mechanical characteristics and can be used, among other things, for soldering plates of tungsten-copper alloys to tubular parts made of stainless steels.

Products in which tubular elements must be hermetically connected to a counterpart located at an angle close to or equal to 90 ° have become widespread in various branches of mechanical engineering. The connection of tubular elements with the counterpart is traditionally performed by welding or soldering. Various heat exchangers can serve as an example of such products. However, there are products in which high requirements are imposed in the form of tolerances for the location of the surfaces of the parts to be joined. Such products are, in particular, elements of installations for the electrochemical processing of atomizer bodies, which are a thin-walled stainless steel tube, to which a flat plate with a hole - a washer - made of a tungsten-copper alloy is soldered. According to the technical requirements, the deviation from the perpendicularity of the surface of a flat plate with a hole (hereinafter referred to as a flat plate) relative to the axis of the outer diameter of the tube should not exceed 0.02 mm.

A known method of soldering pipes to a tube sheet, including fixing a multi-tiered grid of steel Kh18N9T on a tube plate, laying solder on the grid, melting solder in an oven with its uniform distribution over the surface of the tube plate, drilling holes in the tube plate, installing pipes in holes, applying to each tube sheet on the reverse side of a special mixture to limit solder leakage (A.S. 426767, 05.05.74. Bull. No. 17). To implement the known method, an oven is used.

The disadvantages of the known solutions include the need to use a multi-tiered grid of steel Kh18N9T, on which the solder is placed, and a special mixture, including metal powder and a volatile binder (acrylic resin). In addition, the known soldering method includes technologically responsible operations of welding and drilling along the conductor.

A known method of soldering tubular heat exchangers, including a uniform distribution of solder and the formation of fillets around each tube by creating contact between the tube and the tube sheet through solder particles introduced into the gap (A.S. 582926, 05.12.77. Bull. 45). According to a well-known solution, solder particles are used in the form of flakes, the thickness of which is from 0.3 to 0.9 of the size of the gap, and the length and width are from 10 to 90 of their thickness. The shape of the solder particles can be round, ellipsoidal or polygonal. In this case, when the solder is introduced, the soldered product is vibrated in the vertical and horizontal planes, the amplitude of which is commensurate with the size of the solder flakes. Soldering is carried out in a vacuum furnace.

The disadvantages of the known solutions include the need, firstly, to use solder with particles of certain sizes and shapes, and, secondly, to create vibrations to get the solder into the gaps. It is also obvious that the provision of strict requirements for the location of the parts to be joined, in particular, deviations from the perpendicularity of the mating part relative to the axis of the outer diameter of the tube, under such conditions presents significant difficulties.

Known solder for soldering products and a method of soldering, including putting on a tube of solder in the form of a wire ring and joint heating of soldered parts in the field of high-frequency currents (U.S. Pat. RU 2104850, 20.02.1998). According to the well-known solution, heating was carried out in an induction furnace. The authors indicate that the gaps in soldered joints may go beyond the action of capillary forces (paragraph 35 of the description of the known solution). At the same time, the known solution does not provide for any measures to ensure a given relative position of the parts to be soldered, except that these parts are close to each other so that the molten solder ring connects them during the soldering process. Soldering is done in an oven.

The disadvantages of the known solution include the lack of measures for the precise positioning of soldered parts, providing the specified deviations in the relative position of the parts, for example, deviations from the perpendicularity of the surface of one part relative to the axis of the outer diameter of another part.

The closest in terms of essential features - the prototype of the claimed invention - is a device for soldering, including an installation fixture and a compression force transfer mechanism (AS 1220910, 30.03.86. Bull. No. 12). According to a well-known solution, the installation device is an annular flange with through sockets in a circle for placing brazed parts. The compression force transmission mechanism is made in the form of a lever with a fork, in which rollers freely rotating on the axis are placed. The levers are loosely mounted on the axles, which are pressed into the body bridges. The second arm of the levers is placed in the grooves of the jumpers and rests at the stage of fixing the soldered parts against the ends of the fixing screws. The fixing of the parts to be soldered and their preloading takes place in two stages: first, by turning the levers when the fixing screws are screwed in, and finally, when the case is installed on the stand, when the preload of the parts is carried out under the action of the mass of the case.

The disadvantages of the known solutions include the complexity of the design of the device, due to the large range of parts - the authors indicate 18 positions of the main elements - and special requirements for them. Some of the parts in the process of using the device make a rotational movement and come into contact with the solder. In order to avoid "seizing" of these elements, the authors note that all rubbing moving parts must be rubbed with molybdenum diselenide powder, and the rollers must be made of a material that does not interact with the solder and the material of the soldered parts. The disadvantages of the known solutions also include the lack of measures to ensure the exact relative position of the surfaces of the soldered parts. The disadvantages of the known solutions also include the use of body mass for pressing parts. Soldering is carried out in an oven. Judging by the illustration to the description of the well-known solution, this mass is so large that the use of lifting mechanisms is required, as evidenced by the image of the hook, called by the authors a pull with a ring.

A common disadvantage of the known soldering methods is the use of furnaces, which implies the presence of complex technological equipment, significant energy costs and inefficiency in cases where it is necessary to manufacture small batches of products, which are, for example, elements of technological equipment used in the production.

The technical problem to be solved by the present invention is the effective provision of a given deviation from the perpendicularity of the surface of a flat plate relative to the axis of the outer diameter of a tubular part during soldering under conditions of small-scale or single production.

The technical result of the implementation of the invention is a guaranteed technological support for the deviation of a flat plate from perpendicularity within a given tolerance relative to the axis of the outer diameter of a tubular part while simultaneously performing a brazed seam on both sides of a flat plate under soldering conditions on an induction heating installation (hereinafter referred to as an HDTV installation).

The set technical problem is solved through the cumulative implementation of the following activities:

- performing soldering at the HDTV installation with the base of the parts to be joined on the mounting fixture,

- use of a technological support as an installation device with a mandrel installed in the technological support without the possibility of movement,

- installation of a tubular part with an internal diameter on a mandrel, with an emphasis on a technological support, ensuring a diametrical clearance in the connection of a tubular part and a mandrel from 0.01 mm to 0.03 mm and sinking the lower end relative to the seating surface for a flat plate by a value equal to solder wire diameter,

- installation of a flat plate with a hole on a tubular part with a gap along the diameter and with the lower end resting against the mounting surface, made in the form of a flat annular protrusion on the upper plane of the technological support with a deviation from perpendicularity relative to the axis of the mandrel outer diameter of not more than 0.01 mm,

- compression during soldering of a flat plate to the technological support,

- use as a mechanism for transferring the compression force (compression) of a compression spring acting on a flat plate through a bushing in the form of a body of revolution with a central hole, made of ceramic material and containing a cavity in the lower part of the central hole that goes to the lower end.

These features are new, essential, non-obvious, industrially feasible and aimed at achieving the claimed technical result.

In FIG. 1 shows a device for implementing the proposed method for soldering flat plates to tubular parts. In FIG. Figure 2 conditionally shows the brazed seams formed in the process of soldering according to the proposed method on both sides of the flat plate 7.

The positions in FIG. 1 marked:

1 - technological support,

2 - mandrel,

3 - bushing,

4 - compression spring,

5 - technological cargo,

6 - a flat plate with a hole, which must be soldered to a tubular part 7,

7 - tubular part, to which it is necessary to solder a flat plate 6 with a hole,

8 - solder,

9 - inductor of the HDTV installation,

11 - understatement in the technological support,

12 - flat annular protrusion for installing a flat plate 6 with a hole,

13 - hole in the technological support 1 for mandrel 2,

31 - cavity in the lower part of the central hole of the sleeve 3,

51 - hole in the technological load for the mandrel 2

67 - a gap in the interface of a flat plate 6 with a hole and a part 7 of a tubular shape.

It is preferable, but not the only possible, is the implementation of the technological support 1 in the form of a body of revolution.

In the upper part of the technological support 1, a reduction 11 is made in the form of a circle so that a flat annular protrusion 12 is formed. from the understatement 11, did not touch the surface of the technological support 1 (see Fig. 2). A hole 13 is also made in the technological support 1. In FIG. 1 as an example, not excluding other versions of the device for implementing the proposed method, shows a blind hole 13 having a flat bottom. In general, the hole 13 may be through or have a bottom of any shape. A prerequisite is the regulated relative position of the flat annular surface 12 and the outer diameter axis of the mandrel 2 installed in the hole 13: the deviation from the perpendicularity of the flat annular surface 12 relative to the outer diameter axis of the mandrel 2 should not exceed 0.01 mm.

The mandrel 2 is fixed in the hole 13 without the possibility of movement. It is preferable to make the mandrel 2 in the form of a solid cylinder, the diameter of which is smaller than the inner diameter of the tubular part 7 by 0.01 mm to 0.03 mm.

Sleeve 3 has the shape of a body of revolution with a central hole. In the lower part of the central hole of the sleeve 3, a cavity 31 is made coaxially with the central hole, extending to the lower end of the sleeve 3. The dimensions of the cavity 31 are selected so that the sleeve 3 does not touch the solder 8. The shape of the cavity 31 can be any. In FIG. 1 as an example, not excluding other versions of the device for implementing the proposed method, shows the implementation of the cavity 31 in the form of an internal chamfer.

The compression spring 4 rests on the upper plane of the sleeve 3, pressing the flat plate 6 with a hole to the flat annular platform 12 of the technological support 1. The reverse side of the compression spring 4 rests on the plane of the technological load 5. The force of the compression spring 4 is selected in such a way as to ensure constant contact between technological load 5 and technological mandrel 2, on the one hand, and constant compression of the flat plate 6 to the technological support 1, on the other hand.

Technological load 5 acts as a stop for the compression spring 4. The mass of the technological load 5 should not be excessive in order to avoid operator fatigue and eliminate the need to use lifting mechanisms. It is preferable to use technological cargo 5 weighing up to 0.5 kg. A hole 51 is made in the technological load 5 for setting the end of the technological mandrel 2. The diameter of the hole 51 is made in such a way as to ensure the connection of the technological load 5 with the technological mandrel 2 with a gap.

Solder 8 has the shape of a ring. In FIG. the cross section of the solder ring 8 is shown exaggeratedly large. It is preferable to use solder in the form of a ring of wire having a diameter of 00.5 mm to 01.0 mm.

The proposed method for soldering flat plates to tubular parts is as follows.

Part 7 of a tubular shape is installed with an inner diameter on a mandrel 2, with an emphasis on a technological support 1, ensuring a diametrical gap in the connection of a tubular part and a mandrel from 0.01 mm to 0.03 mm. The lower end of the tubular part 7 abuts against the bottom of the understatement 11.

The flat plate 6 is installed on the tubular part 7 with a gap in diameter, determined in the design documentation for the flat plate 6 and the tubular part 7, until the bottom end stops against the flat annular protrusion 12.

Solder 8 is put on the part 7 of a tubular shape in the form of a ring until it stops flat plate 6.

A sleeve 3 is installed on the tubular part 7 until it stops in a flat plate 6 and a compression spring 4 is installed.

A technological load 5 is installed on the technological mandrel 2, while deforming the compression spring 4 to a state of preload.

A device for implementing the proposed method with installed parts that need to be soldered to each other is placed in the inductor 9 of the HDTV installation. Turn on HDTV. When heated, the solder 8 melts and forms brazed seams on both sides of the flat plate 6 (see Fig. 1).

Regime parameters of soldering - temperature, duration, etc. - are not subject to protection in this application.

After the soldering is completed, the HDTV installation is turned off, the parts are allowed to cool, the technological load 5, the compression spring 4, and the bushing 3 are removed. The tubular part 7 with the soldered flat plate 6 is removed. The cycle is completed.

An important feature of the proposed method is the possibility of its implementation outside the furnaces, since only an induction heating installation (“HDTV installation”) is required, which is simpler compared to a furnace. The method does not require the creation and maintenance of a special atmosphere, for example, a protective gas environment or evacuation of the space in the soldering zone.

The presence of a preload of one of the parts to be joined, which is subject to strict requirements for the location of the surfaces, to the base surface of the mounting device makes it possible to reliably meet these requirements. And the implementation of the compression mechanism in the simplest version - in the form of a compression spring - allows you to simplify both the soldering method and the device for its implementation.

An example of the proposed method.

A plate of tungsten-copper alloy W75/Cu25 was soldered to a tube of steel 12Kh18N9T with solder PSR 50KD in the form of a ring of wire ∅0.5 mm.

A bushing 4 made of a MKR tube (“Mullite-silica tubes”, TU 14-8-447-83) and a technological load 5 weighing 0.2 kg were used.

The duration of the operation of the inductor of the HDTV installation in the cycle was 6 s.

According to the technical requirements, the deviation from the perpendicularity of the surface of the flat plate relative to the axis of the outer diameter of the tube should not exceed 0.03 mm.

After the soldering of a batch of parts in the amount of 50 pcs. performed the measurements. The maximum perpendicularity deviation was 0.02 mm.

Proposed as the present invention, the method of soldering flat plates to tubular parts and a device for its implementation are implemented at the Altai Plant of Precision Products for the manufacture of technological elements used in installations for electrochemical processing of spray housings.

Claims (4)

1. A method for soldering flat plates with a hole to tubular parts, which includes installing a flat plate with a hole on a tubular part with a gap in diameter, then placing solder in the form of a wire ring on the tubular part until it stops in a flat plate and jointly heating the soldered parts with high currents. frequency in the induction heating installation, characterized in that the tubular part is installed with an inner diameter with a gap of 0.01 mm to 0.03 mm on a mandrel fixed with a stop in a technological support made with an underestimation, the depth of which is equal to the diameter of the solder wire, with the formation of a flat annular protrusion with a seating surface, the tubular part is installed with an emphasis on the bottom of the understatement, and the flat plate to be soldered is installed on the mentioned surface of the support protrusion, and the gap between the flat plate and the tubular part is selected from the condition for obtaining a brazed seam on both sides of the flat plate, and during soldering, a flat plate is pressed against the technological support by a compression spring. 2. A device for soldering flat plates with a hole for tubular parts, containing an installation device and a compression force transmission mechanism, characterized in that the installation device includes a technological support and a mandrel fixed in the support without the possibility of movement, while the technological support is made with an underestimation, forming an annular protrusion on its upper plane with a seating surface for placing a soldered flat plate on it, and has a hole for mounting the mandrel coaxial to the annular protrusion, and the seating surface of the technological support is located perpendicular to the axis of the mandrel with a deviation not exceeding 0.01 mm, and the mechanism transmission of compression force contains a compression spring acting through a bushing made of ceramic material, made with the possibility of abutting its lower end against the surface of the said flat plate and having a cavity extending to the lower end from the side of its central hole, and a technological weight installed on the technological mandrel for landing with a gap and simultaneously performing the function of a stop for the compression spring. 3. The device according to claim 2, characterized in that the sleeve of the compression force transmission mechanism is made of a mullite-silica tube. 4. The device according to claim 2 or 3, characterized in that the mass of the technological load does not exceed 0.5 kg.

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