JPS6054145B2 - Thermite welding mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for thermite welding of metal parts, in particular for aluminum thermite welding.

This type of welding process involves joining two metal parts of the same or very similar shape by pouring a certain amount of hot welding metal fluid around the joint to be welded. . The molds used in performing this welding operation generally consist of several parts and are designed to enclose the parts to be welded and at the same time direct the hot welding metal fluid to the joints to be welded. It also has a casting cavity that allows it to come into contact with the metal. This welding method is most often used for welding metal moldings, especially railway rails. In the case of aluminum thermite welding, the hot weld metal fluid, most often molten steel, is obtained by deoxidizing iron oxide with aluminum. Since it is impossible for the mold to be in complete contact with the surface of the metal member and the surfaces of other parts of the mold, it is necessary to seal the mold before actually performing the welding operation. This sealing is classically accomplished by sealing with a paste that is sufficiently refractory that it will not be destroyed by contact with hot welding metal fluids. This paste is
It generally consists of silica sand, binder, clay, water, or other additives and is placed in the mold before or after positioning and before pouring the hot weld metal fluid. Although this sealing method provides good results, it also has drawbacks.

In other words, it takes a long time to manufacture, and it is not always easy to place it in the desired position, so care must be taken when handling it. It has also been proposed to use dry joints made of strips of asbestos or organic material instead of classical seals.

However, such methods also have drawbacks. That is, when in contact with the hot welding metal fluid, the weld zone is blown, producing water vapor which is responsible for deteriorating the quality of the resulting weld.It is therefore an object of the present invention to The object of the present invention is to overcome the above-mentioned drawbacks by providing a mold that automatically establishes the required sealing condition as soon as it is placed on the part to be used, i.e. ready for use.

The present invention provides the following molds.

that is, it consists of at least two components for joining at least two metal members by thermite welding and is designed for use in receiving a weld metal body around each joint of the metal members. A mold having a structure forming a casting cavity, wherein at least one of the surfaces of the mold that contacts a part of one of the parts to be welded or another part of the mold forming a protrusion with an inclined side surface facing the outside of the casting cavity, and a protrusion for joining with a part of one of the parts to be welded or with another part of the main mold; This mold is characterized by having a strip made of a compressible material that is hardly affected by heat attached thereto. Here, the expression "slightly unaffected by J heat" means that the compressible material making up the seal is little or not affected by heat when heated by or reacts with the hot welding metal fluid. This means that no gas is generated, and therefore so-called zero blowing does not occur due to this small amount of gas generation.

Desirable materials having these properties are mineral-based felts, such as silicates such as aluminum silicate containing chromium oxide and magnesium silicate;
Chrosolidite (ChrOsOl) with % water of crystallization
It is preferable to use double silicates such as -type sodium iron silicate or asbestos-type magnesium iron silicate with 3% water of crystallization.

At high temperatures, olivine asbestos loses 10 to 20% of its weight.
The weight loss of such mineral-based felts is only 2 to 5%. These types of felts are available on the market and in some cases are manufactured by John Manveille, Ferrum, S. E. P. R. It can also be purchased directly from manufacturers such as (Société ●Europienne ●De ●Produy ●Le Fractaire).

In order to obtain a good seal, the felt used in the mold according to the invention should have a density of about 50 to 200 k9/
d1 is preferably about 100 to 200 kg/I. Preferably, the strip is adhered to the protrusion by either organic or mineral glue.

In the case of organic glues, a strip of glue is applied to some of the projections facing outward with respect to the cavity of the mold to prevent the glue from entraining gas into the casting cavity. In the case of mineral glue, a layer of glue may be applied over the entire protrusion. In one advantageous way of carrying out the invention, the surface of the strip opposite the surface glued onto the protrusion is coated with a malleable metal foil, for example flaky aluminum. ing. Preferably, this foil is adhered to the opposing surface of the strip in the following manner. i.e. a layer of organic glue applied to the part of the facing surface facing outward with respect to the casting cavity, or, for exactly the same reasons as mentioned above, applied to the entire surface of the strip. Preferably, the mineral material is bonded through one of the layers of glue. Examples of mineral glue include RCORSY9A. Glue can be used for cast cores such as the RK3J type from FOSEcOcO or Sochete Boniface.

This metal foil has three advantages in protecting the felt. Firstly, the seal must be rigid, secondly, it can be manufactured in advance due to its rigidity, and finally, when positioning the mold, it must be parallel to the direction in which the mold is set on the part to be welded. Or to prevent felt from getting stuck in a part of this member that is slightly inclined. This third point is very important in the case of rail welding. Sealing between the parts of the mold and the parts to be welded can be achieved simply by gluing a sealant to the protrusion, but the present invention also provides a mold of another embodiment. This means that the component is designed to achieve a self-sealing in the region above the casting cavity, without the need for any sealing material. The area above the casting cavity, i.e.
In areas where sealing is less important than in areas surrounding the cavity, there is no need to use any sealant.

This method also has the advantage of ensuring that the parts of the mold are positioned relative to each other, while at the same time providing ventilation holes for removing air during casting. To this end, in the present invention, the parts of the mold are placed in their proper positions in contact with each other above the casting cavity, and the interfacing surfaces ensure accurate positioning and sealing of the parts therebetween. It is becoming possible to obtain it. Preferably, each of the mutual mating surfaces has a flat mating surface with ridges and grooves that match the grooves and ridges, respectively, of the flat mating surfaces of the other parts of the mold. It's good to be able to do it now. The ridges and grooves of the flat contact surface are arranged symmetrically with respect to the central slot opening in the contact surface so that the two
The two identical parts are connected via ridges on one part and grooves on the other, while the slots combine to form a casting channel capable of guiding hot weld metal fluid into the casting cavity. It is desirable to be familiar. In order to reliably achieve sealing around the casting cavity of the mold of the present invention, a sealing method in which a sealing body is adhered to the protrusion and a sealing method in which a sealant is sealed with fireclay are used in combination. You can also do it.

Although the mold according to the invention can be used for welding metal parts of any kind, a particularly advantageous application is the welding of railway rails. The invention will now be explained by way of example with reference to the accompanying drawings, in which: FIG. In FIG. 1 a mold 10 is shown, one surface 12 of which is designed to be in contact with a surface 14 of the metal part to be welded or another part of the mold 10, indicated at 16. At the same time, mold 1
It has a protrusion 18 forming an integral part of 0.

This protrusion 18 has side surfaces 20 that are inclined at an angle α to the surface 12. The side surfaces 20 are sloped outwardly with respect to the casting cavity 22 (located to the right of the projection 18 in FIG. 1). The angle α is, for example, an acute angle such as 10 degrees, but this value itself is not an important factor. A strip 24 of compressible felt, which is almost unaffected by heat, is placed on the inclined surface 26 of the protrusion 18 in the cavity 2 of the mold.
It is glued via glue 28 applied on the part of the side surface 20 which is arranged in the outward direction with respect to 2 . surface 2
On the surface 30 of the strip opposite 6 is an aluminum strip 32 of the same width as the felt strip 24 and a glue layer disposed outwardly of the surface 30 with respect to the casting cavity 22. 34. FIG. 2 shows a mold 10 and a metal member or other part 16 of the mold to be welded.
FIG. 3 shows a partially compressed seal after partially tightening the mold 10, and FIG. 3 shows a fully compressed seal after fully tightening the mold 10.

The slope of the side surfaces 20 on the protrusion 18 allows the felt strip 24 to adhere better in the proximal portion of the casting cavity 22 than in the remote portions. For this reason, the forces applied during tightening basically act on a very narrow area, and the tightening effect is therefore quite large. On top of that,
The slope of the sides 20 of the protrusion 18 serves to prevent gas from entering the casting cavity 22. The point to keep in mind here is that felt strips are essential. Of course, it is not necessary to achieve complete compression as shown in FIG.

This is the case, for example, when applying a mold according to the invention to a metal part to be welded whose nominal dimensions do not exactly match the design structure of the mold to obtain a hermetic seal. I'm sure-
In general, the felt strip has areas where it is highly compressed and areas where it is less so, but unless the shape of the part to be welded is significantly outside the specification limits for the shape intended for the design of this mold, this will not be possible. The degree of compression of the relatively weakly compressed area is sufficient to provide the required sealing condition. For example, the density is about 1
If the felt is 50kg/I and 6T1n thick, 2.
5wr! Sealing is already achieved when compressed to a thickness of n. The mold of the invention is particularly advantageous when applied to welding rails as shown in FIG.

FIG. 4 shows an exploded perspective view of two rails 36, 38 and a baseplate 44, which are formed through a mold consisting of two side parts 40, 42 of the same shape. They are designed to be butt welded together.

The side portions 40, 42 are adapted to rest on one side of the rails 36, 38 and cover the joint to be welded. Base plate 44
below the rails 36, 38 and on the sides 40, 4 of the mold.
It is designed to be placed under 2. The shapes of the mold components 40, 42 are configured to match the rail so that they can be adapted to the shape of the rail. Mold component 40
, 42 have slots 46 and 48, respectively,
The slot is designed so that when the members 40, 42 are assembled they constitute a funnel suitable for guiding hot weld metal into the gap between the two rails. slot 4
A slot 50 communicates with 6 to facilitate the flow of hot weld metal into the bottom of the mold. Mold component 4
The second slot 48 is also extended by a similar slot (not shown). An opening 52 is provided in the base plate 44 to facilitate the flow of hot weld metal under the two rails at the contact point of the two joints.

The mold components 40 and 42 are also provided with vertical ventilation holes 54 and 56, respectively, which allow the air inside the mold to be evacuated and to be gradually released as the hot weld metal is poured. It can be done in a specific manner. The above-mentioned mold component 40,
42 and the slot in the base plate 44 together define the casting cavity described above.

The seal between each part of the mold and the two rails 36, 38 is
The seal already described in connection with FIGS. 1 to 3 is made of a felt strip coated with aluminum foil and glued to a protrusion with sides sloping outwards with respect to the casting cavity. This is achieved by a sealed body. Mold component 40
includes a seal 58 disposed on each side of the casting cavity on the surfaces in contact with the rails 36, 38 and the mold component 42.

This seal 58 is glued over the entire height of said contact surface, shown on the left side of FIG. . The seal 60 is glued onto a protrusion with sides sloping outwardly relative to the slot 50 over the height of said contact surface shown on the right side of FIG. corresponds to the part of said surface which is applied to the surface.
The upper end of the sealing body 60 is provided with an extension 62 that extends outward from the protrusion that is the adhesive matrix.
The extension has a length of 5 to 10 Tfrm and is designed to prevent leakage of weld metal at the joint between mold components 40 and 42 above rail 38. The lower ends of the seals 58, 60 also include similar extensions (not shown) designed to prevent leakage of weld metal fluid at the joint between the mold member 40 and the base plate 44. .

More specifically with reference to FIG. 5, the seal 60 of the member 40 includes the extension 62 at its upper end and an extension 66 at its lower end. Member 42 likewise includes two seals. However, in FIG. 4, only the upper end of the seal 64 is shown, which is the same as the seal 58 on the member 40. The seals 58, 64 are not provided with extensions, since the seal at this point in the mold is not critical. It should be noted here that when members 40 and 42 are combined, the upper part of seal 64 achieves a seal with the upper part of the contact surface of member 40 that does not have a seal; The sealing with the member 42 is achieved by the seal 58 of 40.

The base plate 44 is provided with a sealing body 66 having the shape of a rectangular frame, which can also be constructed, for example, by stamping around the opening 52.

This seal 66 is glued to a rectangular projection whose one side is angled outwardly with respect to the opening 52 .
FIG. 4 shows that when parts 40, 42 and bed plate 44 are pressed against each other and simultaneously against both rails 36, 38, the sealing of the mold is complete at the level of the casting cavity. , it is clear that. Sufficient conditions therefore exist to direct hot welding metal fluid through the crucible communicating with the funnel formed by openings 46 and 48. Advantageously, the seals for the parts of the mold according to the invention are positioned in place after the mold has been assembled, so that the seals do not self-adhere immediately after the welding operation. Operating in this manner significantly saves time and eliminates the need to rely on the skilled labor required to perform conventional sludge operations. Now, the mold shown in Figure 6 is
It consists of two side shell halves 110, 11' of identical shape and a base plate 112 and is designed to be used in butt welding of rails.

The shell halves 110 and 11' are designed to fit over one side of the joint to be welded and their internal shape is the same as that of the rail halves. The base plate 112 is designed to be underneath both rails and both shell halves 110, 11'. To obtain a seal around the joint to be welded, centered on the casting cavity, a seal made of a strip of compressible material, which is hardly affected by heat, is used, as already mentioned. Just glue it in place. As such, the shell halves 110 of FIG. 7 each have a slot 118 in a surface designed to contact the shape of the rail halves to be welded.
two protrusions 114 and 11 arranged on one side of the
6.

The slot 118 is also designed to define a casting cavity with an opening corresponding to 110''. The two protrusions 114 and 116 are each inclined outwardly with respect to the opening 118 at an angle α0. It is designed to be compatible with adhesive seals.

The seal also adheres to the baseplate 112 around the casting cavity. Above the casting cavity, ie above the rails to be welded, shell halves 110, 11' are arranged on respective flat surfaces 1
20 and 12' and are provided with protrusions on these surfaces to ensure accurate positioning of the shell halves 110 and 11' and surfaces 120 and 12' in contact.
``It is now possible to simultaneously seal the two halves around each other.

Surface 120 includes ridges 122 and grooves 124;
These are each configured to be suitable for mating with a corresponding groove 12C and ridge 122'' on the surface 12'' of the shell half 110''. The raised portion 122 and the groove 124 form the opening 1
26, and as a result 2
When the two shell halves are assembled, the aperture 126 cooperates with the corresponding aperture 126'' to form two apertures 128 and 1.
2 constitutes a casting cavity that communicates with a chamber composed of.
The pouring chamber may also be provided with a central orifice that mates with a removable pouring stopper for passage of a torch when performing preheat welding. Openings 126 and 12
The connections between 8 and 126'' and 12'' are made through holes 130 and 13'', respectively.The overall shape of the ridge 122 and the groove 124 is that of two linear sections forming an angle. ing.

Moreover, the groove 124 communicates on the one hand with the opening 128 and on the other hand with the upper surface of the shell half 110. The depth of groove 124 is greater than the height of ridge 122, so when the shell halves are assembled, blowholes 132 and 13 are formed.
2" (see FIG. 8) to allow air to escape during pouring of the weld metal. The shell half 110 also has an upright shape including a cylindrical duct having a maximum diameter of 136. 7 and 8, the shell halves 110 are provided with an outlet for receiving excess weld metal fluid that has preheated the rail joint. , 11'' have surfaces 120 and 12'' in contact with each other that are wider than the other parts, so that better contact between the halves can be obtained. In FIG. 9, the upper part is similar to the shell half 110 in FIG. The interior surface of the shell half 138 is shown as being identical, but shaped such that the lower portion is sealed by a sludge.

That is, the interior surface of the shell half 138 is provided with ridges 1 disposed similar to those previously described with respect to FIGS. 6-8.
42 and a flat surface 140 with grooves 144. Furthermore, the inner surface has two ridges each disposed on one side of the opening 150 and designed to cooperate with a corresponding ridge on the other identically shaped shell half to define a casting cavity. 146 and 148. These protrusions 146 and 148 both have a shape that corresponds to the shape of the rail halves and are provided with throats 152 and 154 designed to allow the application of a lubrication mixture. In the case of molds consisting of two shell halves of the type shown in Figure 9, the sealing between the lower parts of the two shell halves and the baseplate is achieved by gluing a refractory seal onto the baseplate. .

Each part of the mold of the present invention is manufactured by a conventional method using sand, coarse particles, and a hardening agent as raw materials.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a mold of the present invention having a contact surface with a protrusion to which a seal is adhered before being compressed. FIG. 2 is the same partial cross-sectional view as FIG. 1 after the seal has been compressed. Figure 3 shows the second state when the compression of the seal is completed.
The same partial cross-section as in the figure is shown. FIG. 4 is a perspective view of a three-component mold used for welding railway rails. 5 is a cross-sectional view of a portion of the mold of FIG. 4; FIG. FIG. 6 is a front view of a three-piece mold used for rail welding, with sealing around the casting cavity being achieved by the mutually mating surfaces. FIG. 7 shows the interior of the side shell halves of the mold of FIG. 6. Figure 8 is the 6th
FIG. 2 is a plan view of the mold shown in FIG. FIG. 9 shows a shell half similar to FIG. 7, with sealing around the casting cavity accomplished by a refractory cement seal. 10... Mold, 16... Metal member, 24... Band-shaped body, 36, 38... Rule, 40, 42...
・Mold component, 44... base plate, 58, 60, 6
4... Sealing body, 110, 11'... Side shell half, 112... Base plate, 122, 122...
...Protuberance, 124,124''...Groove, 138...
... Shell half, 152, 154 ... Throat.

Claims (1)

[Claims] 1. Consisting of at least two components for joining at least two metal members by thermite welding and capable of receiving hot welding metal fluid around each joint of the metal members. a mold having a structure defining a casting cavity designed to at least one of the mold surfaces contacting either a part of one of the parts to be welded or another part of the mold; has a protrusion with an inclined side facing towards the outside of the casting cavity so as to join with a part of one of the parts to be welded or with another part of the mold;
A mold characterized in that a strip made of a compressible material that is hardly affected by heat is mounted on the protrusion. 2. Mold according to claim 1, characterized in that the strip consists of a mineral felt, in particular a felt made of aluminum silicate, which may contain oxides of chromium. 3. The mold according to claim 1 or 2, wherein one surface of the strip is bonded to the protrusion. 4. The mold according to claim 1, characterized in that a surface of the strip body other than the surface bonded to the protrusion is coated with malleable metal foil, in particular aluminum foil. . 5 The sloped side surface is approximately 1
Claim 1 characterized in that the angle is 0°.
The mold according to any one of items 1 to 4. 6. Claim 1, characterized in that at least one of the ends of the strip terminates in a shape with an extension extending beyond the protrusion to which the strip is attached. 6. The mold according to any one of items 5 to 6. 7 Castings consisting of at least two components for joining at least two metal parts by thermite welding and designed to receive hot welding metal fluid around each joint of the metal parts. A mold having a structure defining a casting cavity, wherein at least one of the mold surfaces that contacts either a part of one of the parts to be welded or another part of the mold defines a casting cavity. At least one of the mold surfaces that contacts either a part of one of the parts to be welded or another part of the mold has a protrusion with an inclined side surface facing the outside of the part, and the casting cavity a protrusion with an inclined side surface facing the outside of the part for joining with a part of one of the parts to be welded or with another part of the mold;
A strip made of a compressible material that is substantially unaffected by heat is mounted on the protrusion, and each of the mold components is in contact with each other and above the casting cavity. 1. A mold, characterized in that it has mutually abutting surfaces which ensure positioning and sealing relative to each other in the regions of the mold. 8 each mutually mating surface comprises a flat contact surface with one ridge and one groove, said ridge and groove and the groove and ridge on the flat contact surface of another component of the mold, respectively; 8. Mold according to claim 7, characterized in that they cooperate. 9 the ridges and grooves of said flat contact surface are arranged in symmetrical positions with respect to a central slot formed in said surface such that the grooves and ridges of each surface cooperate with each other; 9. The mold of claim 8, wherein the slots cooperate to define one opening through which hot weld metal fluid can be guided into the casting cavity. 10 One end of each groove communicates with the central slot and the other end opens with the exterior of the mold, the depth of each groove is greater than the height of each cooperating ridge, and the groove Claim 9, characterized in that when the weld metal fluid is injected into the casting cavity, a ventilation hole can be formed for discharging air when the weld metal fluid is poured into the casting cavity when the weld metal fluid is in a state in which the casting cavity receives the corresponding protuberance. The mold described in.