WO2007009165A1

WO2007009165A1 - Method and apparatus for applying a surface layer to a member

Info

Publication number: WO2007009165A1
Application number: PCT/AU2006/001001
Authority: WO
Inventors: Leslie Philip Moore
Original assignee: Advanced Intellectual Holdings Pty Ltd
Priority date: 2005-07-15
Filing date: 2006-07-14
Publication date: 2007-01-25

Abstract

Apparatus (10) for applying a surface layer to a rail (16). The apparatus (10) is mounted to a locomotive (14) for movement along the rail (16). A barrier structure (70) of the apparatus (10) has side walls (20, 22), in use disposed against sides of the rail, and spaced forward and rear walls (40, 42) extending between these. In an initial condition, forward wall (40) and rear wall (42) extend downwardly to the upper surface (36) of the rail. Granular metal in a receptacle (62) is fed to a space (72) defined between the walls (20, 22, 40, 42) and heated by application of electric power to electrodes (84,84) extending into the space, to form molten metal. Some of the molten metal sets against the rear wall (42), after which the rear wall is moved upwardly to be clear of the rail. The locomotive (14) is then operated to transport the apparatus (10) along the rail so that molten metal is progressively deposited on the rail forwardly of the originally set metal. When set, the deposited metal forms an integral layer (100) of metal on the rail (16).

Description

METHOD AND APPARATUS FOR APPLYING A SURFACE LAYER TO A

MEMBER

Technical Field of Invention

This invention relates to a method and apparatus for applying a surface layer to a member, such as rail.

Summary of Invention

In one aspect, the invention provides apparatus for applying a surface layer to a member, having a barrier structure for confining molten metal to an area of an upper surface of the member and means for effecting relative movement between the barrier structure and the member such that the molten metal sets to form said layer on the surface, which layer is extended along the surface by progressive setting of the molten metal as said relative movement occurs.

The barrier structure may have a forward wall extending transversely to the direction of said movement, and between spaced opposed side walls of the barrier means such that in use of the apparatus, with the barrier structure disposed on the member, there is defined a space between the side walls and the forward wall for receiving the molten metal, such that the molten metal can flow in the direction away from the forward wall to form said layer.

The barrier structure may have a rear wall moveable to a position at which it defines a rear boundary of the space to enable initial setting of portion of said molten metal against the rear wall, before said relative movement is effected, said rear wall being moveable from said position to a position clear of the set portion, to enable passage of the layer from the barrier structure, as the layer is formed.

Means may be provided for cooling at least portions of said barrier structure. Heating means may be provided for heating the metal in the barrier structure to maintain a forward portion of the metal in a molten state. The heating means may be electric heating means for heating the metal by passing electric current through the metal. Feed means may be provided for feeding metal to said space. The feed means may include a receptacle for receiving the metal in flowable, for example granular, form and a valve operable to release the metal in the receptacle to flow into said space.

The means for effecting movement may be effective in use to move the apparatus along the member. Alternatively, the apparatus may be fixed, and the member moved with respect to the apparatus, or both may be moved.

The member may be elongate, the side walls being positioned, in use of the apparatus, in engagement with respective sides of the member.

The invention also provides a method for applying a surface layer to a member comprising establishing a pool of molten metal on an upwardly directed surface of the member and effecting relative movement between the pool and the member so that material from the pool sets to form said layer on the surface. The pool may be confined at forward and side part thereof by a barrier structure. The barrier structure may have a moveable rear wall, the method further including moving the rear wall to an initial position, prior to said relative movement, at which initial position it engages the surface of the member so as to extend transversely thereacross, solidifying said molten metal from a portion of said pool, against said rear wall, moving said rear wall to be clear of said solidified portion, and then effecting said relative movement.

Brief Description of the Drawings

Preferred embodiments of the present invention are hereafter described, by way of non- limiting example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic side view of a locomotive fitted with apparatus for applying a surface layer to a member, constructed in accordance with the invention;

Figure 2 is a diagrammatic side view of the apparatus incorporated into the locomotive of

Figure 1; Figure 3 is a sectional view of the apparatus of Figure 2, substantially on the line 3-3 in

Figure 2;

Figure 4 is a cross section, substantially on the line 4-4 in Figure 3, showing side walls of the apparatus in an operative position;

Figure 5 is a cross-section like Figure 4, but showing the side walls of the apparatus in an inoperative position;

Figure 6 is cross-section substantially on the line 6-6 in Figure 3, but illustrating the apparatus in a condition of use thereof a rear wall of the apparatus in an initial position;

Figure 7 is a cross-section like Figure 6, but showing the rear wall of the apparatus in a subsequent position; Figure 8 is a cross-section on the line 8-8 in Figure 3, showing the apparatus in a condition for initial melting of metal in the apparatus;

Figure 9 is a cross-section like Figure 9, but showing the apparatus in a condition of motion along a rail member for applying a layer to the upper surface of the rail;

Figure 10 is a transverse cross-section of a rail member having a layer applied by use of the apparatus of the invention;

Figure 11 is a vertical section of feed means incorporated into the apparatus of the invention;

Figure 12 is a diagrammatic side view of another locomotive fitted with a apparatus constructed in accordance with the invention; and Figure 13 is a diagrammatic side view of a modified apparatus constructed in accordance with the invention.

Detailed Description of Preferred Embodiments of the Invention Figure 1 shows an apparatus 10 carried by a locomotive 14 arranged to travel along a railway track 12 having two rails of which only one rail, rail 16, is shown. The rail 16 is a member which is to be resurfaced by the apparatus 10.

Referring to Figures 2 to 5, apparatus 10 has opposed, spaced, side walls 20, 22, which extend in the longitudinal direction of the apparatus 10 and locomotive 14. The side walls are mounted at upper ends thereof for pivotal movement about respective longitudinal axes. Particularly, they are carried by spaced parallel longitudinally extending axles 24, 26, mounted to the locomotive by bearings 28, for rotation about the respective axes of the axles.

Extensible members in the form of hydraulic rams 30, 32 are pivotally coupled at respective first ends thereof to respective side walls 20, 22, and pivotally connected at respective second ends thereof to the locomotive 14. By actuation of the hydraulic rams to extend and contract them, the side walls are movable between the condition shown in Figure 4 and the condition shown in Figure 5, under pivotal movement of the walls about the axes of the axles 24, 26. In the condition shown in Figure 4, the side walls depend downwardly from axles 24, 26. In this condition, the side walls 20, 22 are upright and positioned in engagement with opposite sides of the upper or crown portion 34 of rail 16. Also, the side walls then extend some distance above the upper surface 36 of the rail 16. In the condition shown in Figure 5, the side walls are pivoted outwardly about the axes of axles 24, 26 so that the side walls 20, 22 are cleared from engagement with the rail 16.

The apparatus 10 includes forward and rear walls 40, 42. These are mounted for vertical movement with respect to the locomotive 14 being connected to the locomotive 14 by upright extensible members in the form of hydraulic rams 44, 46. The forward and rear walls 40, 42 are dimensioned such that in the condition of the apparatus shown in Figure 4, where the side walls 20, 22 are upright and in engagement with respective sides of the rail

16, the side walls are in engagement with side edges of the forward and rear walls 40, 42 so that the forward and rear walls provide transverse barriers between the side walls 20, 22.

In these conditions, the lower edges of the forward and rear walls (40, 42) also are brought into engagement with the upper surface 36 of rail 16.

The forward wall 40 can be moved from the position at which it engages the upper surface of rail 16 to a vertically displaced condition at which it is spaced above the side walls, as shown in Figure 5. This movement is effected by actuation of hydraulic ram 44.

Rear wall 42 is likewise positioned, in a lowered condition, such that the lower edge thereof is in engagement with the upper surface 36 of the rail. This condition is shown for example in Figures 7 and 8. Rear wall 42 can be moved to a position above side walls 2O₅ 22, that is to a vertical height similar to that of forward wall 40 in the condition of Figure 5. Figure 7 shows such a position at which the lower edge 48 of the rear wall is lifted to be above the side walls 20, 22. This condition is also illustrated in Figure 9.

The apparatus 10 includes a feed means 58 having hopper 60 having a receptacle 62 and a downwardly depending feedpipe 64 (Figure 11). Granular iron 76 is loaded into receptacle

62, for outflow to the feedpipe 64 under control of a valve 78. As shown, valve 78 is in the form of a butterfly valve located at the top of feedpipe 64 and having a valve element 80 which can be rotated to a position (Figure 11) at which substantially unimpeded outflow from the receptacle 62 to the feedpipe 64 is permitted to a position (not shown) at which the valve element 80 closes the bottom of the receptacle 62 to prevent outflow therefrom.

By adjusting the angular position of the valve element 80 between these positions, by rotation thereof, fine control over the rate of outflow can be achieved.

The side walls 20, 22 together with forward and rear walls 40, 42 define a barrier structure 70 (Figure 3) enclosing a space 72 above the rail 16. The hopper 60 is positioned above this space to permit outflow of the granular iron 76 in the receptacle 62 through the feedpipe 64 to exit from the feedpipe at an outlet 66 immediately above space 72, for delivery of the material to the space 72 under control of valve 78.

The apparatus 10 includes heating means 82, having two upright electrodes 84, 86. These are carried by a yoke 90 (Figure 8 only). This is mounted by an hydraulic ram 92 to the locomotive 14 so as to be movable vertically to dispose the electrodes 84, 86 at the positions shown in Figures 8 and 9, at which lower ends thereof are at relatively forward and rearward locations respectively within space 72. By vertical movement of yoke 90, under contraction of hydraulic ram 92, the electrodes may be moved upwardly to withdraw them from space 72.

Suitable means is provided for cooling the barrier structure 70, particularly the walls 20, 22, 40, 42. As shown in Figures 7 and 9 for example, cavities 18 may be formed in these walls, connected to external lines 52 to enable liquid coolant, such as liquid sodium, to be passed through these to effect cooling.

To use the apparatus 10, the locomotive 14 is first positioned in stationary condition on the track 12, with the side walls 20, 22 pivoted to the positions shown in Figure 5 and with the forward and rear walls 40, 42 at the upper locations described. Then, the hydraulic rams 30, 32 are actuated to pivot the side walls 20, 22 to the positions shown in Figure 4. These movements are also executed with the electrodes 84, 86 in their upper positions and, after execution, the electrodes are moved to the lower positions as shown in Figure 8 by operation of hydraulic ram 92. Also, the forward and rear walls, 40, 42 are then moved to the lower positions illustrated in Figure 8. Subsequently, the valve 78 is actuated to permit outflow of granular iron material from the receptacle 62 to the feedpipe 64 from which the material exits to fall into the space 72 between the walls 20, 22, 40, 42. This operation is shown in Figure 8. Then, an electrical potential is applied to the electrodes 84, 86 from a suitable source (not shown) such that electric current passes between the electrodes and through the granular iron 76 in the space 72. This causes the material to assume a molten state. Particularly, a pool of molten metal 38 is formed in the space 72. By suitable selection of the flow of coolant through rear wall 42 and walls 20, 22 and 40, solidification of metal from the pool of molten metal 38 occurs against the forward (inner) surface of the wall 42, within space 72, to form a solidified region 50 (Figures 6 and 8). Once the solidified region 50 is established, the hydraulic ram 46 is actuated to vertically move the rear wall 42 to the position shown in Figures 7 and 9, where it is well above the upper surface of the pool of molten metal 38 and the solidified region 50. The locomotive 14 is then operated to cause it and the apparatus 10 to move along the track 12 and rail 16. By this action, ongoing solidification of metal from the maintained pool of molten metal 38 occurs forwardly from the initial position of the region 50, the solidified region 50 so being extended rearwardly from the apparatus 10 along the rail 16, to form a layer 100 on surface 36. By virtue of the molten state of the metal as it is laid to form the layer 100, the layer 100 is effectively welded to the upper surface of the rail 16 to form an integral structure. By regulating the speed of transmission of the locomotive along the rail 16, the rate of inflow of material from hopper 60 into the space 72, and the energy applied to the electrodes 84, 86, the deposition of the layer 100 can be regulated as required.

If necessary, provision may be made to reduce oxidation of molten material in the space 72. For example, an inert gas may be supplied to form a blanket thereover.

While the apparatus 10 has been described as being fixedly mounted to the locomotive 14, it may be mounted for movement with respect to the locomotive, or parts of it may be mounted for movement with respect to the locomotive additional to the movements described. For example, the hopper 60 may be vertically movable, and the barrier structure

70, electrodes 84, 86 and hopper 60 may be movable so that they can be positioned sidewardly to align them with the rail 16. Also, the side walls 20, 22 may be vertically movable so that lower edges thereof are above the top of the rail 16.

Two or more apparatuses 10 may be carried by locomotive 14 for treatment of respective ones of two or more rails 16 forming track 12.

The locomotive 114 and apparatus 110 shown in Figure 12 are similar to the locomotive 14 and apparatus 10 described with reference to Figures 1 to 11, and the apparatus 110 functions in the same way as the apparatus 10. In Figure 12, components of the apparatus 110 are shown in position on the locomotive 114. These components include:

a. A feed hopper 160 similar to hopper 60, for receiving granular metal for forming the layer 100 on rail 16; b. A mould mechanism 192 performing the function of the barrier structure 70;

c. A plasma arc furnace 190, which includes electrodes similar to electrodes 84, 86, for heating metal to a molten state in the mould mechanism 192;

d. Chill bars 194 for chilling the mould mechanism 192,

Also, the apparatus 110 includes:

e. A preheating structure 196 for preheating granular metal as this passes from hopper 160 to furnace 190;

f. A pre-reduction chamber 198 in which oxygen entrained with the granular metal from hopper 160 is burnt off;

g. A deburring grinder 154 for facing the sides of the upper part of rail 16 before resurfacing; and

h. A trimmer grinder mechanism 156 including side grinders which face the resurfaced rail 16 at the side edges of the upper part of the rail 16; and

i. A top grinder 174 for facing the upper surface of the resurfaced rail 16.

Figure 13 shows a further apparatus 210 constructed in accordance with the invention. This has a barrier structure 270 similar to barrier structure 70 although, in this case, the rear wall 242 is pivotal from the open position shown, at which it is well clear of the rail 12, to the closed position, shown at 242', at which it rests on the upper surface 36 of rail 12. In this case, instead of the two electrodes 84, 86, there are provided three electrodes 284, 286, 288, spaced in the direction of relative movement between the apparatus 210 and the rail 12. These are arranged so that lower ends thereof are at progressively increasing heights above the upper surface 36 of rail 12, as reckoned in the direction away from the forward part of barrier structure 270. As a result, in use of the apparatus 210, the apparatus deposits three sub-layers of metal, a first layer 200A on the surface 36, a second layer 200B on layer 200A, and a third layer 200C on layer 200B. These sub-layers are fused together to form a layer 200 fused to the rail 12.

By the arrangement of figure 13, it may be possible to achieve one or more of the following advantages:

a) Faster metal deposition rates, to improve the speed of formation of the layer 200;

b) Less tendency to introduce distortion in the rail and or the layer 200, with better normalising and stress relief; and

c) Permitting different compositions of the material forming sub-layers, eg enabling layer 200A to be a "buttering" layer, formed of material of composition between that of the rail and that of the layer 200B. To effect this, multiple hoppers 60 may be provided, one adjacent each electrode, for depositing granular metallic material of different compositions adjacent each electrode.

While, in the described arrangement, the apparatus 10, or the apparatus 110 or the apparatus 210 is moved lengthwise along the rail 16 to effect resurfacing thereof, individual sections of rail could of course be resurfaced by movement of these through a fixed apparatus. Alternatively, relative movement could be effected by movement of both the rail and the apparatus.

Also, while the invention has been described in the context of its use for resurfacing rails or other linear members, it may be adapted to resurface other members, such as by applying a layer to the periphery of a wheel.

Means other than the described locomotive may be used for moving the apparatus or the rail or other member to which a surface layer is to be applied, one relative to the other.

Although heating of the material to form the layer 100 is, in the described embodiment, effected by use of electrodes 84, 86, heating may be effected by other means, such as electron beam heating, laser heating, or magnetic pulse heating.

The described arrangement has been advanced merely by way of explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and combination of novel features herein disclosed.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. Apparatus for applying a surface layer to a member, having a barrier structure for confining molten metal to an area of an upper surface of the member and means for effecting relative movement between the barrier structure and the member such that the molten metal sets to form said layer on the surface, which layer is extended along the surface by progressive setting of the molten metal as said relative movement occurs.

2. Apparatus as claimed in claim 1, wherein the barrier structure has a forward wall extending transversely to the direction of said movement, and between spaced opposed side walls of the barrier means such that in use of the apparatus, with the barrier structure disposed on the member, there is defined a space between the side walls and the forward wall for receiving the molten metal, such that the molten metal can flow in the direction away from the forward wall to form said layer.

3. Apparatus as claimed in claim 1 or claim 2, wherein the barrier structure has a rear wall moveable to a position at which it defines a rear boundary of the space to enable initial setting of portion of said molten metal against the rear wall, before said relative movement is effected, said rear wall being moveable from said position to a position clear of the set portion, to enable passage of the layer from the barrier structure, as the layer is formed.

4. Apparatus as claimed in any one of the preceding claims, having means for cooling at least portions of said barrier structure.

5. Apparatus as claimed in any one of claims 1 to 4, wherein heating means is provided for heating the metal in the barrier structure to maintain a forward portion of the metal in a molten state.

6. Apparatus as claimed in claim 5, wherein the heating means is electric heating means for heating the metal by passing electric current through the metal.

7. Apparatus as claimed in claim 2 or any one of claims 3 to 5, as appended directly or indirectly thereto, wherein feed means is provided for feeding metal to said space.

8. Apparatus as claimed in claim 7, wherein the feed means includes a receptacle for receiving the metal in flowable form and a valve operable to release the metal in the receptacle to flow into said space.

9. Apparatus as claimed in any preceding claim wherein the means for effecting movement is be effective in use to move the apparatus along the member.

10. Apparatus as claimed in any preceding claim for resurfacing said member in the form of an elongate member, said side walls being positioned, in use of the apparatus, in engagement with respective sides of the member.

11. A method for applying a surface layer to a member comprising establishing a pool of molten metal on an upwardly directed surface of the member and effecting relative movement between the pool and the member so that material from the pool sets to form said layer on the surface.

12. The method of claim 11, wherein the pool is confined at forward and side portions thereof by a barrier structure.

13. The method of claim 12, wherein the barrier structure has a moveable rear wall, the method further including moving the rear wall to an initial position, prior to said relative movement, at which initial position it engages the surface of the member so as to extend transversely thereacross, solidifying said molten metal from a portion of said pool, against said rear wall, moving said rear wall to be clear of said solidified portion, and then effecting said relative movement.

14. Apparatus for resurfacing a member, substantially as hereinbefore described with reference to the accompanying drawings.

15. A method of resurfacing a member substantially as hereinbefore described with reference to the accompanying drawings.