EP3186173A1

EP3186173A1 - Hybrid chain scraper and a method for producing same

Info

Publication number: EP3186173A1
Application number: EP15766744.5A
Authority: EP
Inventors: Bernhard Norpoth
Original assignee: Thiele GmbH and Co KG
Current assignee: Thiele GmbH and Co KG
Priority date: 2014-08-28
Filing date: 2015-08-28
Publication date: 2017-07-05
Also published as: DE102014112369A1; WO2016029906A1

Abstract

The invention relates to a chain scraper (4) for arranging on a chain strand (2) in a chain conveyor (1), comprising a web-shaped central element (5) that can be arranged transversely to a longitudinal chain direction (3), scraper tips (7) being arranged at the ends (6) of said central element, and the chain scraper being characterised in that said central element (5) is produced particularly in the form of a forged metal component, one hollow scraper tip (7) being welded to each end (6) thereof, and a cavity (8) that is formed by the end (6) of said central element (5) and the scraper tips (7) being filled with a metal foam (9).

Description

Hybrid chain scraper and method for its production

The present invention relates to a chain scraper for arrangement on a chain strand according to the features in the preamble of claim 1.

The present invention further relates to a method for producing a chain scraper according to the features in claim 10.

Chain scrapers for placement in a scraper conveyor are known from the prior art.

Scratch conveyors are also known as chain conveyors and are used as a continuous conveyor for transporting bulk material, such as sand, coal or flour. Such a chain conveyor consists of one or more circulating chain strands, with corresponding chain scrapers are used to set each part of the bulk material with the chain in motion. The chain conveyor over a conveyor belt has the advantage that it is made more robust, with no too long conveyor lines can be bridged, since the power requirement due to high friction and large masses to be moved is considerable.

Thus, scratches are used in chain conveyors, which run in particular in the bulk material to be conveyed. The scraper tips run either with centrally arranged chain or two centrally arranged chain strands or else with outer chains. As a rule, such a scratch extends transversely to the chain longitudinal direction and at repeated intervals a plurality of chain scrapers are arranged on a conveyor chain.

In particular, the scraper tips are subject to high abrasive wear while running in a guide, in particular a channel or other guide. From DE 84 12 378 U1 a Verschleißendstück for scrape of mining scraper iron conveyors is known to counteract the wear of scraper conveyors. For this purpose, an end piece is welded to a chain scraper directed transversely to the chain so that corresponding chain scrapers can be repaired without any buildup of welds with unwanted hardening or other disadvantages.

A disadvantage of such a previously known chain scraper that this has a high weight due to the massiveness of the individual components. Furthermore, if the scratch tip has possibly been tempered, the entire massive scratch tip must be made of a heat-treatable steel alloy, and it requires increased heat input in order to harden it, for example, by a heat treatment.

Object of the present invention is to provide starting from the prior art, a chain scraper and a method for its production, so that a thus operated scraper conveyor can be operated with improved efficiency, the production costs are low and the chain scraper for a wide range of applications is individually configurable. The aforementioned object is achieved with a chain scraper according to the features in claim 1.

The procedural part of the object is further achieved with a manufacturing method according to the invention with the features in claim 10.

Advantageous embodiments of the present invention are described in the dependent claims.

The chain scraper for arrangement on a chain strand of a scraper conveyor or chain conveyor has a transversely to a chain direction or chain longitudinally arranged web-shaped center body, are arranged at the ends of scraper tips and is inventively characterized in that the center body produced as a particular cast, particularly preferably forged metal component is, at the ends of each a hollow scratch tip is welded, wherein a formed by the end of the center body and the interior of the scratch tip cavity is filled with a metal foam.

The chain scraper is used in particular in at least one inner, preferably two parallel conveyor chains, in which case a clamping piece is screwed to the center body, so that the chain scrapers are detachably coupled to the chain in a form-fitting manner. The scraper has a total of a ridge-shaped course. It extends with an overall length, thus from the extreme end of a scraper tip to the extreme end of the opposite scraper tip, transverse to the chain longitudinal direction. In a preferred embodiment, 30% to 70%, in particular 40% to 60%, very particularly preferably more than 50% but not more than 70% of the total length of a length of the center body, also called center body length covered. This means that a part of the total length is formed by the center body itself. The remaining percentage is preferably covered by half each of the opposite on both sides scratch tips. Thus, for example, if 30% to 70% of the total length were to be formed along the length of the middle body, then again 70% to 30%, each divided by two, thus formed 35% to 15% of the total length of each one scratch tip as scratch tip length.

According to the invention, there are three advantages in particular. On the one hand can be realized by the preferably forged manufactured center body with the hollow, formed with metal foam scraper tips a particularly low weight. It is thus possible to increase the efficiency or the efficiency of a scraper conveyor equipped with the chain scrapers according to the invention. At the same time it is possible to choose the scratch tips and in particular the material of the scraper tips individually for each application. The scratching tips can then be further tempered and in particular at least partially cured within the scope of the invention, wherein due to the hollow scraper tips initially only a small amount of material and thus low material costs must be used to produce the chain scraper. Thus, the production costs are kept low or even reduced compared to known from the prior art chain scrapers.

The third advantage is then that an individual configurability for the intended use is made possible, in particular when using a common-part concept. For example, the center body can basically be manufactured as a common part, and then the chain scraper can be adapted to the customer requirement by individual choice of the scraper tips. For example, scratch tips made of a hardenable steel alloy can be used, these then being subsequently hardened. If a certain hardness with simultaneous residual ductility is desired, it is also possible, in turn, to precisely set these material properties specifically at the scratch tips by selecting the material and / or the tempering process. The strength of the scraper tips of the chain scraper is at least consistent with known from the prior art solid scratch tips, as by filling the cavity with a metal foam in conjunction with the outer hard shell of the scraper tip a particularly high strength and rigidity of the respective chain scraper is possible. The scratch tips particularly preferably have a hardness between 40 and 70 HRC, in particular between 40 and 60 HRC. Particularly preferably between 45 and 59 HRC, very particularly preferably between 48 and 56 HRC. In particular, this means the hardness in the region of the surface of the respective scratch tip to understand. However, the entire material of the hollow scraper tip, that is to say the material of the shell formed by the scraper tip, is particularly preferably through-hardened. The metal foam therein has a different hardness.

For this purpose, in particular a respective scratch tip is welded circumferentially to one end of the middle body. The scratch tip itself is preferably produced as a cast component, extruded component or forging component, so that the scratch tip can be produced from many metallic materials, in particular steel materials, as a hollow component. By making the scratch tip as Gußbauteil, as extruded or as Schmiedebauteil and in particular of the center body as a cast, preferably as a forged component, it is also possible that an already existing Justiernut and / or weld groove is formed as a coupling point, so that after the production of Items can be dispensed with a complex post-processing. After insertion of a corresponding substance for the metal foam and positive positioning or alignment on the center body, the scraper tips can be welded directly to the latter, preferably circumferentially. A post-processing, for example by a cutting process, is thus avoided, which also reduces the cost of manufacture at the same time.

So that the scratch tip can be produced in particular as a cast component, as an extruded component or as a forged component, a scratch tip is particularly preferably formed from two parts. The scratch tip itself is designed as a hollow component open on one side. If the scratch tip is now produced in two parts, this one-sided open hollow component is separated by a parting plane into two parts, so that they are formed as two shells. The parting plane in which the two parts are separated runs in particular orthogonal to the chain longitudinal direction, wherein the two parts are in turn coupled to one another by a continuous weld lying in the parting plane.

In addition to the production of the scratch tip as Gußbauteil, as extruded or as a forging component, it is also possible that materials with each other different material properties and / or mutually different materials are used on a scratch tip. For example, it would be conceivable that in the pulling direction or conveying direction, the front part of the scratch tip has a higher hardness, whereas the rear part of the scratch tip has a higher ductility. Due to the different material pairings and / or material properties at the scratch tip, the service life of a chain scraper according to the invention can be further increased, which lowers the maintenance, servicing and inspection costs of a scraper conveyor equipped with the scraper tips according to the invention.

The material strength for both the scraper tips and the center body is preferably 800 to 1600 MPa, in particular 900 to 1400 MPa.

In particular, however, the invention provides that the center body and the scraper tips can be made from different materials. The center body can then be formed of a comparatively more favorable material, whereas the scratch tips or the parts of the scraper tips are formed from a comparatively higher value, in particular heat-treatable material. However, since the scraper tips themselves have only a small wall thickness but high rigidity behavior due to the metal foam, the total material input of the higher-grade material is relatively low. This reduces production costs as a result of lower raw material costs for the materials to be processed. However, all components are preferably made of metallic material, in particular steel material.

The scratch tips themselves are in particular tempered, the coating in particular having a partial hardening, which is very particularly preferably carried out by inductive hardening. This in turn results in the advantage that the scratch points have a wall thickness of up to a few millimeters and thus have a low intrinsic volume. The energy required to perform the hardening process is thus significantly reduced compared to a solid scratch tip. This in turn reduces production costs due to lower energy consumption. The method according to the invention for producing a chain scraper in at least one of the aforementioned features is characterized by the following method steps:

Providing a central body, preferably the central body is forged or manufactured as a cast component,

Applying hollow scraper tips to a respective end of the central body, wherein a filling material is arranged in the scraper tips,

Circumferential welding of each scraper tip to one end,

Performing a heat treatment so that the filler foams and fills the cavity formed between an end face of the end and the interior of the scratch tip,

- Optional hardening of the scratch tips.

In the context of the invention, the application of the scraper tips at the opposite ends of the center body can take place at the same time or else in chronological succession. Consequently, either both scraper tips can be attached to the ends in parallel and at the same time, or initially only one scraper tip can be attached, welded and optionally the foam material can be foamed therein, and subsequently a scraper tip can be attached at the opposite end, welded and then foamed , It is also conceivable within the scope of the invention that both scraper tips are welded successively and then the filling material is foamed simultaneously in both scraper tips.

According to the invention, it is provided that the strength and / or rigidity in the region of the scratch tip is achieved on account of the filler material swollen or foamed to form the metal foam. The scratch tip itself has a wall thickness of up to a few millimeters, wherein upon reaching an abrasive predetermined wear corresponding scratches replaced and / or the scratch tip must be renewed. This is consistent with a scraper conveyor equipped with solid scraper tips, in particular at a hardenable high-quality steel alloy for the scratch tip of the material use is limited to the wall thickness of the hollow scratch tip and the cavity behind it is filled with a cheaper filling material of a metal foam.

Thus, scraper tips can be used, which are produced in particular by casting, forging or extrusion and can be subsequently individually at least partially aftertreated. For this purpose, in particular an inductive hardening is provided in order to set a wear-resistant material structure in the scratch tips. This is done in the context of the invention in particular such that initially both the scratch tips are welded to the center body and in particular the metal foam is foamed. Subsequent thereto, by at least partial tempering, in particular partial hardening, particularly preferably a partially performed inductive hardening, the scratch tip is at least partially aftertreated. In the context of the invention, however, it is also conceivable that the scratch tip is already processed before welding to the center body with the aforementioned post-processing. It is also conceivable within the scope of the invention to initially weld the scratch tip and then to work with the abovementioned reworking method before foaming the metal foam.

Particularly preferably, the at least partial curing is carried out as inductive hardening. In this case, the scratch tip, in particular the scraper conveyor with welded-on scratch tip, is guided in a translatory manner past a corresponding inductive hardening device. Particular preference is then given to a side of the scratch tip resting in the upper strand or lower strand, in particular a top side and an underside of the scratch tip. In the context of the invention, furthermore, the tip side or front side of the scraper tip which lies on the outside transverse to the chain direction is also hardened. If necessary, the sides facing the material to be conveyed or facing away can also be hardened in a further step.

The filler material is preferably provided by an upstream sintering process and may then be arranged as a bar stock or in pieces in the scraping tip. Then the scratch tip on the free End positioned in particular on the end wall of the center body and thermally joined by an at least partially, preferably completely circumferential weld with the end. In a subsequent thermal treatment, the filler material is then swelled or foamed, so that it completely fills the resulting cavity from the inside and adjusts the scratch tip with a required stiffness or strength. The thermal treatment for foaming the filling material can also be carried out simultaneously with the hardening process. The hardening process, in particular the resulting heat input, preferably during inductive hardening, may also be sufficient to cause foaming of the filling material. The filler is thus foamed during curing.

Further advantages, features, characteristics and aspects of the present invention are the subject of the following description. Advantageous embodiments are shown in the schematic figures:

FIG. 1 shows a chain scraper conveyor according to the invention

Chain scraper in top view,

FIG. 2 shows a chain scraper conveyor with chain scraper in a perspective view;

FIG. 3 shows the chain scraper according to the invention in one

Sectional view along the section line III-III of Figure 1,

Figures 4a to d show a scratch tip according to the invention in different

views

FIG. 5 shows the chain scraper according to the invention with a chain in side view,

FIG. 6 shows an embodiment variant of the invention

Chain scraper with split scraper points and

Figures 7a to d show a part of a split scratch tip in different

Views. In the figures, the same reference numerals are used for the same or similar components, even if a repeated description is omitted for reasons of simplicity.

Figure 1 shows a section of a chain conveyor according to the invention 1 comprising two chain strands 2 and a transverse to the chain longitudinal direction 3 extending chain scraper 4. The chain scraper 4 is inventively designed as a hybrid component and has a web-shaped center body 5, at the ends 6 each have a scratch tip. 7 is welded. According to the invention the scratch tip 7 is hollow and a cavity 8 shown in FIG. 3 is filled in the scratch tip 7 with an indicated metal foam 9.

According to FIG. 2, it can be clearly seen that the scraper tip 7 is coupled with a respective circumferential thermal joining seam, in particular a weld seam 10, with the end face 11 of the end 6 of the center body 5 shown in FIG. For this purpose, the central body 5 is produced in such a way that between the outer end side 1 1 and the middle body side ends 12 of the scratch tip 7, a circumferential weld groove 13, also referred to as a weld groove is formed, in which then the weld 10 is applied or introduced. In particular, the weld joint 13 is circumferentially V-shaped, so that, for example, a fillet weld can be performed as a weld.

Furthermore, it can be seen according to Figure 3, that each a lying chain link 14 of the chain strand 2 between the center body 5 and a coupled via two bolts 15 on the center body 5 coupling piece 16 are positively fixed. About the bolts 15, it is possible to releasably couple the chain scraper 4 according to the invention with the chain strand 2. In particular, nuts 17 of the bolts 15 and bolt heads 18 are recessed relative to the respective surface 19. It can be seen clearly that the respective end face 1 1 of the central body 5 protrudes into the respective cavity 8 or bulges into it. Consequently, the end face 1 1 preferably has a bulbous configuration or bulbous curvature in the direction of the cavity 8. Furthermore, it is easy to see the total length Lges, which extends from one outer end 20 of a scratch tip 7 to the opposite end 20 of the other scratch tip. 7 extends. This total length Lges can be particularly preferably between 500 and 1800 mm. Particularly preferably, the total length Lges is between 600 and 1500 mm, in particular between 850 and 1350 mm. Over a part of 30% to 70%, in particular 40% to 60% of the total length Lges, the center body length L5 of the center body 5 extends. Shown here is not measured from an outermost end point of the center body length L5 of the center body 5, but of a range of circumferential weld joint 13 to the opposite side to understand. Consequently, the measurable from the outside center body length L5. A respective scratch tip length L7 then likewise extends from an inner side of the scratch tip 7, here also in the region of the weld groove 13, to the outer end 20 of the scratch tip 7. Preferably, the center body length L5 is 400 to 800 mm, very particularly preferably 450 to 650 mm ,

The scratch tip 7 shown in FIGS. 4a to 4 is designed according to the invention as a cast component, as an extruded component or as a forging component and has a corresponding cavity 8. The scratch tip 7 can in turn be widened towards its end 20, as can be clearly seen in particular in FIG. 4c. In particular, FIG. 4 shows that a corresponding upper side 22 and an underside 23 opposite the upper side 22 can be hardened. Likewise, the front side 24 located at the end 20, also called the tip side, can be hardened. The side surfaces 25, 26, which face the material to be conveyed or facing away, are then not cured in the invention. Here, the abrasive wear when passing through the groove of a scraper conveyor is low, whereas the abrasive wear on the top 22 and / or the bottom 23 and / or the end face 24 when passing through the channel is correspondingly high, so that by the partial hardening here a longer service life is achieved. At the same time, the production costs are kept low because the side surfaces 25, 26 do not have to be post-treated again consuming.

In order to be able to produce the scraper tip 7, in particular in such a way with a widening as a cast component, as an extruded component or as a forging component, the scraper tip 7 according to FIG. 6 is formed by two parts 7.1, 7.2. Part 7.2 is shown in FIGS. 7a to d. This component can be used in particular as a cast component, as Extruded component or produced as a forging component. A corresponding parting plane extends according to FIG. 6 orthogonal to the chain longitudinal direction 3, so that a corresponding weld seam 21 for coupling the two parts 7.1, 7.2 of the scratch tip 7 runs in the parting plane. The two parts can be coupled to each other before or after they are welded to the circumferential weld 10 to the center body 5, with the parting plane orthogonal to the chain longitudinal direction 3 extending weld 21. In this case, the material swelling and / or foaming can be introduced in order to form the metal foam 9.

Further shown in Figure 3 is still that the respective end 6 of the center body 5 forms the full-face side end face 1 1 and consequently contact surface for coupling with the scratch tip 7. This offers in particular the advantage that the center body 5 is formed as a solid component, for example as a forged component made of a steel alloy, whereas then the coupling piece 16 from a comparatively cheaper to produce steel alloy, which in particular is not reworked and / or tempered, can be produced and hereby a sufficient strength for coupling with the respective lying member of the chain strand 2 is achieved. However, due to the fact that the middle body 5 overlaps the coupling piece 16 on the end faces 11, it is possible to couple the scratch tips 7 over the whole area to the in particular forged center body 5.

REFERENCE CHARACTERS:

1 - Chain conveyor

2 - chain strand

3 - Chain longitudinal direction

4 - chain scraper

5 - middle body

6 - end to 5

7 - scratch tip

8 - cavity

9 - Metal foam

10 - weld

1 1 - front side

12 - middle body end to 7

13 - Welding joint / welding groove

14 - lying chain link

5 - Bolt

16 - Coupling piece

17 - Mother

18 - bolt heads

19 - surface

20 - end to 7

21 - weld to 7.1, 7.2

22 - top

23 - bottom

24 - front side

25 - side surface

26 - side surface

27 - stationary chain link

L5 - centerbody length

L7 - scratch tip length

Lges - total length

Claims

claims

1. chain scraper (4) for arrangement on a chain strand (2) in a chain conveyor (1), comprising a transversely to a chain longitudinal direction (3) arrangeable web-shaped center body (5), at whose ends (6) scraper tips (7) are arranged, characterized in that the center body (5) is made as a particular cast, preferably forged metal component, at the ends (20) each having a hollow scratch tip (7) is welded, one through the end (6) of the center body (6) and the Scratch tip (7) formed cavity (8) with a metal foam (9) is filled.

2. chain scraper according to claim 1, characterized in that each one scratch tip (7) with a circumferential weld (10) to the respective end (6) is welded.

3. chain scraper according to claim 1 or 2, characterized in that the scraper tip (7) is formed in two parts.

4. chain scraper according to the preceding claim, characterized in that the two parts (7.1, 7.2) of the scraper tip (7) are formed separately in a parting plane, wherein the parting plane orthogonal to the chain longitudinal direction (3) is oriented and the two parts ( 7.1, 7.2) are coupled together by a lying in the parting plane, at least partially circumferential weld (21).

5. chain scraper according to one of the preceding claims, characterized in that the scraper tips (7) are made as a cast component or as an extrusion component or as a forging component.

6. chain scraper according to one of the preceding claims, characterized in that the scraper tips (7) are tempered, in particular at least partially cured, more preferably by inductive hardening, wherein preferably the hardened scraper tips (7) has a hardness between 40 and 70 HRC, especially preferably between 40 and 60 HRC.

7. chain scraper according to one of the preceding claims, characterized in that at the ends (6) of the central body and at a coupling point of the scraper tip (7) a circumferential weld groove (13) is formed.

8. chain scraper according to one of the preceding claims, characterized in that the two scraper tips (7) and / or the two parts (7.1, 7.2) of the scraper tips (7) relative to the central body (5) are formed of a mutually different material and / or have different strengths from each other.

A chain scraper according to any one of the preceding claims, characterized in that the chain scraper (4) has an overall length (Lges) which extends transversely to the chain longitudinal direction (3), the center body having a center body length (L5) which is 30% to 70 %, preferably 40% to 60% of the total length (Lges) corresponds.

10. A method for producing a chain scraper (4) according to the features of at least claim 1, characterized by the following method steps:

Providing a forged center body (5),

- applying hollow scraper tip (7) to the end (6) of the central body (5), wherein in each scraper tip (7) a filling material is arranged,

Circulating welding of the scraper tips (7) with the ends (6),

Performing a heat treatment so that the filling material foams and fills the cavity (8) formed between an end face (11) of the end (6) and the interior of the scratch tip (7),

- Optional hardening of the scraper tips (7).

11. The method according to claim 10, characterized in that the scraper tips (7) is produced as a cast component, as an extrusion component or as a forging component.

12. The method according to any one of claims 10 or 11, characterized in that the filler material is sintered and / or arranged as a bar material or in pieces in the scratch tip (7).