COATED SPRING

Abstract

An electrically conductive component, which can be used in motor vehicles, may include a surface having a layered covering. The layered covering may be a melted and cured product of coating with a powder composition. Further, the layered covering may have a layer thickness of greater than 150 m, and the layered covering may be a single-layer covering. The layered covering may also include a pore-like layer structure. The pore-like layer structure of the layered covering may be responsible for an at-least-15% reduction in density of the layered covering relative to a density of the layered covering without the pore-like layer structure.

Claims

1.-15. (canceled)

16. An electrically conductive component comprising a surface with a layered covering, wherein the layered covering has a layer thickness of greater than 150 m, is a melted and cured product of coating with a powder composition, is a single-layer covering, and comprises a pore-like layer structure.

17. The electrically conductive component of claim 16 wherein the layered covering comprises less than 3% by weight of one or more corrosion inhibitors based on the layered covering.

18. The electrically conductive component of claim 16 wherein the pore-like layer structure of the layered covering is responsible for an at-least-15% reduction in density of the layered covering relative to a density of the layered covering without the pore-like layer structure.

19. The electrically conductive component of claim 16 wherein the pore-like layer structure comprises pores having a mean pore diameter of greater than 5 m.

20. The electrically conductive component of claim 16 wherein the layered covering comprises at least 10% by weight of a fiber component based on the layered covering.

21. A layered covering on a surface of the electrically conductive component, wherein the layered covering has a layer thickness of greater than 150 m, is a melted and cured product of coating with a powder composition, is a single-layer covering, and comprises a pore-like layer structure.

22. The layered covering of claim 21 comprising less than 3% by weight of one or more corrosion inhibitors based on the layered covering.

23. A method for coating a surface of an electrically conductive component, the method comprising: providing the electrically conductive component having a surface; providing a powder composition comprising at least one binder component and at least one expanding agent component; pretreating the surface of the electrically conductive component at least one of mechanically or chemically; dying the surface of the electrically conductive component at least until the surface comprises no liquid; and powder-coating the surface of the electrically conductive component with the powder composition, the powder-coating comprising charging the powder composition, grounding the electrically conductive component with the surface, applying the powder composition to the surface, and crosslinking the powder composition at a crosslinking temperature to produce a layered covering in single-layer form with a layer thickness of greater than 150 m.

24. The method of claim 23 wherein the powder composition provided comprises less than 3% by weight of one or more corrosion inhibitors based on the powder composition.

25. The method of claim 23 wherein the layered covering comprises a pore-like layer structure, wherein the pore-like layer structure is responsible for an at-least-15% reduction in density of the layered covering relative to a density of the layered covering without the pore-like layer structure.

26. The method of claim 23 wherein the layered covering comprises a pore-like layer structure with pores that have a mean pore diameter of greater than 5 m.

27. The method of claim 23 wherein the electrically conductive component is grounded after the electrically conductive component is provided and before the surface of the electrically conductive component is pretreated.

28. The method of claim 23 comprising, before the surface of the electrically conductive component is powder-coated, heating the surface of the electrically conductive component to a heating temperature in a range from 30 C. below a gelling onset temperature up to a final crosslinking temperature of the powder composition.

29. The method of claim 23 wherein the powder composition provided comprises at least one fiber component, wherein the layered covering formed during the powder-coating includes at least 10% by weight of the at least one fiber component based on the layered covering.

Description

BRIEF DESCRIPTION OF THE EXAMPLES AND DRAWINGS

[0094] The electrically conductive component of the invention is elucidated, asby way of examplea spring of the invention or torsion rod of the invention, by means of the examples and drawings.

[0095] FIG. 1 shows diagrammatically a spring produced by forming, a torsion rod, and a stabilizer produced by forming, according to the prior art;

[0096] FIG. 2 shows diagrammatically an oblique view of a metal tube element or of a metal rod element of a spring or of a torsion rod, according to one embodiment of the invention.

[0097] FIG. 1 shows different springs according to the prior art, with the designations a) to c). A torsion rod spring 2 is shown under a). The designation b) represents a coil spring 3, and c) represents a stabilizer 4.

[0098] FIG. 2 shows an oblique view of a metal tube element or metal rod element 5 of a spring or of a torsion rod, coated with a layered covering 7, according to one embodiment of the invention. The metal tube element or metal rod element 5 has an outer diameter DA. The layered covering 7 is disposed on the outer surface of the metal tube element or metal rod element 5, and has a layer thickness S with an outer diameter of the layered covering SDA. The layer thickness S is half of the difference between the outer diameter of the layered covering SDA and the outer diameter DA.

Example 1

[0099] In example 1, stone impact bombardment was carried out at 80 km/h and the subsequent corrosion test was carried out according to DIN EN ISO 9227.

[0100] The stone impact testing was carried out under the following conditions: [0101] peripheral speed of the drive wheel: 80 km/h, [0102] test duration: 60 s, [0103] test distance: 350 mm, [0104] blasting medium: basalt chips, grading 2 to 5, [0105] blasting medium quantity: 200 g, [0106] rotary speed of the blasted component: 30 rpm.

[0107] The components under test were subsequently stored for 72 hours in the salt spray cabinet.

[0108] Table 1 below shows the results for 5 springs coated with the coating of the inventors.

TABLE-US-00001 TABLE 1 Results for 5 springs coated with the coating of the inventors. Penetrative Blistering, degree Degree Spring No. impacts up to of blisters of rust 2015_190_V2_1 0 0 (S0) Ri 0 2015_190_V4_1 0 0 (S0) Ri 0 2015_190_V4_2 0 0 (S0) Ri 0 2015_190_V6_1 0 0 (S0) Ri 0 2015_190_V7_1 0 0 (S0) Ri 0

Example 2

[0109] In example 2, stone impact bombardment was carried out at 80 km/h and the subsequent corrosion test was carried out according to DIN EN ISO 9227.

[0110] The stone impact testing was carried out under the following conditions: [0111] peripheral speed of the drive wheel: 80 km/h, [0112] test duration: 60 s, [0113] test distance: 350 mm, [0114] blasting medium: No. 7 crushed stone of JIS A 5001, [0115] blasting medium quantity: 200 g, [0116] rotary speed of the blasted component: 2 rpm.

[0117] The components under test were subsequently stored for 24 hours in the salt spray cabinet.

[0118] Test conditions in the salt spray cabinet: [0119] temperature in the cabinet: 352 C., [0120] air humidification temperature: 471 C., [0121] spraying pressure: 70 to 170 kPa, [0122] amount: 1 to 2.0 ml/h per 80 cm.sup.2, [0123] pH: 6.5 to 7.2 (33 to 35 C.)

[0124] Table 2 below depicts the results for 4 springs (springs 1 to 4) coated with the layered covering of the inventors. Additionally shown are the results for 4 springs (springs 5 to 8) coated with a single-layer system customary in the prior art. Apparent very clearly are the good results for degree of rust with the layered covering of the invention, relative to a coating customary in the prior art. A degree of rust Ri of 0 represents the absence of rust and means that there has been no corrosion of the spring. The degrees of rust Ri of 2.5 and 3 show that rust was present on the springs tested and therefore that corrosion of the springs has taken place.

TABLE-US-00002 TABLE 2 Contrasting of the springs of the invention featuring the layered covering of the invention, in comparison to a prior-art coating Spring No.: Degree of rust Coating 1 Ri 0 inventive coating 2 Ri 0 inventive coating 3 Ri 0 inventive coating 4 Ri 0 inventive coating 5 Ri 3 single-layer system 6 Ri 3 single-layer system 7 Ri 2.5 single-layer system 8 Ri 3 single-layer system

Example 3

[0125] In example 3, the low-temperature impact testing was carried out according to TL 261 under the following conditions:

[0126] The springs for testing were stored for 24 h at (403) C. After the end of the storage time, an impact trial was carried out at low temperatures along the lines of DIN ISO 4532 (with 90 N testing force on rigid base).

[0127] Table 3 shows the results for 2 springs coated with the coating of the inventors. Each spring was tested four times. Penetration impact identifies the maximum measured length of the steel surface partially exposed in an impaction. From the table it is apparent that under fourfold bombardment, penetrative impact of the steel ball on to the steel surface of the springs was not recorded for either of the 2 springs tested. Layer thickness left and right, respectively, refer to the layer thickness measured to the left and right, respectively, of the impaction of the blasted steel ball.

TABLE-US-00003 TABLE 3 Results of low-temperature impact testing with fourfold bombardment of 2 springs coated in accordance with the invention. Spring 2015_164_P VIII Penetrative Layer Layer thick- Layer thick- impact delami- ness left ness right Bombardment [mm] nation [m] [m] Bombardment 1 0.0 none 905 870 Bombardment 2 0.0 none 806 803 Bombardment 3 0.0 none 771 754 Bombardment 4 0.0 none 851 837 Spring 2015_164_3 Penetrative Layer Layer thick- Layer thick- impact delami- ness left ness right Bombardment [mm] nation [m] [m] Bombardment 1 0.0 none 1049 1002 Bombardment 2 0.0 none 809 853 Bombardment 3 0.0 none 1106 1064 Bombardment 4 0.0 none 770 807

Commercial Applicability

[0128] Springs or torsion rods, more particularly in the form of a coil spring, torsion rod spring and/or stabilizer of the type described above, are used in the production of motor vehicles, particularly of chassis of motor vehicles.

LIST OF REFERENCE SYMBOLS

[0129] 2=torsion rod [0130] 3=coil spring [0131] 4=stabilizer [0132] 5=element of a spring or of a torsion rod [0133] 6=metal rod or metal tube [0134] 7=layered covering [0135] DA=outer diameter of the metal rod or metal tube [0136] SDA=outer diameter of the layered covering [0137] S=layer thickness