JP4046024B2 - Structure provided with conductive film, and eddy current reduction device and substrate using the same - Google Patents

Description

【００６７】
表１に示すように、発明例６〜８は、本発明で規定するいずれの条件も満足するので、熱サイクル試験後の表面外観および断面ミクロによる評価は良好であった。
【００６８】
これに対し、比較例１では第１層をニッケル層としたので、第２層からの銅の拡散が見られた。比較例２では第１層および第３層を形成しなかったので、銅およびニッケルの拡散が生じ、表面に著しいクラックの発生があった。
【００６９】
比較例３では第１層を高含有量のリンでニッケル合金層を構成したため、脆化し素地と第１層間で剥離があった。比較例４では第３層をニッケル層としたため、銅およびニッケルの拡散が発生した。
【００７０】
比較例５では第１層および第３層をニッケル層とし、第４層をクロム層としたため、第１層で銅の拡散、第３層で銅およびニッケルの拡散が発生し、さらに表面では割れの発生があった。
【００７１】
【発明の効果】
本発明の構造体によれば、高温また高負荷の熱サイクルに晒される環境においても、高導電性の特性を維持することができる。したがって、これを用いて渦電流減速装置を構成すれば、一層の制動効率の向上が図れる。これらにより、近年、渦電流減速装置に要求される、制動能力の増大や、小型車に搭載が可能になるような軽量化およびコンパクト化への要請に対応することができる。
【００７２】
これを用いて回路基板を構成すれば、渦電流減速装置と同様に、高温に晒される過酷な環境においても高信頼性を維持することができる。
【図面の簡単な説明】
【図１】永久磁石を用いて回転ディスクに制動トルクを発生させる方式の渦電流減速装置の構成例を説明する図である。
【図２】永久磁石を用いて回転ドラムに制動トルクを発生させる方式の渦電流減速装置の構成例を説明する図である。
【図３】本発明の構造体に設けられる「導電性皮膜」の構成例を示す断面図である。
【図４】熱サイクル試験に用いられる試験片を示す図である。
【図５】熱サイクル試験の加熱および冷却サイクルを示す図である。
【符号の説明】
１、１１：回転軸、 ２：回転ディスク
３、１３：案内筒、４、１４：保持部材
５、１５：シリンダー、 ６、１６：ピストンロッド
７、１７：永久磁石、 ８、１８：強磁性材
１２：回転ドラム、 １９：アーム
２０：構造体、 ２１：第１層
２２：第２層、 ２３：第３層
２４：第４層[0001]
[Prior art]
One that uses a conductive structure is an eddy current reduction device used as a braking device for automobiles such as trucks and buses. In this eddy current reduction device, for example, a magnet group in which a large number of magnets are arranged in the circumferential direction is moved, and the magnets are brought close to each other so as to face the rotating disk or the rotating drum (cylindrical type). A method for generating braking torque is used. For example, a permanent magnet or an electromagnet is used as this magnet.
[0002]
Recently, an increasing number of large vehicles are equipped with eddy current reduction devices , and they are being installed in trucks and trailers that have larger loads than before. For this reason, the braking capacity required for the eddy current reduction device tends to increase, and the braking surface temperature of the rotating disk and the rotating drum during braking reaches 650 ° C. or higher, and a device with excellent durability is desired. ing. In response to this, various eddy current reduction devices have been proposed.
[0003]
[Patent Document 1]
JP-A-5-236732 [Patent Document 2]
Japanese Patent Laid-Open No. 10-155266 [Patent Document 3]
Japanese Patent Laid-Open No. 11-308551
[Problems to be solved by the invention]
In an eddy current reduction device that uses a conductive structure as in the above-mentioned patent document, a conductive film may be formed on the surface of the structure in order to obtain high conductivity on the rotor surface. However, as the use under severer conditions than before increases, further performance improvement is required for thermal cycle load and high temperature durability due to repeated braking and non-braking.
[0005]
On the other hand, in circuit wiring used for a substrate on which electronic components are mounted, wiring is usually formed on a base substrate using copper, aluminum, or the like. Even in a board on which these electronic components are mounted, the use environment conditions become more severe, and improvement in performance against thermal durability is demanded.
[0006]
In the board on which the electronic components as described above are mounted, the electrical characteristics of the conductive film such as circuit wiring formed on the board are significantly impaired by a thermal load from the surroundings and a thermal cycle load. Sometimes. Therefore, there is a demand for the development of a structure having a more durable conductive film in a high-temperature environment or a high-temperature cycle environment even for such a conductive film of a substrate circuit.
[0007]
The present invention has been made in view of the above-described situation, and can maintain higher conductivity characteristics even in an environment exposed to a high temperature and high load heat cycle. An object of the present invention is to provide an eddy current reduction device using a structure excellent in heat cycle resistance.
[0008]
[Means for Solving the Problems]
In the following description, an alloy component other than nickel constituting the nickel alloy layer of the first layer and the third layer is referred to as “alloy component”.
[0009]
The structure used in the eddy current reduction device of the present invention (hereinafter simply referred to as “the structure of the present invention ”) is composed of the same kind of alloy components such as phosphorus in the nickel alloy layers of the first layer and the third layer. And the content rate of this alloy component in a 1st layer is made low, and the content of the alloy component of a 3rd layer is made high simultaneously.
[0010]
As a result, the first layer is ductile due to the low content of alloy components such as phosphorus even if a large strain occurs due to the difference in linear expansion coefficient between the substrate and the high conductivity layer, and the first layer is largely broken. In this way, the adhesion between the substrate and the high conductivity layer can be improved. Further, the third layer is excellent in preventing mutual diffusion between copper and nickel, exhibits high-temperature durability, and can exhibit excellent heat cycle characteristics.
[0011]
More specifically, the structure of the present invention includes , from the surface of the structure, a first layer made of a nickel alloy and copper, copper having a conductivity higher than that of members mainly constituting the structure. A second layer constituting a high conductivity layer containing at least one of an alloy, aluminum or an aluminum alloy, a third layer made of a nickel alloy, and a fourth layer made of a nickel simple substance, The third layer is made of at least one selected from phosphorus, tungsten, boron, iron, or cobalt, and the first layer and the third layer are made of the same type of alloy component. It is a structure characterized by having at least a part of a conductive film in which the content of one layer is less than the content of the third layer.
[0012]
Here, when the alloy components other than nickel in the first layer and the third layer are different, the degree of recrystallization of the metal component due to thermal history and thermal interdiffusion is the content of the alloy component. Therefore, it has been found that there are many uncertain factors about how the layers relate to each other, and it is difficult to ensure sufficient thermal reliability.
[0013]
On the other hand, by selecting a means for making the first layer and the third layer the same kind of alloy using nickel as a base material, and adjusting the content ratio with respect to both layers sandwiching the high conductivity layer, The thermal characteristics of the entire formed multilayer film can be controlled.
[0014]
That is, the first layer and the third layer are made of the same type of alloy, and then the content of the alloy component of the first layer close to the structure is made smaller than the content of the third layer. Can be made crystalline from the time of plating deposition while having the effect of preventing thermal diffusion at high temperatures between the high conductivity layer and the structure. This reduces the change even at high temperatures.
[0015]
That is, the coefficient of linear expansion can be brought close to the member in contact, and a state of good adhesion can be maintained even in a thermally severe environment. In addition, the third layer is close to the surface layer and is more easily exposed to the outside air. Therefore, it is necessary to eliminate the occurrence of the sequential voids caused by diffusion, and although there is brittleness due to crystallization of the amorphous part, in order to increase the effect of preventing diffusion, the alloy component is made high in concentration. , No generation of the sequential voids and no peeling of the film.
[0016]
Incidentally, when this sequential void is generated, it grows as a crack generation source, and when connected to the outside air, the metal of the high conductivity layer rapidly oxidizes, and the entire conductive coating layer is destroyed at once.
[0017]
If different alloy components are used for the first layer and the third layer, the behavior between the layers and the change when exposed to heat are only affected by the content of these alloy components. It is very difficult to control the thermal characteristics of the entire film.
[0020]
In this structure, the component contained in the first layer and the third layer is preferably phosphorus, and if the content of the first layer is 4.5% by mass or less, it is almost crystallized before plating deposition. It is desirable because it is thermally stable. In addition, when the content of the third layer exceeds 4.5% by mass, the generation of a sequential void can be suppressed, which is more desirable.
[0021]
The structure of the present invention is provided on the surface thereof with a high conductivity film containing at least one of copper, copper alloy, aluminum or aluminum alloy having a conductivity higher than that of the member mainly constituting the structure. It is characterized by that. Thereby, it becomes possible to reduce the electrical resistance of the structure surface.
[0022]
Here, “conductivity” indicates a constant σ that appears in the local Ohm's law i = σE, where i is the density of the steady current in the conductor and E is the electric field. In other words, “conductivity” means specific electrical conductivity and is also the reciprocal of specific resistance ρ.
[0023]
In the structure of the present invention, it is defined that “the conductive film is provided”, and “the conductive film” is provided on the entire surface of the target structure from the meaning that it is provided on at least an arbitrary part. Is included.
The present invention is characterized by using such a structure, and the gist of the eddy current reduction device of the following (1) and (2).
(1) A rotating disk made of a steel material attached to a rotating shaft, a guide cylinder supported by a non-rotating portion and disposed opposite to the main surface of the rotating disk, and housed in the guide cylinder a holding member, the opposite to the main surface of the rotating disk surface of the holding member, the magnetic poles opposite to each other of the adjacent pole faces, and the pole face is arranged opposite the major surface of the rotary disc plurality An eddy current reduction device comprising a magnet, wherein a conductive film is provided on at least a part of the main surface of the rotating disk, and the conductive film comprises a first layer made of a nickel alloy, copper or A second layer constituting a high conductivity layer made of a copper alloy, a third layer made of a nickel alloy, and a fourth layer made of a simple nickel, wherein the first layer and the third layer contain phosphorus as an alloy component. It is constructed from the same type of alloy , By mass% that, before SL is 2.0 to 4.5% the content of phosphorus in the first layer, the content of phosphorus of said third layer is greater than 4.5%, at most 15% Is an eddy current reduction device.
[0024]
The target here is an eddy current reduction device of a type that generates a braking torque on a rotating disk as exemplified in FIG. 1 described later, wherein the magnet provided is a permanent magnet, an electromagnet, or a mixture thereof. Either is acceptable.
[0025]
The “main surface of the rotating disk” defined here refers to, for example, a circular surface facing the guide cylinder among the three surfaces of the rotating disk, that is, the front and back circular surfaces and the outer peripheral surface.
(2) A rotating drum made of a steel material attached to a rotating shaft, a guide tube supported by a non-rotating portion and arranged to face the main inner surface of the rotating drum, and housed in the guide tube a holding member, the surface facing the main inner surface of the rotary drum of the holding member, the magnetic poles opposite to each other of the adjacent pole faces, and the pole face is arranged opposite the main inner surface of the rotary drum plurality a eddy current reduction apparatus having a magnet, a conductive film is provided on at least a portion of the main plane of the rotary drum, is the conductive film, a first layer of a nickel alloy, copper Or a second layer constituting a high conductivity layer made of a copper alloy, a third layer made of a nickel alloy, and a fourth layer made of nickel alone, wherein the first layer and the third layer contain phosphorus as an alloy component. constructed from the same type of alloy and By mass%, before SL is 2.0 to 4.5% the content of phosphorus in the first layer, the content of phosphorus of said third layer is greater than 4.5%, at most 15% This is an eddy current reduction device.
[0026]
The target here is an eddy current reduction device of a type that generates a braking torque on a rotating drum as illustrated in FIG. 2 described later, and the magnet provided is a permanent magnet, an electromagnet, or a mixture thereof. Either is acceptable.
[0027]
The “main surface of the rotating drum” defined here is a surface that effectively opposes the magnet disposed on the holding member during braking, among the inner peripheral surfaces of the rotating drum attached to the rotating shaft via the arm. Say .
[0029]
DETAILED DESCRIPTION OF THE INVENTION
As a configuration example of the “conductive film” provided in the structure of the present invention, a specific configuration will be described based on the following embodiments. Here, all the embodiments shown are exemplifications of specific configurations of the present invention, and the structure provided with the “conductive film” based on the present invention is not limited thereto.
[0030]
FIG. 1 is a diagram illustrating a configuration example of an eddy current reduction device that uses a permanent magnet to generate braking torque on a rotating disk that is an example of a structure. The configuration example shown in FIG. 1 includes a rotating disk 2 made of a conductor attached to a rotating shaft 1 and a guide cylinder 3 disposed to face the main surface of the rotating disk 2.
[0031]
The guide tube 3 is supported by a non-rotating part of a vehicle or the like, and a holding member 4 that can move in a direction approaching and moving away from the rotary disk 2 is accommodated in the guide tube 3. Is provided with a cylinder 5 for moving the holding member 4 forward and backward. On the other hand, a ferromagnetic body 8 may be disposed on the end surface of the guide cylinder 3 that faces the main surface of the rotating disk 2.
[0032]
A plurality of permanent magnets 7 are arranged at equal intervals in the circumferential direction on the surface of the holding member 4 facing the main surface of the rotating disk 2. The direction of the magnetic poles of the permanent magnet 7 is opposed to the main surface of the rotating disk 2, and the adjacent magnetic poles are arranged in opposite directions.
[0033]
As a drive mechanism for the permanent magnet 7, a cylinder 5 is disposed on the outer end wall of the guide cylinder 3, and a piston rod 6 fitted to the cylinder 5 passes through the outer end wall of the guide cylinder 3 and is coupled to the holding member 4. is doing.
[0034]
FIG. 1 shows a state at the time of braking. At the time of braking, the piston rod 6 of the cylinder 5 moves to the right, the holding member 4 moves forward in the direction perpendicular to the rotating disk 2, and the permanent magnet 7 moves to the rotating disk. Approaching 2 opposite. At this time, when the rotating disk 2 traverses the magnetic force lines that each permanent magnet 7 exerts perpendicularly to the braking surface of the rotating disk 2 through the ferromagnetic material 8, an eddy current is generated in the rotating disk 2 due to a change in magnetic flux in the rotating disk. Flows and braking torque is generated.
[0035]
When switching to non-braking, the operation of the cylinder 5 is switched to move the holding member 4 directly connected to the piston rod 6 to the left, so that the lines of magnetic force exerted on the rotating disk 2 by the permanent magnet 7 are weak.
[0036]
FIG. 2 is a diagram illustrating a configuration example of an eddy current reduction device that uses a permanent magnet to generate braking torque on a rotating drum that is an example of a structure. The configuration example shown in FIG. 1 includes a rotary drum 12 made of a conductor attached to a rotary shaft 11 via an arm 19, and a guide cylinder 13 arranged to face the inner peripheral surface of the rotary drum 12. The
[0037]
The guide tube 13 is supported by a non-rotating portion of a vehicle or the like, and a holding member 14 that is movable in a direction in which the rotating drum 12 is loaded and unloaded is housed in the guide tube 13. A cylinder 15 is provided that is moved 14. On the other hand, the ferromagnetic body 18 may be disposed on the surface of the guide cylinder 13 that faces the inner peripheral surface of the rotating drum.
[0038]
A plurality of permanent magnets 17 are arranged on the surface of the holding member 14 facing the main inner surface of the rotating drum 12 at equal intervals in opposite directions. As in FIG. 1, a cylinder 15 is disposed on the outer end wall of the guide tube 13 as a drive mechanism for the permanent magnet 17.
[0039]
FIG. 2 shows a state at the time of braking. At the time of braking, the holding member 14 is inserted to a position facing the main inner surface of the cylindrical drum by the operation of the cylinder 15. At this time, each permanent magnet 17 exerts a magnetic line of force on the braking circumferential surface of the rotating drum through the ferromagnetic body 18, eddy current flows through the rotating drum 12, and braking torque is generated.
[0040]
When switching to non-braking, since the holding member 14 is carried out from the inner peripheral surface of the cylindrical drum 12, the magnetic lines of force exerted on the rotating drum 12 by the permanent magnet 17 are eliminated.
[0041]
In the configuration example shown in FIG. 1 and FIG. 2 described above, a case where a permanent magnet is used as a magnet is shown. However, an electromagnet can be used as the magnet, and a magnet combining a permanent magnet and an electromagnet can also be used. Also in the eddy current reduction device using these magnets, the principle of generation of the braking torque is the same as when using permanent magnets. However, when switching between braking and non-braking, instead of moving the holding member by switching the operation of the cylinder, the current of the electromagnetic coil is adjusted.
[0042]
At the time of braking of the current type speed reducer, an eddy current flows through the braking surfaces of the rotating disk and the rotating drum, and the rotating disk and the rotating drum are heated by Joule heat accompanying the eddy current. On the other hand, at the time of non-braking, the rotating disk and the rotating drum are cooled. For this reason, a thermal cycle is applied to the braking surfaces of the rotating disk and the rotating drum by repeated braking and non-braking.
[0043]
FIG. 3 is a cross-sectional view showing a configuration example of a “conductive film” provided in the structure of the present invention.
[0044]
The first layer 21 is a layer made of a nickel alloy, and relieves inelastic strain caused by the difference in thermal expansion coefficient between the structure 20 substrate and the high conductivity layer of the second layer 22, and at the same time returns to a substrate such as copper. This is to suppress the diffusion of the. By making the first layer a nickel alloy, the linear expansion coefficient approximates that of iron (structure material), copper, etc. (high conductivity layer composition), and improves the adhesion between the structure substrate and the high conductivity layer Can be made.
[0045]
The nickel alloy layer can be formed by wet electroless plating or electrolytic plating. The thickness of the first layer is preferably 5 to 20 μm. By securing such a thickness, direct contact between the structure 20 substrate and the high conductivity layer of the second layer 22 can be avoided and good adhesion can be obtained.
[0046]
The second layer 22 is composed of a high conductivity layer containing at least one of copper, copper alloy, aluminum, or aluminum alloy. Copper, a copper alloy, aluminum, or an aluminum alloy are all materials having a small electric resistance. However, considering the function, effect, and cost of the high conductivity layer, it is desirable to use copper. When the high conductivity layer is made of copper, a wet plating method can be employed.
[0047]
Even if the high conductivity layer is too thin, the electrical resistance increases. For this reason, in order to ensure high conductivity, it is desirable that the high conductivity layer has a thickness of at least 100 μm. On the other hand, when the thickness of the high-conductivity layer exceeds 300 μm, the conductive performance is saturated.
[0048]
The third layer 23 is a layer made of a nickel alloy, and is located between the high conductivity layer of the second layer 22 and the nickel layer of the fourth layer 24, and heat diffusion such as copper from the high conductivity layer and nickel Has the effect of preventing heat diffusion. In order to exert this effect, the thickness of the third layer 23 is desirably 5 to 20 μm. The nickel alloy layer can be formed by wet electroless plating or electrolytic plating.
[0049]
The fourth layer 24 is a layer composed of nickel as the outermost layer. Nickel is excellent in oxidation resistance in the temperature range of 600 to 700 ° C., and is soft and rich in ductility. It acts to prevent oxidation.
[0050]
The nickel film of the fourth layer 24 is obtained by a wet electroplating method. The film thickness is required to be at least 20 μm in order to prevent the exposure of the substrate, but if it exceeds 100 μm, the obtained effect remains the same.
[0051]
In the “conductive film” of the present invention, the nickel alloy of the first layer and the third layer contains at least one selected from phosphorus, tungsten, boron, iron, and cobalt as an alloy element. This is because these nickel alloys have a copper diffusion rate lower than that of nickel, making it difficult for copper atoms to enter the nickel or iron lattice.
[0052]
The effects in the case of selecting phosphorus are as described above, but the same effects as phosphorus can be expected for other metals that are also limited in the present invention.
[0053]
At the same time, in the “conductive film” of the present invention, when the alloy elements of the first layer and the third layer are selected from phosphorus, tungsten, boron, iron, and cobalt, they are the same species and The content (mass%) needs to be less than the content (mass%) of the third layer.
[0054]
As described above, if the nickel alloy layer is composed of a higher content of the alloy component in the third layer, it crystallizes and becomes brittle in a high temperature environment, but it does not cause a problem because it is in the surface layer and does not lead to failure. Since the component has a higher content, it effectively works to prevent diffusion of copper and nickel.
[0055]
On the other hand, if the nickel alloy layer is composed of an alloy component having a lower content in the first layer, the linear expansion coefficient between the substrate and the high conductivity layer is different, and even if a large strain occurs, the ductility is large. Since there is no destruction, the adhesion between the substrate and the high conductivity layer can be improved.
[0056]
In the “conductive film” of the present invention, it is desirable to select phosphorus as the alloy element of the first layer and the third layer. This is because it is easier to control the phosphorus concentration in the film than to control the concentration of other elements when a film is obtained using a wet plating method.
[0057]
When the alloy element is phosphorus, the content in the first layer is preferably 4.5% by mass or less. Thereby, the linear expansion coefficient of the nickel alloy of the first layer can be approximated to that of iron (structure material) and copper, and the adhesion between the structure body and the high conductivity layer can be improved. . Incidentally, the phosphorus content in the first layer is more preferably 2.0 to 4.5% by mass, which can be made closer to the linear expansion coefficient and can reduce distortion due to stress.
[0058]
On the other hand, the phosphorus content in the third layer is more than 4.5 and not more than 15% by mass because of the relationship of “content of third layer (% by mass)> content of first layer (% by mass)”. Is desirable. With this content, when phosphorus in the nickel alloy is heated, it moves to the copper interface and concentrates, thereby preventing the fourth layer of nickel from diffusing into the high conductivity layer.
[0059]
Up to this point, a rotating drum or rotating disk used in an eddy current reduction device has been described as a structure, and what has been plated thereon has been described, but even if this structure is a circuit board, the operation is equivalent. .
[0060]
That is, when a wiring material such as copper or aluminum used for a circuit board and a nickel material for protecting them from a harsh environment are formed according to the configuration of the present invention, diffusion between these layers or heat The difference in coefficient of thermal expansion due to a typical load is a problem that can occur as well. Accordingly, the structure of the present invention can be similarly applied to a circuit board having such a problem and having a protective film on a conductor such as wiring.
[0061]
【Example】
In order to confirm the effect when the structure provided with the “conductive film” of the present invention is applied to the rotating disk or the drum of the eddy current reduction device shown in FIG. 1 or 2, the Cr—Mo based low alloy is used. A film was formed on the test body as shown in FIG. 4 made of steel under the following basic plating conditions (a) to (d).
(A) First layer nickel alloy layer:
Using a nickel plating solvent containing phosphorus as an alloy component, wet electroless nickel-phosphorous plating was performed at a temperature of 90 ° C. for an appropriate time.
(B) Second layer high conductivity layer:
Using a copper sulfate and sulfuric acid plating bath, wet electroplating was performed at a temperature of 40 ° C. for an appropriate time.
(C) Third layer nickel alloy layer:
Using a nickel plating solvent containing phosphorus as an alloy component, wet electroless nickel-phosphorous plating was performed at a temperature of 90 ° C. for an appropriate time.
(D) Fourth layer nickel simple substance layer:
Using a plating bath of nickel sulfamate, nickel chloride, and boric acid, wet electroplating was performed at a temperature of 50 ° C. for an appropriate time.
[0062]
The plating film deposition conditions vary depending on each chemical, solution concentration, reaction accelerator, stabilizer, etc., so follow the recommended conditions of each plating solution manufacturer or the conditions described in the catalog. What is necessary is just to give each plating.
[0063]
A test piece shown in FIG. 4 was collected from the obtained material, a constant strain was applied to various plating test pieces, a thermal cycle test was performed, and the damage state of the plated portion was evaluated by the surface appearance and the cross-section micro.
[0064]
In the heat cycle test, the load was 0.2% tensile strain, and heating up to 650 ° C. was repeated by high frequency induction heating. As shown in FIG. 5, the thermal cycle was set to RT → heating (10 sec) → 650 ° C. (5 sec) → water cooling (25 sec) → RT, and one cycle was 40 sec.
[0065]
The results of the thermal cycle test (1000 cycles) are shown in Table 1. Of the coating types in the table, “Electric Ni” indicates the fourth nickel single layer of (d) above, and “Electric Cu” indicates the second high conductivity layer of (b) above.
[0066]
[Table 1]

[0067]
As shown in Table 1, since Invention Examples 6 to 8 satisfy any of the conditions defined in the present invention, the surface appearance after the thermal cycle test and the evaluation by the micro section were good.
[0068]
In contrast, in Comparative Example 1, since the first layer was a nickel layer, copper diffusion from the second layer was observed. In Comparative Example 2, since the first layer and the third layer were not formed, copper and nickel were diffused, and significant cracks were generated on the surface.
[0069]
In Comparative Example 3, since the nickel alloy layer was composed of phosphorus with a high content in the first layer, it was embrittled and delaminated between the substrate and the first layer. In Comparative Example 4, since the third layer was a nickel layer, diffusion of copper and nickel occurred.
[0070]
In Comparative Example 5, since the first layer and the third layer were nickel layers and the fourth layer was a chromium layer, copper diffusion occurred in the first layer, copper and nickel diffusion occurred in the third layer, and cracks occurred on the surface. Occurred.
[0071]
【The invention's effect】
According to the structure of the present invention, highly conductive characteristics can be maintained even in an environment exposed to a high temperature and high load thermal cycle. Therefore, if the eddy current reduction device is configured using this, the braking efficiency can be further improved. As a result, in recent years, it is possible to meet the demands for weight reduction and compactness required for an eddy current reduction device, such as an increase in braking capacity and the possibility of mounting in a small vehicle.
[0072]
If a circuit board is configured using this, high reliability can be maintained even in a harsh environment exposed to high temperatures, as in the eddy current reduction device.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of an eddy current reduction device that uses a permanent magnet to generate braking torque on a rotating disk.
FIG. 2 is a diagram illustrating a configuration example of an eddy current reduction device that uses a permanent magnet to generate a braking torque on a rotating drum.
FIG. 3 is a cross-sectional view showing a configuration example of a “conductive film” provided in the structure of the present invention.
FIG. 4 is a view showing a test piece used in a thermal cycle test.
FIG. 5 is a diagram showing heating and cooling cycles of a thermal cycle test.
[Explanation of symbols]
1, 11: Rotating shaft, 2: Rotating disk 3, 13: Guide cylinder, 4, 14: Holding member 5, 15: Cylinder, 6, 16: Piston rod 7, 17: Permanent magnet, 8, 18: Ferromagnetic material 12: Rotating drum 19: Arm 20: Structure 21: First layer 22: Second layer 23: Third layer 24: Fourth layer

Claims (2)

A rotating disk made of steel material attached to a rotating shaft;
A guide tube that is supported by a non-rotating portion and is disposed to face the main surface of the rotating disk;
A holding member housed inside the guide tube;
A plurality of magnets arranged on the surface of the holding member facing the main surface of the rotating disk, the magnetic poles of adjacent magnetic pole surfaces being opposite to each other and facing the main surface of the rotating disk. An eddy current reduction device comprising:
A conductive film is provided on at least a part of the main surface of the rotating disk,
The conductive film includes a first layer made of a nickel alloy, a second layer constituting a high conductivity layer made of copper or a copper alloy, a third layer made of a nickel alloy, and a fourth layer made of nickel alone. With
Said first and third layers is composed of the same species alloy phosphorus alloy components, in mass%, a phosphorus content prior Symbol first layer 2.0 to 4.5%, the An eddy current reduction device characterized in that the content of phosphorus in the third layer is more than 4.5% and not more than 15% . A rotating drum made of a steel material attached to a rotating shaft;
A guide tube that is supported by a non-rotating portion and is disposed opposite the main inner surface of the rotating drum;
A holding member housed inside the guide tube;
A plurality of magnets arranged on the surface of the holding member facing the main inner surface of the rotating drum, the magnetic poles of adjacent magnetic pole surfaces being opposite to each other and facing the main inner surface of the rotating drum. An eddy current reduction device comprising:
Conductive coating provided on at least a portion of the main plane of the rotary drum,
The conductive film includes a first layer made of a nickel alloy, a second layer constituting a high conductivity layer made of copper or a copper alloy, a third layer made of a nickel alloy, and a fourth layer made of nickel alone. With
Said first and third layers is composed of the same species alloy phosphorus alloy components, in mass%, a phosphorus content prior Symbol first layer 2.0 to 4.5%, the An eddy current reduction device characterized in that the content of phosphorus in the third layer is more than 4.5% and not more than 15% .

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