KR20160104170A - A friction plate in pantograph for electric rail car and its manufacturing method - Google Patents

Abstract

The present invention relates to a collective friction plate in a pantograph of an electric rail car and a manufacturing method thereof. The collective friction plate according to the present invention includes an additive of 0.1-6 wt% formed with one or more selected from: 80-92 wt% of Cu, 3-8 wt% of Sn, 1-6 wt% of graphite and Fe; a ferro alloy formed with one or more selected from Fe-Mo, Fe-Ti and Fe-Cr; and Cr, wherein the particle size of the additive is less than or equal to 250 um, and the particle size less than or equal to 45 um in the additive accounts for 30-50 wt% of an entire additive. The manufacturing method according to the present invention comprises: a step of preparing raw material mixed powder which includes additive powder of 0.1-6 wt% formed with one or more selected from: 80-92 wt% of Cu, 3-8 wt% of Sn, 1-6 wt% of graphite and Fe; a ferro alloy formed with one or more selected from Fe-Mo, Fe-Ti and Fe-Cr; and Cr; a step of sintering the mixed power at the temperature of 650-900C after performing pressure-molding on the mixed power; and a step of impregnating machine oil in the sintered body manufactured from the above. The particle size of the additive is less than or equal to 250 um, and the particle size less than or equal to 45 um in the additive accounts for 30-50 wt% of an entire additive. Thereby, the collective friction plate according to the present invention can have excellent heat resistance, abrasion resistance, lubricity and rainfastness.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction plate,

The present invention relates to a current collecting friction plate having heat resistance, durability, lubricity, abrasion resistance and arc resistance and capable of improving the service life of a wetting plate and a method of manufacturing the same.

Generally, a pantograph of a train is installed on the roof of a train or an electric locomotive and collects electricity by contacting with a trolly wire. A collecting friction plate is provided at a portion continuously contacting the electric line. Since the pantograph collecting friction plate is in contact with the electric wire and collects it at the same time as the wetting, it is required to have good conductivity and a sufficient current collecting capacity. Also, the abrasion of the current collecting plate and the electric wire is small and resistance to electric abrasion There is a demand.

Therefore, the conventional technique disclosed in Korean Patent Publication No. 2000-31027 can be cited. The present invention discloses a composition for a current collecting friction plate, which comprises 4 to 7 wt% of abrasion resistant light metal in 82 to 88 wt% of copper, 8 to 12 wt% of tin, and 0.5 to 3 wt% of graphite have.

However, the invention described in the above publication is difficult to expect the abrasion resistance over a certain limit due to the problem of the ratio of the main material and the additive constituting the pantograph collecting friction plate. Particularly, the abrasion resistance against moisture in the external environment, that is, in the rainy season, was markedly decreased, and thus it was not usable for a long time. In addition, the tin content of 8 to 12 wt.% Is alloyed with copper, thereby increasing mechanical properties such as hardness and thus directly affecting abrasion of the electric line, which is a relative material.

Another prior art is the invention disclosed in Korean Patent Application No. 10-2005-0045792. The above-mentioned patent application contains, by weight, 80 to 92% of Cu, 3 to 8% of Sn, 1 to 6% of graphite, and Fe; A ferro alloy composed of at least one selected from Fe-Mo, Fe-Ti and Fe-Cr; Cr; And Cu ₃ P, wherein the Fe, ferro alloy and Cr in the additive have a particle size of 45 to 500 μm, and the additive comprises 0.1 to 6% . However, since the additive such as ferro alloy has a particle size of 45 to 500 占 퐉, the invention described in the above-mentioned patent application restricts the increase of the yield strength of the base material containing Cu as a main component and the plastic deformation due to the distribution of the finer particles And did not significantly affect the inhibition. However, this patent application has been able to improve to some extent the wear problems of the collecting friction plates of Korean Patent Publication No. 2000-31027, which has been disclosed in the above-cited patent publication through the effect of strengthening the dispersion of particles, but due to the use of coarse particles in the range of 45 to 500 mu m We did not consider the pumice effect to the extent that it does not affect the catenary line. The plastic deformation on the friction surface of the collecting friction plate is caused by the displacement of the dislocation, and the particle distribution in the above range does not hinder the displacement of the dislocation, resulting in easy abrasion of the substrate. The additives such as ferro alloys with relatively high hardness tend to protrude because the abrasion due to friction with the catenary line is relatively small compared to the substrate. These large protruding additive particles have a bad influence on the catenary because they generate large chips rather than generating friction particles by friction with the catenary.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a collecting friction plate having excellent heat resistance, wear resistance, lubricity, and durability by optimizing main material, additive particle size, And the like.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention,

80 to 92% of Cu, 3 to 8% of Sn, 1 to 6% of graphite, and Fe; A ferro alloy composed of at least one selected from Fe-Mo, Fe-Ti and Fe-Cr; And Cr: 0.1 to 6%, wherein the additive has a particle size of 250 탆 or less and a particle size of 45 탆 or less in the total additive by weight ratio To 30% to 50%.

The additive may further comprise Cu ₃ P powder having a particle size of 1 to 200 탆.

Further, according to the present invention,

80 to 92% of Cu, 3 to 8% of Sn, 1 to 6% of graphite, and Fe; A ferro alloy composed of at least one selected from Fe-Mo, Fe-Ti and Fe-Cr; And Cr; 0.1 to 6% of an additive powder composed of at least one selected from the group consisting of Cr and Cr;

Pressing the mixed powder and sintering at 650 to 900 ° C; And

And a step of impregnating the sintered body manufactured from the above with machine oil, wherein the additive has a particle size of 250 mu m or less and a particle size of 45 mu m or less in the total additive is 30 to 50% The present invention relates to a method of manufacturing a collective friction plate.

The raw material powder may include Cu ₃ P powder having a particle size of 1 to 200 μm.

As described above, the current collecting friction plate manufactured by the manufacturing method of the present invention can manufacture a current collecting friction plate for an electric railway, which has significantly improved life span as compared with existing products, and can effectively replace the existing collecting friction plates.

Hereinafter, a collecting friction plate of the present invention will be described.

First, the current collecting friction plate of the present invention includes Cu, and it is preferable that the content of Cu is limited to 80 to 92% by weight. When the content of copper is less than 80% by weight, the contact resistance is increased and the current collecting ability is lowered, the mechanical properties are lowered and the wear of the friction plate is increased. When the content of copper exceeds 92% by weight This is because the abrasion of the catenary by the shortage can cause a big problem.

Sn is a constituent of alloying with Cu, and in the present invention, the Sn content is preferably limited to 3 to 8%. If the content is less than 3%, the sintering ability of copper is lowered, and the mechanical properties are not improved, and the life of the friction plate is shortened. Also, when the content exceeds 8%, the electrical wear including arc consumption and the damage due to the increase of resistivity is deteriorated, and the mechanical properties greatly improved by alloying can wear the electric cable which is a relative material.

Graphite is a lubricant which intervenes between a catenary and a friction plate to reduce metal contact and reduce wear, and the content of the graphite in the present invention is preferably limited to 1 to 6%. If the content exceeds 6%, the abrasion of the catenary line is reduced, but the friction plate is not suitable because mechanical and electrical abrasion is increased. If it is less than 1%, the abrasion of the catenary line may increase.

The friction plate of the present invention may also include at least one of Fe, Ferro alloy and Cr as additives. The ferro alloy may be at least one selected from the group consisting of Fe-Mo, Fe-Ti and Fe-Cr.

The above-mentioned Fe, Ferro alloy (Fe-Mo, Fe-Ti, Fe-Cr) and chromium are widely used as a wear-resistant component to uniformly disperse hard particles in a pouch and to provide a pumice effect (plastic deformation To prevent abrasion.

In the present invention, the particle size of the additive is preferably 250 탆 or less. If the particle size exceeds 250 탆, the particle dispersion strengthening effect, that is, the pumice effect is reduced, and the abrasion rate of the collecting plate of the collecting friction plate due to the friction with the catenary line is increased. At the same time, It may have an adverse effect on the environment. In fact, this phenomenon occurred when the electric vehicle was operated, and the collecting friction plate and the wire were sometimes replaced. On the other hand, when the particle size is 250 μm or less, the particle specific surface area will be increased by the finer particles when the current collecting friction plates have the same composition ratio. Such hard particles are, in the case of abrasion due to friction with the catenary, It is possible to suppress the deformation more effectively and thereby serve to slow the projecting speed of the hard particles further. In addition, fine particles of 250 μm or less will not cause overturning of the catenary wires, which would adversely affect friction due to friction with the catenary.

In addition, in the present invention, it is preferable that the additive has a particle size of 45 μm or less and a ratio of the additive to the total additive by 30 to 50% by weight. In this range, the current collecting friction plate has optimum physical and mechanical properties, It is possible to obtain wear characteristics by friction. If the weight ratio is less than 30%, the dispersion strengthening effect to be obtained through the uniform dispersion of the fine hard particles in the soft Cu substrate is reduced, that is, the mechanical properties such as strength and hardness are reduced. On the other hand, Physical properties such as density and conductivity are increased by a small fraction of the particles. If the weight ratio is more than 50%, the physical property is decreased and the fraction of the particles that do not reach the threshold value of the particle size which can exhibit the pumice effect is increased unlike the above-mentioned weight ratio of less than 30% It is possible.

In the present invention, the content of the additive is preferably limited to 0.1 to 6%. If the content of the additive is less than 0.1%, nonuniform wear of the friction plate may occur due to segregation, and if it exceeds 6%, the electrical wear characteristics may deteriorate.

By optimizing the composition of the additive as described above, it is possible to minimize the influence of the catenary, which is a relative material, and to improve the wear resistance and corrosion resistance of the collecting friction plate, and in particular, to ensure durability for a long period of use in the rainy season.

In the present invention, it is preferable to further add Cu ₃ P within the range of the additive component content. Cu-P (Cu ₃ P) is a powder added to improve mechanical properties like Sn, and it is necessary to add it in the form of Cu ₃ P alloy powder because it is likely to segregate when P is added. However, the particle size of the Cu ₃ P powder added at this time is preferably limited to 1 to 200 μm or less. If the size is less than 1 mu m, it is difficult to achieve uniform mixing due to segregation due to re-agglomeration. If the size is more than 200 mu m, it is difficult to uniformly alloy with Cu during sintering, which may cause local wear of the current collecting friction plate.

Next, the manufacturing process of the collective friction plate of the present invention will be described.

First, in the present invention, the mixed powder prepared as described above is prepared, followed by press molding and sintering. The mixed powder is subjected to pressure molding under ordinary conditions, and more preferably, is molded at a pressure of 1.5 to 4 ton / cm ² .

In the present invention, the sintering temperature range is preferably limited to 650 to 900 ° C. That is, the sintering is beneficial from a temperature of 650 ° C, at which sintering begins to take place after the forming, to a temperature of 900 ° C, which minimizes the copper drag due to under-sintering.

In the present invention, by impregnating the pores of the sintered body thus obtained with a machine oil using a vacuum impregnator, lubrication can be compensated to obtain a collecting friction plate superior in wear resistance.

As described above, by optimizing the main material, the additive size and kind, etc., lubricity, abrasion resistance and corrosion resistance are improved, and durability that can be used for a long period of time in a dry season as well as in a wet season is guaranteed.

Hereinafter, the present invention will be described in detail with reference to examples.

(Example 1)

No. Component (wt%) S * Remarks Cu Sn black smoke Cr Fe Fe-Ti Fe-Cr Fe-Mo Cu3P
One
88
5
3
4 25 Comparative Example 1 35 Inventory 1 60 Comparative Example 2
2
85.5
7
3.5
4 15 Comparative Example 3 30 Inventory 2 55 Comparative Example 4
3
88
7
2
3 27 Comparative Example 5 40 Inventory 3 55 Comparative Example 6 4 87 6 3 4 45 Honorable 4 5 83 8 3.5 5.5 40 Inventory 5 6 85.9 6 2.5 4.5 1.1 38 Inventory 6 7 85 6 3 4 2 42 Honorable 7

* In Table 1, S * represents the weight ratio (%) of the powder of the additive Fe, ferro alloy and Cr powder having a particle size of 45 μm or less to the total additive

A mixed powder having the same composition ratios as shown in Table 1 was prepared and molded at a pressure of 2.5 ton / cm ² . The weight ratio (%) of powders having a particle size of 45 탆 or less to the total additives in the additive was controlled to be 250 탆 or less, and the weight ratio of Fe, ferro alloy and chromium powder constituting the additive was controlled to 250 탆 or less. Respectively. Then, the compacts were sintered at a temperature of 750 ° C. for 1 hour under an ammonia gas atmosphere. Subsequently, the pores of the matrix were impregnated with oil to prepare a current collecting friction plate.

The physical and mechanical properties of the thus-produced collecting friction plates were measured using a Brinell hardness tester, a resistance tester, a tensile strength tester, a Charpy impact tester, etc. The results are shown in Table 2 below. Table 3 shows changes in wear of the trolley wire. On the other hand, the abrasion resistance characteristics of Table 3 are measured values after running test for 12 hours at a running speed of 80 km / hr, an applied current of 500 A and a pressing force of 6 kgf. In addition, because of the rapid wear and abnormal wear of the collecting friction plate during the rainy season when there is heavy precipitation in the actual vehicle condition, the condition of spraying water is added.

division density
(g / cm3) Hardness
HB (10/500) Electrical resistivity
(μΩ · cm) The tensile strength
(kgf / cm2) Impact strength
(J / cm2) Comparative Example 1 7.01 36 20 1300 131 Inventory 1 7.19 41 17 1470 143 Comparative Example 2 6.94 36 22 1290 130 Comparative Example 3 7.03 34 23 1250 128 Inventory 2 7.11 40 18 1490 145 Comparative Example 4 7.00 34 24 1280 129 Comparative Example 5 7.01 40 20 1320 137 Inventory 3 7.21 43 17 1520 139 Comparative Example 6 7.05 39 21 1300 132 Honorable 4 7.23 43 18 1560 147 Inventory 5 7.27 42 19 1590 159 Inventory 6 7.35 46 18 1580 153 Honorable 7 7.42 48 19 1610 155

division Friction plate (g) Tram line (mm) division Friction plate (g) Tram line (mm) Comparative Example 1 7.5 0.049 Inventory 1 6.5 0.038 Comparative Example 2 7.9 0.039 Comparative Example 3 7.1 0.047 Inventory 2 6.3 0.036 Comparative Example 4 7.0 0.040 Comparative Example 5 6.0 0.038 Inventory 3 2.4 0.022 Comparative Example 6 6.7 0.040 Honorable 4 3.3 0.035 Inventory 5 3.1 0.038 Inventory 6 2.8 0.029 Honorable 7 2.1 0.021

A feature of the present invention is the size distribution of the additive particles. As shown in Table 2-3, the products of the present invention (1-7) are characterized in that the particle size of 45 mu m or less in the particle size distribution of each additive particle satisfies the entire 30-50% range, And durability.

It can also be seen that Inventive Example (6-7) using Cu ₃ P has better durability than Inventive Example (1-5) which is not.

On the contrary, in Comparative Example 1-6, the weight ratio of the additive having a particle size of 45 μm or less is less than 30% or more than 50%, and its physical and mechanical properties are lower than those in the range of 30% -50% Value. ≪ / RTI > It can be seen that the durability of the friction plate is also influenced by the particle size distribution of the additive particles. In detail, when the weight ratio is less than 30%, it is insufficient to obtain a dispersion strengthening effect to be obtained through uniform dispersion of fine hard particles in a soft Cu substrate. When the weight ratio is more than 50%, less than 30% Unlike the weight ratio, the physical properties are decreased and the fraction of the particles which do not reach the critical value of the particle size which can exhibit the pumice effect is increased, resulting in deterioration of the mechanical toque, resulting in deterioration of the durability of the friction plate.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (4)

80 to 92% of Cu, 3 to 8% of Sn, 1 to 6% of graphite, and Fe; A ferro alloy composed of at least one selected from Fe-Mo, Fe-Ti and Fe-Cr; And Cr: 0.1 to 6%, wherein the additive has a particle size of 250 탆 or less and a particle size of 45 탆 or less in the total additive by weight ratio 30 to 50%.
The collecting friction plate according to claim 1, further comprising Cu ₃ P powder having a particle size of 1 to 200 탆 in the additive.
80 to 92% of Cu, 3 to 8% of Sn, 1 to 6% of graphite, and Fe; A ferro alloy composed of at least one selected from Fe-Mo, Fe-Ti and Fe-Cr; And Cr; 0.1 to 6% of an additive powder composed of at least one selected from the group consisting of Cr and Cr;
Pressing the mixed powder and sintering at 650 to 900 ° C; And
And a step of impregnating the sintered body manufactured from the above with machine oil, wherein the additive has a particle size of 250 mu m or less and a particle size of 45 mu m or less in the total additive is 30 to 50% Wherein the first and second friction plates are made of a metal.
4. The method of claim 3, wherein the raw material powder comprises Cu ₃ P powder having a particle size of 1 to 200 μm.