JP2015021176A - Copper alloy slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member which is usable without supply of a lubricant oil even in an environment so far requiring a supply mechanism supplying a lubricating oil continuously.SOLUTION: A copper alloy slide member contains a sulfide and is dispersed with graphite grains and impregnated with a lubricant oil in voids present in its surface serving as a sliding surface. The copper alloy comprises 0.3-6 mass% of Fe, 3-16 mass% of Sn, 0.3-3 mass% of S and remaining Cu and impurities. The slide member consists of a copper alloy liner serving as a slider of a crank press.

Description

  The present invention relates to a sliding member made of copper alloy. More particularly, the present invention relates to a copper alloy liner such as a gibliner on which a slide of a crank press slides up and down by a rotating crankshaft.

  Various copper alloys are used for the sliding member having the sliding surface. Copper alloys are relatively soft compared to iron and are suitable for sliding members. However, in order to withstand sliding in a high-speed, high-pressure environment for a long time, it is often necessary to continuously supply lubricating oil.

  For example, in the crank press described in Patent Document 1, the slide (8) that moves up and down in FIG. 2 is actually a guide provided around the slide (8) to press the workpiece at a highly accurate position. However, since the slide and the guide naturally slide, a copper alloy gib liner is attached to the guide to prevent seizure.

JP 2012-6057 A

  However, in order to maintain a high-speed, high-speed and continuous operating environment of the crank press, it was necessary to continue to replenish the lubricating oil from the give liner. In addition to the crank press, there are many sliding members that require the supply of lubricating oil, but the machine is complicated to provide a lubricating oil supply and recovery path, reducing the manufacturing yield and processing. There was a problem of increasing man-hours.

  Therefore, an object of the present invention is to provide a sliding member that can be used without receiving supply of lubricating oil in an environment that conventionally requires a continuous supply mechanism of lubricating oil.

  The present invention solves the above problems by a copper alloy sliding member containing sulfide, in which graphite particles are dispersed, and in which a gap existing on a surface serving as a sliding surface is impregnated with lubricating oil.

  When the copper alloy is sintered, it contains sulfides, and if it is exposed on the surface, it acts as a solid lubricant. Further, if graphite particles are contained in the material to be sintered, the graphite particles are dispersed in the structure without dissolving with the components constituting the copper alloy. As the graphite particles dispersed in the structure are slid, the graphite particles diffuse from the region in the structure to the surroundings, and also function as a solid lubricant. In addition to this, the surface gap is impregnated with lubricating oil.

  The sliding member impregnated with the lubricating oil in this manner is solid-lubricated by sulfides and graphite particles that are dispersed on the surface of the tissue, and the lubricating oil is gradually removed from the surface voids including the precipitated portions. By exuding, good lubrication performance can be maintained even if there is no supply of lubricating oil from the outside.

  With the copper alloy sliding member according to the present invention, a sliding surface such as a crank press can be held without providing a lubricating oil supply mechanism in a machine that must hold the sliding surface.

Schematic longitudinal sectional view of an embodiment of a crank press which is an example of a copper alloy sliding member according to the present invention II-II sectional view of FIG. Surface photograph of graphite particle-dispersed copper alloy material obtained in Examples

  The present invention will be described in detail below. The present invention is a copper alloy-based sliding member containing a sulfide, in which graphite particles are dispersed, and voids existing on the surface are impregnated with lubricating oil. The graphite particle-dispersed copper alloy that constitutes the sliding member is produced by sintering a material in the same manner as in the production of a general copper alloy. It can be obtained by mixing and sintering.

  In the present invention, it is necessary that at least a part of the sulfide is deposited unevenly in a specific region in the structure of the copper alloy. The sulfide itself is effective to some extent with any element in the alloy. In order to precipitate such sulfides, the material of the copper alloy sliding member according to the present invention needs to contain a predetermined amount of sulfur. The optimum range of the amount of sulfur is considered to be around the upper and lower limits depending on the combination with other elements contained in the copper alloy. However, at least 0.2% by mass or more of the copper alloy is precipitated. Since there are too few sulfides and it is difficult to expect the effect of improving solid lubricity, the content is preferably 0.2% by mass or more. On the other hand, if it exceeds 5.0% by mass, the strength of the copper alloy may be excessively reduced due to the compatibility with the copper alloy.

  On the other hand, the graphite particles need to be dispersed in the copper alloy sliding member according to the present invention. It is desirable to use graphite for powder metallurgy as the material of the graphite particles used here for sintering at the time of production. This is because if there is no heat resistance, it may be denatured during heating and the solid lubricating performance may not be fully exhibited.

  The amount of graphite particles dispersed in the copper alloy sliding member is preferably 0.5% or more and 10% or less of the total mass with the copper alloy. If it is less than 0.5%, the solid lubricating performance is hardly exhibited. On the other hand, if it exceeds 10%, the graphite particles are too much, and the strength of the sliding member may not be maintained.

  The particle size of the graphite particles dispersed in the copper alloy sliding member is preferably 2 μm or more and 200 μm or less. If it is too small, the effect of improving the slidability is not sufficiently exhibited. On the other hand, if it is too large, the structure of the copper alloy is weakened.

  The copper alloy sliding member according to the present invention preferably has 5% or more voids in the volume. If the air gap is too small, the volume in which lubricating oil can be stored is too small, and long-term sliding cannot be maintained. Moreover, since there are few voids, it is difficult to impregnate, and the efficiency of oozing during sliding also deteriorates. On the other hand, if the gap exceeds 20%, the sliding member is likely to be damaged due to insufficient strength of the copper alloy itself. For this reason, the volume occupied by the voids is preferably 20% or less of the copper alloy portion.

  In order to achieve such a porosity, it is desirable to sinter a powder mixture having voids therein when preparing a copper alloy used in the sliding member according to the present invention. Since the voids existing between the powders remain while being deformed during sintering, a route through which the lubricating oil passes from the surface voids to the gaps inside the alloy structure remains.

  As one embodiment of the present invention, a dispersion mixed material of a sulfur-containing copper alloy and graphite particles having high slidability alone will be described. The configuration of the following alloy is merely an example, and the present invention is not limited to this. The copper alloy used for the alloy part in this embodiment is a copper alloy containing a predetermined amount of tin, iron, and sulfur, with the balance being copper and impurities.

  The copper alloy according to the present embodiment preferably contains 3.0% by mass or more of tin. Tin has the effect of improving the matrix strength of copper alloys, improving wear resistance and corrosion resistance, and maintaining good sliding properties. However, if it is less than 3.0% by mass, these effects are insufficient. There is a risk of becoming. On the other hand, the tin content is preferably 16.0% by mass or less. If it exceeds 16.0% by mass, the mating material may be remarkably worn, and good sliding characteristics may not be obtained.

  The copper alloy according to the present embodiment preferably contains 0.3 mass% or more of iron. Iron forms an Fe—S-based compound that improves the slidability of the copper alloy together with sulfur described later. This is because iron is preferably contained in an amount of 0.3% by mass or more in order to form a necessary amount of the Fe—S compound in order to ensure the necessary slidability. On the other hand, the iron content is preferably 6.0% by mass or less. If the iron content exceeds 6.0% by mass, the hardness of the copper alloy will increase too much, and when used as a sliding member, there is a high risk of attacking the counterpart material and causing it to wear. is there.

  The copper alloy according to the present embodiment preferably contains 0.3% by mass or more of sulfur. Sulfur reacts with copper, iron, or both to form the above sulfides. This sulfide has solid lubricity like graphite and molybdenum disulfide, reduces the coefficient of friction, improves the familiarity, and provides good sliding characteristics in the sliding state. In addition, the presence of these sulfides makes the above copper alloy short chips in which chips are cut off during cutting, so that the copper alloy is less likely to wrap around the blade used for cutting and improves cutting performance. It can also be made. When sulfur is less than 0.3% by mass, these effects may not be obtained or may be insufficient. On the other hand, if it exceeds 3.0% by mass, there is a high possibility that sulfur will lower the strength, so that it is preferably 3.0% by mass or less. Furthermore, from the metal phase diagram of Cu-S, in order to exhibit sufficient sliding performance, it is more preferable that it is 1.5 mass% or less.

  The copper alloy according to the present embodiment may contain other residual components in addition to the above-described elements and copper as a residue. This residual component is a component that may be intentionally included in order to provide a more beneficial effect without impairing the effective properties of the copper alloy although it is a minor component, and impurities that are inevitably included. In addition, some of them are included to such an extent that the characteristics of the copper alloy are not impaired.

  The said copper alloy concerning this embodiment may contain 0.01 mass% or more of phosphorus as said residual component. Phosphorus acts as a deoxidizer, has the effect of suppressing the occurrence of gas defects and the like and improving the soundness of the copper alloy. However, the effect will become inadequate that it is less than 0.01 mass%. On the other hand, the phosphorus content is preferably 0.3% by mass or less. If phosphorus exceeds 0.3% by mass, an Fe—P compound is formed with iron, the hardness of the entire copper alloy increases excessively, and seizure resistance decreases. .

  The above impurities are components that are inevitably included when using recycled materials in consideration of the environment, or when sharing equipment in the preparation of the copper alloy and the casting of the sliding member. Of course, from the viewpoint of physical properties, the content of this impurity is preferably as small as possible and more preferably not, but it is difficult to make it zero.

  The amount of lead contained in the copper alloy according to the present embodiment as the impurity is preferably 0.25% by mass or less. Since the influence of lead on the human body cannot be ignored, the amount of lead contained in the copper alloy is preferably as small as possible, and more preferably below the detection limit. If it exceeds 0.25% by mass, the presence of lead may not be negligible even when processing the amount of cutting that occurs when the sliding member is cut or when reusing the copper alloy.

  Further, the amount of molybdenum contained in the copper alloy according to the present embodiment as the impurity is preferably 0.01% by mass or less, and more preferably less than the detection limit. When molybdenum is contained as molybdenum disulfide combined with sulfur in the copper alloy, molybdenum disulfide is oxidized during the preparation of the copper alloy, the manufacture of the sliding member, and the use of the sliding member. This is because an unintended sulfur content is generated and the copper alloy may be affected.

  In addition, the elements that can be included in the copper alloy according to the present embodiment as the impurities include nickel, silver, carbon, zirconium, manganese, bismuth, indium, selenium, aluminum, oxygen, boron, tungsten, zinc, antimony, Although silicon etc. are mentioned, all of these contents are preferable in it being less than 0.01 mass%, and it is more preferable in it being less than a detection limit. Among these, in particular, if there is a large amount of nickel, the hardness of the copper alloy will increase, and if there is a large amount of silver, the copper alloy alone will be insufficient as a solid lubricant and will need to be used in combination with a lubricating oil. There is a risk of dropping from the copper alloy.

  The component amount of the copper alloy according to the present embodiment described here is not the mixing ratio of the raw materials in the manufacturing stage, but the mass excluding the weight of graphite in the copper alloy portion obtained by melting the raw materials. Mixing ratio. The remainder excluding the graphite particles and the above elements is copper.

  The sliding member according to the present invention can be manufactured by heating and melting, sintering, etc. by adding graphite particles to a material in a general casting method or powder metallurgy method. The sintering temperature is preferably 800 ° C. or higher. When the temperature is less than 800 ° C., the formation of the structure is insufficient, and the sliding performance is not fully exhibited, and the strength is likely to be lowered. On the other hand, if the temperature exceeds 1100 ° C., some elements including graphite particles may be modified to leave the alloy, and other unexpected modifications may be caused. Therefore, sintering at 1100 ° C. or lower is preferable. Further, in order to prevent the graphite particles from being oxidized to carbon dioxide as much as possible, it is preferable to sinter in a reducing atmosphere. The form of sintering is not particularly limited, and for example, a bimetal obtained by placing powder on a steel plate to be sintered may be used, and the sintered portion may be polished.

  In addition, the sliding member according to the present invention improves the slidability by filing the surface after sintering and polishing it with sandpaper or other materials so as to reduce irregularities other than the surface voids on the surface as much as possible. From the point of view is desirable.

Furthermore, the sliding member according to the present invention needs to be brought into contact with the lubricating oil after impregnation with the lubricating oil after the sintering or the polishing. Further, the viscosity of the lubricating oil is preferably an ISO viscosity grade of 10 cSt or more and 500 cSt or less (40 ° C.). In this case, the range in which the lubricating oil is impregnated exhibits the effect only on the surface, but the entire copper alloy may be impregnated.
If the viscosity is too high, it will not be possible to enter the gap in the alloy structure from the above gap. On the other hand, if the viscosity is too low, it quickly leaks during sliding and it becomes difficult to maintain sliding performance.

  As a mechanical member specifically used as the copper alloy sliding member according to the present invention, for example, the give liner 10 of the crank press P shown in FIGS.

  The crank press P of this embodiment is also provided with a slide 2 that can be moved up and down in a column 1 that is erected in a quadrangular square in plan view, as in the prior art. The slide 2 is connected to the crankshaft 5 via a connecting rod 6 and a support shaft 7 and moves up and down between the chain line state and the solid line state in FIG. 1 as the crankshaft 5 rotates. For this reason, if a required metal mold is attached to the lower surface of the bolster 3a of the slide 2 and the upper surface of the bolster 3b below the support column 1, and a work is placed between the metal molds, the work is press-molded through the metal mold by raising and lowering the slide 2. Is done.

  A guide 4 is bolted to the surface of the column 1 corresponding to the range in which the slide 2 moves up and down. Gibbers 10, 10 ', which are copper alloy sliding members according to the present invention, are attached to the sliding surface of the guide 4 with the slide 2 by bolting. In the figure, 8 is a vertical tie rod.

  A slide 2 is provided so as to be movable up and down in a column 1 standing upright in a quadrilateral square in plan view, and a required mold (not shown) is attached to both the bottom surface of the slide 2 and the bolsters 3a and 3b below the column 1, A work is placed between the dies, and the work is press-molded through the dies by raising and lowering the slide 2 (solid line and chain line state in FIG. 1).

  In the conventional crank press P of the lubricating oil supply type, it is necessary not only to form a lubricating oil flow groove in the gibbliner 10 and introduce the lubricating oil as needed, but also to provide an oil reservoir, a scattering prevention mechanism, and the like. However, by using the copper alloy sliding member according to the present invention, those mechanisms relating to the supply of the lubricating oil can be omitted.

Hereinafter, examples in which the present invention is specifically implemented will be described. The copper alloy and graphite particles containing each element by mass% listed in Table 1 below are mixed so that the graphite particles are 0.5% to 10% of the total mass with the copper alloy. And sintered at a temperature of about 1000 ° C. The apparent density of the material powder before mixing the graphite particles was 2.5 Mg / m ³ .

  A surface photograph of the graphite particle-dispersed copper alloy material thus obtained is shown in FIG. This copper alloy material was sufficiently impregnated with lubricating oil.

P Crank press 1 Post 2 Slide 3a, 3b Bolster 4 Slide guide 5 Crankshaft 6 Connecting rod 8 Tie rod 10 Gibliner

Claims (3)

A copper alloy sliding member having a sliding surface of a copper alloy,
A copper alloy sliding member, wherein the copper alloy contains a sulfide, and graphite particles are dispersed in the copper alloy, and a lubricating oil is impregnated in a void existing on a surface serving as a sliding surface.   The copper alloy contains iron in an amount of 0.3% by mass to 6.0% by mass, tin in an amount of 3.0% by mass to 16.0% by mass, and sulfur in an amount of 0.3% by mass to 3.0% by mass. 2. The copper alloy sliding according to claim 1, wherein the balance is copper and a residual component, and the mass of the graphite particles is 0.5% or more and 10% or less of the total mass with the copper alloy. Element.   A copper alloy liner, wherein the sliding member as the copper alloy sliding member according to claim 1 or 2 is a liner that supports a slide of a crank press.