KR101364950B1 - The method of producing heavy-duty guide roller of v type using powder metallugy - Google Patents

Abstract

The present invention relates to a method for manufacturing a V-type heavy load guide roller using power metallurgy. The present invention is to obtain density and strength having high homogeneity when a V-type heavy load guide roller is manufacture by powder metallurgy. In order to transfer uniform pressure to the entire surface of a molded body (Mold), the molded product is divided into two molded bodies (Two molds), but the two molded products formed to be coupled safely are coupled to be one body (guide roller) as a thermosetting composition. And then, the coupled molded bodies pass a sintering process at 1180°C, a sizing process, and a common quenching process.

Description

The method of producing heavy-duty guide roller of V type using powder metallugy}

The present invention relates to a method of manufacturing a guide roller using powder metallurgy. Specifically, in the manufacture of a V-shaped guide roller by metal powder molding, a shaft hole and a columnar shape are formed on the same center to obtain high density and strength of homogeneity. While sharing the axial hole of the molded body with the metal powder molding (A) having an insert, the cylindrical insert is pushed into the circular groove of the metal powder molding (B) together with the heat-sealing composition containing tungsten carbide particles, and then the temperature is 500 ° C. The present invention relates to a method of manufacturing a V-shaped high load guide roller using powder metallurgy which is sintered by passing a series of furnaces divided into 700 ° C, 900 ° C, and 1180 ° C at a constant speed for 3 hours, and undergoes a post-treatment operation.

In order to obtain a guide roller as a finished product as described above, the divided metal powder molded bodies of A and B are combined together with the heat-sealed composition and sintered together. It is inserted into a wire or thin film tape and sintered.

The reason for separating and molding into two molds is that when the guide roller is formed of metal powder, it may not be possible to mold the metal powder with one mold, or it may be extremely difficult to form and take out the metal powder. Even if the molding is possible, it can be said that the mold cannot be adopted if the piezoelectric transfer difference is large when the press pressure is applied when forming the metal powder.

This is the most essential requirement in forming metal powder.

In the process of developing high load guide roller using powder metallurgy and filing, the company which has produced high load guide roller by rotary cutting machine device with metal or alloy rod-like body, but cutting method is only by highly skilled workers. Since it can produce a normal product and the time required to manufacture a unit product takes a long time, it loses its competitiveness due to a drop in productivity and has turned to powder metallurgy.

Initially, the circumferential upper half product, which was formed by powder-forming only bearing grooves and shaft holes on both sides of the guide roller, was sintered and then cut into V-shaped grooves to obtain a finished product.

This can be said to be a compromise between the powder metallurgy method and the cutting method.

This method can be referred to as a powder compact in which the press pressure is uniformly transmitted and formed, but the strength is insufficient in the unsintered state, and thus the V-shaped cutting part must be cut after sintering. As a result, the problem caused by expensive material loss occurred.

As a method for improving the material loss as described above, as shown in FIG. 1, the V-shaped grooves 14 and 14 'are formed in which the semi-circular body 11 and 11' intermediate rails (not shown) are in close contact with each other. The coupling grooves 12 and 12 'and the protrusions 13 and 13' are integrally formed at the ends of the circular grooves 15 and 15 into which bearings (not shown) are inserted at the centers of both ends of the bodies 11 and 11 '. Developed a guide roller.

This can also be referred to as a divided body (mould), which has a relatively good density distribution of the molded body, but in the event of a severe impact, the connection part of the projection and the coupling groove may occur. When a certain period of time begins to occur, the deepening occurs and the bearing is not rotated smoothly, resulting in an impact, which eventually leads to separation of the molded body at the joint.

Through such a process, the pressure distribution during powder molding can be uniformly divided and divided molds (dividing molds) can be obtained without separation. By improving the composition of the molded body and complementing the heat-sealed composition of the joint, there is almost no difference in density distribution in the entire structure and high density, which can greatly improve the physical properties and increase the bonding strength of the two molded parts. It was possible to provide a method for manufacturing a high load guide roller.

Powder metallurgy produced large iron products from sponge iron in ancient or medieval times. However, the origin of powder metallurgy in the modern sense was the production of platinum coin in the early 19th century. Platinum, which was a relatively high melting point metal at that time, was difficult to melt-cast and was produced by powder metallurgy. Later, in 1900, it was used as a processing method for high melting point metals (tungsten, molybdenum), which became more popular. Subsequently, in 1923, after Godidge's metal tungsten production, Schroetey patented a tungsten carbide sintering tool as cobalt powder, and its use became active as the powder metallurgy became known since Krupp manufactured Wrdia in 1927.

In recent years, metal powder and alloy powder manufacturing techniques have been improved, and powder metallurgy sintered products have various mechanical structural parts such as guide rollers, gears, cams, bearing parts, friction parts, or heat-resistant filters using permeability and impregnation. It is used in various fields such as porous parts.

The advantage of the powder metallurgy sintering method is that the melting point can be significantly lowered through fine powder sintering of the material having a high melting point, the dimensions are good, and the alloy is easy. In addition, it is possible to make porous metal materials, excellent in wear resistance, self-lubricating properties and good surface condition.

In addition, sintered steel parts can be surface-hardened, heat-treated, and steam-processed to produce mass-produced alloys that are economical and cannot be made by the dissolution method. Once firing occurs, the powder cannot be used again, and because the powder has a large surface area relative to its volume, it is highly reactive with oxygen, which leads to oxidative corrosion quickly, difficult to store, requires a lot of equipment, and is expensive and limited in shape.

Therefore, there is a case that the production using the pressure of the gas and the fluid and the thermal control is difficult to cause the explosion of the metal powder.

In addition, the most significant problem is that powder metallurgy is formed by a press of powder without fluidity, so that the pressure transmission to each part of the mold is not uniform. Since the strength is inferior, the molding must be designed in the form of a divided body so that the pressure transmission is uniform during molding, and at the same time, the mold must be manufactured, and the powder molded body composition must also be formulated to increase physical properties. When completed, they shall be strongly bonded so as not to break or break at the connection.

By effectively separating the shape of the guide roller and making the distribution of press pressure uniformly anywhere in the mold during powder molding, by increasing the density of the structure of the molded body and homogenizing it, the strength property is increased and the metal powder composition of the guide roller molded body is appropriate. It is possible to expect the synergistic effect of strength by achieving the high quality of the product by improving the quality of the product, by making the structure fine and the quenching effect by giving the beautiful luster of nickel and copper alloy, and by increasing the hardness chemical resistance and oxidation resistance, and the wear resistance and corrosion resistance To improve the durability and to provide a method of manufacturing a V-shaped high load guide roller using powder metallurgy which has a strong bonding force by simultaneously bonding the bonding parts of the two separate molded parts to have a heat bonding adhesive force and a binding force. have.

In order to achieve the object of the present invention, an annular outer wall (A4) and an annular inner wall (A5) are formed on the outer circumferential protrusion (A3) extending from the shaft hole (A1) and the annular locking jaw (A2) formed in the inner center portion. The circular groove B1 is formed at the inner center of the cylindrical projection A3 of the metal powder molded body A in which the bearing groove A6 is formed between the annular jaws B2 inside the circular groove B1. ) Is formed on the outer side of the metal powder molded body (B) having a bearing groove (B5) formed between the annular outer wall (B3) formed to the outside, such as the molded body (A) and the annular inner wall (B4) formed inward The metal powder molded bodies (A) and (B), which are configured to be connected to the grooves B1 and connected to each other, are 2.4 wt% nickel, 2.1 wt% copper, 0.4 wt% molybdenum, 0.3 wt% manganese, and 0.15 wt% beryllium, respectively. The molded body by molding into a metal powder composition composed of iron V-shaped heavy load guide formed by inserting and connecting the cylindrical projection A3 of A) together with the heat-sealing composition into the circular groove of the metal powder molded body B into an integral V-shaped guide roller molded body, followed by sintering and quenching. The object of the present invention could be achieved by providing a method for producing a roller.

The V-shaped high load guide roller manufactured by the present invention has high density and at the same time homogeneous density, which can withstand high loads, and has a beautiful gloss, which is elegant in appearance, excellent in wear resistance and corrosion resistance, and ensures durability and strong connection. It can be said to be a safe V-shaped high load guide by preventing the phenomenon of separation by the bonding force.

1 is an exploded perspective view of a conventional V-shaped guide roller
Figure 2 is an exploded perspective view of the present invention V-shaped guide roller molded body (A) and (B)
3 is a bisected cross-sectional view of the present invention V-shaped guide roller molded bodies (A) and (B).
Figure 4 is a perspective view of the present invention V-shaped guide roller

In order to achieve the object of the present invention, the shape of the unit molded body constituting the guide roller is formed so that the press pressure is uniformly transmitted to the entire mold when forming the molded body with the metal powder composition, and is required by the guide roller formed by the metal powder composition. The metal powder composition was formed to give excellent physical properties, and at the same time, the method of manufacturing a guide roller having excellent physical properties by efficiently forming, connecting, sintering, and finishing the unit moldings is described by process.

In forming a V-shaped guide roller by a powder molding method, a metal powder composition molded body (A) having a axial hole and a columnar protrusion formed on the center thereof coincides with the axial hole with the metal powder molded body (A). Step of forming in the form of a molded body (mold) divided in the form of a metal powder molding (B) is provided with a circular groove to accommodate the insertion

Comprising a metal powder composition of 2.4% by weight of nickel, 2.1% by weight of copper, 0.4% by weight of molybdenum, 0.3% by weight of manganese, 0.15% by weight of beryllium, the remaining iron

Inserting the cylindrical protrusions A3 of the molded body A together with the heat-sealing composition into the circular grooves of the molded body B, thereby joining them into one metal powder composition molded body (guide roller molded body) C;

Sintering the combined metal powder compacts through a furnace in a non-oxidizing atmosphere partitioned at a temperature of 500 ° C, 700 ° C, 900 ° C and 1180 ° C at a constant rate for 3 hours

It can be said to be a manufacturing method of a V-shaped high load guide roller including a step of quenching in a conventional manner in a state maintained at a temperature of 700 ~ 800 ℃.

In the above method, the configuration of the divided moldings (A) and (B) constituting the V-shaped guide roller will be described in detail. As shown in FIGS. 2 and 3, the metal powder composition molded body (A) has a shaft hole formed at the center thereof inward. A1 and a bearing groove A6 having a circumferential protrusion A3 extending from the annular engaging jaw A2 and having a bearing (not shown) mounted between the annular outer wall A4 and the annular inner wall A5 to the outside. ) Is formed and another metal powder molding (B) has a circular groove (B1) is formed in the inner center, the annular jaw (B2) is formed inside the circular groove (B1) and the molded body (A) on the outside Similarly, a bearing (not shown) groove B5 is formed between the annular outer wall B3 and the annular inner wall B4.

The outer side of the molded body A and the outer side of the molded body B are formed in the same shape, and the combination of the molded body A and the molded body B causes the cylindrical projection A3 of the molded body A to be formed into a circular shape of the molded body B. The lower end of the cylindrical protrusion A3 is placed in the annular locking jaw B2 of the molded body B, and the inner end of the molded body B is the annular locking jaw A2 of the molded body A. ) Is coupled in the state of contact with the guide roller is molded into the molded body (C) as shown in FIG.

In the forming method of the molded articles (A) and (B), the bearing grooves (A6, B5) are both in contact with the press, so that the molded articles (A) and (B) are in the form of ordinary light and narrow, so that the transmission of pressure is most efficient. Because it is delivered in the form of uniformly delivered, the density is high and the tissue density is large.

Molding pressures of the molded bodies (A) and (B) are molded at a high pressure of 4 to 5 ton / cm ² .

As a next step, in the metal powder composition of the molded articles (A) and (B)

Nickel has a specific gravity of 8.98, melting point of 1,455 ℃ and gives high gloss when alloying with iron, and is rich in ductility and malleability, making it an excellent alloy with iron and copper. When nickel is added to iron, the appearance of the product can be enhanced by giving a beautiful nickel plating luster together with copper.

In powder molding mainly composed of iron powder, the nickel content of 2.4% by weight can provide the advanced level of nickel gloss, can finely sinter the sintered structure, increase the corrosion resistance, and the mechanical strength and tension that a high load guide roller must have. It can be said that the composition ratio of the range that can guarantee the strength.

In addition, copper has a specific gravity of 8.96, a melting point of 1,083 ° C, and is a metal with excellent ductility and malleability. It is widely used in the powder metallurgy field mainly composed of iron. When 2.1 wt% of copper is added to the metal, the strength and hardness are improved. can do.

Molybdenum can be said to be an amount which can express the strength, hardness, and abrasion resistance necessary for the structure of a guide roller because the amount of molybdenum is small compared to the amount to be added and the amount of nickel and copper is sufficient. Adding more amounts tends to weaken impact resistance.

Beryllium is a very light and hard metal with a specific gravity of 1.85 and melting point of 1,280 ℃. It is alloyed with nickel and copper when added to the metal powder of the guide roller which contains iron as its main component, resulting in high hardness and excellent oxidation resistance. It is a metal that can contribute to improving the durability of large metals.

Manganese has a specific gravity of 7.44 and a melting point of 1,245 ° C., indicating that hardness and temper resistance are improved even when only 1.5% by weight of a silvery metal is added.

The composition may be a composition in which the metal powder uses fine powder particles of several tens of microns in the sintering process, and melting and crystallization are performed smoothly because there is no big difference between melting points of the metal. In addition, the thermal fusion composition has a great meaning in the process of combining the molded bodies (A) and (B). Since the V-shaped roller manufactured in the present invention has a V-shaped groove formed in the molded body (A) and the molded body (B), the groove is placed on the rail, so that a very large shear force is generated in the axial direction at the roller joint. If the molded body (A) and (B) of the roller is pulled out and leads to a big accident.

The heat fusion composition may be referred to as a heat fusion composition composed of 40 to 60 wt% nickel, 92 wt% of fine metal powder composed of copper to 40 to 60 wt%, 3 wt% of tungsten carbide particles, and 5 wt% of fluorite fine powder.

Above, nickel, copper and fluorspar fine powder (CaF2) are tens of micron fine particles and tungsten carbide particles are 100 ~ 120 mesh size. As particles pulverized by or the like, up to 120 mesh can be pulverized, of which tungsten particles of 100 to 120 mesh are used.

The thermal fusion composition has an adhesion function by nickel and copper by fusion sintering by sintering treatment, but the tungsten particles are not melted at the sintering temperature, so the particles remain as they are. The tungsten particles were brought into engagement with the bonding surface of the sintered body A and the sintered body B to obtain a shear force 1.5 times larger than the adhesive force due to the fusion of the metal powder.

In addition, if the sintering process is performed by increasing the temperature at a constant rate in the sintering process, the plastic deformation can be greatly reduced.The sintering termination temperature is 1180 ℃, which must be terminated at the crystal precipitation temperature of iron. Deformation or dimensional deformation occurs.

In addition, the temperature of quenching (Quenching) will vary depending on the carbon content in the present invention was carried out in the 700 ~ 800 ℃ range.

The V-shaped high load guide roller manufactured by the above method is designed to be stable in high load by dividing the mold to share the shape and shaft of the ordinary light beam so that the press pressure can be easily and uniformly transmitted during molding. It is composed of homogeneous tissue with a high density and almost no difference in density, so structural strength can be secured and the beautiful glossiness of nickel and plating alloy is generated by efficient metal powder composition and processing. By providing the product with high quality, strength, hardness, and oxidation resistance, the wear resistance and corrosion resistance were improved, and a V-shaped high load guide roller having excellent durability was obtained.

Such a V-shaped guide roller may be referred to as a V-shaped high load guide roller that can be used for moving ships in shipyards and large sliding doors that move along rails on rails in industrial facilities such as machine shops, painting facilities, and steel mills.

In order to find out the physical properties of the V-shaped high load guide roller manufactured according to the present invention is shown in the following examples.

Example (1)

Formed by press molding at a press pressure of 4.5 ton / cm ² with a metal powder composed of 2.4 wt% nickel, 2.1 wt% copper, 0.4 wt% molybdenum, 0.3 wt% manganese, 0.15 wt% beryllium, and 94.65 wt% iron. ) And (B) to form a heat-sealed composition comprising 92% by weight of nickel powder, 92% by weight of copper powder, 8% by weight of fluorite powder, and 3% by weight of tungsten particles of 100 to 120 mesh. The molded body inserted between the joints of (A) and (B) is injected into a furnace maintained at 500 ° C., and then sintered by passing the furnace maintained at 1180 ° C. in 3 hours after passing the furnace maintained at 1180 ° C. via diesel. The V-shaped high load guide roller was manufactured by quenching with a sintered body maintained at 700 ℃ to 800 ℃.

The maximum, minimum, average density, and porosity of 10 locations of the V-shaped high-load roller molded body (A) manufactured by the method of Example (1) were measured. The test measurement results as shown in Table 1 were obtained.

Example (2)

In addition, in order to find out the bonding strength between the connecting parts of the molded bodies (A) and (B), the molded bodies adhesively sintered with a heat-fused composition composed of 95 wt% of metal powder composed of 55 wt% nickel and 45 wt% copper and 5 wt% of formed powder ( Shear stress was compared with the molded article (C) prepared in D) and Example (1). The joint shear stress of the molded body D was 12.2 kg / mm ² and the joint shear stress of the molded body C was 29.3 kg / mm ³ (in this case, the copper alloy mixed powder is substituted for the tungsten particles).

A: metal powder molding B: metal powder molding
A1: Shaft hole B1: Round groove
A2: annular locking jaw B2: annular locking jaw
A3: columnar protrusion B3: annular outer wall
A4: annular outer wall B4: annular inner wall
A5: annular inner wall B5: bearing groove
A6: Bearing groove C: V type heavy load guide roller

Claims (4)

A bearing groove A6 is formed between the annular outer wall A4 and the annular inner wall A5 which are formed on the inner side thereof, and have a circumferential protrusion A3 extending from the axial hole A1 and the annular locking jaw A2. A circular groove B1 is formed at the inner center of the cylindrical protrusion A3 of the metal powder molded body A in which is formed), and an annular jaw B2 is formed at the inside of the circular groove B1. Between the annular outer wall B3 formed outwardly like the molded body A and the annular inner wall B4 formed inwardly, the grooves B1 are formed so as to correspond to the circular grooves B1 of the metal powder molded body B in which the bearing grooves B5 are formed. The metal powder molding (A) and the metal powder molding (B), which are configured to be connected to each other, are molded into the metal powder composition, respectively, and the columnar protrusions (A3) of the metal powder molding (A) are formed together with the heat fusion composition. Into the circular groove (B1) of the Method of producing multiple molded product was then guides of the V-shaped high load is to be processed by the sizing process and the quenching roller formed of sintered The method of claim 1,
The metal powder of the metal powder moldings (A) and (B) is 2.4% by weight of nickel, 2.1% by weight of copper, 0.4% by weight of molybdenum, 0.3% by weight of manganese, 0.15% by weight of beryllium, and the rest of which is a metal powder composition. Manufacturing method of V-shaped high load guide roller The method of claim 1,
The heat-sealing composition is composed of 40 to 60 wt% of nickel fine powder, 40 to 60 wt% of copper fine powder, 3 wt% of 100 to 120 mesh tungsten carbide particles and 5 wt% of fluorite fine powder. Method of manufacturing a V-shaped high load guide roller, characterized in that the heat-sealed composition The method of claim 1,
In the sintering process, the V-shaped heavy load guide roller is formed by passing the integrated metal powder compact at a constant speed for 3 hours in each furnace maintaining the temperature at temperatures of 500 ° C, 700 ° C, 900 ° C and 1200 ° C. Manufacturing Method

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