KR100789994B1 - Bush type sliding bearing comprising of sintered segments with sloped joining surface - Google Patents

Abstract

A bush type sliding bearing comprising sintered segments with a sloped joining surface and a method for manufacturing the same are provided to maximize a joining area between the segments and thus to achieve a rigid sintered layer. A method for manufacturing a bush type sliding bearing comprising sintered segments with a sloped joining surface includes the steps of: pressing and inserting a plurality of ring type sintered segments comprising a part of the whole sintered layer into an inside of a cylindrical steel substrate; and joining between each sintered segments and between the sintered segments and the steel substrate by sintering the sintered segments in a sintering furnace. In the method, the joining surface of the ring type sintered segments is formed to be sloped, and a cylindrical metal pipe or metal rod is inserted to strongly compress the joining surface through thermal expansion of the metal pipe or the metal rod during sintering.

Description

Bush type sliding bearing using segment sintered material with inclined joint surface and its manufacturing method {BUSH TYPE SLIDING BEARING COMPRISING OF SINTERED SEGMENTS WITH SLOPED JOINING SURFACE}

Figure 1a is a perspective view separately showing a circular metal tube, a segment sintered material formed with an inclined joint surface and a steel substrate used in the manufacture of a bush-type sliding bearing using a segment sintered material formed with an inclined joint surface according to the present invention.

FIG. 1B is a cross-sectional view illustrating a method of assembling the circular metal tube, the segment sintered material having the inclined joint surface, and the steel substrate shown in FIG. 1A.

Figure 1c is a cross-sectional view schematically showing a pressure sintering joining method by a circular metal tube of the manufacturing method of the sliding bearing according to the present invention.

Figure 2a is a perspective view separately showing a circular metal rod, a segment sintered material formed with an inclined joint surface and a steel substrate used in the manufacture of a sliding bearing using a segment sintered material formed with an inclined joint surface according to the present invention.

FIG. 2B is a cross-sectional view illustrating a method of assembling the circular metal rod, the segment sintered material having the inclined joint surface, and the steel substrate shown in FIG. 2A.

Figure 2c is a cross-sectional view schematically showing a pressure sintering joining method by a circular metal rod in the manufacturing method of the sliding bearing according to the present invention.

3 is a cross-sectional view illustrating a state in which a circular metal tube or a circular metal rod is removed after pressure sintering bonding according to the method illustrated in FIG. 1C or 2C.

4A is a perspective view of a bush-type sliding bearing using a segment sintered material having a sloped joint surface according to the present invention.

4B is a sectional view of the bush-type sliding bearing shown in FIG. 3A.

             Explanation of symbols on the main parts of the drawings

1: segment sintered material 3: round metal tube

5: round metal bar 7: steel base

9: sliding bearing 11: sintered layer

13: sintering furnace 15: inside the sintering furnace

17: Puncher 19: Press

21: heater 23: release agent

The present invention relates to a bush-type sliding bearing using a segment sintered material and a method of manufacturing the same. More specifically, the bonding between the segment sintered materials forming the sintered layer is not only firm but also the area of the joint surface is increased to impregnate the lubricant. The present invention relates to a bush-type sliding bearing using a segment sintered material having an inclined joint surface capable of increasing a width and a method of manufacturing the same.

Applicants have found that even when a sintered layer having a large size (volume, length of lubricating surface, area of lubricating surface) is formed on a steel substrate, the sintered metal structure of the entire sintered layer is dense and uniform, Developed the excellent "slide bearing using sintered sintered material" and filed a patent application on September 27, 2005 (application number: 10-2005-89672, application date: September 27, 2005). The invention 10-2005-89672 forms a sintered layer consisting of iron-based metal powder and a solid lubricant on the sliding side surface of the steel substrate, a plurality of constituting part of the entire sintered layer using the iron-based metal powder and the solid lubricant After sintering and molding the segment sintered material in advance, it is forcibly pressed into the steel substrate sliding side surface, and sintered between each segment sintered material and between the segment sintered material and the steel substrate to form a sintered layer. However, according to the invention 10-2005-89672, there is a disadvantage that the sintered joint between the segment sintered material and the steel substrate is not smooth, especially when forming the bush-type sliding bearing. This is because no pressure is applied between the segment sintered material and the steel substrate during the sintering joining process.

Applicant has disclosed the invention that can solve this problem of the invention 10-2005-89672 as Korean Patent Application No. 10-2006-0058006. The 10-2006-0058006 invention is a plurality of ring-shaped segment sintered material constituting a part of the entire sintered layer inside the cylindrical steel substrate, and sintered in the sintering furnace and between each segment sintered material and segment sintered material and In joining steel substrates, a circular metal tube or metal rod is inserted into the ring-shaped segment sintered material with the inner surface of the segment sintered material and a release agent interposed therebetween, so that the metal tube or metal rod is thermally expanded during sintering. It is characterized in that to press to the steel substrate side, according to the 10-2006-0058006 invention, there is an effect that can obtain a solid joint between the ring-shaped segment sintered material and the cylindrical steel substrate.

According to the 10-2005-89672 invention and the 10-2006-0058006 invention, not only the bonding between the ring-shaped sintered material and the cylindrical steel substrate is strong, but the sintered metal structure of the entire sintered layer is dense and uniform, and A sliding bearing having excellent precision in the dimensions and shape of the layer can be obtained, but it has a disadvantage in that the strength is weak for use as a sliding bearing for a high load (about 700 Kg / cm 2 or more). This weakness of strength is due to the sintering of the ring-shaped segment sintered materials without any pressing between the ring-sintered sintered materials, which are connected to each other and then re-sintered in forming the sintered layer of the sliding bearing. do. That is, since no force is applied between the ring-shaped segment sintered materials in close contact with each other in the sintering joining process, even after the formation of the sintered layer, no strong bond is formed between the ring-shaped segmented sintered materials, It brings about the weakness of the sintered layer strength.

The present invention has been made to solve the above-mentioned problems of the prior art, in forming a bush-type sliding bearing having an integral sintered layer by injecting a large number of pre-formed ring-shaped segment sintered material into a cylindrical steel substrate, wherein each ring-shaped segment It is an object of the present invention to provide a bush-type sliding bearing using a segment sintered material having an inclined joint surface capable of forming a high strength sintered layer by forming strong bonding between the sintered materials and a method of manufacturing the same.

Another object of the present invention is to provide a bush-type sliding bearing using a segment sintered material having an inclined joint surface capable of widening the lubrication impregnation area and a manufacturing method thereof.

The sliding bearing according to the present invention to achieve the above object is to form a sintered layer by stacking a plurality of ring-shaped segment sintered material on the friction side surface of the cylindrical steel substrate, the joint surface of each ring-shaped segment sintered material is in contact with each other The joining surface is formed to be inclined to maximize the joining area.

In the manufacturing method of the sliding bearing according to the present invention to achieve the above object, a large number of ring-shaped segment sintered material constituting a part of the entire sintered layer inside the cylindrical steel substrate is press-fitted, and sintered in the sintering furnace, In joining between the segment sintered material and the steel substrate, the joint surface of each ring-shaped segment sintered material is formed to be inclined, and the ring-shaped sintered material is in close contact with the inner surface of the ring-shaped segment sintered material and a release agent therebetween. By inserting a circular metal tube or metal rod, the metal tube or metal rod is thermally expanded during sintering, so that a strong compression is made at the inclined joint surface between each ring-shaped segment sintered material and the joint surface between the ring-shaped segment sintered material and the steel shell. It is done.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the bush-type sliding bearing using the segment sintered material formed with the inclined joint surface according to the present invention and a manufacturing method thereof.

Figure 1a is a perspective view of the circular metal tube, the segment sintered material formed with the inclined joint surface and the steel substrate separately used for the manufacture of the bush-type sliding bearing using the segment sintered material formed with the inclined joint surface according to the present invention, Figure 1b 1A is a cross-sectional view showing a method of assembling the circular metal tube, the segment sintered material and the steel substrate having the inclined joint surface shown in FIG. 1A, and FIG. 1C is a pressure sintering joining method using the circular metal tube in the manufacturing method of the sliding bearing according to the present invention. Figure 2a is a schematic cross-sectional view, Figure 2a is a circular metal rod used in the manufacture of the sliding bearing using the segment sintered material formed with the inclined joint surface according to the present invention, the segment sintered material formed with the inclined joint surface and the steel substrate is shown separately 2 is a perspective view of the circular metal rod shown in FIG. Figure 2c is a cross-sectional view showing a method of assembling the substrate, Figure 2 is a schematic cross-sectional view showing a pressure sintering joining method by a circular metal rod in the manufacturing method of the sliding bearing according to the invention, Figure 3 is shown in Figure 1c or 2c Figure 4a is a cross-sectional view showing a state in which a circular metal tube or a circular metal rod is removed after pressure sintering joining according to the method, Figure 4a is a perspective view of a bush-type sliding bearing using a segment sintered material formed with an inclined joint surface according to the present invention, Figure 4b Sectional drawing of the bush type sliding bearing shown in 3a is shown, respectively.

1A to 1C or 2A to 2C, a feature of the present invention is to form an inclined joint surface of the ring-shaped segment sintering material 1 so that the adjacent ring-shaped segments due to the expansion of the metal tube 3 or the metal rod during sintering joining. The bonding surfaces of the sintered material 1 are strongly adhered to each other, and after the sintering bonding is finished, the strong bonding state can be maintained for a long time by the wide bonding surface. To this end, a small ring-shaped segment sintered material (1) constituting a part of the entire sintered layer (11) is formed by using a sintered material in which iron-based metal powder and a solid lubricant are mixed. Then, the ring-shaped segment sintered material 1 having this inclined joint surface is selected as many as the size of the total sintered layer 11 to be molded and sintered again while being pressed into the sliding side surface of the cylindrical steel base 7. Each segment sintered material 1 is bonded together, and each segment 1 and the steel base 7 are bonded together. At this time, not only for the strong bonding between the outer circumferential surface of the ring-shaped segment 1 and the inner circumferential surface of the steel substrate 7, but also for the strong bonding between the joint surfaces of the ring-shaped segments 1, the inner circumferential surface of the ring-shaped segment 1 The metal tube 3 or the metal rod 5 in close contact with the inner circumferential surface thereof is inserted through the release agent 23 so that the metal tube 3 or the metal rod 5 thermally expands during sintering. When the metal tube 3 or the metal rod 5 is thermally expanded in close contact with the inner surface of the segment 1, the ring-shaped segment sintered material 1 is pressed to the steel substrate 7 side, and the pressing force is the ring-shaped segment. In addition to acting between the inner circumferential surface of the sintered material 1 and the steel base material 7, it also acts on the joint surface of each said ring-shaped segment sintered material 1. Therefore, strong bonding is made between the ring-shaped segment sintered materials 1 during the bonding sintering.

To this end, as shown in FIGS. 1A and 1B, a ring-shaped segment sintered material 1 having a required number of inclined joint surfaces, a circular metal tube 3, a cylindrical steel substrate 7, and a release agent ( 23) Prepare. In addition, as shown in Figures 2a and 2b the metal tube 3 can be replaced by a round metal rod (5).

The ring segment sintered material (1) is sintered by using an iron-based metal powder and a solid lubricant, wherein the iron-based metal powder is 10 to 50% by weight of copper powder, nickel, titanium, silicon, aluminum, cobalt, chromium, manganese Or 0.1-30% by weight of one or two or more metal powders selected from tin, and the remainder of iron powders uniformly mixed using a mixer. As the solid lubricant, graphite and molybdenum disulfide in powder form are used. At least one solid lubricant selected from (MoS ₂ ) or tungsten disulfide (WS ₂ ) is selected and used. Among the iron-based metal powders, in particular, the iron powder is preferably made of finely divided iron powder of 250 mesh or less, so that the sintered metal structure of the sintered layer can be densified and the bonding property is improved when sintering and joining the steel substrate. . The content of the copper powder in the segment sintered material (1) is not particularly limited, it can be selectively applied within the range of 10-50% by weight depending on the density of the sintered metal structure required. If the copper content is less than 10% by weight, the densification degree of the sintered metal is lowered. If the copper content is more than 50% by weight, the iron-based metal particles in the sintered metal are completely surrounded by the copper particles, thereby exhibiting the original strength and friction characteristics of the iron-based sintered material. There will be no. In addition, the iron-based metal powder is added 0.5-30% by weight of at least one or more metal powder selected from nickel, titanium, silicon, aluminum, cobalt, chromium, manganese or tin to obtain high load resistance and at the same time secondary bonding sintering It is preferable to improve the adhesiveness between the sea segment sintered material 1 and the steel substrate 7. In addition, the iron-based metal powder may be added 2-20% by weight of one or more metal powders selected from zinc, lead, tin, tungsten and molybdenum in order to reduce iron adhesion to the counterpart material and improve lubricity. . When the ring-shaped segment sintered material 1 is formed to have a very small size compared to the entire sintered layer 11, the ring-shaped segment sintered material 1 can not only be sintered and formed in a very dense and uniform structure, but also can increase the accuracy of dimensions and shapes. As a result, the structure of the whole sintered layer 11 which joins and molds these segment sintered materials 1 is not only very dense and uniform in structure but also very precise in dimension and shape.

The metal pipe 3 or the metal bar 5 is a stainless steel pipe or a stainless steel bar having a high thermal expansion rate without melting at the junction sintering temperature (usually 600-1100 ℃) (thermal expansion coefficient of stainless steel: 1.9 / ℃ ) Is preferred, but is not necessarily limited thereto. The metal tube 3 and the metal rod 5 should have a circular plane of diameter that can be in close contact with the ring segment sintered material 1.

The release agent 23 is necessary in order to facilitate the separation of the metal tube 3 or the metal rod 5 from the segment sintered material 1 after sintering. As the mold release agent 23, a known mold release agent such as silicone resin, wax, carbon powder or the like is used.

As the material of the cylindrical steel substrate 7, a material having high strength and hardness, such as carbon steel or stainless steel, and which can be easily sintered with an iron-based metal is used.

Hereinafter, the manufacturing method of the bush-type sliding bearing using the segment sintered material having the inclined joint surface according to the present invention will be described.

First, as shown in FIG. 1B or 2B, the segment sintered material 1 having the inclined joint surface formed therein is pressed into the cylindrical steel substrate 7 before being introduced into the sintering furnace 13 and sintered. It is laminated by pressing with the puncher 17 etc. which are operated by (9). At this time, a release agent 23 is applied to the inner surface of the segment sintered material 1 in contact with the metal tube 3 or the metal rod 5 so that the metal tube 3 or the metal rod 5 can be easily separated after sintering. do.

Next, as shown in FIG. 1C, the assembly of the steel base 7, the segment sintered material 1 and the metal tube 3 on which the inclined joint surface is formed, or the steel base 7, as shown in FIG. 2C, The assembly of the segment sintered material 1 and the metal rod 5 in which the inclined joint surface was formed is arrange | positioned in the inside of the sintering furnace 15, and the temperature of the inside of the sintering furnace 15 is controlled by the heater 21 of the sintering furnace 13. It raises to 600 degreeC-1100 degreeC, and the segment sintered material 1 is sintered secondary. Sintering time is suitable for 5 minutes-100 minutes. In the sintering process, the metal tube 3 or the metal rod 5 is thermally expanded by sintering heat to press the segment sintered material 1 to the steel substrate 7 side, and the inner wall of the steel substrate 7 is also thermally expanded. Strong adhesion is applied between the joining surfaces of the segment sintered material 1 and between the segment sintered material 1 and the steel substrate 7 to form a firm bond.

Referring to FIG. 3, when the sintering joining between each segment sintered material 1 and the segment sintered material 1 and the steel substrate 7 is completed, an integral sintered layer 11 is formed inside the steel substrate 7. When the upper and lower portions of the cutting line C are cut and removed, the bush sliding bearings shown in FIGS. 4A and 4B are obtained.

4A and 4B, the sliding bearings 9 manufactured by the above-described process are strongly bonded to each other by the joining surfaces of the ring-shaped segment sintered materials 1 to form a sintered layer 11 having an integrated strength and durability. In addition to forming, the sintered layer 11 is firmly bonded to the steel substrate 7 so that even when a large load is applied for a long time, there is no separation of the sintered layer. The joining surface (part shown by dashed line) of the sintered layer 11 is easily impregnated with lubrication compared with other parts. Therefore, when the joint surface is inclined to increase the joint area, not only the joint strength at the joint surface is increased but also a wider lubricant impregnated surface is formed.

According to the present invention having the above-described configuration, a strong bonding is formed between the ring-shaped segment sintering materials forming the sintered layer, thereby not only forming a high-strength sintered layer but also having an effect of widening the lubricating impregnation area.

Although the present invention has been described with reference to the embodiments shown in the accompanying drawings, the scope of protection of the present invention is not intended to be limited thereto, and the scope of protection of the present invention is set forth in the detailed description of the claims and all equivalent embodiments thereof. It should be interpreted as crazy.

Claims (2)

On the frictional side surface of the cylindrical steel substrate, a plurality of ring segment sintered materials are laminated to form a sintered layer, and the joint surfaces in which each ring segment sintered material contacts each other are inclined to maximize the joint area. Bush-type sliding bearing using faceted segment sintered material. In a large number of ring-shaped segment sintered material constituting a part of the entire sintered layer inside the cylindrical steel substrate, and sintered in the sintering furnace to join each segment sintered material and between the segment sintered material and the steel substrate, The joining surfaces of the ring-shaped segment sintered materials are inclined to each other, and a circular metal tube or a metal rod is inserted into the ring-shaped segmented sintered material in close contact with the inner surface of the ring-shaped segmented sintered material through a release agent. Or a bush using a segment sintered material having an inclined joint surface, wherein the metal rod is thermally expanded so that a strong compression is performed at the joint surface between the inclined joint surface between each ring-shaped segment sintered material and the ring-shaped segment sintered material and the steel machine. Manufacturing method of mold sliding bearing.

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