KR20080002664U - A module type powder molding bush with high performance - Google Patents

Abstract

The present invention relates to a modular high-performance powder molding bush, which is diffusion-bonded to the inside of a steel housing and combined with a powder compact containing a suitable sintered density, strength, wear resistance and uniformly distributed lubricating oil. Excellent lubrication cycles can be extended even in the event of excessive shock, and the life cycle is increased by about 2 times through durability improvement by hardening heat treatment / surface polishing treatment and modular shape optimization. To provide a new modular, high performance powder molding bush that can be extended.

That is, in the present invention, when constructing a modular high-performance powder molding bush, the bush is composed of a steel housing and a powder molded body which is press-molded into the steel housing, heat treated and processed, and the powder molded body is press-molded therein. It is formed by integrally forming a welded joint in the state of forming a concave-convex stepping corresponding to two or three or more steel housings, and in the state of mutually fitting with the neighboring bush. Hardness can be adjusted by the steel, the inner surface of the bush can be adjusted by the heat treatment, and the alloying of chromium, molybdenum and phosphorus to harden the base structure and to extrude the finely dispersed composite compound to further improve wear resistance, Low friction lubrication is maintained by graphite or molybdenum disulfide contained.

In addition, the bush of the present invention has an allowable load of 800-1200 kg / cm ² or more due to the combined magnetic lubrication effect of the solid lubricant and the wet lubricant impregnated with the steel housing material having further wear resistance by alloying and hardening heat treatment. It is improved by, and maintains abrasion resistance and low friction lubrication (friction coefficient 0.03-0.10), so that the lubrication-free period is greatly increased, the grease lubrication cycle is improved to 1000-3,300 hours or more.

Bush, steel housing, powder molding, step, joint, oil supply hole

Description

A module type powder molding bush with high performance

1 is a perspective view showing a first preferred embodiment of the present invention

2 is a cross-sectional view of FIG.

3 is a perspective view showing a second embodiment of the present invention

4 is a cross-sectional configuration of FIG.

5 is a cross-sectional configuration view showing another example of the second embodiment;

6 is a perspective view showing a third embodiment of the present invention

7 is a cross-sectional configuration of FIG.

8 is a manufacturing process block diagram of the bush of the present invention

9 is a cross-sectional view of the shaping state of the bush of the present invention

☞ Explanation of symbols used in the main part of the drawing ☜

1: Bush 2, 2 ': Steel housing

3: powder molding 4,4 ': step

5: Junction 6: Oil supply hole

The present invention relates to a modular high-performance powder-forming bush, and more particularly, a powder molded body which is hot-diffused and bonded to the inside of a steel housing and contains a suitable sintered density, strength, wear resistance and uniformly distributed lubricating oil. It is possible to extend the excellent lubrication cycle even under load and impact, and extends the life by about 2 times through durability improvement by hardening heat treatment / surface polishing treatment and modular shape optimization, and at least 100 times of lubricating oil lubrication cycle. It is to provide a new modular high performance powder molding bush that can be extended (about 3300 hours).

Existing technologies generally have several soccer moving parts that transmit power and operate machines in hydraulic excavators, machine tools, presses, injection machines, industrial machinery, construction equipment, etc., which reduce friction between shafts and shaft holes. In general, steel and metal are mainly used for joining and sliding bearings of copper alloy-based aluminum alloys, synthetic resins, or oilless bearings, and have been used to improve the lubricity of shafts and shaft holes without frequent grease lubrication.

Existing alloy layers such as copper alloys, aluminum alloys, copper alloys, and synthetic resins are formed and made of copper, aluminum, copper, and synthetic resins with low strength and abrasion that are incomparable with iron-based alloy layers. This low, high abrasion is not suitable for use for heavy or heavy loads.

Therefore, high-performance journal bearings with abrasion resistance, impact resistance, heat resistance, chemical resistance, etc., which can endure in increasingly harsh working environments, have been developed in various fields, and oilless bearings, which do not need to supply lubricant oil, have been developed. It is being used in various ways.

However, these oilless bearings are artificially impregnated with synthetic resin-based plastic bearings made of Teflon-based composite resins with lubricating properties in raw materials, and sintered bodies made of crystalline by applying heat or pressure to the powder. Bearing has the advantage that it can be used for a long time without lubricating oil.Because it is a low density small alloy or resin plastic, it has low strength and low hardness and is vulnerable to repeated loads and abrasions. Sintered bearings have a high degree of shrinkage due to densification when sintered into a mixed iron powder of a certain composition, and the bonding state between the mixed iron powder and the steel metal is unclear due to thermal deformation of the steel metal at the sintering temperature. If not, it will be manufactured in a very unstable state. It is emerging as a big issue there.

In addition, in order to increase the load resistance, abrasion resistance, and heat resistance, there is a method of press molding the powder to press-in a circular steel metal and resintering it, but it is difficult to control the mixing of the powder layer with a uniform distribution so that the product having the required molding density or strength is required. There is a disadvantage in that it is difficult to manufacture, there is a problem that the impregnation of the lubricating oil due to the non-uniform density, it is difficult to obtain a stable quality.

Meanwhile, conventional steel bearings having a double layer structure composed of a metal and a small alloy layer include copper, copper-tin, copper-zinc-lead, aluminum bronze, aluminum, linkage, synthetic resin, and the like.

They are not suitable for long periods of lubrication under heavy loads of 300-500 kg / cm ² or higher because of the low strength and hardness of the small-bonded alloy layer in contact with the sliding mating element (shaft or pin). As such, hardness and strength could not be increased by heat treatment and structure control methods.

In addition, the steel bushes currently used, namely, carburized heat treated bushes and high frequency heat treated steel bushes, have a non-lubricating period of more than 10 to 50 hours even if they are coated with a molybdenum disulfide coating or coated with a phosphate coating. In this case, the operation of oil-free operation will not be possible due to the fact that frictional joints, sintering, wear, etc. are extremely remarkable, and even serious damage to peripheral parts such as shafts or pins which are sliding relative elements. Causes

Therefore, in the case of the existing bush can have a load resistance only in a continuous refueling state, and generally has a problem that the shock absorption ability is insufficient because it is hardened by heat treatment.

In addition, in case of brass bush, the load resistance at high load is inferior, wear resistance is much weaker than iron bush, and even though continuous lubrication at high load or special treatment of peripheral parts is caused by impurities, foreign substances and wear debris in wet lubricant It has the disadvantage that it can't prevent surface fatigue by fritting and cavitation.

On the other hand, as another example, there is also an example of a small alloy bearing consisting only of iron-based copper alloy composed of iron, copper, carbon (compound carbon, that is, solid carbon) without a metal if the steel for high loads and oil-free (US Patent No. 54,730) ).

However, this sliding bearing is made of iron-based small alloys without metal, so that the load transfer capability may be superior to that of non-ferrous alloy bearings. However, when the sliding bearing contains a large amount of solid lubricant (molybdenum disulfide and / or free carbon) in the molded body, And since sintering is difficult, there are manufacturing limitations.

In addition, in the case of steel, in the case of manufacturing a bearing using only the iron-based small alloy without metal, the diameter and length of the bearing are limited to the small size.

In other words, when a large amount of the dry lubricant is contained by increasing the diameter and length, the molding and sintering itself becomes crumbly, which makes it practically impossible to manufacture for a desired use.

Therefore, this technique generally can not include a dry lubricant to maintain the rigidity of the small-bonded alloy bearing, and even if included, is limited to a very small amount, even if it contains a solid lubricant to form and sinter, the sintered body lacks the rigidity.

Therefore, in case of steel, iron, copper, compound carbon, that is, iron-based small alloys composed of solid carbon, only lubricating oil should be used.In this case, instable friction coefficient and frictional heat at high load and low speed Overheating due to accumulation, wear and tear, impact vulnerabilities, separation, loss of back oil, problems such as press-fit into the housing, impact resistance problems, machining problems, handling problems.

The present invention was made as a result of the test by manufacturing a variety of metal mixed alloy layer in view of the conventional unstable problem as described above, high-performance wear-resistant powder molding that made the inner circumferential surface of the steel housing and the powder molded body in a stable bonding state To provide a bush.

Another object is to provide a high-performance powder-forming bush of excellent performance that can have a load-bearing and abrasion resistance, extended durability life and long oil-free period by the type and mixing composition of the metal mixed powder.

The present invention is a modular high-performance powder-forming bush is a press-molded powder molded body in the steel housing, the powder molded body applied to the bush length is 20 ~ 80 m / m or less single-stage modular powder molding high-performance bush 1 embodiment), double-ended modular powder molding bush having a powder molding length of 80 m / m to 150 m / m or less (second embodiment), and multi-stage modular high performance powder molding bush having a powder molding length of 150 m / m or more (third embodiment) It is characterized by consisting of).

FIG. 1 is a perspective view showing a first preferred embodiment of the present invention, and FIG. 2 is a cross-sectional view of the configuration of the present invention.

The present invention relates to a modular high-performance powder molding bush (1), the configuration of which is the configuration of the injection molding the powder molding (3) in the steel housing (2) as shown.

The constituent structure of the powder compact (3) is a structure in which the Fe-Cu-Cr-Ni-Sn-based iron-based sintered alloy layer is bonded, and the alloy powder is 15-35wt% of copper component and 55-75wt of iron (Fe) component. %, Graphite component 0.3 ~ 4.5wt%, molybdenum disulfide (MoS2) 0.1-3.0wt%, nickel (Ni) 0.1-3.5wt%, chromium (Cr) 0.1-2.5wt%, phosphorus (P) 0.1-2.5wt% , Zinc (Zn) 0.2-3.5wt%, sulfur (S) 0.3-3.0wt%, tin (Sn) 0.5-3.5wt% by component composition to provide a high-performance product formed by molding the molded powder.

Under the powder molding conditions, the molding pressure is 2.5ton ~ 5ton m / ㎠, the sintering density is 5.8 ~ 6.4, the porosity is 15 ~ 20%, and the sintered body thickness is 3.5 ~ 4m / m.

3 is a perspective view showing a second embodiment of the present invention, Figure 4 shows a cross-sectional configuration of FIG.

This is to provide a bush (1) extending in length by connecting the two steel housing (2) (2 ') configured as in the first embodiment by integrally interconnecting.

The preferred connection configuration of the steel housings (2) and (2 ') is to form an uneven step (4) (4') in the steel housing (2) (2 ') and the neighboring steel housings (2) (2'). It is the structure which integrated and formed the junction part 5 welded in the state which mutually couple | bonded with.

5 shows another example of the second embodiment, which is configured to supply oil by forming an oil supply hole 6 in the joint portion 5.

Figure 6 shows a perspective view showing a third embodiment of the present invention, Figure 7 shows a cross-sectional configuration of Figure 6, which is three or more steel housings (2) configured as in the first embodiment 2 ') can be interconnected to provide a long bush (1).

8 shows a manufacturing process block diagram of the bush 1 of the present invention, and FIG. 9 shows a cross-sectional view of the molding state of the bush 1 of the present invention.

The present invention is composed of the results of experiments of various kinds of alloying elements, the high load of 800-1200 kg / cm ² or more, has a long period of oil-free period of 1000 to 3300 hours or more in the bush itself under low speed, Due to the reinforcement, high-performance bushes with load resistance, abrasion resistance and durability, fatigue strength, separation prevention and back oil loss prevention as well as stable low friction lubrication and wear resistance, impact resistance and surface fatigue resistance of the low density iron-based alloy layer To provide.

Bush (1) (1 ') provided in the present invention is a process for cutting the steel housing (pipe) (2) (2') to a predetermined length and the primary processing, and the primary steel housing (2) (2 Applying a diffusion adhesive to the inner circumferential surface of '), inserting a metal powder into the inner circumferential surface of the steel housing (2) (2'), and performing a heat treatment on the press-molded powder compact (3); , Through the process of processing the powder compact (3), and the process of impregnating in oil.

The press-molding of the powder compact 3 has a cylindrical hollow as shown in FIG. 9, a shaft core 10 is installed in the center, and a lower pressing JIG 11 is installed at the bottom of the molding mold 12 of the molding apparatus. After inserting the steel housing (2), and then filling the mixed powder between the steel housing (2) and the molding die 12, and inserting the upper pressing JIG (13) to the upper end of the molding die 12 Modular high performance powder molded bush 1 in which powder compact 3 is formed by pressure molding, and powder compact 3 is integrally formed in steel housing 2 by sintering the powder compact 3 together with steel housing 2. To prepare.

In addition, when graphite or molybdenum disulfide is contained in the powder compact 3, they act as a dry lubricant, and a lubricant such as lubricating oil or grease is applied to the powder compact 3 heat-treated for use of the bush for a long time without lubrication. Impregnating may be further included.

Further, according to the present invention, as shown in the second to third embodiments, the steel housings 2 and 2 'having the same diameter are joined in the longitudinal direction to produce the bush 1 having a long length in the longitudinal direction. can do.

The bush 1 having a long length in the longitudinal direction forms the step 4 and 4 'corresponding to the steel housing 2, 2', and then joins them to each other to weld or braze to produce a bush having a long length. can do.

Preferably, as a TIG welding or brazing method, it is only necessary to provide a bush having a long length by brazing at the same time as the sintering joint in the joining process using silver or copper solder or by torch brazing after the sintering joint.

The effect of the modular high performance powder molding bush 1 according to the present invention made as described above is as follows.

1) The modular high-performance bush (1) is a steel steel in which the steel housing (2) is capable of hardness control by hardening heat treatment, and the inner surface of the bush (1) is capable of hardness control by heat treatment, and alloying of chromium, molybdenum and phosphorus is performed. Through the hardening of the matrix and finely dispersed complex compound, the wear resistance is further improved, and low friction lubrication is maintained by the graphite or molybdenum disulfide contained therein.

2) The alloy layer in which the steel housing (2) of the bush (1) is further abrasion-resistant by alloying and hardening heat treatment has an allowable load of 800-1200 kg / due to the combined magnetic lubrication effect of the embedded solid lubricant and the wet lubricant. It improves more than cm ² , and maintains abrasion resistance and low friction lubrication (friction coefficient 0.03-0.10), so that the lubrication-free period is greatly increased, improving the grease lubrication cycle to more than 1000-3,300 hours.

Claims (7)

In constructing the modular high performance powder molding bush 1, The bush (1) and the steel housing (2), Modular high-performance powder molding bush, characterized in that consisting of a powder molded body (3), which is press-molded into the steel housing (2), hardened heat treatment and processed. The method of claim 1, The bush (1) forms a concave-convex step (4) (4 ') corresponding to two steel housings (2) (2'), which are hardened and heat-treated and processed by powder molding (3). A modular high-performance powder-forming bush, characterized in that the steel housing (2) (2 ') to form a welded joint (5) in the state of being fitted together. The method of claim 1, The bush 1 forms an uneven step 4 and 4 ′ corresponding to three or more steel housings 2 and 2 ′ where the powder molded body 3 is press-molded therein to be hardened and heat treated and processed. A modular high-performance powder-formed bush, characterized in that it is formed by forming a joint (5) welded in the state of mutually fitting with the neighboring steel housing (2) (2 '). The method according to any one of claims 1 to 3, The powder compact (3) is 15-35wt% copper component, 60-75wt% iron (Fe) component, 0.3-4.5wt% graphite component, molybdenum disulfide (MoS2) 0.1-3.0wt%, nickel (Ni) 0.1-3.5 wt%, chromium (Cr) 0.1-2.5wt%, phosphorus (P) 0.1-2.5wt%, zinc (Zn) 0.2-3.5wt%, sulfur (S) 0.3-3.0wt%, tin (Sn) 0.5-3.5 Modular high performance powder forming bush, characterized in that consisting of wt%. The method according to any one of claims 1 to 3, The powder compact 3 is a modular high performance, characterized in that the sintered molding density of 5.8 ~ 6.4, porosity 15 ~ 20%, sintered body thickness 3.5 ~ 4 m / m under 2.5ton ~ 5ton m / ㎠ molding pressure Powder molding bush. The method according to any one of claims 1 to 3, The powder compact 3 is a modular high performance powder molding bush, characterized in that the oil is impregnated The method of claim 2 or 3, Modular high-performance powder-forming bush, characterized in that to form the oil supply hole (6) to the joint portion 5 can supply the oil.

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