JP2002295600A - Chain bush, connection pin for chain, and chain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chain bush, a connection pin for a chain, and a chain which can be assembled without changing the current man-hours of assembling process and are excellent in durability. SOLUTION: The chain bush freely rotatably inserts a connection pin of which the both ends are fixed to a connecting hole of an outer link plate, and at the same time, is comprised by being fitted the both ends to the connecting hole of an inner link plate, and, the chain bush forms a multiple layered bearing material, which is comprised by impregnating and covering an impregnated resin compound that is mainly composed of a fluorine resin, into a cylindrical shape to a porous layer formed on the surface of a metal member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chain bush,
The present invention relates to a chain connecting pin and a chain using the same.

[0002]

2. Description of the Related Art Chain transmissions combining gears and chains are widely used in bicycles, motorcycles, general industrial equipment, and the like. Conventionally, in order to increase the durability life of a chain, 1) seal grease between a connecting pin and a bush and rubber seal it, 2) insert a sliding material between the connecting pin and a bush, and 3) use a sintered oil-impregnated bush. (Actual Kaiping 1
-149048, 10-250818). An example of a chain using a sintered oil-impregnated bush will be described with reference to FIG. FIG. 3 is a partially cutaway sectional view of a conventional chain. In the chain 1, the inner link plates 2, 2 and the outer link plates 3, 3 are connected by chain connecting pins 4. Both ends of the chain connecting pin 4 are fixed to the outer link plates 3, 3, and the sintered oil-impregnated bush 7 is externally fitted. Both ends of the sintered oil-impregnated bush 7 are firmly fitted to the inner link plates 2 and 2, and the roller 6 is fitted externally as needed. The chain transmission operates by gear teeth (not shown) meshing with the sintered oil-impregnated bush 7 or the roller 6.

[0003]

However, the method 1) has a problem that the sliding torque is increased by the rubber seal and that the grease is easily leaked due to the deterioration of the rubber seal. In the above method 2), there is a problem that the space for accommodating the sliding material and the thickness of the chain bush are reduced to secure this space, and the rigidity is reduced. In the methods 1) and 2),
There is a problem that the number of parts increases and the number of assembling steps increases. In the above method 3), in order to balance the slidability and the rigidity of the sintered oil-impregnated chain bush, the sintered density must be maintained within a predetermined range, and there is a problem that the production becomes difficult. .

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and can be assembled without changing the current assembling man-hours. An object of the present invention is to provide a chain that uses a computer.

[0005]

A chain bush according to the present invention has a connecting pin rotatably inserted into a connecting hole of an outer link plate and both ends fitted into a connecting hole of an inner link plate. The chain bush is formed by molding a multilayer bearing material in which a porous layer formed on the surface of a metal member is impregnated and coated with an impregnated resin composition containing a fluororesin as a main component into a cylindrical shape. It is characterized by.

[0006] The impregnated resin composition is characterized in that a carbon fiber and an inorganic filler having a Mohs' hardness of 4 or less are mixed with a resin containing a fluororesin as a main component.

[0007] A multi-layer bearing material in which a porous layer formed on the surface of a metal member is impregnated and coated with an impregnated resin composition containing a fluororesin as a main component is formed into a cylindrical shape to form a chain bush. Thereby, the slidability with the chain connecting pin or the like can be maintained in the impregnated coating portion, and the mechanical strength can be maintained in the metal member. As a result, a chain excellent in slidability and durability can be obtained without changing the thickness of the conventional chain bush or the number of assembling steps.

The chain connecting pin of the present invention is rotatably inserted into a bush fitted in the connecting hole of the inner link plate, and has both ends fixed to the connecting hole of the outer link plate. The connection pin has a fluorine resin-containing nickel plating layer.

By providing a fluorine resin-containing nickel plating layer on the surface of the chain connecting pin, slidability and wear resistance are improved. As a result, a chain excellent in slidability and durability can be obtained without changing the thickness of the chain bush or the number of assembling steps by replacing the conventional chain connecting pin.

In the chain according to the present invention, both ends of a chain bush fitted in the connection hole of the inner link plate and a chain connection pin rotatably inserted in the chain bush are fixed to the connection hole of the outer link plate. The chain is characterized by using the above-mentioned chain bush. Further, the chain connecting pin is the chain connecting pin.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a chain according to the present invention will be described with reference to FIG. FIG. 1 is a partially cutaway sectional view of a chain. In the chain 1, the inner link plates 2, 2 and the outer link plates 3, 3 are connected by chain connecting pins 4. Both ends of the chain connecting pin 4 are fixed to the outer link plates 3, 3, and the chain bush 5 is fitted to the outside. The chain bush 5 is formed by molding a multilayer bearing material formed of a porous layer 5a impregnated and coated with an impregnated resin composition 5c containing a fluororesin as a main component and a metal member 5b into a cylindrical shape. The porous layer 5a impregnated and covered with the resin composition 5c slides on the chain connecting pin 4. Further, both ends of the chain bush 5 are tightly fitted to the inner link plates 2, 2, and a roller 6 is externally fitted as required. The chain transmission is
Gear teeth (not shown) operate by meshing with the chain bush 5 or the roller 6.

The multilayer bearing material forming the chain bush 5 will be described with reference to FIG. FIG. 2 is an enlarged sectional view for explaining a multilayer bearing material. In the multilayer bearing material, a porous layer 5a of a sintered metal or the like is formed on the surface of a metal member 5b such as a steel plate, and the porous layer 5a is impregnated and coated with an impregnated resin composition 5c mainly containing a fluororesin. It has a three-layer structure. The impregnated coated surface becomes the sliding surface, and a multilayer bearing material having excellent sliding characteristics under high surface pressure can be obtained.

As the metal member 5b, steel (rolled steel for structural use such as SPCC) or a metal other than steel, for example, a copper alloy such as stainless steel or bronze can be used. In addition, it is preferable that the surface of the metal member 5b be plated (copper or a copper alloy such as bronze) equivalent to that of the sintered metal layer in order to enhance the adhesion to the sintered metal layer. Porous layer 5a
As a sintered metal layer is preferred, as the sintered metal layer,
Copper or a copper alloy such as bronze is preferable because of its excellent friction and wear characteristics. The thickness of the sintered metal layer is 50 to 400 μm, preferably 100 to 300 μm. When the thickness is 50 μm to 400 μm, it is easily formed into a cylindrical shape and has excellent wear resistance.

The chain bush 5 is obtained by molding a plate-shaped multilayer bearing material into a cylindrical shape. The porous layer 5a can be an inner peripheral surface of a cylinder or an outer peripheral surface of a cylinder. Further, an impregnated coating layer may be formed on the inner peripheral surface of the cylinder. A preferred embodiment is a porous layer 5a impregnated with the impregnated resin composition 5c.
Is formed on the inner peripheral surface of the cylinder so that the metal can slide with the chain connecting pin 4.

The fluororesin constituting the impregnated resin composition 5c is a known PTFE represented by-(CF ₂ -CF ₂ ) _n-.
(Hereinafter abbreviated as polytetrafluoroethylene resin), PTFE has a perfluoroalkyl ether group (-
_{C p F 2p -O -) (} p is an integer from 1 to 4) or a polyfluoroalkyl group _{(H (CF 2) q -} ) (q is modified PTFE obtained by introducing such as an integer) from 1 to 20 can be used. For these PTFE and modified PTFE, any of a suspension polymerization method for obtaining a general molding powder and an emulsion polymerization method for obtaining a fine powder may be employed. And more preferably, 500,000 to 3,000,000. As commercially available PTFE, Teflon 7J manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd., and as commercially available modified PTFE,
DuPont Fluorochemical: Teflon TG70J, Daikin Industries: Polyflon M111, Polyflon M1
12, Hoechst: Hostaflon TFM1600, Hostaflon TFM1700 and the like.

The above-mentioned fluororesin can be used in combination with a crystalline resin capable of improving abrasion resistance and creep resistance, preferably a crystalline resin having a melting point of 280 ° C. or higher. For example,
Examples include polyphenylene sulfide resin, polyether ether ketone resin, polyimide resin, polyether ketone resin, nylon 46 resin, and the like. Among these, polyphenylene sulfide resin, polyether ether ketone resin, and polyimide resin, which can further improve the wear resistance and creep resistance, are preferable, and the most preferable is polyphenylene sulfide resin.

As the carbon fiber usable in the present invention, any of a pitch-based or a PAN-based carbon fiber can be used as long as it can reinforce the impregnated resin composition by being used in combination with an inorganic filler described later. The fiber length of carbon fiber is 0.05mm
It is preferably a short fiber of 1 to 1 mm, more preferably 0.05 to 0.1 mm. Fiber diameter is φ20 μm or less,
Preferably, it is φ7 μm to φ15 μm, and the aspect ratio is 5 to 80, preferably 20 to 50. A carbon fiber having these properties is excellent in the effect of reinforcing the impregnated resin composition, and is excellent in wear resistance and creep resistance. The type of yarn is not particularly limited, but a product baked at 1000 ° C. (carbonized product) is preferable to a product baked at 2000 ° C. or processed at a higher temperature (graphitized product). Regarding the firing temperature, a low-temperature fired product aimed at low elasticity or a high-temperature fired product aimed at high elasticity can be used.

Commercially available carbon fibers are pitch-based products manufactured by Kureha Chemical Co., Ltd .: Crecamild M101S, M101F, M
101T, M107S, M1007S, M201S, M
207S, manufactured by Osaka Gas Chemical Company: Donna Carbon S24
1, S244, SG241, SG244 as PAN system, manufactured by Toho Rayon Co., Ltd .: Vesfight HTA-CMF
0160-0H and CMF0070-0H.

The inorganic filler having a Moh's hardness of 4 or less that can be used in the present invention can be used as long as it plays a role of micro reinforcement in the impregnated resin composition and can contribute to improvement of creep resistance and wear resistance. In the present invention, Mohs hardness
The reason for setting it to 4 or less is to improve the characteristics of friction and wear. Inorganic fillers with a Mohs hardness of 4 or less are fibrous,
Although the shape is not limited, such as plate-like or granular, the size is preferably 100 μm or less. The size refers to the average fiber diameter in the case of a fibrous substance, and refers to the average particle diameter in the case of a plate-like or granular form. For micro-reinforcement between carbon fibers, a plate-like material is more preferable than a fibrous material, and a granular material is more preferable than a plate-like material, and the size is more preferably in the range of 1 to 50 μm. If the particle size is extremely small, less than 1 μm, the composition does not have sufficient abrasion resistance. Examples of such an inorganic compound include calcium sulfate, calcium carbonate, and magnesium sulfate.

The calcium sulfate may be an anhydrous salt type or a hemihydrate type. Preferred calcium sulfate is an anhydrous salt type. In addition, magnesium sulfate may be an anhydrous salt type or a heptahydrate, but an anhydrous salt type is preferred. Commercially available inorganic fillers that can be suitably used in the present invention include calcium sulfate having a Mohs' hardness of 2-3, manufactured by Noritake Co., Ltd .: D-101A (anhydrous salt type), D-200 (anhydrous salt type), FT-2 Examples of calcium carbonate having a hemihydrate salt and Mohs 'hardness of 3 include NA600 manufactured by Nissan Kogyo Co., Ltd., and magnesium sulfate having a Mohs' hardness of 2 to 3 include magnesium sulfate reagent manufactured by Wako Pure Chemical Industries, Ltd.

The compounding ratio of the impregnated resin composition is preferably 3 to 30% by volume of carbon fiber, 1 to 25% by volume of an inorganic filler having a Mohs' hardness of 4 or less, and the balance being a fluororesin. When a part of the fluororesin is replaced with a crystalline resin having a melting point of 280 ° C. or higher, the mixing ratio is 3 to 3%.
0% by volume, 1 to 25% by volume of inorganic filler having Mohs hardness of 4 or less, 5 to 40% by volume of crystalline resin having a melting point of 280 ° C or higher,
The balance is preferably a fluororesin. If the amount of the carbon fiber exceeds 30% by volume, there is a problem in formability. If the amount is less than 3% by volume, the reinforcing effect is poor, and sufficient creep resistance and wear resistance cannot be obtained. If the inorganic filler having a Mohs hardness of 4 or less exceeds 25% by volume, molding becomes difficult. If the amount is less than 1% by volume, the desired micro-reinforcing effect and damage mitigation effect are poor, and sufficient sliding characteristics cannot be obtained. If the crystalline resin with a melting point of 280 ° C or more exceeds 40% by volume, the coefficient of friction increases under high load, causing problems such as an increase in initial torque and an increase in heat generation due to friction. No effect. The blending amount of the fluororesin is the balance of the total blending amount.

It is to be noted that known additives listed below can be blended within a range not to impair the object of the present invention. For example, P
Excludes wear enhancers such as TFE lubricating powder, molybdenum disulfide, etc., carbonized powders, electrical property improvers such as zinc oxide and titanium oxide, cracking improvers such as graphite, and metals that may cause environmental pollution such as lead and cadmium. Other metal oxide powders, thermal conductivity improvers such as graphite, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA),
Toughness improvers such as tetrafluoroethylene-hexafluoropropylene copolymer (FEP) are exemplified.

The fluorine resin-containing nickel plating layer formed on the surface of the chain connecting pin of the present invention will be described. The fluororesin-containing nickel plating layer is a nickel-phosphorus composite plating layer in which a fluororesin powder is dispersed, and a connecting pin for a chain, for example, a stainless steel (SUS304) coupling pin in a plating solution in which the fluororesin fine powder is dispersed. Is obtained by plating. The plating process is
There are an electroless plating method, an electroplating method, and a combination thereof. In particular, the electroless plating method is preferable because it is simple, the thickness of the plating layer becomes uniform, and the fluororesin can be dispersed and the nickel-phosphorus composite plating layer can be easily formed.

In the electroless plating method, nickel hyposulfite, an acetic acid agent, a stabilizer, a pH buffer, an appearance modifier, and a dispersing agent are added to a hypophosphite reduction bath, and fine powder of a fluororesin is further dispersed. Heat the resulting plating solution to about 80 ° C or higher,
In this method, a nickel-phosphorus composite plating layer is formed on the surface by immersing a chain connecting pin in the plating solution. In the electroless plating, the plating portion of the connection pin may be directly polished after degreasing and pickling.
Electroless plating may be performed after zinc substitution plating to further improve adhesion.

The nickel-phosphorus composite plating layer in which a fluororesin is dispersed by the electroless plating method is formed by immersion in a heated plating solution until a composite plating having a desired thickness is obtained. The thickness of composite plating is 0.5
2525 μm is preferred. If the layer thickness is less than 0.5 μm, pinholes are likely to be generated in the composite plating layer, and the wear resistance is reduced. If the thickness is more than 25 μm, the adhesion of the composite plating may be reduced.

The particle size of the fine powder of the fluororesin forming the nickel plating layer in which the fluororesin is dispersed is 0.05 to 5 μm, preferably 0.1 to 2 μm, and more preferably 0.2 to 2 μm.
0.8 μm. If the particle size is smaller than 0.05 μm, it is difficult to handle, and if the particle size is larger than 5 μm, it is difficult to be retained on the nickel plating layer.

The amount of the fine fluororesin powder contained in the fluororesin-dispersed nickel plating layer is 6 to 20% by weight. If the content is less than 6% by weight, the sliding characteristics are reduced and frictional heat is easily generated. On the other hand, if it exceeds 20% by weight, it becomes difficult to form a plating layer. The mixing ratio of the fine fluororesin powder contained in the plating layer can be easily adjusted by changing the amount of the fine fluororesin powder dispersed in the plating solution.

As the fluororesin, PTFE, modified PT
FE or the like can be used, and is appropriately selected from these.
In particular, PTFE is preferable because it is excellent in functional aspects such as sliding characteristics and non-adhesion to toner, price, availability, and ease of handling.

In the chain of the present invention, excellent wear resistance and durability can be obtained by replacing the chain bush 5 of the multilayer bearing material formed into a cylindrical shape with a conventional sintered oil-impregnated bush. Further, even if a fluorine resin-containing nickel plating layer is formed on the surface of the chain connecting pin 4, a chain having excellent wear resistance and durability can be obtained as described above. Further, both of them are combined with the chain bush 5 of the present invention.
By replacing the link pin 4 with a chain, a chain having more excellent wear resistance and durability can be obtained.

[0030]

The chain bush of the present invention is formed by molding a multi-layer bearing material having a porous layer formed on the surface of a metal member and impregnated and coated with an impregnated resin composition containing fluororesin as a main component into a cylindrical shape. Therefore, a chain excellent in slidability and durability can be obtained without changing the thickness of the chain bush or the number of assembling steps. In particular, since the impregnated resin composition is made of a resin containing a fluororesin as a main component and carbon fibers and an inorganic filler having a Mohs hardness of 4 or less, it is grease-free, and there is no fear of grease leakage or deterioration, and Has excellent wear resistance and durability.

The chain connecting pin of the present invention has a fluorine resin-containing nickel plating layer on its surface, and therefore has excellent wear resistance and durability.

Since the chain of the present invention is assembled using at least one of the above-described chain bush and the above-described chain connecting pin, the slidability and durability can be achieved without changing the plate thickness and the number of assembly steps of the conventional chain bush. A chain with excellent properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of a chain.

FIG. 2 is an enlarged sectional view of a multilayer bearing material.

FIG. 3 is a partially cutaway sectional view of a conventional chain.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chain 2 Inner link plate 3 Outer link plate 4 Chain connecting pin 5 Chain bush 5a Porous layer 5b Metal member 5c Impregnated resin composition 6 Roller 7 Sintered oil impregnated bush

Claims (5)

[Claims] 1. A chain bush in which both ends of a connection pin fixed to both ends of a connection hole of an outer link plate are rotatably inserted and both ends are fitted into the connection hole of an inner link plate. A chain bush characterized by forming a cylindrical bearing into a multilayer bearing material in which a porous layer formed on the surface of a member is impregnated and coated with an impregnated resin composition containing a fluororesin as a main component. 2. The resin according to claim 1, wherein said impregnated resin composition contains at least carbon fiber and Mohs hardness of 4 based on fluororesin.
The chain bush according to claim 1, wherein the following inorganic filler is blended. 3. A chain connecting pin rotatably inserted into a chain bush fitted in a connecting hole of an inner link plate and having both ends fixed in a connecting hole of an outer link plate. A chain connecting pin comprising a nickel plated layer containing a fluororesin. 4. A chain in which both ends of a chain bush fitted in a connection hole of an inner link plate and a chain connection pin rotatably inserted in the chain bush are fixed to connection holes of an outer link plate. 3. A chain, wherein the chain bush is at least the chain bush according to claim 1 or 2. 5. A chain in which both ends of a chain bush fitted into a connection hole of an inner link plate and a chain connection pin rotatably inserted through the chain bush are fixed to connection holes of an outer link plate. A chain, wherein the chain connecting pin is at least the chain connecting pin according to claim 3.