JP2013108598A - Sliding part and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a high performance sliding part and a guide part at low cost by forming a sliding surface having low sliding resistance and high surface hardness even on an uneven surface of the part and an inner hole of the part.SOLUTION: A plated film 102 is formed on the surface of the sliding part of a structural base material 101, and dispersed diamond microparticles 103 are codeposited on the outermost surface thereof so that the sliding surface having low sliding resistance is formed even on the uneven surface or the surface of the inner hole of the part, and the hardness in the plated film can be enhanced by heat treatment of the plated surface.

Description

The present invention relates to a sliding part that is an opposing part having a sliding part, a guide part of an article transfer mechanism, and a sliding electrode in which the sliding part serves as an electrical contact.

Many movable machines such as a power machine and an internal combustion engine have a portion that slides between opposing parts. These sliding parts are required not to attack each other, to have low sliding resistance and not to wear. The guide parts of the article transfer mechanism are required to have low sliding resistance so that the conveying material is transferred with low friction and high hardness so that the guide parts do not wear.

In addition, mobile information terminals such as mobile phones often use a single-axis or two-axis rotary hinge having a rotation mechanism, and the slidability and fixing torque of the hinge itself are required. The slip ring is equipped with a slip ring equipped with a hinge, and the slip ring has a structural micro-processing accuracy of the sliding contact, low sliding resistance (friction), and low electrical resistance. It is required at the same time.

On the other hand, it is industrially used to impart new functions and characteristics not found in structural base materials by surface modification of other materials on the outside of the structural base materials such as metals. , CVD, coating, etc., and various methods are applied depending on the application.

Japanese Patent Laid-Open No. 2007-232026 JP 2003-197340 A Japanese Patent Laid-Open No. 2001-211610 JP 2009-9718 A JP 2007-39720 A JP 2006-225730 A

Matsubara Hiroshi, New material production by nano diamond composite in plating film, surface science, vol. 30, no. 5, pp. 279-286, 2009.

The prime movers that continuously rotate or reciprocate, such as internal combustion engines and electric motors, have facing sliding parts that do not attack each other, have low sliding resistance, and do not wear. For such purposes, a lubricant is used or the surface of a part is modified.

For example, various measures are taken to reduce wear loss even in an annular part called a piston ring for maintaining an airtightness between a piston and an inner wall of an internal combustion engine or forming an oil film on the inner wall of the cylinder. Patent Document 1 and the like show that the Forming an amorphous hard carbon film on the outer peripheral sliding surface of the piston ring to reduce friction loss generally requires an expensive vapor deposition apparatus, and there remain problems in terms of productivity and the like.

Also, among the electrodes used in various devices and circuits, many electrodes, such as those for sliding type and applications that open and close very frequently, have low electrical resistance and low sliding resistance or high hardness There is a need for both properties. However, gold, silver, copper, aluminum, etc., which have low electrical resistance and are preferable as conductors, have a disadvantage that they are worn hard by repeated contact and sliding when used as electrode materials because of their low hardness and high friction coefficient. ing. For this reason, metals such as chromium, molybdenum, and tungsten, which have higher hardness or lubricity at the expense of electrical characteristics, and their compounds are used as electrode materials or added to good conductor electrode materials. Has been done. However, the low electrical characteristics, that is, the degradation of the performance of the device itself and the reduction of the power utilization efficiency, demands an electrode material having high electrical conductivity while maintaining the hardness and lubricity.

In rotating and sliding electrodes such as slip rings and rotary joints, measures such as sequentially moving the electrodes (for example, refer to Patent Document 2) or disengaging them when unnecessary (for example, refer to Patent Document 3) may be taken. However, there is a problem that it cannot be applied to parts of small portable devices because the structure is complicated or large.

On the other hand, it is known that DLC (diamond-like carbon) or its type can be formed on the surface of the electrode by vapor deposition such as CVD or PVD to achieve both low sliding resistance and high hardness. However, since the electrical resistance is high, it cannot be applied as it is as the surface treatment of the electrode material, so it is necessary to maintain the conductivity by exposing the electrode base material in the post-treatment (for example, see Patent Document 4). . As with DLC, there is a method (for example, Patent Document 5) that solves the problem by forming a conductive diamond layer on the metal surface by CVD or PVD, but in either case, DLC or diamond thin film is formed. There are technical problems that it is difficult to form a uniform film on an uneven surface, and economic problems such as expensive equipment for the gas phase treatment.

The present invention has been made to solve these problems efficiently and effectively, and an object thereof is to provide a sliding component having excellent sliding performance and to provide an efficient manufacturing method thereof. is there.

The present invention produces a coating having high hardness and lubricity on the surface of the sliding part of the sliding component by plating and heat treatment, and can solve the above-mentioned problems very efficiently. In addition, when the metal matrix material is selected from gold, silver, copper, etc., it is possible to produce a coating with high hardness and lubricity and high electrical conductivity. Therefore, it is extremely efficient to produce this coating on the outer surface of the sliding contact. In particular, the above-mentioned problems can be solved.

Matsubara, one of the present inventors, devised a method for forming a composite plating film in which a large amount of diamond fine particles as much as 14 vol% are dispersed in a metal matrix (see Patent Document 6). Subsequent analysis demonstrated that the diamond particles contained in the plating film are dispersed and adsorbed on the surface layer, and that a friction coefficient of about 0.03 can be obtained without using lubricating oil (Non-Patent Document). 1).

FIG. 1 shows a schematic diagram of the composite plating film of the present invention. A plating film 102 is formed on the surface of the sliding portion of the substrate 101, and the diamond fine particles 103 dispersed on the outer surface side of the plating film are co-deposited. It is considered that the diamond fine particles co-deposited on the surface impart hardness and lubricity to the plating film.

Furthermore, in the case of a normal non-composite plating treatment, the plating film is further cured by performing a heat treatment thereafter. On the other hand, whether or not the curing phenomenon occurs even when heat treatment is performed in composite plating has been uncertain until now, but in the present invention, heat treatment is performed as a post-treatment of composite plating, and the same as a normal non-composite plating film It is confirmed that the plating film can be cured. For example, in nickel phosphorus plating, when the plating film itself is about Hv = 550, it is hardened to about Hv = 900 by performing heat treatment at about 400 ° C.

Moreover, in this invention, a subject can be solved more effectively by performing a blast process in addition to a composite plating film. The blast treatment includes, for example, a dry treatment represented by sand blast and dry ice blast and a wet treatment represented by water blast, and various media, pressures, and flow rates are selected according to the purpose. In the examples, wet blasting using a slurry in which fine particles of zinc oxide or aluminum oxide having a particle size of about several tens of μm are suspended in water is applied, but other blasting methods and blasting conditions are also effective. Needless to say.

In FIG. 2, the schematic diagram at the time of applying a blast process to the composite plating of this invention is shown.

In 2A of FIG. 2, the surface of the sliding portion of the base material 201 is roughened by blasting, and then a composite plating film 202 is formed. Diamond fine particles 203 are co-deposited on the surface layer of the plating film. It shows a state. The peeling resistance of the plating film is improved by blasting the substrate.

2B shows a state in which the composite plating film 212 is formed on the base material 211 and the diamond fine particles 213 are co-deposited on the surface layer of the plating film. The unevenness caused by the blasting of the plated film brings about further improvement in lubricity by point contact.

In 2C of FIG. 2, the surface of the plating film is improved by forming a composite plating film 222 after the surface of the sliding portion of the substrate 221 is roughened by blasting, thereby improving the peeling resistance of the plating film. By subjecting the surface of the diamond particles 223 to eutectoid blasting to the surface, fine irregularities are produced on the surface, and the lubricity can be further improved.

As described above, by applying composite plating containing diamond fine particles according to the present invention, there is an effect that both the hardness and the lubricity of the sliding part or the guide part can be achieved.

Moreover, there is an effect that the peeling resistance of the plating film can be enhanced by performing the plating treatment after the surface of the base material is blasted.

Furthermore, there is an effect that the lubricity of the plating film can be further improved by blasting the surface of the plating film.

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS.

FIG. 3 shows a guide post 1300 and a guide pin 310 used in a mold or the like as an embodiment of claims 1 to 3.

The guide post and the guide pin itself do not directly contribute to the plastic working by the mold, but are one of important mechanisms for ensuring the fitting between the molds and preventing the deviation. A plurality of guide posts are mounted on one of the molds, and guide pins are mounted at corresponding positions on the other mold. Accordingly, the guides are required to have no looseness and high lubricity. 3, 301 and 302 are screw holes for fixing the guide post itself to the mold, and 303 is a guide hole for inserting a guide pin.

By manufacturing the guide hole surface 303 and the opposing surface 311 of the guide pin 310 according to the present invention, the sliding performance can be effectively enhanced. Needless to say, the sliding performance can be effectively improved by processing the sliding surfaces such as the guide rails and the guide rollers in the same manner as well as the guide posts and the guide pins.

The present embodiment according to the first to third aspects is characterized in that a composite plating film can be easily applied even on the inner surface such as the guide hole 303.

Next, details of the plating method will be described. It is possible to disperse the diamond fine particles in the metal matrix constituting the plating film by immersing the base material while stirring the plating bath in which the diamond fine particles are dispersed (suspended) with a gas containing oxygen. is there. As the gas containing oxygen, in addition to pure oxygen, a mixture of oxygen and another inert gas such as nitrogen can be used. In practice, air is preferably used.

There is no particular limitation on the plating bath used for electroless plating, and any plating bath usually used for electroless plating can be used. For example, a phosphinic acid-based electroless plating bath containing phosphinic acid or a salt thereof. An electroless plating bath containing formaldehyde, an electroless plating bath containing dimethylamine borane, and the like.

A complexing agent is usually added to these plating baths. Examples of such a complexing agent include carboxylic acids having 3 to 6 carbon atoms such as lactic acid, tartaric acid, citric acid, glycine, iminoacetic acid, succinic acid, malic acid, gluconic acid, and metal salts thereof, or ammonia. Citric acid and its metal salt are used as a preferable complexing agent. These complexing agents can be used alone or in combination of two or more. The content of the complexing agent in the plating bath can be appropriately selected according to the type and thickness of the target plating film, but is usually about 0.05 to 2.0M, particularly 0.1 to 0.1M. It is preferably about 1.0M.

A material having a plating film in which nanodiamond particles are dispersed in a metal matrix can also be produced by electrolytic plating. There is no particular limitation as a plating bath for electroplating, and any of the baths usually used for electroplating can be used, for example, an electroplating bath without using a citric acid / nickel complex-based electroplating bath, a complexing agent, Examples thereof include ammine complex electrolytic plating baths.

The amount of the diamond fine particles dispersed in the electroless plating bath or the electrolytic plating bath can be appropriately selected according to the properties of the target plating film, but is usually about 0.01 to 30 g / L, particularly about 0. It is preferable to set it as about 5-20 g / L.

The amount of the gas containing oxygen introduced into the plating bath is preferably about 10 to 2,000 mL / min, particularly about 100 to 500 mL / min when a 100 mL to 1 L plating bath is used. In the case of a plating bath larger than this, an introduction amount approximately proportional to the volume is preferable.

The details of the plating method, heat treatment method, and blasting method are the same in the following examples.

FIG. 4 schematically shows an example of a sliding component used in a valve mechanism of an internal combustion engine as an embodiment of claim 5.

The cam 400 is rotated by the camshaft 410 and opens and closes the valve 440 pressed by the spring 430 via the cam lifter 420.

At that time, the rotational sliding surface 401 of the cam shaft and the sliding surface 421 of the cam lifter 420 continue to be rubbed at a high speed of several thousand revolutions per minute. Therefore, reducing the frictional resistance during this period is an extremely important issue from the viewpoint of reducing resistance loss of the internal combustion engine and preventing wear of the sliding parts.

In the present invention, at least one of the cam sliding surface 401 and the valve lifter sliding surface 421 is surface-modified with a composite plating film, so that the object can be effectively achieved.

FIG. 5 schematically shows a sliding part used as a piston ring as an embodiment of claim 6.

5A shows a piston 500, a top ring 510, a second ring 520, and an oil ring 530 disassembled. A top ring 510, a second ring 520, and an oil ring 530 are attached to the grooves 501, 502, and 503 provided in the piston, respectively.

5B of FIG. 5 illustrates the outer peripheral cross section of each piston ring. A composite plating portion 512 according to the present invention for enhancing the slidability applied to the outermost peripheral surface of the top ring section 511 is indicated by hatching. Similarly, the lower outermost peripheral surface 522 of the second ring cross section 521 is processed by the present invention for improving the slidability and indicated by hatching. Further, the oil ring 530 has a laminated three-layer structure of a top rail 531, a spacer 533, and a bottom rail 534, and hatching shows that the outer peripheral portions of the two side rails are subjected to composite plating.

5C in FIG. 5 shows a one-side cross-section in which a ring is fitted to the upper part of the piston. A state in which a top ring 515, a second ring 525, and an oil ring 536 are fitted into the groove portion 505 from above is shown.

The top ring is used to form an oil film at a high speed, and its outer periphery has been conventionally hardened by applying a chromium nitride hard film or the like by a PVD method, or by applying hard chrome plating, etc. In order to prevent wear, a further reduction in sliding resistance has been demanded.

The second ring is used for gas sealing and oil scraping, and the outer periphery thereof is provided with a notch in the lower part so as to meet the purpose. The sliding surface is a thin area of the edge portion at the top of the cut.

The oil ring has a shape in which a corrugated spacer is sandwiched between two upper and lower side rails. Since the outer periphery of the side rail slides with the inner wall of the cylinder, it has been conventionally hardened with a chromium nitride film or a chromium plating film.

Thus, the sliding resistance can be effectively reduced by subjecting the outer peripheral sliding portion of each piston ring to the composite plating treatment and the blasting treatment according to the present invention. Moreover, diamond composite nickel phosphorous plating or the like can also be applied when repelling chromium plating, and even in that case, a Vickers hardness of about HV = 700 to 1000 can be obtained, so that a hardness comparable to that of the prior art can be achieved.

FIG. 6 shows an embodiment of a sliding component used as a rotary hinge according to claim 7.

An exploded view of the hinge pin 600 of the rotating shaft portion, the rotating component 610 and the screw 620 is shown coaxially. The base portion 601 of the hinge pin is fixed so as not to rotate to the fixed component side by a notch 602. The outer periphery 603 of the sliding portion is hatched to indicate that the surface treatment is performed according to the present invention. This part is used by inserting a rotary sliding hole 611 of the rotating part and fixing it up and down with a nut 620.

One or both of the hinge pin sliding outer periphery 603 and the rotational sliding hole 611 of the sliding component are surface-treated according to the present invention, so that they can be used in a state where the rotational resistance is low and the wear of both is small.

Since the space is limited in the case of minute fixed parts and rotating parts, it is impossible to provide a sliding mechanism such as a bearing in the rotating sliding part of the rotating parts, so the present invention effectively achieves the object. it can.

Needless to say, the shape of the rotating hinge, the fixing method, and the shape of the rotating component are not limited to the example shown in FIG.

FIG. 7 illustrates an embodiment of a sliding component used as a slip ring according to claim 8.

A slip ring is an element for connecting an electric signal line or power line between a rotating body and a fixed body. Infinite rotation is possible by placing a sliding electrode on the sliding surface between the rotating body and the fixed body. I have to.

FIG. 7 illustrates a state where the fixed body 700 and the rotating body 710 are separated. On the inner peripheral surface of the inner hole 701 of the circular fitting portion 702 provided on the fixed body, a fixed body side electrode 703 is patterned with one terminal or a plurality of terminals. A rotating body side electrode 713 is patterned on one or more terminals on the outer peripheral surface of a circular fitting portion 712 provided on the rotating body. Further, the rotating body is provided with a through hole 711, and for example, a rotating hinge as shown in FIG. 6 can be accommodated therein.

Each of the fixed body and the rotating body is an insulator around the electrode portion, and each signal line and power line are electrically isolated. Then, the sliding part terminal is connected to the fixed part external terminal 704 and the rotating part external terminal 714 via the inside of the insulator.

703 and 713, which are rotating sliding part electrodes, are desired to have low electrical resistance and sliding resistance and high hardness. Therefore, diamond fine particle composite plating is performed on a base material of a good conductor such as gold, silver, or copper. And the objective can be effectively achieved by performing blasting.

It should be noted that the outer shape of the slip ring, the form of the electrode and the number of wires, the form of the external electrode and the number of terminals are not limited to those of the present embodiment.

FIG. 8 shows an embodiment of a sliding component used as a potentiometer according to claim 9.

Potentiometers include a rotary potentiometer that detects a rotation angle and a linear potentiometer that detects a linear position. Here, an example of a rotary potentiometer is shown. The rotary potentiometer is a variable resistor that is internally arranged in an annular shape, and is an element that applies a voltage between both terminals and measures the potential of the intermediate terminal to obtain an angle.

Terminals 801 and 803 and an intermediate electrode 802 are provided on one surface of the substrate 800, and the terminals are electrically connected by a variable resistance film 804. Further, the intermediate electrode is connected to a Ryoden rotor facing surface 805.

The rotor 810 is a good conductor, and has a through hole at the center and a rotary friction element 811 at the outer portion.

The substrate and the rotor are sandwiched and fixed between a fixed pin base 820 and a fastener 830.

The rotary scraper comes into contact with the variable resistance film and takes out the intermediate potential of the terminal pair. The rotation angle can be detected by utilizing the fact that the extracted potential varies depending on the angle of the rotor.

The rotor and the rotor-facing surface and the rotary friction element and the variable resistance film must be electrically connected, and are required to have low friction and low wear. Therefore, by applying the surface treatment technique of the present invention to one or both of the opposing contact surfaces between the rotor and the rotor-facing surface, and the surface where the rotary scraper contacts the variable resistance coating, the rotor , Can prevent the wear of the rotary scraper.

FIG. 9 shows an example of a swinging part used as a rotary cutting tool according to claim 10.

The rotary cutting tool includes a drill 910, an end mill 920, and the like, and carbide rods such as diamond and tungsten carbide are used for the tip portions 914 and 924 of the rotating rod-like body. Further, in the groove portions 912 and 922 connected from the outer peripheral portions 911 and 921 and the pocket portions 913 and 923, DLC (diamond-like carbon), TiN (titanium nitride), TiAlN (titanium nitride) are used in order to avoid wear due to an object to be cut or cutting waste. Aluminum) is often applied.

In the present invention, nano-diamond fine particle composite plating is applied instead of the vapor phase coating. Due to the characteristics of the plating, the concave portion can be well coated and the wear resistance can be improved.

As described above, the present invention is industrially applicable.

Example of cross-sectional structure of diamond fine particle composite plating Example of cross-sectional structure of blasted diamond fine particle composite plating Appearance example of guide posts and guide pins Example of a valve mechanism of an internal combustion engine Piston ring structure example Example of rotating hinge structure Example of slip ring structure Potentiometer structure example Examples of drill and end mill structures

DESCRIPTION OF SYMBOLS 101 Structural base material 102 Metal matrix 103 Diamond particulate layer 201 Structural base material 202 Metal matrix 203 Diamond particulate layer 211 Structural base material 212 Metal matrix 213 Diamond particulate layer 221 Structural base material 222 Metal matrix 223 Diamond particulate layer 300 Guide post 301 Guide post Fixing screw hole 302 Guide post fixing screw hole 303 Guide hole 310 Guide pin 311 Guide pin outer peripheral sliding surface 400 Cam 401 Cam outer peripheral sliding surface 410 Cam shaft 420 Cam lifter 421 Cam lifter sliding surface 430 Spring 440 Valve 5A Piston overall appearance 5B Ring Cross section 5C Piston and ring fitting cross section 500 Piston 501 Top ring groove 502 Second ring groove 503 Oil ring groove 510 Top ring cross section 512 Top ring outer peripheral plating layer 515 Top ring fitting cross section 520 Second ring 521 Second ring 522 Second ring outer peripheral plating layer 523 Second ring cutout 525 Second ring fitting cross section 530 Oil ring 531 Oil ring top rail 532 Top Rail outer peripheral plating layer 533 Oil ring spacer 534 Oil ring bottom rail 535 Bottom rail outer peripheral plating layer 536 Oil ring fitting section 600 Hinge pin 601 Hinge pin base 602 Hinge pin base notch 603 Hinge pin sliding surface 604 Hinge pin bolt part 610 Rotating part 611 Rotating part Sliding inner surface 620 Nut 700 Slip ring fixing part 701 Fixing part insertion hole 702 Fixing part circular fitting part 7 3 fixing portion sliding electrode 704 fixed portion external electrode 710 slip ring rotation unit 711 rotates portion through hole 712 rotating part circular fitting portion 713 rotating unit sliding electrode 714 rotating portion external electrode 800 Potentiometer substrate 801 terminal 1
802 Intermediate terminal 803 Terminal 2
804 Variable resistance coating 805 Rotor facing surface 810 Rotor 811 Rotating friction element 820 Rotor fixing pin base 821 Fixing pin 830 Rotor fixing pin fastener 831 Fixing pin through hole 910 Drill 911 Drill outer peripheral portion 912 Drill groove portion 913 Drill pocket 914 Drill tip 920 End mill 921 End mill outer periphery 922 End mill groove 923 End mill pocket 924 End mill tip

Claims (10)

At least one of the sliding part pair or the sliding part of the article transfer mechanism guide part is a structural base material whose main component is a material selected from the group consisting of resin, metal, semiconductor, glass, ceramics, and the surface of the base material A metal selected from the group consisting of nickel, copper, tin, chromium, zinc, lead, cobalt, iron, gold, silver, platinum, palladium, rhodium, indium, iridium, or ruthenium A composite plating film having a matrix as a main component and a thickness of 10 nm to 500 μm, containing 0.01 vol% to 20 vol% of diamond fine particles having an average primary particle diameter of 1 nm to 1000 nm dispersed inside the plating film, A sliding component, wherein the plating film is heat-treated at 200 ° C. or more and 700 ° C. or less. For at least one of the sliding part pair or the guide part of the article transfer mechanism, the surface of the base material made of a material selected from the group consisting of resin, metal, semiconductor, glass, and ceramics is processed into a predetermined shape and then polished A metal selected from the group consisting of nickel, copper, tin, chromium, zinc, lead, cobalt, iron, gold, silver, platinum, palladium, rhodium, indium, iridium, or ruthenium After forming a composite plating film having a thickness of 10 nm to 500 μm in which 0.01 vol% to 20 vol% of fine diamond particles having an average primary particle diameter of 1 nm to 1000 nm are dispersed in the matrix, the plating film is heated to 200 ° C. or higher. Claims characterized by having both high hardness and low friction properties by heat treatment at 700 ° C or lower. A method of manufacturing the sliding parts.   The sliding component according to claim 1, wherein at least one of the surface of the sliding portion of the structural substrate before the plating treatment or the surface of the plating film after the plating treatment is blasted. parts.   3. The sliding part or guide part according to claim 2, wherein at least one of the surface of the sliding part of the structural substrate before the plating treatment or the surface of the plating film after the plating treatment is subjected to a blasting treatment, whereby the robustness of the plating film is obtained. The method for producing a sliding component according to claim 2, wherein the lubricity is improved. 5. A sliding part, wherein a composite plating film is formed on the sliding surface by the manufacturing method according to claim 2 or 4 and used as a valve mechanism part of an internal combustion engine. A sliding component, wherein a composite plating film is formed on the sliding surface by the manufacturing method according to claim 2 or 4 and used as a piston ring. 5. A sliding part, wherein a composite plating film is formed on a sliding surface portion by the manufacturing method according to claim 2 or 4 and used as a rotary hinge. In a slip ring device in which one or more concentric conductive films are formed on an annular non-conductive plate material on a rotating support and electrical connection is maintained even by rotation, the conductive film and the conductive film are opposed to the conductive film. Then, at least one sliding surface of the sliding portion in electrical contact is formed as a composite plating film by the manufacturing method according to claim 2 or 4 and used as an electrode. Sliding parts. In a potentiometer device in which a resistance element is formed on a substrate and detects a contact position by outputting a variable resistance value by a sliding contact, a portion that is opposed to and electrically contacts the surface of the resistance element is slid A sliding component, wherein a composite plating film is formed by the manufacturing method according to claim 2 or 4 and used as an electrode. 5. A drill or end mill made of a material such as cemented carbide and comprising a tip portion for cutting a hole and the like and a barrel portion extending from the tip portion to the chuck portion. A sliding component, wherein a composite plating film is formed by a manufacturing method and used as a cutting tool.

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