JP4627713B2 - Sliding member and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sliding member and a method for manufacturing the same, and more particularly to a sliding member for surface pressure resistance that has good initial conformability and can maintain low friction for a long period of time, and a method for manufacturing the same.

  2. Description of the Related Art Conventionally, a method of providing a lubricating film on a sliding surface of a metal sliding member is known in order to improve the sliding characteristics of the sliding surface of the metal sliding member that accompanies sliding. As an example, there is a method in which a solid lubricant powder such as molybdenum disulfide is sprayed onto a sliding surface of a sliding member and adhered to the sliding surface (see Patent Document 1).

JP 2004-60619 A

  The base structure of the base material constituting the sliding member is generally composed of martensite formed by quenching such as induction quenching and carburizing quenching, and the hardness is HV500 to 800. On the other hand, the hardness of the molybdenum disulfide particles used as the solid lubricant is a Mohs hardness of 1 (≈HV50).

  For this reason, as described above, when the solid lubricant is sprayed onto the sliding surface of the sliding member that has been subjected to quenching treatment such as induction hardening and carburizing quenching, the sliding member whose hardness is to be processed as described above. Therefore, the solid lubricant is attached to the sliding surface of the sliding member.

  When the above-mentioned sliding member is used in a sliding part under a high surface pressure such as a piston or cylinder of a hydraulic device such as a pump or a motor used in construction machinery, industrial machinery, etc. However, in the long term, the solid lubricant will be separated from the surface of the sliding surface of the sliding member, so that the sliding surface of the sliding member is maintained in a low friction state for a long time. It is difficult.

  In addition, when the sliding member is used in an oil environment, the solid lubricant peeled off from the sliding surface of the sliding member is mixed in the lubricating oil. It is known that the surface can be maintained with low friction, but there is a grudge that the low friction effect cannot be sufficiently obtained in a device using a large amount of oil with respect to the sliding member.

  The present invention has been made in view of the above circumstances, and has an effect of conformability at the initial stage of sliding even under high surface pressure sliding conditions such as construction machinery and industrial machinery, and has low friction over a long period of time. An object of the present invention is to provide a sliding member capable of maintaining the above and a manufacturing method thereof.

  In order to achieve the above object, the present invention provides a sliding member having a sliding surface, wherein the sliding structure has a base structure in which the surface structure of the sliding surface is composed of ferrite and martensite. It is characterized by comprising a base material and a solid lubricant particle lump portion made of solid lubricant particles that are driven into the ferrite exposed on the sliding surface of the base material.

The second invention is a sliding member having a sliding surface, the base material having a base structure in which the surface structure of the sliding surface is composed of ferrite and martensite, and sliding of the base material It is characterized by comprising a solid lubricant particle lump portion made of solid lubricant particles driven into ferrite exposed on the surface, and a low friction coating layer formed on the sliding surface.
Furthermore, the third invention, in the first or second invention, the particles of the solid lubricant is less metal than the hardness of the high the martensite than the hardness of the ferrite, a resin, a glass particle It is characterized by being mixed as a mixed material.
The fourth invention is characterized in that, in the third invention, the mixed material has a content of 10 wt% or less and a particle size of 1 to 10 μm.

Furthermore, the fifth invention is a method of manufacturing a sliding member having a sliding surface, wherein the base structure of the base material to be the sliding member is composed of ferrite and martensite. A solid lubricant particle lump is formed by implanting solid lubricant particles into ferrite exposed on the sliding surface of the base material.

The sixth invention is a method of manufacturing a sliding member having a sliding surface, wherein the base structure of the base material to be the sliding member is composed of ferrite and martensite. The solid lubricant particles were driven into ferrite exposed on the sliding surface of the base material to form a solid lubricant particle lump, and then a low friction coating layer was formed on the sliding surface. It is characterized by that.
Furthermore, a seventh aspect of the present invention, in the invention of the fifth or sixth, as particles of the solid lubricant, low metal than the hardness of the high the martensite than the hardness of the ferrite, a resin, a glass particle A mixed material is used.

Further, an eighth invention is an apparatus characterized in that the sliding member of the first or second invention is provided in a sliding part.

  According to the sliding member of the present invention, even under high surface pressure sliding conditions such as construction machinery, industrial machinery, etc., the sliding surface has an effect of conformability at the initial stage of sliding, and is low for a long time. Since friction can be maintained, the replacement time of the sliding member can be prolonged, and its maintainability can be improved.

  In addition, according to the manufacturing method of the present invention, it is possible to provide a sliding member that can be used under high surface pressure by driving solid ferrite particles of ferrite in the structure of the base material. It is inexpensive and can be manufactured in a short time.

  Embodiments of a sliding member and a manufacturing method thereof according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of the metal structure on the surface of the sliding member of the present invention. In FIG. 1, the base material 2 constituting the sliding member 1 has a base structure of a mixed structure of martensite 3 and ferrite 4. Ferrite 4 is exposed on the surface (sliding surface) 5 of the base material 2. In the ferrite 4 exposed on the surface 5 of the base material 2, for example, particles 6 having a particle diameter of about 5 to 20 μm of a solid lubricant such as molybdenum disulfide and graphite are implanted to form a particle lump 7 of the solid lubricant. Is formed. On the surface 5 of the base material 2, a low friction layer 8 of, for example, molybdenum disulfide having a thickness of about 1 to 10 μm is further formed.

  The metal structure on the surface of the base material 2 is a mixed structure of martensite 3 and ferrite 4 as described above. The hardness of martensite 3 is, for example, HV 500 to 800, and the hardness of ferrite 4 is HV≈50.

  On the other hand, the hardness of the particles 6 of solid lubricant such as molybdenum disulfide and graphite used as the propellant is HV 40-60. For this reason, when the solid lubricant particles 6 are sprayed onto the surface of the base material 2, the ferrite 4 has the same hardness as that of the solid lubricant particles 6. 6 penetrates and accumulates in the ferrite 4 to form a solid lubricant particle lump 7 on the exposed portion side of the base material surface 5 in the ferrite 4.

  One embodiment of the sliding member of the present invention described above is a high level such as a piston, piston shoe, cylinder, rotor, cam plate, and valve plate in hydraulic equipment such as pumps and motors used in construction machines and industrial machines. It can be used for sliding parts used under surface pressure. In this case, the low friction layer 8 is effective in the initial conformability in sliding.

  When the low friction layer 8 peels off as the surface of the sliding member 1 slides, the surface structure of the sliding member 1 is composed of the martensite 3 and the solid lubricant particle lump 7. Since the solid lubricant particle lump 7 exposed on the sliding surface penetrates the ferrite 4, the sustainability to the base material 2 is high.

  For this reason, the solid lubricant particle lump 7 penetrating into the ferrite 4 can maintain the sliding surface of the sliding member 1 with a low frictional sliding characteristic even after a lapse of time. The life of the equipment using the member 1 can be extended, and the reliability thereof can be improved. Further, with the extension of the life of the sliding member 1, the replacement time of the sliding member 1 is extended, and maintenance work such as replacement can be reduced.

Next, an embodiment of the manufacturing method of the sliding member of the present invention will be described with reference to FIG.
First, as shown in FIG. 2A, the first step of making the surface structure of the base material 2 in the sliding member 1 a mixed structure of martensite and ferrite will be described. The material is generally steel having a carbon content of 0.77% or less (hypereutectoid steel). The base material 2 in the sliding member 1 made of this is subjected to heat treatment such as furnace quenching, induction quenching, laser quenching, and flame quenching as shown in FIG.

  FIG. 3 is an iron-carbon equilibrium diagram used in the description of the present invention. The horizontal axis indicates the carbon content W (%), the vertical axis indicates the temperature T (° C.), A indicates the austenite structure, B Is a structure of ferrite and cementite, and C is a structure of austenite and ferrite. The sliding member 1 of the structure C of austenite and ferrite in FIG. 3 is subjected to heat treatment within a range of, for example, a quenching heating temperature not less than A1 point and not more than A3 point, and then cooled by water, oil, etc. The metal structure of the surface of the base material 2 in the member 1 can be composed of a mixed structure of martensite 3 and ferrite 4.

  When the heating temperature T of the base material 2 in the sliding member 1 is set closer to the point A1, the exposed area ratio of the ferrite 4 on the surface of the base material 2 in the sliding member 1 can be lowered, and the heating temperature T is set to A3. If it is set closer to the point, the exposed area ratio of the ferrite 4 on the surface of the base material 2 in the sliding member 1 can be increased.

  Next, the second step of forming the solid lubricant particle lump 7 on the ferrite 4 in FIG. 2B will be described. The solid lubricant particle lump 7 is formed by allowing the solid lubricant particles 6 to penetrate the ferrite 4.

  FIG. 4 shows an example of an apparatus in which the solid lubricant particles 6 are injected and collided with the ferrite 4. In FIG. 4, the same reference numerals as those in FIG. 1 denote the same parts. The base material 2 in the sliding member 1 is fixed to the fixing jig 40. This fixing jig 40 is driven in a vertical direction (X direction) on the paper surface of FIG. 4 by a driving mechanism (not shown), on the paper surface of FIG. 4, at a right angle (Y direction), and on the paper surface of FIG. It is possible to move in three directions.

  An injector 41 for injecting the solid lubricant particles 6 is disposed at a position facing the fixing jig 40. This injector 41 has a tank 42 for accumulating particles 6 of solid lubricant as an injection material, an injection nozzle 43 provided at the lower part of the tank 42, and a high-pressure unit 44 connected to the injection nozzle 43. And an air supply pipe 45.

  The injector 41 supplies high-pressure air to the high-pressure air supply pipe 45 so that the high-pressure air is squeezed by the throttle portion 44 and accelerated and ejected from the injection nozzle 43 onto the surface of the base material 2 in the sliding member 1. Let

  At this time, since the downstream side becomes a low pressure by the air constriction portion 44, the solid lubricant particles 6 in the tank 42 are sequentially moved into the injection nozzle 43, and from the injection nozzle 43 together with the high-pressure air. It is ejected to the surface and collides with the surface. Then, the solid lubricant particles 6 penetrate into the ferrite 4 exposed on the surface of the base material 2, and the portion of the ferrite 4 is formed in the solid lubricant particle lump 7.

  The fixing jig 40 is driven in a vertical direction (X direction) on the paper surface of FIG. 4 by a driving mechanism (not shown), on the paper surface of FIG. 4, at a right angle (Y direction), and on the paper surface of FIG. ) In the three directions, most of the ferrite 4 exposed on the surface of the base material 2 can be formed in the solid lubricant particle lump 6.

  If the solid lubricant particles 6 that collide with the surface of the base material 2 and have not adhered or penetrated are recovered by a recovery device and sprayed onto the surface of the base material 2, the solid lubricant particles 6 can be reused. It becomes possible, and material costs can be reduced.

  The injector 41 is not limited to the above-described one, and for example, a commercially available shot peening machine or sand blasting machine can also be used.

  Next, the third step of forming the low friction layer 8 on the surface of the base material 2 processed in the second step as shown in FIG. 2C will be described. Disulfide as a solid lubricant When the surface of the base material 2 is coated with molybdenum, a treatment such as spraying or dripping is used.

  The reason is that when the surface temperature of the base material 2 rises to 200 ° C. or higher, the martensite is tempered and the surface hardness is lowered.

  The sliding member which can be used under high surface pressure can be manufactured by the above-mentioned process. According to the manufacturing method of the present invention, a sliding member that can be used under high surface pressure can be provided by driving solid lubricant particles into ferrite in the structure of the base material. Is inexpensive and can be manufactured in a short time.

In the above manufacturing method, it is also possible to use a mixture mixed with particles 6 of the solid lubricant that is the propellant. As the mixed material, higher than the hardness of the ferrite 4, it can be used lower metal than the hardness of the martensite 3, resin, glass particles. By mixing the mixture into the propellant, the penetration and uniformity of the solid lubricant particles 6 into the ferrite 4 can be improved.

  However, if the content of these mixed materials exceeds 10 wt%, the low friction layer 8 formed on the surface of the sliding member 1 is destroyed and dropped off, so the content of the mixed materials should be suppressed to 10 wt% or less. Is preferred. The particle size of the mixed material is preferably 1 to 10 μm. This is because the processing speed can be improved by containing the hard particles.

  Further, in the third step of the manufacturing method described above, the low friction layer 8 formed on the surface of the sliding member 1 may be coated with diamond-like carbon (DLC) that can be processed at 200 ° C. or lower. It is possible to manufacture the sliding member of the present invention. It is also possible to form the low friction layer 8 on a resin-based coating layer that exerts a great effect on low friction at the initial stage of sliding. As the material, acrylic, polyethylene, POM, nylon, PET, polyamide, polyimide, fluororesin, or the like can be used.

  Moreover, in the above-mentioned embodiment, it manufactures by the 1st process of heat-processing a base material, the 2nd process of forming the solid lubricant particle lump 7, and the 3rd process of forming the low friction layer 8. However, when the sliding member 1 uses a material composed of martensite 3 and ferrite 4, the first step can be omitted.

  In the above-described embodiment, the case where the base material 2 in the sliding member 1 is made of steel has been described. However, the surface of the sliding member 1 is composed of graphite, martensite 3 and ferrite 4. Such a cast iron can provide the sliding member of the present invention, and the manufacturing method thereof is also possible.

  In the above-described embodiment, the low friction layer 8 is formed on the surface of the sliding member 1. However, by causing the solid lubricant particle lump 7 to protrude from the surface of the sliding member 1, the solid lubricant particle lump is formed. 7 exhibits the effect of the conformability at the sliding initial stage of the sliding surface. Therefore, in the present invention, the formation of the low friction layer 8 can be omitted.

It is sectional drawing which shows typically one Embodiment of the metal structure of the surface of the sliding member of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the sliding member of this invention. It is an iron-carbon equilibrium diagram related to heat treatment in the production method of the present invention. It is a figure which shows the structure of an example of the particle-injection apparatus used for the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sliding member 2 Base material 3 Martensite 4 Ferrite 6 Solid lubricant particle 7 Solid lubricant particle lump 8 Low friction layer

Claims (8)

  A sliding member having a sliding surface, the base material having a matrix structure in which the surface structure of the sliding surface is composed of ferrite and martensite, and the ferrite exposed on the sliding surface of the base material A sliding member comprising: a solid lubricant particle lump portion formed by a solid lubricant particle that has been driven.   A sliding member having a sliding surface, wherein the surface structure of the sliding surface is a base material having a base structure composed of ferrite and martensite, and the ferrite exposed on the sliding surface of the base material. A sliding member comprising: a solid lubricant particle lump portion formed by particles of a solid lubricant that is driven in; and a low friction coating layer formed on the sliding surface. Mixed in the sliding member according to claim 1 or 2, the particles of the solid lubricant is less metal than the hardness of the high the martensite than the hardness of the ferrite, a resin, a glass particle as a mixed material A sliding member characterized in that   The sliding member according to claim 3, wherein the mixed material has a content of 10 wt% or less and a particle size of 1 to 10 μm.   A method of manufacturing a sliding member having a sliding surface, wherein the base structure composed of ferrite and martensite is formed on the surface structure of the sliding surface of the base material to be the sliding member. A method for manufacturing a sliding member, wherein solid lubricant particles are formed by implanting solid lubricant particles into ferrite exposed on a sliding surface.   A method of manufacturing a sliding member having a sliding surface, wherein the base structure composed of ferrite and martensite is formed on the surface structure of the sliding surface of the base material to be the sliding member. Solid sliding material particles are driven into ferrite exposed on the sliding surface to form a solid lubricant particle lump, and then a low friction coating layer is formed on the sliding surface. Production method. Mixing method of manufacturing a sliding member according to claim 5 or 6, as the particles of the solid lubricant, low metal than the hardness of the high the martensite than the hardness of the ferrite, a resin, a glass particle A method for producing a sliding member, characterized by using a mixture of materials.   A device comprising the sliding member according to claim 1 in a sliding portion.

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