JP6688113B2 - Surface processing method for sliding bearing and sliding bearing - Google Patents

Description

  The present invention relates to a surface processing method for a slide bearing and a slide bearing.

  Conventionally, roughening of the sliding surface of the sliding member (formation of irregularities) was performed with a short pulse (picosecond pulse) laser irradiation device to generate irregular shapes on the sliding surface, and adhesion and durability with resin The surface processing method of the sliding member which improves the property is known. (For example, refer to Patent Document 1). In the conventional surface processing method, a laser light irradiation step of irradiating a sliding surface of a sliding member with a laser beam, a resin coating step of applying a fluororesin coating to the sliding surface subjected to the laser irradiation, and the resin coating A firing step of firing the sliding surface coated with the fluororesin by the step is performed.

  However, in the conventional surface processing method, the adhesion between the base material roughened by laser irradiation and the resin formed on the base material is not sufficient, and the resin may peel off from the base material. Particularly, in the slide bearing, the resin is easily peeled off on the inner peripheral surfaces of both ends in the axial direction of the slide bearing in which the lubricating oil flows into or out of the slide bearing. Further, in order to improve the roughness of the uneven portion when roughening, it is necessary to perform laser irradiation for a long time, and if the roughness of the uneven portion on the entire inner peripheral surface of the slide bearing is improved, the processing cost will be increased. Was sometimes high.

JP, 2007-289963, A

  Therefore, in view of the above problems, the present invention improves the roughness of the uneven portion formed on the inner peripheral surface of the sliding bearing while suppressing the processing cost, and it is possible to prevent the resin from being peeled off. An object is to provide a method and a plain bearing.

In the present invention, there is provided a surface processing method for a sliding bearing in which a concave and convex portion is formed on the inner peripheral surface of the sliding bearing by using a laser irradiation device, wherein the laser irradiation device is used to form a surface parallel to the circumferential direction of the sliding bearing. The laser beam is radiated onto the row in the direction, and the laser light is radiated so that the distance between the adjacent pulse centers of the laser light radiated onto the row is shorter than the spot radius at both axial ends of the slide bearing. However, the roughness of the uneven portion at both axial ends of the slide bearing is formed so as to be larger than the roughness of the uneven portion at the axial center of the slide bearing, and a resin film is formed on the uneven surface of the slide bearing. Is formed .

In the present invention, a laser beam is continuously irradiated on a row, and a sliding bearing in which a concave and convex portion is formed on the inner peripheral surface by the irradiated laser light, the concave and convex portions at both axial ends of the sliding bearing. The roughness of the portion is formed to be larger than the roughness of the uneven portion at the central portion in the axial direction of the slide bearing, and the resin film is formed on the surface of the uneven portion of the slide bearing .

According to the present invention, it is possible to reduce the number of times of laser light irradiation in the laser irradiation processing of the axial center inner peripheral surface of the slide bearing in which peeling of the resin film is less likely to occur than both axial inner peripheral surfaces. It is possible to reduce the processing cost. Further, it is possible to roughen the irregularities on the inner peripheral surfaces of both ends in the axial direction of the sliding bearing, in which the lubricating oil flows in or out of the bearing, and the adhesion with the resin film is improved. Thereby, peeling of the resin film can be prevented. In addition, the resin film enters the surface of the uneven portion and is brought into close contact therewith, so that the adhesive force with the resin film is improved.

According to the present invention, in particular, by forming rough uneven portions on the inner peripheral surfaces of both ends in the axial direction of the slide bearing, in which lubricating oil flows in or out, the adhesion with the resin film is improved. Thereby, peeling of the resin film can be prevented. In addition, the resin film enters the surface of the uneven portion and is brought into close contact therewith, so that the adhesive force with the resin film is improved.

The schematic front view which shows the slide bearing which concerns on embodiment of this invention. The flowchart figure which similarly shows the surface processing method of a slide bearing. The schematic front view which shows the surface processing process of the base material which similarly comprises a slide bearing. (A) Similarly, a plane enlarged view showing a surface processing process of the plain bearing, (B) a plane enlarged view showing a surface processing process on the end surface, (C) a plane showing a surface processing process after FIG. 4 (B). Enlarged view. The top view which similarly shows a plain bearing. The plane enlarged view which shows the surface processing process in the surface of a center part. Similarly, the top view which shows the slide bearing after surface processing. (A) Similarly, a plane enlarged view showing a concavo-convex portion when the sliding member is irradiated with laser light once, and (B) a plane enlarged view showing a concavo-convex portion when the sliding member is continuously irradiated with laser light. Similarly, the front cross-sectional enlarged view which shows a sliding member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments below.

FIG. 1 is a front view of a plain bearing 1, where the top and bottom of the drawing are the vertical direction, and the front and back directions of the drawing are the axial direction (front-back direction).
The slide bearing 1 is a member for rotatably supporting the rotary shaft 2 and is formed in a cylindrical shape. When the rotating shaft 2 is pivotally supported by the slide bearing 1, a predetermined gap is formed, and lubricating oil is supplied to this gap from an oil passage (not shown).
The plain bearing 1 may be configured by combining two semi-cylindrical members.
The rotary shaft 2 is a shaft that is rotated by a power source (not shown), and is, for example, a crankshaft or a camshaft.

  FIG. 2 is a flowchart showing the surface processing of the sliding bearing 1 according to the embodiment of the present invention. As shown in FIG. 2, in the surface processing of the slide bearing 1, a laser beam irradiation step S100 of irradiating the inner peripheral surface of the slide bearing 1 with a laser beam and a resin coating on the inner peripheral surface subjected to the laser irradiation are performed. A resin coating step S200 to be performed and a firing step S300 of firing the inner peripheral surface coated with the resin in the resin coating step S200 are performed.

  The laser irradiation performed in the laser irradiation step S100 will be described below. As shown in FIG. 3, first, a base material 11 that constitutes the slide bearing 1 is prepared. The base material 11 may be cleaned to remove impurities such as fats and oils, but may not be cleaned since the entire surface of the base material 11 is irradiated with laser light in the subsequent process. The material of the base material 11 to which the laser light is irradiated is not particularly limited, and is an iron-based, aluminum-based, or copper-based metal material, or a composite material in which an aluminum-based or copper-based material is fixed and joined to the back metal. May be used. The base material 11 is formed in a flat plate shape. In the present embodiment, the plain bearing 1 is manufactured by subjecting the base material 11 formed in a flat plate shape to a surface treatment to form a cylindrical shape. You may perform surface processing after shape | molding in a shape. The thickness of the base material 11 is preferably 0.5 mm or more. By using the base material 11 having this thickness, it is possible to easily form the resin film 12 formed on the base material 11 without gaps, without penetrating when the laser light is irradiated.

  As shown in FIG. 3, by irradiating the base material 11 with laser light by the laser irradiation device 101, the uneven portion 13 is created on the base material 11. The laser irradiation device 101 includes a laser light source 101A that emits laser light, and a pulse width control device 101B that controls the pulse width of the laser light from the laser light source 101A. The laser irradiation apparatus 101 in this embodiment is set so that the pulse width is picoseconds or less.

  The laser light source 101A is fixed to a work table (not shown), and by moving the base material 11 in the direction of the arrow in FIG. Is continuously irradiated. The laser light is continuously irradiated onto a row parallel to the moving direction of the base material 11.

  Here, the laser light with which the base material 11 is irradiated will be described. Laser processing using a laser beam can perform fine processing with high precision without bringing a tool or the like into contact with a workpiece. As the laser light with which the base material 11 is irradiated, for example, any one of a YAG laser, a semiconductor laser, a liquid laser, and a gas laser may be selected and used. Among them, the YAG laser is particularly used from the viewpoint of workability. preferable.

As shown in FIG. 4A, the laser light is applied to the base material 11 in a circular shape in a plan view having a spot diameter 2r. The spot diameter of the laser light is configured to be several to several tens of μm. The spot diameter is the minimum diameter of laser light. The energy intensity per unit area of the laser light is preferably 10 MW / mm ² or more in power density.

  The laser light applied to the base material 11 that is a portion forming the axial end of the slide bearing 1 is applied to the rows in a direction parallel to the circumferential direction of the slide bearing 1. Further, as shown in FIG. 4B, the laser light is continuously irradiated so that a circle formed by the predetermined irradiation of the laser light and a circle formed by the next irradiation overlap with each other. That is, the laser light is irradiated so that the distance between the adjacent pulse centers of the laser light irradiated on the row becomes shorter than the spot radius r. The pulse center is the center of the circular laser light that is emitted. As shown in FIG. 4B, the distance D1 between the pulse center P (n) of the circle formed by the predetermined irradiation and the pulse center P (n + 1) of the circle formed by the next irradiation is the spot. It is formed to be shorter than the radius r.

  After the concavo-convex portions 13 are formed on the rows by the laser light, the base material 11 is moved to irradiate the laser light on the rows substantially parallel to the formed rows. That is, as shown in FIG. 4C, after the row L (m) is formed by the laser light, the row L (m + 1) parallel to the row L (m) formed by activating the base material 11 is formed. The laser light is emitted to the laser.

Next, surface processing of the entire inner peripheral surface of the base material 11 will be described with reference to FIGS. 4 to 7.
As shown in FIG. 5, the axially upstream row is L (1), and the axially downstream row is L (N) (N is a predetermined number).
Laser irradiation from a row of L (1) to L (a) (a is a predetermined number) and from a row of L (N- (a-1)) to L (N) (a is a predetermined number) As shown in FIG. 4B, irradiation is continuously performed so that a circle formed by a predetermined irradiation of laser light and a circle formed by the next irradiation overlap.
In other words, the surface 11a of the base material 11 which is a portion forming the inner peripheral surface of the upstream end in the axial direction of the slide bearing 1 and the inner peripheral surface of the downstream end in the axial direction of the slide bearing 1 are formed. On the surface 11b of the base material 11 which is a portion, the circle formed by the predetermined irradiation of the laser light and the circle formed by the next irradiation are continuously irradiated so as to overlap with each other.

  Further, as shown in FIG. 6, the laser irradiation from the row L (a + 1) to the row L (N−a) is divided into a circle formed by a predetermined irradiation of laser light and a circle formed by the next irradiation. Irradiate continuously so that they do not overlap. That is, the laser light is irradiated so that the distance D2 between the adjacent pulse centers of the laser light irradiated on the row becomes the spot diameter 2r or more. As shown in FIG. 6, the distance D2 between the pulse center P (n) of the circle formed by the predetermined irradiation and the pulse center P (n + 1) of the circle formed by the next irradiation is calculated from the spot diameter 2r. Is also formed to be long.

  In other words, on the surface 11c of the base material 11 which is a portion forming the inner peripheral surface of the central portion in the axial direction of the plain bearing 1, a circle formed by a predetermined irradiation of laser light and a next irradiation are formed. Irradiation is performed continuously so that the circles do not overlap.

  With such a configuration, as shown in FIG. 7, the roughness of the surfaces 11a and 11b forming the inner peripheral surface of the end portion of the sliding bearing 1 in the axial direction is determined by the roughness of the central portion of the sliding bearing 1 in the axial direction. Is larger than the surface 11c forming the inner peripheral surface of the. Note that, in the present embodiment, the roughness is the roughness in the direction parallel to the row of the laser light that is continuously irradiated.

  The movement of the substrate 11 during the transition from the process of forming the row L (m) to the process of forming the row L (m + 1) may be discontinuous movement or continuous movement. May be. That is, during the transition from the process of forming the row L (m) to the process of forming the row L (m + 1), the irradiation of the laser light may be stopped and the substrate 11 may be moved, or the irradiation of the laser light may be performed. The base material 11 may be moved by continuing.

  Here, the fine shape of the concave-convex portion 13 formed by continuously irradiating the base material 11 with laser light in rows will be described. FIG. 8 is a schematic surface enlarged view showing the uneven portion 13 of the base material 11. As shown in FIG. 8A, when the substrate 11 is irradiated with the laser light once, a concave portion 13a having a circular shape in plan view centered on the center (pulse center) of the laser light is formed, and the periphery thereof is formed. , A crown-shaped convex portion 13b is formed. The convex portion 13b is formed in a so-called milk crown shape, and the base material 11 is deformed. Also, some of the droplets will be scattered around. Further, as shown in FIG. 8B, the concave-convex portion 13 applies the laser light to the base material 11 so that the distance D1 between the adjacent pulse centers of the laser light irradiated on the row becomes shorter than the spot radius r. By irradiating the substrate 11 with laser light such that the distance D2 between the pulse centers on adjacent columns is longer than 1/2 of the spot radius r and shorter than the spot diameter 2r. Unevenness is formed, and a stripe shape is formed. The droplets deformed on the base material 11 adhere to the adjacent concave portions 13a and convex portions 13b and are solidified.

Next, as shown in FIG. 9, a resin film 12 is formed on the surface of the base material 11 on which the uneven portion 13 is formed. The resin film 12 is a film made of a solid lubricant and a binder resin. The solid lubricant that can be used in the embodiment of the present invention is not particularly limited, but molybdenum disulfide (MoS ₂ ), graphite, h-BN, tungsten disulfide (WS ₂ ), polytetrafluoroethylene (hereinafter , PTFE), fluororesins, Pb, CF and the like. These solid lubricants have a function of lowering and stabilizing the friction coefficient and a function of preventing seizure. In order to sufficiently exert these effects, the average particle diameter of the solid lubricant is preferably 15 μm or less, and particularly preferably 0.2 μm to 10 μm.

  The solid lubricant may be used alone or in combination of two or more. Further, the content of the solid lubricant contained in the material of the resin film 12 is preferably 10% by mass to 80% by mass, more preferably 40% by mass to 60% by mass, and the content of the solid lubricant falls within the range. Due to this, a film having excellent friction characteristics and abrasion resistance is obtained.

  The binder resin is not particularly limited, but those having high heat resistance are preferable, and examples thereof include polyamide imide, polyimide, epoxy resin, phenol resin, polyamide (nylon), fluororesin (PTFE, FEP, etc.), and elastomer. These binder resins provide solid lubricant retention and wear resistance. The content of the binder resin in the resin film 12 is preferably 10% by mass to 80% by mass. When the content of the binder resin is within this range, the retention of the solid lubricant in the resin film can be maintained, and a coating film excellent in retention of the solid lubricant and abrasion resistance can be obtained.

The material of the resin film 12 may include an additive other than the above. Examples thereof include hard particles such as Al ₂ O ₃ , Si ₂ N ₄ , TiO ₂ and SiO ₂ and extreme pressure agents.

  The method of forming the resin film 12 on the surface of the base material 11 is not particularly limited, but for example, after mixing the material of the resin film 12 on the surface of the base material 11 having the uneven portions 13 and applying the mixture by spraying, at 150 ° C to 300 ° C You may form by drying and baking. In addition to the spray coating method (for example, air spraying, air electrostatic coating, etc.), a tumbling method, a dipping method, a brush coating method, a roll type method or the like may be used. The thickness of the resin film 12 is preferably 1 μm to 50 μm.

  The resin film 12 formed on the base material 11 may have a plurality of holes that serve as oil reservoirs and open on the sliding surface. The shape of the opening surface of the hole is not particularly limited. For example, it may be circular, elliptical, polygonal, or the like. This hole may be formed using the YAG laser described above. The depth of the holes is preferably 5 μm or more and 40 μm or less. By having a depth within this range, it is possible to suppress the outflow of lubricating oil and the like, and to retain the lubricating oil and foreign substances. Further, the depth of the hole is preferably smaller than the thickness of the resin film 12. Further, the hole does not necessarily have to be formed in the entire sliding surface, and may be formed in a specific portion.

  In addition, the resin film 12 formed on the base material 11 improves initial conformability and has excellent sliding characteristics even under severe sliding conditions. May be. In this case, it suffices that adjacent grooves form peaks, and the shape of the valleys of the grooves is not particularly limited. It is sufficient that the lubricating oil can be secured, and examples thereof include a semicircular shape, a triangular shape, and a trapezoidal shape. The semi-circular shape and the triangular shape are preferable because the rate of formation of the crests is high and the initial contact surface pressure is high, so that abrasion and deformation are likely to occur and the initial conformability can be satisfactorily achieved. Particularly, the semicircular shape is preferable because a large amount of lubricating oil can be secured in the groove.

As described above, the method for processing the surface of the slide bearing 1 in which the uneven portion 13 is formed on the inner peripheral surface of the slide bearing 1 by using the laser irradiation device 101 is described. The laser beam is radiated onto the row in the direction parallel to the direction, and the distance D1 between the adjacent pulse centers of the laser light radiated onto the row becomes shorter than the spot radius r at both axial ends of the slide bearing 1. Thus, the laser light is emitted.
With this structure, the number of times of laser light irradiation is reduced in the laser irradiation processing of the inner peripheral surface of the central portion of the sliding bearing 1 in the axial direction in which peeling of the resin film is less likely to occur than in the inner peripheral surfaces at both ends in the axial direction. Therefore, the processing cost can be reduced.

Further, the roughness of the uneven portion 13 on the surfaces 11a and 11b at both axial ends of the slide bearing 1 is formed to be larger than the roughness of the uneven portion 13 on the surface 11c at the axial center of the slide bearing 1. It is a thing.
With such a configuration, in particular, it is possible to form the rough portions 13 on the inner peripheral surfaces of both ends in the axial direction of the sliding bearing 1 through which lubricating oil flows in or out, and to closely contact the resin film 12. Power improves. Thereby, peeling of the resin film 12 can be prevented.

1 sliding bearing 11 base material 12 resin film 13 uneven portion

Claims (2)

A surface processing method for a slide bearing, which comprises forming an uneven portion on the inner peripheral surface of the slide bearing using a laser irradiation device,
Using the laser irradiation device, irradiating a laser beam on a row in a direction parallel to the circumferential direction of the slide bearing,
At both ends in the axial direction of the slide bearing, the laser light is irradiated so that the distance between adjacent pulse centers of the laser light irradiated on the row is shorter than the spot radius ,
The roughness of the uneven portion at both axial ends of the slide bearing is formed to be larger than the roughness of the uneven portion at the axial center of the slide bearing,
Forming a resin film on the surface of the uneven portion of the plain bearing,
Surface processing method for plain bearings. A sliding bearing in which a laser beam is continuously irradiated on a row, and an uneven portion is formed on an inner peripheral surface by the irradiated laser beam,
The roughness of the uneven portion at both axial end portions of the slide bearing is formed to be larger than the roughness of the uneven portion at the axial center portion of the slide bearing ,
A resin film is formed on the surface of the uneven portion of the plain bearing,
Plain bearing.

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