JP2005161419A - Manufacturing method of sliding member and sliding member manufactured thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding member manufacturing method and a sliding member manufactured thereby, which have good manufacturing efficiency and can reduce manufacturing costs.
Disclosed is a sliding member having a sliding surface in which concave portions to be oil pools are distributed when sliding against each other via a mating member and a lubricant, and a portion excluding the concave portions is smooth. A manufacturing method, comprising: a concave portion forming step for forming a concave portion on a sliding surface; and a convex portion removing step for removing micro convex portions generated around the concave portion by the concave portion forming step by microblasting. .
[Selection] Figure 1

Description

  The present invention relates to a method of manufacturing a sliding member that slides on each other via a lubricant, and in particular, a manufacturing method of a sliding member in which concave portions that act as oil reservoirs are distributed on a sliding surface and the manufacturing method thereof. The present invention relates to a sliding member.

  In a sliding member of a bearing or an automobile part, a concave portion that becomes an oil reservoir may be formed when the counterpart material and the lubricant slide with each other. As a manufacturing method for forming the concave portion on the sliding surface in this manner, for example, a method of irradiating laser light (laser processing) is known (for example, see Patent Document 1).

  In addition, when forming the recess by laser processing, for example, when the sliding member, which is a workpiece, is a metal material, the metal melted by the irradiation of the laser beam is formed although the recess is formed at the portion irradiated with the laser beam. It is not separated and removed by sublimation, but is cooled around the recess and solidifies again, so that it remains as a minute projection around the recess. For this reason, for the purpose of removing this convex part, in patent document 2, super finishing polishing is performed and the site | part except the recessed part is finished smoothly.

  However, in the manufacturing method of the sliding member described in Patent Document 1 and Patent Document 2, super finishing polishing is a method with a relatively low processing efficiency, and thus the manufacturing cost of the sliding member finally obtained is low. There was a problem that would become expensive.

  In addition, when a super-finishing grindstone with a coarse count is selected in order to increase the processing efficiency, it is difficult to satisfactorily finish the surface roughness of the flat portion excluding the concave portion. For this reason, the super finishing grindstone count is set to at least two stages, the super finishing polishing process with a coarse count for the purpose of removing the convex portion, and the super finishing grind with the aim of smoothing the flat portion. The finish polishing step must be performed separately, which again increases the manufacturing cost of the sliding member.

Further, when forming the recess by laser processing, the bottom surface of the formed recess becomes rough, and the flow of the lubricant is disturbed, so that the effect of improving the sliding friction characteristics is difficult to obtain. There was a point.
JP 7-133704 A JP 2001-254808 A

  The present invention has been made in order to solve the problems associated with the prior art described above, and provides a manufacturing method of a sliding member and a sliding member manufactured thereby, which have good manufacturing efficiency and can reduce manufacturing costs. The purpose is to provide.

  The object of the present invention is achieved by the following means.

The present invention provides a sliding member having a sliding surface in which concave portions to be oil reservoirs are distributed when sliding against each other via a counterpart material and a lubricant, and a portion excluding the concave portions is smooth. In the manufacturing method,
A recess forming step of forming the recess on the sliding surface;
A method of manufacturing a sliding member, comprising: a convex portion removing step of removing micro convex portions generated around the concave portion by the concave portion forming step by microblasting.

  Further, the present invention is manufactured by the concave portion forming step of forming the concave portion on the sliding surface and the convex portion removing step of removing micro convex portions generated around the concave portion by the concave portion forming step by microblasting. This is a sliding member.

  According to the manufacturing method of the sliding member and the sliding member manufactured thereby according to the present invention, the concave portions are distributed on the surface of the sliding member and the minute convex portions generated around the concave portions are removed to form the concave portions. By smoothing the removed part, if it functions as an oil reservoir when sliding against each other through the mating material and lubricant, the contact part between the frictional sliding surfaces should be sufficiently lubricated It is possible to provide a sliding member that can improve the lubrication performance by distributing the oil at a low manufacturing cost.

  Hereinafter, the manufacturing method of the sliding member which concerns on this invention, and the sliding member manufactured by it are demonstrated in detail.

  Regarding the manufacturing method of the sliding member according to the present invention, the surface of the workpiece, which is the surface to be processed as the sliding member, is subjected to the concave forming process and the subsequent convex removing process so that the distributed concave and flat surfaces are obtained. A sliding surface constituted by the portion can be formed.

  As the recess forming process, any one of shot blasting, micro roll forming, and laser processing can be selected. That is, even in the case of a high-hardness sliding member made of metal, for example, an effective recess can be formed by causing plastic deformation or heat deformation.

  The diameter of the spherical particles used for shot blasting is preferably in the range of 0.1 mm to 0.5 mm. The spherical particles are preferably composed of ceramic or ceramic-coated spherical particles.

  The reason for this is that when the diameter of the spherical particles is less than 0.1 mm, the diameter of the opening of the micro-recess formed is reduced, and the recess functioning as an oil reservoir cannot be formed substantially, This is because when the diameter of the spherical particles exceeds 0.5 mm, the diameter of the opening of the minute recess formed is increased and the oil reservoir does not function sufficiently. In addition, when the spherical particles are made of a material softer than ceramic, sufficient sliding deformation cannot be generated in the sliding member that is a workpiece, and effective concave portions may not be formed.

  The convex portion removal treatment is preferably a microblast process in which spherical particles having a diameter in the range of 2 μm to 50 μm are projected at a projection pressure in the range of 0.1 MPa to 0.5 MPa.

  That is, when the diameter of the spherical particles is less than 2 μm, it does not have sufficient processing capability, and therefore the ability to remove the minute convex portions is substantially insufficient, while the diameter of the spherical particles is 50 μm. This is because when it exceeds, the surface roughness of the flat portion excluding the concave portion cannot be satisfactorily finished. Further, when the projection pressure is less than 0.1 MPa, the ability to remove minute convex portions is insufficient, and when it exceeds 0.5 MPa, the surface roughness of the flat portion excluding the concave portions can be satisfactorily finished. It will be impossible.

  The spherical particles are preferably made of cemented carbide or ceramic.

  That is, when the spherical particles are made of a material softer than cemented carbide, the sliding member cannot be plastically deformed, and the convex portion may not be removed.

  Furthermore, the sliding member according to the present invention has a sliding surface in which concave portions are distributed and a portion excluding the concave portions is smooth. The concave portions dispersed on the sliding surface function as an oil reservoir when sliding against each other via the counterpart material and the lubricant, and the friction coefficient is greatly reduced.

  About distribution of a recessed part, it is desirable to make the total area ratio of a recessed part with respect to the sliding surface which mutually slides through the surface of a counterpart material and a lubricant into the range of 5%-40%.

  That is, when the total area ratio is less than 5%, the oil does not substantially function as an oil reservoir, so that the effect of reducing friction cannot be sufficiently obtained. On the other hand, when the total area ratio exceeds 40%, it cannot sufficiently withstand the Hertz contact surface pressure generated during sliding, and pitching due to the formation of fine cracks starting from the recesses and scuffing associated therewith occurs. As a result, the roughness of the sliding surface is deteriorated, and the friction reducing effect may be reduced.

  Furthermore, with respect to the portion of the flat portion excluding the concave portion on the sliding surface, if the surface roughness Ra exceeds 0.3 μm, scuffing occurs due to insufficient resistance to the Hertz contact surface pressure generated during sliding. As a result, the roughness of the sliding surface deteriorates, so that the friction tends to increase rapidly as described above. Therefore, it is desirable that the surface roughness of the flat portion excluding the concave portion on the sliding surface is 0.3 μm or less in terms of the center line average roughness Ra.

  DESCRIPTION OF EMBODIMENTS Embodiments of a processing apparatus that embodies a manufacturing method of a sliding member according to the present invention and the operation thereof will be described with reference to the drawings.

(Embodiment of the present invention)
FIG. 1 is a schematic configuration diagram illustrating a processing apparatus 10a that performs a recess forming process on a surface to be processed of a sliding member according to an embodiment of the present invention.

  The processing apparatus 10a that performs the recess forming process generally includes a driving means 20a that rotationally drives a cylindrical member W as a work to be a sliding member, and hard spherical particles (shot) toward the outer peripheral surface of the cylindrical member W. ) A shot blasting device 30a for projecting 32a. The cylindrical member W is, for example, a cylindrical member of a camshaft or a crankshaft, and is made of, for example, hardened steel or cast iron. The outer peripheral surface of the cylindrical member W is a surface to be processed on which a recess is to be formed.

  Then, by projecting the spherical particles 32a from the shot blasting device 30a onto the outer peripheral surface of the cylindrical member W, a concave portion forming process for forming a concave portion on the outer peripheral surface of the cylindrical member W, that is, a shot blasting process is performed. By subjecting the cylindrical member W to the recess formation process, a sliding member having a sliding surface in which the recesses are distributed is manufactured. In the example of illustration, the upper part of the cylindrical member W becomes a process part in which a recessed part is formed by shot blasting. The processing portion sequentially moves as the cylindrical member W rotates.

  FIG. 2 is a schematic configuration diagram illustrating a processing apparatus 10b that performs a convex portion removing process on a surface to be processed of a sliding member according to an embodiment of the present invention.

  Since the main body of the processing apparatus 10b that performs the convex portion removal process can be made common to the processing apparatus 10a, only the differences from the processing apparatus 10a will be outlined below.

  That is, the microblast device 30b that projects the hard spherical particles 32b toward the outer peripheral surface of the cylindrical member W is provided.

  Then, by projecting the spherical particles 32b from the microblast device 30b onto the outer peripheral surface of the cylindrical member W, the convex portion removal processing of the outer peripheral surface of the cylindrical member W, that is, microblast processing is performed. By subjecting the cylindrical member W to the convex portion removal process, a minute convex portion generated around the concave portion is removed, and a sliding member having a sliding surface in which the flat portion excluding the concave portion is smoothed is manufactured.

  Hereinafter, the processing apparatus 10a and the processing apparatus 10b will be described in detail.

  The driving means 20a includes a chuck (not shown) that detachably holds the rotation shaft Wa of the cylindrical member W, a motor M that is connected to the chuck and rotationally drives the cylindrical member W, and the like. The cylindrical member W rotates in the rotation direction indicated by the arrow in the figure. The rotational speed of the cylindrical member W can be varied by adjusting the rotational speed of the motor M. The cylindrical member W rotates at 30 rpm, for example.

  The shot blasting device 30a is disposed above the cylindrical member W. The spherical particles 32a stored in the particle tank 33a are supplied to the pipe hose 36a via the particle supply device 35a. A supply source 34a for supplying a gas (for example, air) that is a medium for carrying the spherical particles 32a is connected to one end of the pipe hose 36a, and a blast nozzle 31a is connected to the other end of the pipe hose 36a. . The spherical particles 32a supplied to the pipe hose 36a are mixed with the spherical particle carrying medium.

  The tip of the blast nozzle 31a is disposed at a position spaced a predetermined distance from the processing portion. The separation distance is, for example, 100 mm. The diameter of the spherical particles 32a to be projected is appropriately selected within the range of 0.1 mm to 0.5 mm, and the projection pressure is appropriately selected within the range of 0.1 MPa to 0.5 MPa. As an example, spherical particles 32a made of zirconia ceramic having a diameter of 0.3 mm are projected at an injection pressure of 0.5 MPa.

  Reference numeral 21a in the drawing represents a controller that controls the entire processing apparatus 10a, and the controller 21a controls the operation of the driving means 20a, the supply source 34a, and the particle supply apparatus 35a.

  Following the recess forming process by the processing apparatus 10a, a protrusion removing process by the processing apparatus 10b is performed.

  The driving means 20b includes a chuck (not shown) that detachably holds the rotation shaft Wa of the cylindrical member W, a motor M that is connected to the chuck and rotationally drives the cylindrical member W, and the like. The cylindrical member W rotates in the rotation direction indicated by the arrow in the figure. The rotational speed of the cylindrical member W can be varied by adjusting the rotational speed of the motor M. The cylindrical member W rotates at 30 rpm, for example.

  The microblast device 30b is disposed above the cylindrical member W. The spherical particles 32b stored in the particle tank 33b are supplied to the pipe hose 36b via the particle supply device 35b. One end of the pipe hose 36b is connected to a supply source 34b that supplies a gas (for example, air) that is a medium for carrying the spherical particles 32b, and the other end of the pipe hose 36b is connected to a blast nozzle 31b. . The spherical particles 32b supplied to the pipe hose 36b are mixed with the spherical particle carrying medium.

  The tip of the blast nozzle 31b is disposed at a position spaced a predetermined distance from the processing portion. The separation distance is, for example, 100 mm. The diameter of the spherical particles 32b to be projected is appropriately selected in the range of 2 to 50 μm, and the projection pressure is appropriately selected in the range of 0.1 to 0.5 MPa. As an example, spherical particles 32b made of alumina ceramic having a diameter of 20 μm are projected at an injection pressure of 0.5 MPa.

  Reference numeral 21b in the figure denotes a controller that controls the entire processing apparatus 10b, and the controller 21b controls the operation of the driving means 20b, the supply source 34b, and the particle supply apparatus 35b.

  As described above, when manufacturing the sliding member, the processing apparatus 10a and the processing apparatus 10b according to the present embodiment have a diameter of 0.1 mm to 0.5 mm on the surface to be processed of the workpiece to be the sliding member. After projecting the spherical particles 32a in a range of a projection pressure in the range of 0.1 MPa to 0.5 MPa and performing a recess formation process for forming a recess on the surface to be processed, the coverage of the workpiece to be a sliding member Projection removal processing is performed by projecting spherical particles 32b having a diameter in the range of 2 μm to 50 μm on the processing surface in a range of projection pressure of 0.1 MPa to 0.5 MPa to remove the microprojections on the processing surface. And a method of manufacturing a sliding member that forms a sliding surface in which concave portions are distributed, and the concave portions are distributed on the sliding surface of the sliding member that slides with a counterpart material via a lubricant. Can significantly reduce friction with the mating material A sliding member can be obtained.

  Further, since the concave portion forming step and the convex portion removing step can be processed by one processing apparatus during the manufacturing, the manufacturing process can be greatly simplified. That is, since shot blasting was selected as the recess forming step, a projection unit for injecting spherical particles (shots) having a diameter in the range of 0.1 to 0.5 mm and spherical particles having a diameter in the range of 2 to 50 μm This is because by providing two injection units including a projection unit for injection, the concave portion forming step and the convex portion removing step can be performed by a single blasting machine.

(Comparison)
After forming concave portions on the sliding surface of the sliding member by laser processing, the concave portions were formed on the outer peripheral surface of the cylindrical member by removing minute convex portions around the concave portions by superfinish polishing. As a result, the cylindrical member was formed with a surface in which concave portions similar to those in the above embodiment were distributed.

  However, the total time required for manufacturing is about twice that of the above embodiment.

  As described above, the present invention has developed a processing technique that has a great effect directly related to the simplification of the manufacturing process as a result of intensive development of the blasting method in the manufacturing method of the sliding member having excellent sliding characteristics. It has been found and is industrially useful. That is, according to this invention, the manufacturing method of the sliding member which can simplify a manufacturing process and can reduce manufacturing cost was able to be provided.

  In particular, when shot blasting is selected as the recess forming step, a projection unit for injecting spherical particles (shots) having a diameter in the range of 0.1 to 0.5 mm and a spherical shape having a diameter in the range of 2 to 50 μm. By providing two injection units including a projection unit for injecting particles, the concave portion forming step and the convex portion removing step can be performed with one blasting machine, so the concave portion is formed on the surface of the sliding member. In addition, when removing the fine convex portions generated around the concave portions to finish the flat portions excluding the concave portions smoothly, it is possible to increase the production efficiency and to reduce the production costs.

  Furthermore, when the concave portion is formed by laser processing, an effect of improving the surface roughness of the bottom surface of the concave portion can be obtained, and a greater effect of improving friction characteristics can be realized.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a technique for manufacturing a sliding member in which concave portions that function as oil reservoirs are distributed on a sliding surface.

It is a schematic block diagram which shows the processing apparatus which performs a recessed part formation process with respect to the to-be-processed surface of a sliding member based on one Embodiment of this invention. It is a schematic block diagram which shows the processing apparatus which performs a convex part removal process with respect to the to-be-processed surface of a sliding member based on one Embodiment of this invention.

Explanation of symbols

10a A processing device for performing a recess forming process,
10b Processing device for performing convex part removal processing,
20a, 20b driving means,
21a, 21b controller,
30a, 30b Shot blasting device,
31a, 31b blast nozzle,
32a, 32b spherical particles,
35a, 35b particle supply device,
W Cylindrical member.

Claims (8)

In the manufacturing method of the sliding member having a sliding surface in which the concave portions to be oil reservoirs are distributed when sliding against each other via the counterpart material and the lubricant, and the portion excluding the concave portions is smooth,
A recess forming step of forming the recess on the sliding surface;
A method of manufacturing a sliding member, comprising: a convex portion removing step of removing micro convex portions generated around the concave portion by the concave portion forming step by microblasting.   2. The method for manufacturing a sliding member according to claim 1, wherein the recess forming step is one of shot blasting, micro roll forming, and laser processing.   2. The recess forming step is a shot blasting process in which ceramic or ceramic-coated spherical particles having a diameter in a range of 0.1 mm to 0.5 mm are projected onto the sliding surface. The manufacturing method of the sliding member as described in any one of.   The convex portion removing step is a microblast process in which spherical particles having a diameter in a range of 2 μm to 50 μm are projected onto the sliding surface in a range of a projection pressure of 0.1 MPa to 0.5 MPa. The manufacturing method of the sliding member as described in any one of Claims 1-3 which do.   5. The method for manufacturing a sliding member according to claim 4, wherein the spherical particles are made of cemented carbide or ceramic.   The sliding member manufactured by the method of any one of Claims 1-5.   The sliding member according to claim 6, wherein the total area ratio of the recesses relative to the sliding surface is in the range of 5% to 40%. The sliding member according to claim 6 or 7, wherein the surface roughness of the flat portion excluding the concave portion on the sliding surface is Ra 0.3 µm or less.

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