JP2003239973A - Sliding member and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a sliding member having such configuration that the number of parts of the oilless sliding member such as a sliding bearing is reduced and manufacturable simply in a mechanical process. <P>SOLUTION: An inside diameter of a ringlike housing is set to be larger than an outside diameter of a spherical face inner ring to be incorporated, and a diamond-like carbon (DLC) is formed on a face to slide of inner periphery on which a spherical face seat of the housing is formed or outer periphery of the spherical face inner ring. Drawing for shrinking diameter of the whole housing is applied to the housing after storing the spherical face inner ring into the inside diameter to manufacture the sliding member easily and make a slide face an extremely low friction resistance face by the DLC membrane. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a sliding member such as a round type or a rod end type plain bearing, and relates to a sliding surface on either the inner peripheral surface of a housing or the outer peripheral surface of a spherical inner ring incorporated therein. Diamond-like carbon (D
The present invention relates to an oil-free sliding member which is provided with an LC film, has a spherical inner ring built therein, and has a housing formed by drawing to remarkably improve the productivity.

[0002]

2. Description of the Related Art A rod end type slide bearing or a round type slide bearing having a male or female screw portion has a structure in which a spherical inner ring is incorporated in a ring-shaped housing to support rotation, rocking and turning motions. Such slide bearings are known in various configurations such as an insert type, a welding type, an oil-free type, etc. due to the difference in the configuration and the manufacturing method.

The insert type is a structure in which an insert member which is divided into two in the circumferential direction is used in order to incorporate the spherical inner ring into the ring-shaped housing, and the inner peripheral surface of the cut insert member and the outer peripheral surface of the spherical inner ring slide. Will move.
The welding type has a configuration in which the ring-shaped housing itself is divided into two in the circumferential direction, and the inner peripheral surface of the machined housing and the outer peripheral surface of the spherical inner ring slide.

In the oil-free type, a liner made of tetrafluoroethylene resin reinforced with glass or metal mesh is provided on the inner surface of the housing, and the liner is used as a solid lubricant to provide self-centering with the spherical inner ring. It has an insert type or a welding type. In addition, instead of welding, the whole may be sandwiched between two housings and then caulked, or an adhesive may be applied to the contact surface and then heated and pressure-bonded.

[0005]

In the case of the insert type structure, there is no welding process and only a mechanical process of fitting, but there is a large number of parts such as a ring-shaped housing, a spherical inner ring, two divided insert members. There is. On the other hand, in the case of the welding type structure, a welding process is required, but there is an advantage that the number of parts is reduced as compared with the insert type only with the ring-shaped housing and the spherical inner ring divided into two.

In the case of a non-lubricating type construction, the number of lubricating liners as parts increases, and since either the insert type or the welding type is used for manufacturing, there is any of these problems, and basically the parts and process are There is a problem that there are many.

Further, the ring-shaped housing is manufactured by an end mill or forging process, and a cutout portion for fitting the spherical inner ring is provided on the end face side, and the spherical inner ring is fitted into the inner circumferential surface of the housing from the cutout portion. Although there is a configuration in which the housing is rotated and incorporated, the housing, the spherical inner ring, and the number of parts are small, but there is a problem that rattling occurs at the time of use due to the cutout portion, and that the processing process of the housing requires labor.

[0008] The oil-free slide bearings are in great demand for applications such as when maintenance-free is required, or where they are used in places or environments where lubricating oil is disliked, but for the above reasons, they cannot be provided inexpensively. In order to provide it at low cost, it is required to reduce the number of parts and processes, but as mentioned above, it was not possible to meet the demand because of its basic structure.

The present invention provides a sliding member which has a structure in which the number of parts of an oil-free sliding member such as the sliding bearing is reduced and which can be easily manufactured by a mechanical process, and a manufacturing method thereof. It is an object.

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made various studies on the structure and manufacturing method of an oil-free sliding bearing which can be composed of only two parts, a non-split type housing and a spherical inner ring incorporated therein. As a result, the inner diameter of the ring-shaped housing is made larger than the outer diameter of the spherical inner ring to be built in advance, and the spherical inner ring is housed within the inner diameter and then plastic deformation is performed to reduce the entire diameter of the housing, that is, drawing process. Can be manufactured by adding a diamond-like carbon (DL) to the inner peripheral surface of the housing having the spherical surface formed on the inner peripheral surface or the outer peripheral surface of the spherical inner ring.
It has been found that even if (C) is deposited and the above-mentioned drawing process is performed, the deposited DLC does not peel off at all and can withstand long-term sliding friction and can be lubricated without oil.

Further, the inventors have found that the DLC film formed on the spherical seat of the housing has a linear or scale-like fine pattern that can be observed with a microscope after undergoing the plastic deformation.
It is considered that a compressive stress due to the plastic deformation is generated and enters the film, and it was found that the film does not separate even after the plastic deformation is completed, and the present invention was completed.

That is, the present invention is a sliding member having a sliding surface with another member, having a DLC film formed on the sliding surface directly or through one or more underlayers, The sliding member is characterized by having a fine pattern observable with a microscope, which is generated by plastic deformation of the sliding member directly or indirectly received on the surface of the DLC film.

Further, according to the present invention, in the sliding member having the above-mentioned structure, the fine pattern has a linear shape and / or a scale shape, and the underlayer has Ti, V, Cr, Mo, W, Si.
Among these, a structure made of any one of carbides or nitrides, a base layer made of a metal or alloy plating layer, and further, a sliding member, a spherical inner ring having an outer peripheral surface having a convex spherical sliding surface, and A ring-shaped housing having a concave spherical sliding surface on its inner peripheral surface for its built-in, and a DLC film on the spherical inner ring and / or housing,
We also propose a sliding member characterized by.

Further, according to the invention, the sliding surface of the sliding member is D
The step of forming an LC film, the step of directly or indirectly subjecting the sliding member including the sliding surface to plastic deformation, and the microscopically observable microscopic portion in the DLC film on the sliding surface after undergoing plastic deformation A sliding member manufacturing method characterized by forming a pattern.

Further, the present invention comprises a spherical inner ring having an outer peripheral surface having a convex spherical sliding surface, and a ring-shaped housing having an inner peripheral surface having a concave spherical sliding surface for incorporating the same. In the method for producing a sliding member, the step of forming a DLC film on the outer peripheral surface of the spherical inner ring or the inner peripheral surface of the housing, or both, directly or through one or more underlayers, and the ring-shaped housing And a step of subjecting the housing to a drawing process or a bending process to reduce the inner and outer diameters of the spherical inner ring after the spherical inner ring is disposed on the inner peripheral surface of the sliding member.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the DLC film to be formed on the sliding surface can be formed by using a known apparatus used for a vapor phase growth method, and a source material is evaporated from a solid. Or, due to the difference in the raw material means such as obtaining from a gas such as toluene or acetylene gas, the excitation method of the raw material molecules, and the difference in the film formation means on the surface to be deposited, the sputtering method, the ion sputtering method, the plasma sputtering method, the CVD method. Various film forming methods such as the PVD method are known and can be appropriately selected from these. For example, in the PVD method, the surface to be film-formed is subjected to cleaning treatment such as pure water cleaning and chemical cleaning, and then sputter cleaning is performed in a vacuum chamber, and a required source gas is flowed into the film forming chamber to provide a base layer.
Further, a DLC film is formed.

Therefore, since the vapor phase growth method is adopted,
It is possible to mix a metal in the DLC film, improve the adhesion to a sliding member made of a metal material, achieve a stepwise change in the thermal expansion coefficient in the film thickness direction, and further mix Si. It is also possible to reduce the friction coefficient of the DLC film. For example, by appropriately mixing a metal such as Ti, Si, W, Cr, or Mo from the film formation initial layer to the intermediate layer, DL
Various configurations such as changing the content concentration in the C film thickness direction can be adopted.

Further, since the vapor phase growth method is adopted,
Depending on the material type of the sliding member on the film formation side, for example, a metal material such as carbon steel, stainless steel, or Cr steel, it is possible to reduce the difference between the coefficient of thermal expansion of DLC, which is ceramic, and the coefficient of thermal expansion of metal and DLC. Ti, V, Cr, Mo, W, S having excellent wettability and thermal expansion coefficient intermediate between these two
A carbide or nitride such as i can be appropriately selected as the underlayer and the film can be formed first. Also, the underlayer is 1
In addition to the layers, it is also preferable to form a plurality of underlayers of the above-mentioned materials or other various materials in a laminated manner, if necessary.

For example, TiC + DLC, TiN + TiC
+ DLC, TiC + SiC + DLC, SiC + DLC,
WC + DLC, MoC + DLC, CrC + WC + DLC
Various laminated configurations such as the above can be appropriately adopted.

It is also preferable to provide an underlayer by plating in addition to the above underlayer by the vapor phase growth method. The plating film is a metal plating such as Cr or Ni, a Cr alloy, or Ni.
Alloy plating such as alloy can be appropriately selected.

In the present invention, the thickness of the DLC film is not particularly limited, but it is set to 0.
The range of 5 to 5 μm is preferable, and the thickness of the underlayer is 0.5.
The thickness is preferably 3 μm or less, and the film thickness is preferably 5 μm or less even when the underlayer is included.

In the present invention, the DLC film may be provided on the sliding surface of the sliding member, for example, in the case of a sliding bearing, on one or both of the inner peripheral surface of the ring-shaped housing and the outer surface of the spherical inner ring. When a DLC film is provided on either one of them, a resin film having a low friction coefficient such as a known fluororesin or various metal plating films can be appropriately provided on the other sliding surface. The metal plating film is made of C, depending on the purpose of corrosion resistance, rust prevention, wear resistance, heat resistance, impact resistance, scratch resistance, etc.
r, Zn, Ni, Cu, Sn, Pb, Au, Ag, Al
It can be selected as appropriate. The thickness of the plating film is selected depending on the purpose and material, but is preferably about 3 to 20 μm.

In the present invention, the step of subjecting the sliding member including the sliding surface to plastic deformation, for example, in the case of a sliding bearing, after disposing the spherical inner ring on the inner peripheral surface of the ring-shaped housing, the inner and outer diameters of the spherical inner ring are arranged in the housing. As a drawing method for reducing, a known machining can be appropriately selected, that is, a method and a jig can be appropriately selected and applied according to the shape and form of the workpiece.

As a concrete example, when the spherical inner ring is incorporated in the ring-shaped housing having the structure shown in FIG. 1, the inner diameter, the outer diameter, and the ring width dimension which are set so as to have the required shape after the drawing work on the work pedestal (not shown). The housing material set in advance is inserted and arranged, and further, the spherical inner ring is arranged by supporting a shaft (not shown) by inserting the spherical inner ring into the inside thereof, and the assembly is drawn by a diaphragm in which the inside diameter is gradually reduced. Draw with a jig.

Further, it is also possible to place the shaft in the inner diameter portion and arrange it in the housing material and draw it with a drawing jig. Further, since the housing and the spherical inner ring of the plain bearing after drawing are in contact with each other, a clearance process is performed and adjustment is performed so that the required rotation is possible.

In the above process, the DLC film is formed on the inner peripheral surface of the housing, the outer peripheral surface of the spherical inner ring, or both, but when the film is formed on the housing when the plastic deformation force is applied to the housing, the spherical inner ring is of course formed. The external force also acts on the DLC film provided on the outer peripheral surface of the. Further, although the example of the drawing jig in which the inner diameter portion is gradually reduced in diameter has been described, it goes without saying that a known processing method such as using a device for directly pressing can be applied.

In the present invention, the characteristic feature of the DLC film, that is, the fine pattern observable with the microscope, which is generated by the plastic deformation of the sliding member, is scaly as shown in FIG.
Or, it has a linear shape or a property including both. In FIG. 3, the striped pattern in the left-right direction is a scale-like fine pattern, and the striped pattern in the up-down direction is a scratch in a test or the like, but film peeling due to the scratch does not occur at all.

Generally, it is not desirable to apply plastic deformation to a member having a film formed on the surface thereof, because it usually causes the film to peel off, and it is common sense that drawing of the above-mentioned ring-shaped housing is not expected. is there. The inventors considered drawing the member formed on the assumption of convenience in manufacturing, and studied various films having low frictional resistance that enable this, and as a result, the DLC film is most suitable. Further, they have found that a fine pattern that can be observed with a microscope is formed on the film after processing.

More specifically, it is considered that these fine patterns enter the pattern due to the compressive stress generated in the film by the force associated with the plastic deformation. In the DLC film, compressive stress originally called internal stress exists as ceramics, but the force due to elastic deformation applied by drawing acts on the film, and after the external force is released, the original compressive stress and external force are applied. It is assumed that the accompanying compressive stress remains and a fine pattern that can be observed with a microscope is formed. It is usually thought that this leads to the occurrence of visible cracks and peeling of the film, but it has been found that such a situation does not occur at all.

Although the detailed mechanism is unknown, the structure peculiar to the DLC film, which is tolerant to the presence of internal stress, causes the film to peel off even if partial internal stress is deposited on the film. Furthermore, it is considered that the function as a sliding member is not impaired at all even after long-term use.

[0031]

Example 1 In order to manufacture the round type sliding bearing shown in FIG. 1, a stainless steel ring-shaped housing material was cut, and the inner peripheral surface thereof was processed by a plasma sputtering apparatus to a thickness of 0. 7 μm TiC film, 1.3 μm thick DLC
A film was formed. The ring-shaped housing has an outer diameter of 36.60.
mm, inner diameter 32.136 mm, width 15.05 mm. Separately, a spherical inner ring made of stainless steel was formed by grinding. The spherical inner ring has an outer diameter of 28.575 mm, an inner diameter of 18.00 mm, and a width of 20.00 mm.

The above housing material is inserted and arranged in a work cradle (not shown), a spherical inner ring is further arranged therein, and the assembly is drawn by a drawing jig whose inner diameter is gradually reduced. did. After the drawing process is completed, the spherical inner ring does not rotate by coming into contact with the inner circumferential surface of the ring-shaped housing, so that a clearance process is performed to allow the spherical inner ring to rotate smoothly.

The ring-shaped housing, which has been drawn, has an outer diameter of 33.00, which is the planned size of a plain bearing product.
mm, inner diameter 28.580 mm, and width 16.00 mm. As a result of observing the DLC film surface on the inner peripheral surface of the housing with an optical microscope (magnification: 65 times), the surface had a scale-like fine pattern shown in FIG.

The round type slide bearing thus obtained was used for an axial load durability test. The test condition is that the load is 78
It was carried out under the conditions of 40 N and a frequency of 11.3 Hz, which was applied 161.07 × 10 ⁶ times in the axial direction. No damage such as film peeling occurred at all on the DLC film on the inner peripheral surface of the housing in the round type slide bearing which had been subjected to the durability test.

Example 2 In order to manufacture the round type slide bearing shown in FIG. 1, a ring-shaped housing material made of bearing steel was cut, and a DLC film having a thickness of 2.0 μm was formed on the inner peripheral surface thereof by a plasma sputtering device. A film was formed. Ring-shaped housing has an outer diameter of 36.60 m
m, inner diameter 32.136 mm, width 15.05 mm. Separately, a spherical inner ring made of stainless steel was formed by grinding, and a DLC film having a thickness of 2.0 μm was formed on the outer peripheral surface by a plasma sputtering device. The spherical inner ring has an outer diameter of 2
8.579 mm, inner diameter 18.00 mm, width 20.00 m
The size is m.

The above housing material is inserted and arranged in a work cradle (not shown), and a spherical inner ring is arranged inside the work cradle. These assembled bodies are drawn by a drawing jig whose inner diameter is gradually reduced. did. After the drawing process is completed, the spherical inner ring does not rotate while coming into contact with the inner peripheral surface of the ring-shaped housing, so that a required clearance is provided to allow the spherical inner ring to rotate smoothly.

The ring-shaped housing, which has been drawn, has an outer diameter of 33.00, which is the planned size of a plain bearing product.
mm, inner diameter 28.585 mm, and width 16.00 mm. DL of the inner peripheral surface of the housing and the outer peripheral surface of the spherical inner ring
As a result of observing the surface of the C film with an optical microscope (magnification: 65 times),
The inner surface of the housing had a scaly shape, and the outer peripheral surface of the spherical inner ring had a partially linear fine pattern on the surface.

Example 3 In order to manufacture the rod end type plain bearing shown in FIG. 2, a ring-shaped housing material made of stainless steel was cut. The ring-shaped housing has an outer diameter of 26.00 mm, an inner diameter of 19.176 mm, and a width of 11.50 mm. Next, this housing material was welded to the rod. Separately, a spherical inner ring made of stainless steel is formed by grinding, and the outer peripheral surface thereof has a thickness of 2.0 by a plasma sputtering device.
A μm DLC film was formed. The spherical inner ring has an outer diameter of 19.0
The dimensions are 50 mm, inner diameter 10.00 mm, and width 14.00 mm.

The above-mentioned housing material is inserted and arranged in a work cradle (not shown), a spherical inner ring is arranged inside the housing material, and these assemblies are processed by a bending jig that presses from the end surface side of the housing material. gave. After the completion of the bending process, the spherical inner ring does not rotate by coming into contact with the inner peripheral surface of the ring-shaped housing, so that a required clearance is provided to allow the spherical inner ring to rotate smoothly.

Further, the ring-shaped housing which has been subjected to the bending process has an outer diameter of 26.00 which is a predetermined size of the sliding bearing product.
The dimensions were mm, inner diameter 19.055 mm, and width 11.00 mm. As a result of observing the surface of the DLC film on the outer peripheral surface of the spherical inner ring with an optical microscope (magnification: 65 times), a scaly fine pattern was partially present.

[0041]

According to the present invention, a sliding member such as a round type or a rod end type sliding bearing can be constituted by only two parts, a non-split type housing and a spherical inner ring built into the housing. It can be easily manufactured by storing it in the inner diameter and then subjecting the housing to plastic deformation that reduces the entire diameter, that is, drawing.

The present invention is, of course, an oil-free sliding bearing, which is used in the case where maintenance-free is required in the past, or in a place where lubricating oil is disliked or in an atmosphere.
Since the sliding surface is formed of a high hardness DLC film, the gap can be designed tight and low friction resistance that can be said to be a fraction to a few tenths compared to conventional resin is realized. In addition, by significantly reducing dust from the sliding surface, it can be applied to a new application. For example, underwater equipment, food manufacturing equipment, chemical manufacturing equipment, various manufacturing equipment in a vacuum atmosphere,
Alternatively, it can be applied to a semiconductor device manufacturing apparatus and various apparatuses in a clean room.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a round type slide bearing according to the present invention, in which A is an overall explanatory view and B is a longitudinal explanatory view of a main part.

FIG. 2 is an explanatory view showing a rod end type plain bearing according to the present invention, in which A is an overall explanatory view and B is a longitudinal sectional explanatory view of a main part.

FIG. 3 is a schematic view of a micrograph of the surface of the DLC film formed on the inner peripheral surface of the housing of the round type plain bearing according to the present invention.

[Explanation of symbols]

1 ring-shaped housing, 2 spherical inner ring, 3 rod

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masao Ito             Asahi Seiki, 6-570, Houtou-cho, Sakai City, Osaka Prefecture             Within Kou Co., Ltd. F term (reference) 3J011 AA06 AA20 QA04 QA11 SE02

Claims (10)

[Claims] 1. A sliding member having a sliding surface with another member,
A diamond-like carbon (DLC) film formed directly or through one or more underlayers on the sliding surface, and
A sliding member having a fine pattern observable by a microscope, which is generated by plastic deformation of the LC film surface directly or indirectly received by the sliding member. 2. The sliding member according to claim 1, wherein the fine pattern has a linear shape, a scale shape, or both. 3. The underlying layer is Ti, V, Cr, Mo, W, S
A carbide or a nitride of any one of i.
The sliding member according to. 4. The sliding member according to claim 1, wherein the underlayer comprises a metal or alloy plating layer. 5. A sliding member comprising a spherical inner ring having an outer peripheral surface having a convex spherical sliding surface, and a ring-shaped housing having an inner peripheral surface having a concave spherical sliding surface for incorporating the same. DL on the spherical inner ring or housing or both
The sliding member according to claim 1, which has a C film. 6. A step of forming a film of diamond-like carbon (DLC) on the sliding surface of the sliding member, a step of directly or indirectly subjecting the sliding member including the sliding surface to plastic deformation,
A method for producing a sliding member, comprising forming a fine pattern observable with a microscope on the film surface of the sliding surface after undergoing plastic deformation. 7. The method for producing a sliding member according to claim 6, wherein the fine pattern has a linear shape, a scale shape, or both. 8. The slide according to claim 6, further comprising a step of depositing a DLC after depositing an underlayer made of a carbide or a nitride of any one of Ti, V, Cr, Mo, W and Si. Method for manufacturing moving member. 9. The method for manufacturing a sliding member according to claim 6, further comprising the step of forming a base layer made of a metal or alloy plating layer and then forming a DLC film. 10. A sliding member comprising a spherical inner ring having an outer peripheral surface having a convex spherical sliding surface, and a ring-shaped housing having an inner peripheral surface having a concave spherical sliding surface for incorporating the same. And a step of forming a diamond-like carbon (DLC) film on the outer peripheral surface of the spherical inner ring or the inner peripheral surface of the housing, or both, directly or through one or more underlayers; A method of manufacturing a sliding member, which comprises a step of arranging a spherical inner ring on a peripheral surface and then subjecting the housing to a drawing process or a bending process for reducing the inner and outer diameters thereof.