JP2017096340A - Plain bearing and plain bearing manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join a protective layer and an overlaying layer appropriately.SOLUTION: A plain bearing comprises an alloy layer 3 structured by alloy, an overlaying layer 5 formed on one side of the alloy layer 3 and contacting with a target component which is a target to receive load and a protective layer 4 contacting the surface of the alloy layer 3 side of the overlaying layer 5 and being harder than the overlaying layer 5, the surface 4a of the protective layer 4 contacting with the overlaying layer 5 is formed so that the arithmetic mean roughness Ra is not less than 0.1 μm. Maximum height Rz of the surface 4a of the protective layer 4 contacting with the overlaying layer 5 can be not more than 3 times of the layer thickness of the protective layer 4. The arithmetic mean roughness Ra of the surface 4a of the protective layer 4 contacting with the overlaying layer 5 can be not more than 6 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sliding bearing that receives a load of a target member that performs rotational movement and reciprocating movement, and a sliding bearing manufacturing method that manufactures the sliding bearing.

  Conventionally, for example, a sliding bearing is used to support a crankshaft in an engine of an automobile.

  As a plain bearing, there is known a plain bearing comprising a base back metal, an alloy layer formed on the back metal and excellent in heat dissipation, and an overlay layer formed on the alloy layer and excellent in sliding characteristics. It has been.

  When the slide bearing is used, the foreign matter may damage the overlay layer and the alloy layer, and the alloy constituting the alloy layer may protrude toward the target member. If the alloy protrudes toward the target member in this way, adhesion may occur between the alloy and the target member, and the target member may be burned.

  On the other hand, a technique for protecting the interior by providing a protective layer made of diamond-like carbon (DLC) or the like between the surface layer and the alloy layer is known (for example, Patent Document 1).

Special table 2012-500365 gazette

  When a protective layer is provided on a slide bearing, an overlay layer is formed on the protective layer. However, depending on the bonding state between the protective layer and the overlay layer, the overlay layer may be peeled off from the protective layer. May occur.

  This invention is made | formed in view of the said subject, The objective is to provide the technique which can join a protective layer and an overlay layer appropriately.

  In order to achieve the above object, a sliding bearing according to one aspect of the present invention includes an alloy layer formed of an alloy and an overlay layer formed on one side of the alloy layer and in contact with a target member to be subjected to a load. And the protective layer harder than the overlay layer in contact with the surface on the alloy layer side of the overlay layer, and the arithmetic average roughness Ra of the surface in contact with the overlay layer of the protective layer is 0.1 μm or more.

  In the slide bearing, the maximum height Rz of the surface of the protective layer that contacts the overlay layer may be three times or less the thickness of the protective layer.

  In the sliding bearing, the arithmetic average roughness Ra of the surface of the protective layer that contacts the overlay layer may be 6 μm or less.

  In the sliding bearing, the target member is a rotating shaft extending in a predetermined direction, and the protective layer is formed so as to be in contact with a part including both end portions in the predetermined direction on the surface opposite to the one side of the overlay layer. It may be.

  In the sliding bearing, the protective layer may be in contact with one surface of the alloy layer, and the arithmetic average roughness Ra of the one surface of the alloy layer may be 0.1 μm or more.

  In order to achieve the above-mentioned object, a sliding bearing manufacturing method according to another aspect of the present invention includes an alloy layer formed of an alloy and a target member that is formed on one side of the alloy layer and that receives a load. A sliding bearing manufacturing method for manufacturing a sliding bearing having an overlay layer in contact with an alloy side surface of the overlay layer and a protective layer harder than the overlay layer, wherein the alloy layer is provided on one side of the back metal. An alloy layer joining step for joining, a protective layer forming step for forming on the one side of the alloy layer a protective layer having an arithmetic average roughness Ra of 0.1 μm or more on the surface contacting the overlay layer of the protective layer, and protection An overlay layer forming step of forming an overlay layer on one side of the layer.

  In the sliding bearing manufacturing method, the alloy layer joining step includes an alloy layer forming step in which the arithmetic average roughness Ra of one surface of the alloy layer is 0.1 μm or more, and in the protective layer forming step, The protective layer may be formed by laminating the alloy layer so that the thickness of the protective layer is substantially uniform.

  Further, in the sliding bearing manufacturing method, in the protective layer forming step, the arithmetic average roughness Ra of the surface that contacts the overlay layer of the protective layer is reduced to 0 by subjecting the surface on one side of the protective layer to roughening. It is good also as 1 micrometer or more.

  According to the present invention, the protective layer and the overlay layer can be appropriately bonded.

It is typical sectional drawing of the sliding bearing which concerns on one Embodiment of this invention. It is a flowchart of the sliding bearing manufacturing method which concerns on one Embodiment of this invention. It is typical sectional drawing of the sliding bearing which concerns on the modification of this invention.

  Hereinafter, based on an accompanying drawing, a slide bearing concerning one embodiment of the present invention is explained. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a schematic cross-sectional view of a plain bearing according to an embodiment of the present invention.

  In FIG. 1, a target member that is subject to receiving or supporting a load is disposed on the upper side of the sliding bearing 1 in the drawing. The slide bearing 1 is formed in a shape corresponding to the target member and the situation in which the target member is used. For example, if the target member is a rotating shaft such as an engine crankshaft, the sliding bearing 1 is configured in a cylindrical shape or a semi-cylindrical shape surrounding the rotating shaft, and the target member reciprocates on a plane. If it is a member, it is formed in a planar shape. In the following description, a case where the target member is a rotating shaft such as a crankshaft will be described as an example.

  The sliding bearing 1 includes a back metal 2 serving as a base material, an alloy layer 3 formed on the rotating shaft side of the back metal 2, a protective layer 4 formed on the rotating shaft side of the alloy layer 3, and a protective layer 4. It has an overlay layer 5 formed on the rotating shaft side and in contact with the rotating shaft.

  The back metal 2 is made of metal such as steel, for example.

  The alloy layer 3 is bonded to the surface of the back metal 2 on the rotating shaft side. The alloy layer 3 is made of, for example, a metal alloy including at least one of copper, tin, bismuth, indium, lead, aluminum and the like. The alloy layer 3 is joined to the back metal 2 by, for example, spraying and sintering the powdery material constituting the alloy layer 3 on the back metal 2 and rolling it.

  The arithmetic average roughness Ra (JIS B 0601-2001) of the surface 3a on the rotating shaft side of the alloy layer 3 is 0.1 μm or more. The arithmetic average roughness Ra of the surface 3a of the alloy layer 3 is preferably 6 μm or less. Moreover, it is preferable that the maximum height Rz (JIS B 0601-2001) in the surface 3a of the alloy layer 3 is three times or less of the layer thickness (thickness in the vertical direction of the drawing) of the protective layer 4.

  The protective layer 4 is made of diamond-like carbon (DLC), ceramic such as silicon nitride, or the like. Diamond-like carbon includes DLC (Me-DLC) to which metal is added, W-DLC to which tungsten (W) is added, DLC (Ti-DLC) to which titanium (Ti) is added, and Chrome (Cr). Added DLC (Cr-DLC) can be used. The protective layer 4 is harder than the overlay layer 5 (for example, the value of Pickers hardness (HV) is high). The protective layer 4 is joined to the alloy layer 3 by, for example, PVD (physical vapor deposition), PCVD (plasma chemical vapor deposition), or the like. The thickness of the protective layer 4 is, for example, 2 μm to 20 μm. Since it is necessary for the protective layer 4 to release heat generated in the overlay layer 5 to the alloy layer 3 side when the rotation shaft rotates, it is preferable that the protective layer 4 has high thermal conductivity.

  The arithmetic average roughness Ra (JIS B 0601-2001) of the surface 4a on the rotating shaft side of the protective layer 4 is 0.1 μm or more. In consideration of ensuring that the entire thickness of the plain bearing 1 does not become unnecessarily thick and ensuring the strength necessary for joining the protective layer 4 and the overlay layer 5, the arithmetic average roughness of the surface 4a of the protective layer 4 is obtained. The thickness Ra is preferably 6 μm or less. Further, considering that the entire thickness of the sliding bearing 1 is not increased more than necessary and that the strength necessary for joining the protective layer 4 and the overlay layer 5 is ensured, the maximum in the surface 4a of the protective layer 4 is obtained. The height Rz (JIS B 0601-2001) is preferably 3 times or less the thickness of the protective layer 4.

  The overlay layer 5 is made of, for example, a metal such as copper, tin, bismuth, indium, lead, aluminum, or a metal alloy including at least one of them. The overlay layer 5 is bonded to the protective layer 4 by, for example, PVD, PCVD, sputtering, or the like.

  Next, a sliding bearing manufacturing method according to an embodiment of the present invention will be described.

  FIG. 2 is a flowchart of a sliding bearing manufacturing method according to an embodiment of the present invention.

  First, the back metal 2 which is a flat steel material is prepared, and the alloy layer 3 is joined on the back metal 2 (alloy layer joining process: S11). Specifically, a powdery material for forming the alloy layer 3 is sprayed on the back metal 2 so that the layer thickness is uniform, and is put into a sintering furnace to sinter the powdery material. Thereafter, the back metal 2 on which the powdery material is sintered is rolled by a rolling mill. Thereby, the alloy layer 3 is joined on the back metal 2.

  Next, the surface 3a of the alloy layer 3 is polished to adjust the state (roughness and the like) of the surface 3a of the alloy layer 3 (alloy layer polishing step: S12). In the present embodiment, the arithmetic average roughness Ra of the surface 3a on the rotating shaft side of the alloy layer 3 is 0.1 μm or more, and further, the arithmetic average roughness Ra of the surface 3a of the alloy layer 3 is 6 μm or less, Alternatively, the maximum height Rz on the surface 3a of the alloy layer 3 is adjusted so as to satisfy at least one of three times the thickness of the protective layer 4 or less. In addition, after performing an alloy layer joining process (S11), when the state of the surface 3a of the alloy layer 3 has already satisfy | filled the above-mentioned roughness state, an alloy layer grinding | polishing process (S12) is not performed. May be. Here, when it is necessary to execute the alloy layer polishing step, the alloy layer polishing step corresponds to the alloy layer forming step, and when it is not necessary to execute the alloy layer polishing step, the alloy layer bonding step is performed as an alloy. This corresponds to the layer forming step.

  Next, the protective layer 4 is formed on the alloy layer 3 (protective layer forming step: S13). Specifically, the protective layer 4 having substantially the same thickness is formed on the alloy layer 3 by CVD, PCVD, or the like. Here, in the protective layer forming step, the protective layer 4 having substantially the same layer thickness is formed on the alloy layer 3, so that the state of roughness, etc. on the surface 4a of the protective layer 4 is substantially the same as that of the surface 3a of the alloy layer 3. become. That is, the arithmetic average roughness Ra of the surface 4a of the protective layer 4 is 0.1 μm or more, and the arithmetic average roughness Ra is 6 μm or less, or the maximum height Rz is the thickness of the protective layer 4. It will satisfy | fill at least any one of 3 times or less.

  Next, the overlay layer 5 is formed on the protective layer 4 (overlay layer forming step: S14). Specifically, the overlay layer 5 is formed by CVD, PCVD, sputtering, or the like. Here, the surface 4a of the protective layer 4 has an arithmetic average roughness Ra of 0.1 μm or more, and the arithmetic average roughness Ra of the surface 4a of the protective layer 4 is 6 μm or less, or the protective layer 4 has a maximum height Rz of 3 times or less the thickness of the protective layer 4, the bonding strength between the protective layer 4 and the overlay layer 5 can be made relatively strong. Note that the surface of the overlay layer 5 may be polished by a polishing apparatus.

  Next, the intermediate member formed up to the overlay layer 5 is processed into a shape to be used (for example, a cylindrical shape or a semi-cylindrical shape), and the sliding bearing 1 is completed (shape processing step: S15).

  As described above, according to the sliding bearing according to the present embodiment, the arithmetic average roughness Ra of the surface 4a of the protective layer 4 is 0.1 μm or more, so that the protective layer 4 and the overlay layer 5 are relatively strong. It can join and can prevent appropriately that the overlay layer 5 peels from the protective layer 4. FIG.

  Next, the sliding bearing which concerns on the modification of this invention is demonstrated.

  FIG. 3 is a schematic cross-sectional view of a plain bearing according to a modification of the present invention.

  The sliding bearing 1 according to the modification is an example of a bearing that receives a load of a rotating shaft, and the protective layer 4 is entirely on the surface opposite to the axis of the overlay layer 5 (the entire surface of the alloy layer 3 on the axial direction side). Instead, it is formed in a part including both axial end portions (left and right end portions in the drawing).

  Since the rotary shaft has a large amount of displacement in the vertical direction of the drawing at both ends of the sliding bearing 1, the overlay layer 5 is likely to be damaged at both ends. Since the slide bearing 1 according to this modification includes the protective layer 4 at a portion where the possibility of breakage is high, the alloy layer 3 can be appropriately protected. Moreover, since the range which the alloy layer 3 and the overlay layer 5 contact directly can be ensured, the heat which generate | occur | produces in the overlay layer 5 by rotating a rotating shaft can be effectively released to the alloy layer 3 side. .

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  For example, in the above-described embodiment, the axial-side surface 3a of the alloy layer 3 is set to the above-described predetermined roughness state, and the protective layer 4 having substantially the same layer thickness is formed thereon by PVD, PCVD, sputtering, etc. The surface 4a on the shaft side of the protective layer 4 has a roughness state substantially the same as that of the surface 3a, that is, a predetermined roughness state, but the present invention is not limited to this. For example, the surface 3a of the alloy layer 3 Without forming a rough state, the protective layer 4 is formed on the alloy layer 3, and the surface 4a on the shaft side of the protective layer 4 is subjected to rough surface processing such as blasting in which an abrasive is sprayed on the surface. Thus, the state of the surface 4a may be set to a predetermined roughness state.

  Moreover, in the said embodiment and modification, the protective layer 4 may be comprised by the several layer comprised by the material of a different composition, and the overlay layer 5 is comprised by the several layer comprised by the material of a different composition. It may be configured.

  In the above embodiment, the alloy layer 3 is formed by sintering and joined to the back metal 2. However, the present invention is not limited to this, and the back metal 2 is formed by forging to form the back metal 2. You may make it join. Even in this case, the roughness of the alloy layer 3 is preferably the same as in the above embodiment.

  In the above embodiment, the sliding bearing 1 is provided with the back metal 2. However, the present invention is not limited to this, and the alloy layer 3 may be used as the base material without including the back metal 2. The alloy layer 3 in the case of using as a base material may be formed by forging, for example. Even in this case, the roughness of the alloy layer 3 is preferably the same as in the above embodiment.

1 Sliding bearing 2 Back metal 3 Alloy layer 4 Protective layer 5 Overlay layer

Claims (8)

An alloy layer composed of an alloy;
An overlay layer formed on one side of the alloy layer and in contact with a target member to be subjected to a load;
A protective layer harder than the overlay layer, in contact with the surface of the overlay layer on the alloy layer side,
A plain bearing in which an arithmetic average roughness Ra of a surface of the protective layer contacting the overlay layer is 0.1 μm or more. 2. The plain bearing according to claim 1, wherein a maximum height Rz of a surface of the protective layer that contacts the overlay layer is not more than three times a thickness of the protective layer. 3. The plain bearing according to claim 1, wherein an arithmetic average roughness Ra of a surface of the protective layer contacting the overlay layer is 6 μm or less. The target member is a rotating shaft extending in a predetermined direction,
The said protective layer is formed so that it may contact in part including the both ends of the said predetermined direction in the surface on the opposite side to the said one side of the said overlay layer. Of plain bearings. The protective layer is in contact with the surface on the one side of the alloy layer,
The plain bearing according to any one of claims 1 to 4, wherein the arithmetic average roughness Ra of the one side surface of the alloy layer is 0.1 µm or more. An alloy layer composed of an alloy, an overlay layer formed on one side of the alloy layer and in contact with a target member to be subjected to a load, in contact with the surface of the overlay layer on the alloy side, from the overlay layer A sliding bearing manufacturing method for manufacturing a sliding bearing having a hard protective layer,
An alloy layer bonding step of bonding the alloy layer to one side of the back metal;
A protective layer forming step of forming, on the one side of the alloy layer, a protective layer having an arithmetic average roughness Ra of 0.1 μm or more of a surface that contacts the overlay layer of the protective layer;
A slide bearing manufacturing method comprising: an overlay layer forming step of forming the overlay layer on the one side of the protective layer. The alloy layer joining step includes an alloy layer forming step of forming the arithmetic mean roughness Ra of the one side surface of the alloy layer to be 0.1 μm or more,
The sliding bearing manufacturing method according to claim 6, wherein in the protective layer forming step, the protective layer is formed by laminating the protective layer on an alloy layer so that the layer thickness is substantially uniform. In the protective layer forming step, the arithmetic average roughness Ra of the surface of the protective layer that comes into contact with the overlay layer is 0.1 μm or more by subjecting the surface on the one side of the protective layer to roughening. The sliding bearing manufacturing method according to claim 6.

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