JP2018054106A - Slide member and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member that can maintain slide performance even when a lining of the slide member is worn by usage, and can extend a service life.SOLUTION: A slide member includes: a backing metal layer; and a lining layer being provided on one face of the backing metal layer and forming a slide surface. The slide member has a plurality of recesses opened on the slide surface, and a depth of each recess is larger than a thickness of the lining layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sliding member and a method of manufacturing the same, and more specifically, even if the lining of the sliding member is worn due to long-term use, the sliding performance can be maintained and the life can be extended. The present invention relates to a moving member and a manufacturing method thereof.

  Conventionally, in various machines such as construction machines and automobiles, a sliding member such as a slide bearing has been used in order to enable rotation of a shaft inserted into a housing, and a technique related thereto is also disclosed (for example, (See Patent Document 1).

  The sliding member includes, for example, a bush having a back metal layer and a lining layer, and the bush is made of a bimetallic sintered alloy formed by sintering metal powder on the surface of the back metal layer. Bonding gold forms a lining layer. Moreover, the sliding member provided with this bush is used as a slide bearing in, for example, a fuel injection pump, an engine, a transmission, a shock absorber, and the like. The plain bearing has a cylindrical shape, and a cylindrical mating shaft is supported by a hollow portion formed in the inside thereof.

  As a technique for forming a bush with a bimetallic sintered alloy, for example, Patent Document 2 discloses a back metal plate, a Fe-based sintered sliding material layer sintered and bonded on the back metal plate, and the Fe-based sintered material. A bushing comprising: a diffusion layer of Fe-based alloy grains formed in the vicinity of the joint interface between the sliding material layer and the back metal plate; and a Cu alloy phase formed in the vicinity of the joint interface and extending toward the joint interface. Has been proposed.

  Conventionally, as a slide bearing, a technique has been proposed in which a sliding surface is provided with a large number of recesses (indents) serving as oil reservoirs to improve slidability (see, for example, Patent Document 3).

JP 2007-333185 A International Publication No. 2007/086861 JP 2014-163470 A

When using a slide bearing, the rotating shaft (mating shaft) is supported by its sliding surface (inner circumferential surface), but the lining layer that forms the sliding surface of the sliding bearing is worn by sliding with the mating shaft. . If the lining layer is worn by use and the back metal layer is exposed, the desired sliding performance cannot be exhibited, so that the slide bearing must be replaced. It is only necessary to replace the lining layer with the lining layer remaining. However, in the actual work site, the lining layer has disappeared due to troublesome replacement work or difficult replacement when the construction equipment is in operation. In some cases, it can be replaced. However, if the operation with the back metal layer exposed is continued, the lubricity of the sliding surface is lowered, and the sliding property is lowered.
Accordingly, an object of the present invention is to provide a sliding member capable of maintaining sliding performance and extending its life even when the lining layer of the sliding member is worn due to long-term use, and a method for manufacturing the same. It is in.

  As a result of intensive studies, the present inventor has found that the above problem can be solved by causing a recess (indent) provided in the lining layer to reach the back metal layer and forming an oil reservoir in the back metal layer. It came to be completed.

That is, the present invention is as follows.
(1) A sliding member provided with a backing metal layer and a lining layer that is provided on one surface of the backing metal layer and forms a sliding surface, and has a plurality of recesses that open to the sliding surface. The sliding member is characterized in that a depth of the concave portion is larger than a thickness of the lining layer.
(2) The sliding member according to (1), wherein the lining layer is a porous metal sintered layer made of sintered metal.
(3) In the above (2), the sintered metal is at least one selected from the group consisting of iron-based sintered metal, copper-based sintered metal, and iron-copper alloy-based sintered metal. The sliding member as described.
(4) When viewed from a direction perpendicular to the sliding surface, the ratio of the area of the concave portion to the entire area of the sliding surface is 30% or less. Any of (1) to (3), The sliding member as described in any one.
(5) comprising a step of forming a lining layer on one surface of the back metal layer, and a step of forming a plurality of recesses opening on the surface of the lining layer, wherein the depth of the recesses is greater than the thickness of the lining layer. The manufacturing method of the sliding member, wherein the concave portion is formed to be large.
(6) The method for manufacturing a sliding member according to (5), wherein the recess is formed by at least one of cutting and pressing.
(7) A sliding bearing comprising the sliding member according to any one of (1) to (4).

  In the sliding member of the present invention, since the concave portion (indent) provided in the lining layer reaches the back metal layer, the lining layer forming the sliding surface is worn out by long-term use, and the back metal layer is exposed. Even in this case, the sliding performance is maintained by the oil reservoir provided in the back metal layer. Therefore, according to the present invention, even if the lining layer of the sliding member is worn due to long-term use, the sliding performance can be maintained and the life can be extended.

It is a conceptual diagram which shows the external appearance of the sliding member which concerns on embodiment. It is sectional drawing of the sliding member which shows the state which the lining layer was worn out and was lose | disappeared by use. It is the figure which showed the process of step S01-step S04 in the manufacturing method of the sliding member which concerns on embodiment. It is the figure which showed the process of step S05-step S07 in the manufacturing method of the sliding member which concerns on embodiment. (A) And (b) is the figure which showed the manufacturing method of the color which concerns on another Example, respectively.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a sliding bearing 40 that is a sliding member of the embodiment. The slide bearing 40 has a cylindrical outer shape. A lining layer 11, a back metal layer 15, a collar are arranged along a radial direction from an inner peripheral surface (inner side) 7 to an outer peripheral surface (outer side) 8 as a sliding surface. Thirty three layers are arranged concentrically. The slide bearing 40 according to the present embodiment is a slide bearing used to allow rotation of a mating shaft (hereinafter also simply referred to as “shaft”) inserted through a housing of various machines such as a construction machine and an automobile (not shown). It is used by being press-fitted into the housing. The shaft passes through a hole formed in the center of the slide bearing 40 and is rotatably supported.

  The sliding member of the present invention has a plurality of recesses (indents) 5 that open to the sliding surface 7. The depth of the recess 5 is larger than the thickness of the lining layer 11 and reaches the back metal layer 15. Therefore, as shown in FIG. 2, when the lining layer 11 that forms the sliding surface is worn and disappears due to long-term use of the sliding bearing 40 that is a sliding member, and the back metal layer 15 is exposed, There is a recess 5. Since the recess 5 is present in the back metal layer 15, the lubricating oil can be held in the recess 5, so that the sliding performance on the back metal layer 15 is maintained.

The lining layer 11 is a member that is in direct contact with the rotating shaft, and rotates while the shaft slides, so that low friction, wear resistance, seizure resistance, and the like are required. The lining layer 11 is preferably a porous metal sintered layer composed of a sintered body (sintered alloy) obtained by sintering metal powder.
Examples of the sintered metal include iron-based sintered metal, copper-based sintered metal, and iron-copper alloy-based sintered metal. Examples of the iron-based sintered metal include Cu: 13.5 to 22.5 mass%, Sn: 1.5 to 2.5 mass%, C: 0.5 to 3.0 mass%, and the balance Can be exemplified by metals composed of Fe and inevitable impurities.

  The thickness of the lining layer 11 may be appropriately adjusted according to the shaft diameter of a desired slide bearing. For example, when a shaft having a diameter of 40 to 80 mm is inserted, 0.4 to 1.8 mm is preferable. -1.5 mm is more preferable.

  The back metal layer 15 is made of a plate-like metal member and is a member that receives a load from the shaft. A bimetal constituted by a two-layer structure of the back metal layer 15 and the lining layer 11 constitutes a bush 20 that mainly serves as a sliding member. As will be described later, this bimetal is impregnated with a lubricating oil and subjected to a heat treatment to ensure a predetermined strength. As a metal which comprises the back metal layer 15, an iron-type metal is mentioned, for example.

  The thickness of the backing metal layer 15 may be appropriately adjusted according to the shaft diameter of a desired slide bearing. For example, when a shaft having a diameter of 40 to 80 mm is inserted, 1.0 to 2.1 mm is preferable, and 1.3 -1.8 mm is more preferable.

  In the present invention, the bushing 20 constituted by the backing metal layer 15 and the lining layer 11 stores the groove 6 for supplying lubricating oil from the outside and the lubricating oil supplied from the groove 6 on the sliding surface of the lining layer 11. A plurality of recesses 5 that can be formed are formed.

  The recess 5 opens to the sliding surface, the depth thereof is larger than the thickness of the lining layer 11, and the bottom reaches the back metal layer 15. By forming the recess 5 up to the backing metal layer 15, even when the lining layer 11 is worn and slid by the backing metal layer 15, the sliding performance can be improved without causing seizure or the like. The bottom of the recess 5 is preferably 0.3 mm or more deep from the surface of the back metal layer 15, that is, from the interface between the lining layer 11 and the back metal layer 15. Since the depth of the concave portion 5 in the back metal layer 15 is 0.3 mm or more, an amount of lubricating oil necessary for allowing the sliding to continue even after the lining layer 11 is worn and disappeared is retained. be able to. The recess 5 does not penetrate the back metal layer 15. As shown in FIGS. 1 and 2, the bottom of the recess 5 has a hemispherical shape, but the shape is not particularly limited.

  In the present invention, in order to ensure fracture resistance, it is preferable that the ratio of the area of the recess 5 to the entire area of the sliding surface 7 is 30% or less when viewed from the direction perpendicular to the sliding surface 7. .

In the present invention, when the recess 5 is formed in the bush 20, the back surface of the bush 20, that is, the surface on the back metal layer 15 side may be raised due to the stress of the processing machine (for example, a press machine). Therefore, it is preferable to provide the collar 30 on the back metal layer 15 side of the bush 20.
The collar 30 is made of a metal member having a cylindrical shape, and is also a member for maintaining the overall shape of the sliding bearing 40 and fixing the sliding bearing 40 (bush 20) to another member such as a housing. When the bush 20 is press-fitted into the inner surface of the collar 30, the slide bearing 40 is formed.

  Next, the manufacturing method of the sliding member of the present invention will be described in the case of a slide bearing.

  As shown in FIGS. 3 and 4, the manufacturing method of the plain bearing 40 according to the present embodiment includes a powder spreading process (step S01), a sintering / rolling process (step S02), and a recess forming process (step S03). The bush forming step (step S04), the heat treatment step (step S05), the press-fitting step (step S06), and the oil impregnation / finishing step (step S07) are provided. Hereinafter, each step will be specifically described.

  As shown in FIG. 3, in the powder spraying step (step S01), first, a back metal (back metal layer 15), which is a plate-like metal member, is prepared. For example, an iron-based member or the like is used as the material of the back metal layer 15. Next, the metal powder for forming the lining layer 11 is spread | diffused on the surface 15a of the back metal layer 15 using a spreading device, and the spreading | diffusion layer 11b is formed. As the metal powder, for example, a powder in which iron powder and copper powder are mixed substantially uniformly can be used. In this way, the spreading layer 11b is spread almost uniformly on the surface of the plate-like backing metal layer 15, thereby constituting the plate-like pre-sintering member 10b.

  Next, in the sintering / rolling step (step S02) shown in FIG. 3, the pre-sintering member 10b configured in the powder spraying step (step S01) is placed in a sintering furnace and heated with a heater, and the main layer in the spraying layer 11b The sprayed layer 11b is sintered in an atmosphere at a temperature lower than the melting point of the component iron powder (for example, 800 to 1300 ° C.). As a result, the spreading layer 11 b becomes a porous sintered metal layer (lining layer 14), and the pre-sintering member 10 b becomes a sintered alloy 10 made of a bimetal of the back metal layer 15 and the lining layer 11. In the present embodiment, the sintering process is repeated a plurality of times, and at the same time, by performing a rolling process in which the sintered alloy 10 is rolled with a roller during the sintering process, the plate thickness of the sintered alloy 10 is reduced. . Further, in the present embodiment, the sintered alloy 10 is formed by the continuous sintering method, but it is also possible to adopt a configuration in which it is formed by another method such as a single body sintering method.

  The above steps S01 and S02 correspond to the process of forming the bush 20 in the present invention.

Subsequently, the recess forming step (step S03) shown in FIG. 3 is performed. In step S <b> 03, a plurality of recesses 5 are formed in the bush 20. The formation method of the recessed part 5 is not specifically limited, Cutting process, press work, etc. are mentioned.
In the recess forming step, when the recess 5 is formed by cutting, the bottom of the recess 5 is formed of a metal constituting the back metal layer 15, and when the recess 5 is formed by pressing, the bottom of the recess 5 is a lining. It is made of a metal constituting the layer 11.
By forming the recess 5 by pressing, the bottom of the recess 5 is formed by the oil-impregnated lining layer 11. Therefore, even when the back metal layer 15 is exposed, supply of lubricating oil from the interior of the recess 5 can be expected.

  The depth of the recess 5 is not particularly limited as long as it is larger than the thickness of the lining layer 11 and does not penetrate the bush 20, that is, smaller than the thickness of the bush 20. Preferably, as described above, the bottom of the recess 5 is preferably 0.3 mm or more deeper than the interface between the lining layer 11 and the back metal layer 15. In this step, the groove 6 can be formed at the same time.

  Next, in the bush forming step (step S04) shown in FIG. 3, the sintered alloy 10 formed in steps S01 to S03 is bent by a press machine or the like so that the lining layer 11 is on the inner side, and is cylindrical. A shaped bush 20 is formed. By this bush forming step, the inner peripheral surface of the bush 20 that will later become the inner peripheral surface of the slide bearing 40, which is a sliding member, is formed.

  Next, in the heat treatment step shown in FIG. 4 (step S05), the bushing 20 is subjected to heat treatment such as carburizing and tempering, and the bushing 20 is subjected to lining hardening and surface modification. By this treatment, the hardness of each of the backing metal layer 15 and the lining layer 11 is improved (for example, the backing metal layer 15 is Vickers hardness 100 to 400, the lining layer 11 is Vickers hardness 300 to 800), and the strength of the bush 20 is improved. .

  Next, in the press-fitting process (step S06) shown in FIG. 4, the bush 20 subjected to the heat treatment is press-fitted into the collar 30 which is a cylindrical metal member (for example, an iron-based member) to form the slide bearing 40. Since the collar 30 is not heat-treated like the bush 20, its hardness is smaller than that of the backing metal layer 15 (for example, Vickers hardness 100 to 200). Further, the inner diameter dimension of the collar 30 is formed to be the same as or slightly smaller than the outer diameter dimension of the bush 20 so that the bush 20 can be press-fitted. By this press-fitting process, the outer peripheral surface of the collar 30 that will later become the outer peripheral surface of the sliding bearing 40 that is a sliding member is formed.

  Next, in the oil-impregnating / finishing step (step S07) shown in FIG. In the oil impregnation step, the high-viscosity lubricating oil is heated to lower the viscosity, and the slide bearing 40 is immersed in the lubricating oil and left in a vacuum atmosphere. As a result, the air in the pores of the slide bearing 40 is sucked out of the pores, and the low-viscosity lubricating oil is sucked into the pores of the slide bearing 40. When the sliding bearing 40 that has sucked the lubricating oil is taken out into the air and allowed to cool to room temperature, the lubricating oil whose viscosity has been lowered returns to the original high-viscosity lubricating oil within the pores of the sliding bearing 40 and loses fluidity. Thereby, high-viscosity lubricating oil can be kept in the pores of the slide bearing 40.

  As described above, in the slide bearing 40 that is the sliding member according to the present embodiment, the lining layer 11 is formed by sintering the metal powder on the surface of the back metal layer 15 that is a plate-like metal member. A bimetallic sintered alloy 10 is formed. And the sintered alloy 10 is shape | molded as the cylindrical bush 20, and after the bush 20 is heat-processed, the bush 20 is press-fit in the collar 30 which is a cylindrical metal member, and the slide bearing 40 is formed. . That is, as shown in FIG. 1, the plain bearing 40 according to the present embodiment has three layers of the lining layer 11, the back metal layer 15, and the collar 30 arranged from the inside to the outside. That is, the plain bearing 40 is configured by the bush 20 and the collar 30 provided around the bush 20.

  By configuring as described above, when the slide bearing 40 is press-fitted into the housing, the outer peripheral surface of the slide bearing 40 is less likely to be galling. Specifically, since the collar 30 disposed on the outer periphery of the slide bearing 40 is not subjected to heat treatment, the hardness of the collar 30 is smaller than that of the back metal layer 15 and the like. For this reason, when the slide bearing 40 is press-fitted into the housing, the occurrence of galling can be suppressed at the portion of the collar 30 that comes into contact with the housing.

  Further, the overall hardness of the slide bearing 40 can be suppressed by arranging the collar 30 that has not been heat-treated in the outer peripheral portion. Thereby, the strong hit which the slide bearing 40 generate | occur | produces locally can be reduced, seizure resistance and wear resistance can be improved, and it can make it hard to produce a crack.

  In addition, even when the slide bearing 40 having a large thickness (radial thickness) is formed, the radial thickness of the collar 30 may be adjusted, and the thickness of the sintered alloy 10 can be made constant. For this reason, even when the slide bearing 40 has a large thickness, it can be easily molded.

  Furthermore, according to the present embodiment, the sintered alloy 10 is formed from the plate-like pre-sintering member 10b, and the bush 20 is formed by bending the sintered alloy 10, so that only the sintered material is formed. Thus, it is not necessary to form a cylindrical part and can be easily processed. In addition, since it is not necessary to press-fit only the highly brittle sintered material into the back metal layer, cracks do not occur when the sintered material is pressed into the back metal layer.

  In addition, since the groove or the concave portion can be formed by the groove processing or the concave portion (indent) processing at the stage of the plate-like sintered alloy 10, the groove or the concave portion is easily formed on the inner peripheral surface of the slide bearing 40. Thus, the sliding characteristics on the inner peripheral surface of the slide bearing 40 can be improved.

  As described above, according to the present embodiment, the slide bearing 40 is formed such that when it is press-fitted into the housing, the collar 30 that is the back metal part of the slide bearing 40 is less likely to be galvanized, is not easily cracked, and is easy to form grooves, recesses, and the like. It can be manufactured.

  In addition, the “collar 30 which is a cylindrical metal member” of the present invention can be formed by cutting from a pipe material or a solid material, or the end portions of a plate-shaped (band-shaped) member are butted together (rolled). ) May be formed, and can be appropriately selected in terms of cost and equipment. However, it is preferable to create a cylindrical shape from a plate-like member because a collar can be produced at a lower cost. In that case, finish processing is performed with the seam closed in order to provide a tightening allowance. Furthermore, when a collar is formed by winding a plate-like member, not only the joints may be joined by welding, but they may be joined in a clinch shape.

  Hereinafter, the case where the collar 30 is formed from a plate-like member and is joined in a clinch shape will be described with reference to FIG. Specifically, as shown in FIG. 5 (a), a plate-like member having clinch shapes (substantially circular engaging convex portions 17a and engaging concave portions 17b at both ends is wound by a bending machine or the like not shown. Then, the bending member 17c having a semi-cylindrical central portion is formed, and the radius of curvature of the inner peripheral surface of the bending member 17c is substantially the same as or slightly larger than the radius of curvature of the outer peripheral surface of the bushing 20. The outer surface of the bending member 17c formed by this rough bending step is the outer peripheral surface of the collar 30, that is, the outer peripheral surface of the slide bearing 40.

  Next, as shown in FIG. 5B, the central portion (semi-cylindrical portion) of the bending member 17c is set on the upper die 52s side which is a semi-cylindrical fixed die. Then, the lower mold 52m, which is also a semi-cylindrical movable mold, is brought close to the end of the bending member 17c as indicated by an arrow U shown in FIG. Thereby, the clinch shape is engaged by deforming both side ends of the bending member 17c, which is a plate-like member, along the semi-cylindrical surface of the lower mold 52m. Specifically, both end portions of the bending member 17c, which is a plate-like member, are joined by causing the engaging convex portion 17a to enter and engage with the engaging concave portion 17b. In this way, the collar 30 that is the outer member is formed. Thereafter, the bush 20 is press-fitted into the cylindrical collar 30 to form the slide bearing 40.

  According to the sliding member of the present invention, since the bottom of the recess 5 provided in the bush 20 reaches the back metal layer 15, the lining layer 11 forming the sliding surface is worn and the back metal layer 15 is exposed. Even if it is a case, since the recessed part 5 provided in the back metal layer 15 functions as an oil reservoir, sliding performance can be ensured. In addition, when the recessed part 5 is formed by press work, since the bottom part of the recessed part 5 is formed with the metal which comprises the lining layer 11, sliding performance can be maintained more reliably.

  The sliding member of the present invention can maintain the sliding performance even when the lining of the sliding member is worn, and can extend the life. The sliding member of the present invention is particularly suitably used as a sliding bearing and is industrially useful.

5 Recess 6 Groove 7 Inner peripheral surface (sliding surface)
8 Outer peripheral surface 11 Lining layer 15 Back metal layer 20 Bush 30 Color 40 Slide bearing

Claims (7)

A sliding member provided with a backing metal layer and a lining layer provided on one surface of the backing metal layer to form a sliding surface,
Having a plurality of recesses opening in the sliding surface;
The depth of the said recessed part is larger than the thickness of the said lining layer, The sliding member characterized by the above-mentioned.   The sliding member according to claim 1, wherein the lining layer is a porous metal sintered layer made of sintered metal.   The sliding according to claim 2, wherein the sintered metal is at least one selected from the group consisting of iron-based sintered metal, copper-based sintered metal, and iron-copper alloy-based sintered metal. Element.   The ratio of the area of the recess to the area of the entire sliding surface when viewed from a direction perpendicular to the sliding surface is 30% or less, according to any one of claims 1 to 3. Sliding member. Forming a lining layer on one side of the back metal layer;
Forming a plurality of recesses opening in the surface of the lining layer,
The method for manufacturing a sliding member, wherein the recess is formed so that the depth of the recess is greater than the thickness of the lining layer.   6. The method for manufacturing a sliding member according to claim 5, wherein the formation of the recess is performed by at least one of cutting and pressing.   A sliding bearing comprising the sliding member according to any one of claims 1 to 4.

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