JP2013194753A - Sliding member and method of manufacturing the sliding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding member configured to prevent seizure in a backing plate portion of the sliding member when press-fitted into a housing, as well as cracks, while allowing a groove or indent to be easily formed, and to provide a method of manufacturing the sliding member.SOLUTION: In a bearing 40, a bimetal sintered alloy 10 is formed by forming a sintered layer 11 by sintering metal powder on the surface of a backing plate 15 that is a plate-like metal member. The sintered alloy 10 is formed as a cylindrical bush 20. After heat treatment is applied to the bushings 20, 20, the bushings 20, 20 are press-fitted into a collar 30 that is a tubular metal member. A gap formed between the bushings 20, 20 on the inner peripheral surface of the collar 30 is configured as a groove 40a for a lubricant.

Description

  The present invention relates to a sliding member and a technique for manufacturing the sliding member, and more particularly, to a technique for manufacturing a sliding member excellent in both strength and workability.

  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 and Patent Document 2).

JP 2007-85363 A JP 2007-333185 A

According to the technique described in Patent Document 1, a metal powder is sintered on a plate-shaped backing metal to form a two-layered plate-shaped material, and the plate-shaped material is molded into a cylindrical shape and slid. It constitutes a member.
Further, according to the technique described in Patent Document 2, a cylindrical sintered material is press-fitted into an inner peripheral portion of a cylindrical back metal to constitute a sliding member.

  According to the technique described in Patent Document 1, grooves and indents can be formed at the stage of the plate-like material. However, since the hardness of the back metal is increased when heat-treating the sliding member, the back metal part of the sliding member may be galled when the sliding member is press-fitted into the housing. Further, since the sliding member becomes hard as a whole, the sliding member is easily cracked.

  On the other hand, according to the technique described in Patent Document 2, it is difficult to increase the processing accuracy of the cylindrical sintered material. In addition, since the sintered material is highly brittle, there is a possibility that cracking may occur when press-fitting into the back metal. In addition, since a cylindrical member is used instead of a plate-like member from the beginning, the formation of grooves and indents has been limited.

  In view of the situation as described above, the present invention provides a sliding member and a sliding member that are less likely to be galling, cracked, and easily formed into grooves, indents, and the like when pressed into a housing. A method for manufacturing a moving member is provided.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a plurality of bushes that are cylindrical members are sliding members formed by being press-fitted into a collar that is a cylindrical member, and the bushes are arranged on the inner peripheral surface of the collar. A gap is formed in the gap, and the gap is configured as a groove for lubricating oil.

  According to a second aspect of the present invention, the two bushes are pressed into the collar from both sides.

  According to a third aspect of the present invention, the bush is formed of a bimetallic sintered alloy formed by sintering metal powder on the surface of a back metal that is a plate-like metal member.

  According to a fourth aspect of the present invention, a plurality of bushes, which are cylindrical members, are press-fitted into a collar, which is a cylindrical member, to form a gap between the bushes on the inner peripheral surface of the collar, It is constituted as a groove for use.

  According to a fifth aspect of the present invention, the two bushes are pressed into the collar from both sides.

  According to a sixth aspect of the present invention, the bush is formed of a bimetallic sintered alloy formed by sintering metal powder on the surface of a back metal that is a plate-like metal member.

  As effects of the present invention, the following effects can be obtained.

  According to the sliding member and the manufacturing method of the sliding member according to the present invention, when press-fitting into the housing, the back metal part of the sliding member is less likely to be galvanized, hardly cracked, and grooves, indents, etc. can be easily formed. It becomes possible to do.

The figure which showed each process in the manufacturing method of the sliding member which concerns on 1st embodiment. (A) is an axial center direction sectional view of the sliding member which concerns on 1st embodiment, (b) is an axial center direction sectional view of the state which penetrated the axis | shaft similarly to the sliding member. (A) is an axial center direction sectional view of the sliding member which concerns on 2nd embodiment, (b) is an axial center direction sectional view of the state which similarly inserted the axis | shaft in the sliding member.

[Bearing 40]
First, the manufacturing method of the bearing 40 which is a sliding member which concerns on 1st embodiment is demonstrated using FIG.1 and FIG.2.
The bearing 40, which is a sliding member according to the present embodiment, is a slide bearing that is used to make a shaft inserted into a housing (not shown) rotatable, and is used by being press-fitted into the housing.

  As shown in FIG. 1, the manufacturing method of the bearing 40 according to this embodiment includes a powder spraying process (step S01), a sintering / rolling process (step S02), a bushing process (step S03), and a heat treatment process (step S03). Step S04), a press-fitting step (Step S05), and an oil impregnation / finishing step (Step S06). Hereinafter, each step will be specifically described.

  In the powder spraying step (step S01) shown in FIG. 1, first, a back metal 15 that is a plate-like metal member is prepared. For example, an iron-based member is used as the material of the back metal 15. Next, metal powder in which copper powder and iron powder are mainly mixed substantially uniformly is sprayed on the surface 15a of the back metal 15 using a spraying device to form the sprayed layer 11b. In this way, the spreading layer 11b is spread almost uniformly on the surface of the plate-like back metal 15 to constitute the plate-like pre-sintering member 10b.

  Next, in the sintering / rolling step (step S02) shown in FIG. 1, the pre-sintering member 10b configured in the powder spraying step (step S01) is placed in a sintering furnace and heated by a heater, and the metal in the spraying layer 11b. The spray layer 11b is sintered in an atmosphere at a temperature lower than the melting point of the powder (for example, about 800 degrees). Thereby, the spreading layer 11 b becomes the porous sintered layer 11, and the pre-sintering member 10 b becomes the sintered alloy 10 made of the bimetal of the back metal 15 and the sintered 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.

  Next, in the bush forming step (step S03) shown in FIG. 1, the sintered alloy 10 formed in the sintering / rolling step (step S02) is wound by a press or the like so that the sintered layer 11 is on the inner side. Bending is performed to form a cylindrical bush 20. At this time, two bushes 20 are formed for each bearing 40. By this bush forming step, the inner peripheral surface of the bush 20 that will later become the inner peripheral surface of the bearing 40 that is a sliding member is formed.

  Next, in the heat treatment step shown in FIG. 1 (step S04), the bush 20 is subjected to a heat treatment such as carburizing and quenching and tempering, and the bush 20 is subjected to surface modification. By this treatment, the surface hardness of each of the backing metal 15 and the sintered layer 11 is improved (for example, the backing metal 15 is Vickers hardness 150 to 400, the sintered layer 11 is Vickers hardness 300 to 800), and the strength of the bush 20 is improved. To do. The surface modification treatment is not limited to the carburizing treatment method, and other treatments for improving the surface hardness such as nitriding and nitrocarburizing treatment methods may be used.

  Next, in the press-fitting process (step S05) shown in FIG. 1, two bushes 20 and 20 subjected to heat treatment are respectively applied to the collar 30 which is a cylindrical metal member (for example, an iron-based member) from both sides (FIG. 1). In the vertical direction) to form the bearing 40. By this press-fitting process, the outer peripheral surface of the collar 30 which will later become the outer peripheral surface of the bearing 40 which is a sliding member is formed. At this time, as shown in FIG. 2A, the bushes 20 and 20 are press-fitted so that a gap is formed between the bushes 20 and 20 on the inner peripheral surface of the collar 30. The said gap formed in is formed as a groove 40a for lubricating oil. That is, the width of the gap formed between the bushes 20 and 20 becomes the width D of the groove 40a. As a result, as shown in FIG. 2B, when the shaft A is inserted through the inner peripheral surface of the bearing 40, the groove 40a functions so that the lubricating oil passes therethrough.

  In addition, since the heat treatment like the bush 20 is not performed on the collar 30, the surface hardness is smaller than that of the back metal 15 (for example, Vickers hardness 50 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.

  Next, in the oil impregnation / finishing step (step S06) shown in FIG. 1, the bearing 40 is impregnated with an oil component made of high viscosity lubricating oil using an oil impregnation machine. In the oil impregnation step, the high-concentration lubricating oil is heated and liquefied to lower the viscosity, and the bearing 40 is immersed in the lubricating oil and left in a vacuum atmosphere. As a result, air in the pores of the bearing 40 is sucked out of the pores, while liquefied lubricating oil is sucked into the pores of the bearing 40. When the bearing 40 that has sucked the lubricating oil is taken out into the air and allowed to cool to room temperature, the liquefied lubricating oil returns to the original high-viscosity lubricating oil in the pores of the bearing 40 and loses fluidity. As a result, the high-viscosity lubricating oil can be retained in the pores of the bearing 40.

  As described above, in the bearing 40 which is a sliding member according to the present embodiment, as shown in FIGS. 2A and 2B, a plurality of (two in the present embodiment) bushes 20. 20 is press-fitted into a collar 30 that is a cylindrical member, and a gap formed between the bushes 20 and 20 on the inner peripheral surface of the collar 30 is configured as a groove 40a for lubricating oil.

  By configuring as described above, the groove 40a for the lubricating oil can be formed only by press-fitting the bushes 20 and 20 into the collar 30, so that it is not necessary to separately perform groove processing or indent processing. That is, it is possible to easily form grooves and indents on the inner peripheral surface of the bearing 40 and improve the sliding characteristics on the inner peripheral surface of the bearing 40.

  Moreover, the width | variety D of the groove | channel 40a can be easily adjusted by comprising the clearance gap formed between bushes 20 and 20 as the groove | channel 40a. Specifically, when the bushes 20 and 20 are press-fitted into the collar 30, the width of the gap formed between the bushes 20 and 20 is changed by changing the length of the collar 30 that is press-fitted in the axial direction. Thus, the width D of the groove 40a can be adjusted. Alternatively, by changing the length of the bushes 20 and 20, the width of the gap formed between the bushes 20 and 20 can be changed to adjust the width D of the groove 40a.

  Further, in the bearing 40 that is a sliding member according to the present embodiment, the two bushes 20 and 20 that are cylindrical members are press-fitted from both sides of the collar 30 that is the cylindrical member, and the inner peripheral surface of the collar 30. , The gap formed between the bushes 20 and 20 is configured as a groove 40a for lubricating oil.

  By configuring as described above, when the bushes 20 and 20 are press-fitted into the collar 30, compared with the case where the two bushes 20 and 20 are press-fitted from one side of the collar 30, effort is not applied. In fact, the groove 40a for lubricating oil can be formed with a simple configuration. That is, it is possible to easily form grooves and indents on the inner peripheral surface of the bearing 40 and improve the sliding characteristics on the inner peripheral surface of the bearing 40.

  Further, in the bearing 40 which is a sliding member according to the present embodiment, as shown in FIG. 2A, three layers of the sintered layer 11, the back metal 15, and the collar 30 are arranged from the inside to the outside. ing. And each surface hardness is comprised so that it may become small as it goes outside from the inner side.

  By configuring as described above, when the bearing 40 is press-fitted into the housing, the outer peripheral surface of the bearing 40 is less likely to be galling. Specifically, since the collar 30 disposed on the outer periphery of the bearing 40 is not heat-treated, the surface hardness of the collar 30 is smaller than that of the back metal 15 or the like. For this reason, when the bearing 40 is press-fitted into the housing, it is possible to suppress the occurrence of galling at the portion of the collar 30 that contacts the housing.

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

In addition, even when the 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 thickness of the bearing 40 is large, it can be easily formed.
In this embodiment, the two bushes 20 and 20 are press-fitted into the collar 30. For example, three bushes 20, 20, and 20 are press-fitted into the collar 30, and the bushes 20, 20, 20 are between the bushes 20, 20, 20. 3 or more bushes 20, 20... Can be press-fitted into the collar 30.

[Second Embodiment]
Next, a bearing 140 which is a sliding member according to the second embodiment will be described with reference to FIG.
In addition, about the bearing 140 demonstrated in this embodiment, since the structure and manufacturing method are substantially the same as said 1st embodiment, below, it demonstrates centering on a different part from 1st embodiment.

  In the bearing 140 which is a sliding member according to the present embodiment, a bushing 120 is formed by bending a bimetallic sintered alloy formed by sintering metal powder on the surface of the back metal 15 which is a plate-like metal member. Is molded. At this time, a groove 140b is formed by groove processing at the stage of the plate-like sintered alloy 10 as shown in FIG. As a result, as shown in FIG. 3B, when the shaft A is inserted through the inner peripheral surface of the bearing 140, it functions so that the lubricating oil passes through the grooves 140b and 140b separately from the groove 40a. is there.

  In the configuration according to the present embodiment, the groove 140b for the lubricating oil can be separately formed even when the number of grooves is insufficient with only the grooves 40a formed between the bushes 120 and 120. This is particularly useful when the axial length is relatively long.

  As described above, according to the present embodiment, grooves and indents are formed on the inner peripheral surface of the bearing 140 by forming grooves and indents by groove processing or indent processing at the stage of the plate-like sintered alloy. Thus, the sliding characteristics on the inner peripheral surface of the bearing 140 are further improved.

10 Sintered Alloy 11 Sintered Layer 15 Back Metal 20 Bush 30 Color 40 Bearing 40a Groove

Claims (6)

A plurality of bushes that are cylindrical members are sliding members that are formed by being press-fitted into a collar that is a cylindrical member,
A gap is formed between the bushes on the inner peripheral surface of the collar,
The gap is configured as a groove for lubricating oil,
A sliding member characterized by that. Two bushes are pressed into the collar from both sides,
The sliding member according to claim 1. The bush is formed by a bimetallic sintered alloy formed by sintering metal powder on the surface of the back metal which is a plate-like metal member.
The sliding member according to claim 1 or 2, characterized by the above. A plurality of bushes that are cylindrical members are press-fitted into a collar that is a cylindrical member,
Forming a gap between the bushes on the inner peripheral surface of the collar;
Configuring the gap as a groove for lubricating oil;
A method for manufacturing a sliding member. In the collar, the two bushes are press-fitted from both sides, respectively.
The manufacturing method of the sliding member of Claim 4 characterized by the above-mentioned. The bush is formed of a bimetallic sintered alloy formed by sintering metal powder on the surface of a back metal that is a plate-like metal member.
The manufacturing method of the sliding member of Claim 4 or Claim 5 characterized by the above-mentioned.

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