JP4463079B2 - Sliding bearing manufacturing method and sliding bearing - Google Patents

Description

  The present invention relates to a sliding bearing manufacturing method and a sliding bearing.

  A slide bearing can support a rotating shaft and the like in a more compact space than a rolling bearing, and is economically advantageous. Conventionally, these plain bearings are made by cutting a metal tube as a raw material, rounding and welding a metal strip of the raw material into a ring, forming a cup shape by pressing a metal plate as a raw material, and this cup-shaped product Is manufactured by a method of cutting a ring, and steel, white metal or the like is used as a metal material.

  In many cases, a plain bearing manufactured by these manufacturing methods is formed into a cylindrical shape by cutting or welding, and then an oil groove is formed on its inner surface by grinding or coining. (For example, refer to Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 2002-263955 Japanese Patent Laid-Open No. 11-37156

A conventional slide bearing manufacturing method in which an oil groove is formed on the inner diameter surface by grinding or coining after being formed into a cylindrical shape by the above-described machining or welding is performed by grinding or There is a problem that a separate process of the coining process is required, which increases the manufacturing process and increases the manufacturing cost.
Of the above-described sliding bearing manufacturing methods, the method of cutting a metal tube as a raw material has a large amount of cutting, a low material yield, and a high manufacturing cost. Moreover, the method of rounding and welding the metal strip is good in yield of the material, but the dimensional accuracy such as roundness is deteriorated. On the other hand, the method of forming by pressing using a metal plate as a raw material has the advantage that the yield of the raw material is relatively good and the dimensional accuracy is relatively excellent.

  Therefore, an object of the present invention is to manufacture a slide bearing having an oil groove on its inner diameter surface at a low cost with good dimensional accuracy.

  In order to solve the above-described problems, the present invention forms a blank made of a metal plate into a cup shape by a press process including a drawing process using a cylindrical punch, and cuts the formed cup-shaped product into a ring. In the sliding bearing manufacturing method of forming at least one cylindrical body and manufacturing a sliding bearing from the cylindrical body, a pressing process is provided in the press work, and a plurality of outer diameter surfaces of the cylindrical punch used in the pressing process are provided. These protrusions are formed as grooves on the inner diameter surface of the cup-shaped molded product, and the grooves transferred on the inner diameter surface of the cup-shaped molded product are formed by cutting the ring. A method of forming an oil groove on the inner diameter surface of the slide bearing while leaving the cylindrical body was adopted.

  In other words, a press working method that includes a drawing process that can form a cylindrical part with high yield and accuracy from a metal plate is adopted, and the cylindrical part is squeezed and reduced between the punch and the die for further press precision. There is an ironing process that can determine the inner diameter and thickness, etc., and a plurality of protrusions are provided on the outer diameter surface of the cylindrical punch used in the ironing process, and these protrusions serve as grooves on the inner diameter surface of the cup-shaped molded product. By transferring and transferring the grooves transferred to the inner diameter surface of the cup-shaped product to the inner surface of the slide bearing while leaving the groove cut and cut, another process for grinding and coining is performed. In this way, a slide bearing having an oil groove on the inner diameter surface can be manufactured at low cost with good dimensional accuracy. In addition, the number of the cylindrical bodies for slide bearings collected from the cup-shaped molded product may be plural.

  By setting the lubrication condition on the outer diameter side ironing surface, which is the outer diameter surface of the cup-shaped molded product in the ironing step, to a substantially fluid lubrication state, the roundness of the inner diameter of the cup-shaped molded product, the amount of uneven thickness of the cylindrical portion Further, the surface roughness of the inner diameter surface can be improved, the dimensional accuracy of the slide bearing can be further improved, and the surface roughness of the inner diameter surface serving as the bearing surface can be made fine and smooth.

  The present inventors conducted a squeezing and ironing test using an SCM415 steel sheet as a blank material using a press tester, and investigated the roundness of the inner diameter of the cup-shaped molded product and the amount of uneven thickness of the cylindrical portion. As a result, when high-viscosity press working oil with excellent lubricity is applied to the die side (the outer diameter side ironing surface of the cup-shaped molded product), the inner diameter roundness and cylinder of the cup-shaped molded product that becomes a cylindrical body for a slide bearing The present inventors have found that the uneven thickness is improved and the surface roughness of the inner diameter surface is finer and smoother than the outer diameter surface.

  First, an example of the surface roughness investigation results is shown in FIG. 6, whereas the surface roughness of the blank material is about Ra 0.49 μm on both the front and back surfaces, whereas the inner surface of the cup-shaped molded product The surface roughness is very fine, Ra 0.15 μm. The surface roughness of the outer diameter surface of the cup-shaped molded product is Ra 0.44 μm, which is not much different from the surface roughness of the blank material. The surface roughness of the inner and outer diameter surfaces of the cup-shaped molded product shown in FIG. 6 was measured in the axial direction, but the surface roughness measured in the circumferential direction was almost equivalent to these. This measurement result is the reverse of what is observed with normal drawing and ironing, and with normal drawing and ironing, the outer diameter surface of the cup-shaped product that is squeezed with a die has a finer surface roughness and an inner diameter. The surface roughness of the surface is not much different from the surface roughness of the blank material.

  The results of these surveys are considered as follows. That is, the surface roughness of the outer diameter surface of the cup-shaped molded product was not much different from the surface roughness of the material. The material to be processed and the die were hardly in contact with the ironed surface on the outer diameter side of the cup-shaped molded product. It is considered that the fluid lubrication was almost achieved. In this way, when the lubrication condition on the die side is set to a substantially fluid lubrication state, there is almost no shearing force on the ironing surface on the outer diameter side caused by friction with the die, and the stress at the ironing part between the punch and the die is reduced by the plate thickness. As shown in FIG. 7, the material is uniformly reduced in thickness in the thickness direction.

  FIG. 7 shows a plate thickness cross-sectional photograph of the upper end portion of the cup-shaped molded product. As the above estimation is verified, the upper end portion of the cup-shaped molded article in which the press working oil having excellent lubricity is applied to the die side is uniformly extended in the axial direction in the plate thickness direction. In this way, when the material is uniformly reduced in thickness in the plate thickness direction and stretched in the axial direction, the inner diameter surface of the cup-shaped molded product that contacts the punch moves relative to the punch surface in the axial direction, and this relative movement. It is considered that the surface roughness of the inner diameter surface became fine due to sliding with the punch surface. On the other hand, the outer diameter side of the upper end portion of the cup-shaped molded product obtained by normal drawing and ironing process is remarkably extended in the axial direction. This is because the outer diameter surface side of the cup-shaped molded product is preferentially reduced in thickness and sheared due to friction with the die, and the inner diameter surface side is not so reduced in thickness. As described above, in the normal drawing and ironing process in which the inner diameter surface side is not so thinly deformed, the inner diameter surface of the cup-shaped molded product hardly moves relative to the punch surface, so the surface roughness is not much different from that of the material.

  In the processing method in which the lubrication condition on the outer diameter side ironing surface is in a substantially fluid lubrication state, as shown in FIG. 7, the upper end surface of the cup-shaped molded product becomes uniform in the plate thickness direction. Yield can be improved. Further, by reducing the blank diameter, the press load necessary for drawing is also reduced.

  Next, with respect to the inner diameter roundness and the cylindrical portion thickness deviation, as shown in Table 1 later, it was confirmed that excellent dimensional accuracy of 10 μm or less was obtained. The results of these surveys are considered as follows. That is, as described above, when the die-side lubrication condition in the ironing process is substantially fluid lubricated and the material is uniformly reduced in thickness in the thickness direction, the amount of uneven thickness of the cylindrical portion of the cup-shaped molded product is reduced. In addition, the inner diameter surface of the cup-shaped molded product that contacts the punch moves relatively along the punch surface in the axial direction so that it conforms to the shape of the outer diameter surface of the punch. It is considered that the degree is well maintained. On the other hand, in the normal drawing and ironing process, the inner diameter side of the cup-shaped molded product is not deformed to a great extent and hardly moves relative to the punch surface. Not much improvement.

  By reducing the number of squeezing in the squeezing process of the press working to 3 times or less and making the squeezing process a squeezing and squeezing process that is performed simultaneously with the final squeezing process, the number of dies and processes for press working are reduced. The manufacturing cost can be further reduced.

  Incidentally, it is known that the drawing and ironing process can obtain a larger drawing ratio than a simple drawing process. That is, in drawing, the drawing limit is determined by fracture at the punch shoulder due to the tensile stress caused by the deformation resistance of the shrinking flange and the wrinkle holding force at the flange. Since the tensile stress from is cut off at the ironing portion, the drawing limit becomes high and a large drawing ratio can be obtained.

  By making the number of times of drawing in the drawing process one time and making the ironing process a drawing and ironing process that is performed simultaneously with this one drawing process, the manufacturing cost can be further reduced, and dimensional accuracy due to mold setting errors, etc. The decrease can also be suppressed.

  By using a cold-rolled steel plate as the metal plate, the material cost can be reduced.

  By making the cold-rolled steel sheet a phosphate-coated steel sheet, the holding capacity of the pressing oil on the outer diameter side ironing surface in the ironing process is increased, and the outer diameter is reduced by using a lower pressing oil. The lubricating condition on the side ironing surface can be set to a substantially fluid lubrication state.

  A plain bearing manufactured by any one of the manufacturing methods described above can be inexpensive and have good dimensional accuracy.

  The manufacturing method of the plain bearing of the present invention employs a pressing method including a drawing process capable of forming a cylindrical portion with a relatively high yield and accuracy from a metal plate. In this pressing, the cylindrical portion is placed between a punch and a die. The ironing process is provided to allow the inner diameter and thickness to be more accurately determined by reducing the thickness of the ironing iron, and by providing a plurality of protrusions on the outer diameter surface of the cylindrical punch used in the ironing process, these protrusions are cup-shaped. The groove was transferred to the inner surface of the molded product as a groove, and the groove transferred to the inner surface of the cup-shaped product was left on the cylindrical body to be cut in a ring, and an oil groove was formed on the inner surface of the slide bearing. Therefore, a slide bearing having an oil groove on the inner diameter surface can be manufactured at a low cost and with good dimensional accuracy without providing a separate process of grinding or coining.

  By setting the lubrication condition on the outer diameter side ironing surface, which is the outer diameter surface of the cup-shaped molded product in the ironing step, to a substantially fluid lubrication state, the roundness of the inner diameter of the cup-shaped molded product, The surface roughness of the inner diameter surface can be improved, the dimensional accuracy of the slide bearing can be further improved, and the surface roughness of the inner diameter surface serving as the bearing surface can be made fine and smooth.

  By reducing the number of squeezing in the pressing process to 3 or less and making the ironing process a drawing ironing process that is performed at the same time as the final drawing process, the number of press molds and the number of processes can be reduced. Cost can be further reduced.

  When the number of times of drawing in the drawing process is set to 1 and the ironing process is a drawing and ironing process that is performed simultaneously with this one drawing process, the manufacturing cost can be further reduced, and the dimensional accuracy is reduced due to a setting error of the mold. Can also be suppressed.

  By using a cold-rolled steel plate as the metal plate, the material cost can be reduced.

  By using the cold-rolled steel sheet as a phosphate-coated steel sheet, the holding ability of the pressing oil on the outer diameter side ironing surface in the ironing process is increased, and a lower pressing oil is used to reduce the outer diameter side. The lubrication condition on the ironing surface can be set to a substantially fluid lubrication state.

  A plain bearing manufactured by any one of the manufacturing methods described above can be inexpensive and have good dimensional accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This plain bearing 1 is a cold-rolled steel plate (SCM415) that has been subjected to a phosphate film treatment, and as shown in FIG. 1, a plurality of oils are formed in a herringbone shape on a cylindrical inner surface. A groove 2 is formed. The oil groove 2 may have another shape such as a spiral shape.

  FIG. 2 shows a schematic process for manufacturing the slide bearing 1. First, in the punching process, the raw material SCM415-made cold-rolled steel plate made of SCM415 is punched into a circular blank, and then this blank is formed into a cup-shaped product in a single drawing and squeezing process by pressing. Is done. After that, the cup-shaped molded product is cut into a round shape in the cutting step to form a cylindrical body from which the upper end of the cup and the bottom of the cup have been removed. Finally, the cylindrical body is heat-treated in the heat treatment step to produce the plain bearing 1. The In the cutting step, a plurality of slide bearing cylindrical bodies can be cut into a ring from one cup-shaped molded product. Further, the cylindrical body can be halved to form a half-sliding bearing.

  As shown in FIG. 3, in the drawing and ironing process in which the circular blank 3 is used as the cup-shaped product 4, the lubrication condition on the outer diameter side ironing surface of the cup-shaped product 4 is substantially fluid lubricated. A press working oil having excellent lubricity is applied to the die 11 side, and a plurality of protrusions 12 a are provided in a herringbone shape on the outer diameter surface of the cylindrical punch 12, and these protrusions 12 a are cup-shaped molded products 4. The oil groove 2 is transferred to the inner diameter surface of the nozzle. As shown in FIG. 4, the cup-shaped molded product 4 released from the die 11 has a cylindrical portion whose diameter is expanded by a springback phenomenon, and an inner diameter surface on which the oil groove 2 is formed is provided with the protrusion 12a. The cup-shaped molded product 4 can be easily pulled out from the punch 12 because it is lifted from the outer diameter surface of the punch 12.

  About the plain bearing 1 manufactured by the manufacturing process of FIG. 2, the surface roughness of the circumferential direction and axial direction of the internal diameter surface was measured. The measured dimensions of the slide bearing 1 are an outer diameter of 28 mm, a length of 16 mm, and a wall thickness of 1.0 mm. The circumferential surface roughness was measured at three locations, 2 mm each from the both ends of the slide bearing 1 and the central position in the length direction, and the axial surface roughness was measured at four locations with a 90 ° phase in the circumferential direction. As shown in FIG. 6, the surface roughness of the blank material 3 is about Ra 0.49 μm on both the front and back surfaces, and the surface roughness of the outer diameter surface of the cup-shaped molded product 4 that becomes the outer diameter surface of the slide bearing 1 is Both the circumferential direction and the axial direction are about Ra 0.44 μm.

  5A and 5B show an example of the measurement results of the surface roughness. FIG. 5A shows the circumferential surface roughness measured at the center in the length direction of the slide bearing 1 and is very fine as Ra 0.18 μm. Although illustration is omitted, the circumferential surface roughness measured at positions of 2 mm from both ends is also in the range of Ra 0.05 to 0.3 μm, which is finer than the surface roughness of the blank 3 and the outer diameter surface. . FIG. 5B shows the axial surface roughness measured with one phase, which is Ra 0.15 μm. Although illustration is omitted, the axial surface roughness measured at other phases is also very fine with Ra of 0.3 μm or less.

  Table 1 shows the results of measuring the inner diameter roundness and the cylindrical part thickness deviation of the slide bearing 1. The number of measurement samples is 6, and the measurement positions in the axial direction of the inner diameter roundness and the cylindrical portion thickness deviation are the same three positions as the measurement positions of the circumferential surface roughness of the inner diameter surface. In each axial position, measurement was performed at a total of 12 locations at 4 locations with a 90 ° phase in the circumferential direction. As can be seen from these measurement results, any of the plain bearings 1 has an inner diameter roundness and a cylindrical portion thickness deviation of 10 μm or less, and good dimensional accuracy is obtained.

  In the above-described embodiment, the raw material is a phosphate-coated cold-rolled steel plate made of SCM415, and the drawing process in the press process is performed only once, and the ironing process is performed simultaneously with this one drawing process. However, the drawing process may be a drawing and ironing process in which the drawing process is performed a plurality of times of 3 or less and the ironing process is performed simultaneously with the final drawing process. Moreover, a raw material is not limited to the thing of embodiment, It can also be other types of metal plates, such as another steel plate and a white metal.

Notched front view showing an embodiment of a slide bearing Process drawing which shows the outline manufacturing process of the plain bearing of FIG. Schematic diagram illustrating the drawing and squeezing process of FIG. Front sectional drawing which shows the state which released the cup-shaped molded object shape | molded by the drawing ironing process of FIG. 3 from the die | dye. a and b are graphs showing the surface roughness in the circumferential direction and the axial direction of the inner surface of the plain bearing manufactured in the manufacturing process of FIG. Graph showing the surface roughness of the inner and outer diameter surfaces of the cup-shaped molded product and the surface roughness of the blank material in the drawing ironing test Thickness cross-sectional photograph of the upper end of a cup-shaped product in the drawing ironing test

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sliding bearing 2 Oil groove 3 Blank 4 Cup-shaped molding 11 Die 12 Punch 12a Projection

Claims (6)

A blank made of a metal plate is formed into a cup shape by a press process including a drawing process using a cylindrical punch, and the formed cup-shaped product is cut into round pieces to form at least one cylindrical body. In the manufacturing method of a sliding bearing for manufacturing a sliding bearing from a cylindrical body, an ironing step is provided in the pressing process, and a lubrication condition on an outer-diameter side ironing surface that is an outer diameter surface of the cup-shaped molded product in the ironing step is In a substantially fluid lubrication state , a plurality of ridges are provided on the outer diameter surface of the cylindrical punch used in the ironing process, and these ridges are transferred as grooves to the inner diameter surface of the cup-shaped molded product. An oil groove is formed on the inner diameter surface of the slide bearing while leaving the groove transferred to the inner diameter surface of the object in the cylindrical body formed by cutting the ring. The diaphragm the number stop at step was 3 times or less, the ironing method for producing a sliding bearing according to claim 1 which process to a final times of the stop step and simultaneously drawn and ironed process. The sliding bearing manufacturing method according to claim 2 , wherein the number of times of drawing in the drawing step is one, and the ironing step is a drawing and ironing step performed simultaneously with the single drawing step. The manufacturing method of the slide bearing in any one of Claim 1 thru | or 3 which used the metal plate of the said raw material as the cold rolled steel plate. The manufacturing method of the sliding bearing of Claim 4 which used the said cold-rolled steel plate as the phosphate film processing steel plate. A plain bearing manufactured by the manufacturing method according to claim 1 .