Method for producing surface-treated cylindrical body

Abstract

To provide a new technique for surface-treating only the outer surface of a cylindrical body.SOLUTION: A means for solving the above problem is a method of manufacturing a surface-treated cylindrical body, the method comprising a closing step of liquid-tightly closing an opening of the cylindrical body in order to prevent expansion of air, and a surface treatment step of immersing the cylindrical body having the closed opening in a surface treatment liquid, wherein the closing step includes filling the inside of the cylindrical body with a filling member and liquid-tightly closing the opening of the cylindrical body with a lid member, and, in the surface treatment step, the tubular body is immersed in a surface treatment liquid at a temperature higher than the outside air temperature to surface-treat the outer surface of the tubular body without surface-treating the inner surface of the tubular body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a surface-treated cylindrical body. [Background technology]

[0002] The cylindrical body is used as a component of a bearing unit for a railway vehicle (Patent Documents 1 and 2). In particular, a cylindrical body having a narrowed portion that narrows from the opening side of the cylindrical body toward the center of the cylindrical body is used as a component of a bearing unit for a railway vehicle (outer ring, see Figure 6). Also, it is conventionally known to perform a surface treatment of the cylindrical body (chemical conversion treatment to form an oxide film; manganese phosphate treatment (phosphate coating treatment)) in order to improve the life and initial break-in of the bearing unit for a railway vehicle (Patent Document 2).

[0003] Here, when using it as a component (outer ring) of a bearing unit for a railway vehicle, it was necessary to perform surface treatment only on the outer surface of the cylindrical body.

[0004] A known prior art technique involves placing a covered cylinder on a mesh jig and immersing the cylinder in a surface treatment solution at a temperature higher than the ambient temperature, thereby performing a surface treatment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-129252 [Patent Document 2] Patent No. 6789430 Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional method, when a covered cylinder is immersed in a surface treatment solution whose temperature is higher than the ambient temperature, the air inside expands, causing the lid to come off. When the lid comes off the cylinder, the inner surface of the cylinder may also be surface-treated.

[0007] As a result of intensive research, the inventors have developed a new technique for surface treating only the outer surface of a cylindrical body. That is, an object of the present invention is to provide a new technique for surface treating only the outer surface of a cylindrical body.

[0008] Furthermore, a preferred embodiment of the present invention has as its object to provide a novel technique for surface treating only the outer surface of a cylindrical body.

[0009] Another object of a preferred embodiment of the present invention is to provide a new manufacturing technique for a cylindrical body that can be used as a component (outer ring) of a bearing unit for a railway vehicle. [Means for solving the problem]

[0010] [1] The present invention, which solves the above-mentioned problems, is a method for manufacturing a surface-treated cylindrical body. The present invention is characterized by comprising a closing step of liquid-tightly closing the opening of the cylindrical body, and a surface treatment step of immersing the cylindrical body with the closed opening in a surface treatment liquid. The closing step of the present invention is characterized in that it includes filling the inside of the cylindrical body with an interposing member and liquid-tightly closing the opening of the cylindrical body with a lid member. Furthermore, the surface treatment process of the present invention is characterized in that the cylindrical body is immersed in a surface treatment liquid at a temperature higher than the ambient temperature, thereby surface treating the outer surface of the cylindrical body without surface treating the inner surface of the cylindrical body.

[0011] [2] In a preferred embodiment of the present invention, the closing step includes filling the interposing member into each of the openings of the cylindrical bodies at least one by one; the inner surface of the cylindrical body has a narrowed portion that narrows from the opening side of the cylindrical body toward the center of the cylindrical body, The interposing member has a reduced diameter portion that reduces in diameter to correspond to the narrowed portion of the cylindrical body. [1] A method for manufacturing the surface-treated cylindrical body described above.

[0012] [3] In a preferred embodiment of the present invention, the lid member has a lid main body and a closing part that closes the opening by fitting into the inner surface of the opening of the cylindrical body, the blocking portion is made of an elastic material; The method for manufacturing a surface-treated cylindrical body according to [1] or [2], wherein the interposing member is made of a resin material.

[0013] [4] In a preferred embodiment of the present invention, in a state where the interposing member is filled in the cylindrical body and the opening of the cylindrical body is closed with the lid member, The method for manufacturing a surface-treated cylindrical body according to any one of [1] to [3], wherein the volume of air remaining in the cylindrical body after the closing step is lower than 1 / 200 of the volume of air remaining when the opening of the cylindrical body is closed only by the lid member.

[0014] [5] A preferred embodiment of the present invention is the method for manufacturing a surface-treated cylindrical body according to any one of [1] to [4], wherein the cylindrical body is a cylindrical body.

[0015] [6] The present invention also provides a method for manufacturing a bearing unit for a railway vehicle, characterized in that the cylindrical body is a cylindrical body and is manufactured by the manufacturing method described in [5], and a surface-treated cylindrical body is used.

[0016] [7] The present invention also provides a method for manufacturing a rolling bearing, characterized in that the cylindrical body is a cylindrical body and is a surface-treated cylindrical body manufactured by the manufacturing method described in [5]. [Effects of the Invention]

[0017] According to the present invention, a new technique for surface treating only the outer surface of a cylindrical body can be provided. [Brief explanation of the drawings]

[0018] [Figure 1] 3 is a flowchart showing each step in a manufacturing method of the cylindrical body 1 of the present embodiment. [Figure 2] 3A to 3C are schematic diagrams illustrating a closing step and a surface treatment step in the manufacturing method of the cylindrical body 1 of the present embodiment. [Figure 3] 1A and 1B are diagrams showing a cylindrical body 1 of the present embodiment, in which (1) is a perspective view and (2) is a cross-sectional schematic view. [Figure 4] 1A and 1B are a front view and a plan view, respectively, of an interposing member 2 of the present embodiment. [Figure 5] 1A and 1B are a front view and a bottom view, respectively, of a cover member 3 of the present embodiment. [Figure 6] 1 is a reference schematic diagram showing one aspect of a bearing unit for a railway vehicle according to an embodiment of the present invention; [Figure 7] 1 is a diagram showing an example of the remaining air volume inside a conventional cylindrical body and a state in which the air expands when immersed in a surface treatment liquid 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] A method for manufacturing the surface-treated cylindrical body 1 will be described below, but it goes without saying that the technical scope of the present invention is not limited to the examples.

[0020] <1> Manufacturing method of surface-treated cylindrical body 1 The present invention is a method for manufacturing a surface-treated cylindrical body 1, a closing step of liquid-tightly closing the opening 11 of the cylindrical body 1; a surface treatment step of immersing the cylindrical body 1 with the closed opening 11 in a surface treatment liquid 5; This is a method for manufacturing a surface-treated cylindrical body 1 having the above structure.

[0021] The closing step in the present invention is characterized in that the interposing member 2 is filled into the inside of the cylindrical body 1 and the opening 11 of the cylindrical body 1 is closed liquid-tightly with the lid member 3. Furthermore, the surface treatment process in the present invention is characterized in that the cylindrical body 1 is immersed in a surface treatment liquid 5 at a temperature higher than the ambient temperature, thereby surface treating the outer surface of the cylindrical body 1 without surface treating the inner surface 13 of the cylindrical body 1.

[0022] By filling the inside of the cylindrical body 1 with the interposing member 2 and liquid-tightly sealing the opening 11 of the cylindrical body 1 with the lid member 3, the volume of air remaining in the cylindrical body 1 after the closing step is reduced. Furthermore, by reducing the volume of air remaining in the cylindrical body 1 after the closing step, it is possible to suppress the degree of air expansion due to heating, even when the cylindrical body 1 is immersed in the surface treatment liquid 5 whose temperature is higher than the outside air temperature. Therefore, by adopting the above-mentioned configuration, it is possible to suppress the degree of air expansion due to heating, and therefore the lid member 3 is less likely to come off the cylindrical body 1. That is, by adopting the above-described embodiment, the inner surface 13 of the cylindrical body 1 is not surface-treated, and the outer surface of the cylindrical body 1 can be selectively surface-treated.

[0023] A preferred embodiment of the method for manufacturing the surface-treated cylindrical body 1 will now be described in detail. First, the cylindrical body 1, which is the object to be surface treated, will be described in more detail.

[0024] In this embodiment, the cylindrical body 1 serving as the object to be surface treated is a cylindrical body. However, in the present invention, there is no particular limitation on the shape of the object to be surface treated, as long as it is a cylindrical body 1.

[0025] In this embodiment, the cylindrical body 1 is made of metal. Here, preferred examples of the metal include steel and iron. There is no particular limitation on the material of the cylindrical body 1, and examples of the cylindrical body 1 include metal, wood, and rubber.

[0026] Furthermore, the cylindrical body 1 is not particularly limited in its use, and a preferred example is the cylindrical body 1 for a bearing unit A for a railway vehicle (outer ring of a bearing unit A for a railway vehicle).

[0027] There is also no particular limitation on the size of the cylindrical body 1. The overall shape of the cylindrical body may be one in which one opening 11 and the other opening 11 are different in size (for example, a cylindrical body in the shape of a truncated cone).

[0028] In a preferred embodiment of the present invention, the inner surface 13 of the cylindrical body 1 has a narrowed portion 131 that narrows from at least one opening 11 side of the cylindrical body 1 toward the center of the cylindrical body 1 .

[0029] In a preferred embodiment of the present invention, the cylindrical body 1 has narrowed portions 131 that narrow from both openings 11 toward the center of the cylindrical body 1 .

[0030] In a preferred embodiment of the present invention, the central portion of the cylindrical body 1 has a central inner surface portion 132 that has a shape similar to that of the opening 11 but has a smaller inner diameter than the opening 11 .

[0031] Each step in the method for manufacturing the surface-treated cylindrical body 1 will be described in more detail below with reference to FIG.

[0032] (S1) Closure process In this specification, the closing step is a step of closing the opening 11 of the cylindrical body 1 liquid-tightly.

[0033] In this embodiment, the closing step includes filling the inside of the cylindrical body 1 with the interposing member 2 and closing the opening 11 of the cylindrical body 1 with the lid member 3 in a liquid-tight manner. By adopting the above-described embodiment, the outer surface of the cylindrical body 1 can be surface-treated without surface-treating the inner surface 13 of the cylindrical body 1.

[0034] First, the interposing member 2 and the lid member 3 will be described in more detail.

[0035] (i) Filling member 2 In this specification, the interposing member 2 is a member that fills the inside of the cylindrical body 1 and reduces the volume of air remaining in the cylindrical body 1 after the closing step.

[0036] The shape of the interposing member 2 preferably has a side surface that corresponds to the internal shape of the above-mentioned cylindrical body 1. Furthermore, the side surface preferably has a shape that follows the narrowed portion 131 of the cylindrical body 1 when the interposing member 2 is filled inside the cylindrical body 1.

[0037] As a preferred embodiment of the interposing member 2, when the internal shape of the cylindrical body 1 includes a cylindrical portion, it is preferable that the interposing member 2 comprises a truncated cone portion 21 and a cylindrical portion 22. By adopting the above-mentioned form, the interposing member 2 can easily reduce in diameter in correspondence with the narrowed portion 131 of the cylindrical body 1, further reducing the remaining air volume within the cylindrical body 1. In addition, the truncated cone portion 21 makes it easy to attach and detach the interposing member 2.

[0038] As a preferred embodiment of the interposing member 2, when the internal shape of the cylindrical body 1 includes a rectangular cylindrical portion, it is preferable that the interposing member 2 has a frustum portion and a column portion. By adopting the above-mentioned form, the interposing member 2 can easily reduce in diameter in accordance with the narrowed portion 131 of the cylindrical body 1, further reducing the remaining air volume inside the cylindrical body 1. In addition, the frustum portion makes it easy to attach and remove the interposing member 2.

[0039] The interposing member 2 preferably has a tapered portion 211 whose diameter is reduced. The interposing member 2 preferably has a reduced diameter portion 211 whose diameter is reduced to correspond to the narrowed portion 131 of the cylindrical body 1 . By adopting the above-mentioned configuration, when the interposing member 2 is filled into the cylindrical body 1, the volume of air remaining in the cylindrical body 1 can be further reduced.

[0040] In this embodiment, the interposing member 2 also has a gripping hole 23 . Here, it is preferable that there are two or more gripping holes 23. Furthermore, it is preferable that gripping holes 23 are arranged at positions where fingers can be inserted into each of them with one hand. By adopting the above configuration, no special tools are required and the interposing member 2 can be easily attached and detached manually. This makes it easy to replace and adjust the interposing member 2, and reduces the operating costs of the cylindrical body 1.

[0041] Here, the size of the interposing member 2 is not particularly limited as long as it corresponds to the size of the cylindrical body 1.

[0042] Here, the interposing member 2 is preferably made of a resin material. The resin material is preferably a nylon resin material. Preferred examples of the nylon resin material include monomer cast nylon (MC nylon), nylon 6, and nylon 66. Among them, the nylon resin material is preferably monomer cast nylon (MC nylon). By adopting the above-mentioned configuration, the inside of the cylindrical body 1 is less likely to be damaged, and the interposing member 2 can be made lightweight, resulting in better workability.

[0043] Moreover, the interposing member 2 is preferably made of a material that is durable and chemical-resistant.

[0044] (ii) Lid member 3 In this specification, the cover member 3 is a member that closes the opening 11 of the cylindrical body 1 in a liquid-tight manner. The lid member 3 has a lid main body 31 and a closing part 32 that closes the opening 11 by being fitted onto the inner surface 13 of the opening 11 of the cylindrical body 1.

[0045] The cover member 3 is preferably made of an elastic material. The cover member 3 is preferably made of a rubber material.

[0046] Furthermore, the cover member 3 preferably has at least one of weather resistance, ozone resistance, chemical resistance, and heat resistance, more preferably two or more, more preferably three or more, and even more preferably all of these properties.

[0047] Here, the cover member 3 is preferably made of a hard elastic material. A preferred example of the hard elastic material is ethylene propylene rubber (EPDM).

[0048] The hardness of the lid member 3 made of an elastic material is preferably 55 degrees or more, preferably 60 degrees or more, and more preferably 65 degrees or more. Here, the hardness of the elastic material can be a value measured using a known hardness meter. Furthermore, the hardness values ​​of the elastic materials mentioned above are values ​​that do not include hardness tolerances, and products that fall within the range of hardness tolerances are also included in the lower limit values ​​of the hardness mentioned above.

[0049] The hardness of the lid member 3 made of an elastic material is preferably 75 degrees or less, and more preferably 70 degrees or less.

[0050] However, in the present invention, the blocking portion 32 may be made of any elastic material.

[0051] It is preferable that the overall shape of the cover member 3 when viewed from above corresponds to the shape of the inner surface 13 of the cylindrical body 1. Here, when the cylindrical body 1 is a cylindrical body, the overall shape of the lid member 3 is a disk shape.

[0052] The outer shape of the lid main body 31 is similar to the shape of the inner surface 13 of the cylindrical body 1, but is larger than the inner surface 13 of the cylindrical body 1. With the above configuration, the closing portion 32 made of an elastic material is fitted into the cylindrical body 1, and the lid main body 31 closes the opening 11 of the cylindrical body 1, thereby making it possible to close the cylindrical body 1 liquid-tightly.

[0053] It is also preferable that the lid body 31 has no holes. However, the lid member 3 may have small holes that are capable of liquid-tightly closing the cylindrical body 1.

[0054] The closing portion 32 preferably has a closing means 33 having an outer shape larger than the inner surface 13 of the cylindrical body 1, and a groove portion . By adopting the above-mentioned configuration, when the closing portion 32 made of an elastic material is inserted under an external force, the closing means 33 is folded, and when the external force is removed, the cylindrical body 1 can be closed liquid-tightly.

[0055] In this embodiment, there are two closing means 33 and two grooves 34 (see first closing means 331, first groove 341, second closing means 332, and second groove 342 in the drawing). By adopting the above-mentioned configuration, the cylindrical body 1 can be closed liquid-tightly more reliably.

[0056] (iii) Closure process The closing step of using the above (i) interposing member 2 and (ii) lid member 3 on the cylindrical body having the narrowed portion 131 will be described in more detail below.

[0057] First, a cylindrical body having a narrowed portion 131 is prepared. Next, the cylinder is filled with the interposing member 2. At this time, the interposing member 2 is filled so that the reduced diameter portion 211 of the interposing member 2 corresponds to the narrowed portion 131 of the cylinder. More specifically, at least one interposing member 2 is filled into each opening 11 of the cylindrical body. In this embodiment, the faces of the cylindrical portions 22 of the filled interposing members 2 are arranged so as to face each other. Then, the cover member 3 is fitted into each opening 11 of the cylindrical body so as to seal it liquid-tightly.

[0058] The closing portion 32 is designed to be slightly larger than the opening 11 of the cylindrical body 1 , so that the closing portion 32 made of an elastic material is compressed and comes into close contact with the inner surface 13 of the cylindrical body 1 . By adopting the above configuration, the liquid-tightness inside the cylindrical body 1 can be ensured.

[0059] Furthermore, the lid body 31 is designed to be larger than the opening 11 of the cylindrical body 1, so that the closing part 32 made of an elastic material is compressed to close the opening surface of the cylindrical body 1 liquid-tightly. By adopting the above configuration, the liquid-tightness inside the cylindrical body 1 can be ensured.

[0060] In a state where the interposing member 2 is filled into the cylindrical body 1 and the opening 11 of the cylindrical body 1 is closed with the lid member 3, When the remaining air volume in the cylindrical body 1 after the closing step is taken as 1 when the remaining air volume in a state in which the opening 11 of the cylindrical body 1 is closed only by the lid member 3, the remaining air volume is preferably lower than 1 / 3, more preferably lower than 1 / 5, more preferably lower than 1 / 10, more preferably lower than 1 / 15, more preferably lower than 1 / 20, more preferably lower than 1 / 50, more preferably lower than 1 / 100, and more preferably lower than 1 / 200.

[0061] Here, the remaining air volume when the opening 11 of the cylindrical body 1 is closed only by the cover member 3 is 4,288 cm 3 The remaining air volume in the cylindrical body 1 after the closing step (filling with the interposing member 2 and closing with the lid member 3) of this example was 20 cm 3 It was.

[0062] Furthermore, in a preferred embodiment of the present invention, the cover member 3 does not cover the outer surface 12 of the cylindrical body 1 even after the closing step.

[0063] The relationship between the cylindrical body 1, the lid member 3, and the interposing member 2 after the closing step is as follows. First, the interposing member 2 is filled inside the cylindrical body, and its shape and material reduce the remaining air volume in the cylinder. Next, the lid member 3 is fitted into the opening 11 of the cylindrical body, and because the closing portion 32 is made of an elastic material, it tightly adheres to the inner surface 13 of the cylinder. By adopting the above configuration, the opening 11 of the cylindrical body 1 can be liquid-tightly closed with both the lid member 3 and the interposing member 2 effectively reducing the remaining air volume in the cylinder. As described above, the cylindrical body 1, the cover member 3, and the interposing member 2 work in conjunction with each other to effectively reduce the volume of air remaining in the cylindrical body 1 and improve the airtightness and durability of the cylindrical body 1.

[0064] (S2) Surface treatment process In this specification, the surface treatment step is a step of immersing the cylindrical body 1 with the opening 11 closed in the surface treatment liquid 5. Here, the surface treatment liquid 5 is a surface treatment liquid having a temperature higher than the outside air temperature. Normally, when an object to be surface-treated is immersed in a surface treatment liquid 5 having a temperature higher than the ambient temperature, the air inside the object expands. Therefore, in the present invention, the expansion of the air is suppressed and the lid member 3 is made difficult to remove, so it is preferable to immerse the object to be surface-treated in the surface treatment liquid 5 having a temperature higher than the ambient temperature. Here, the surface treatment liquid 5 is preferably a liquid having a temperature that is, for example, 10°C or more higher than the ambient temperature, preferably 20°C or more higher, preferably 30°C or more higher, preferably 40°C or more higher, preferably 60°C or more higher, preferably 80°C or more higher, or preferably 100°C or more higher.

[0065] The surface treatment liquid 5 is preferably a liquid having a temperature of, for example, 50°C or higher, preferably 60°C or higher, preferably 70°C or higher, preferably 80°C or higher, preferably 100°C or higher, or preferably 120°C or higher. Furthermore, the surface treatment liquid 5 may be, for example, a liquid having a temperature below the boiling point, preferably below 300°C, preferably below 200°C, preferably below 150°C, preferably below 100°C, or preferably below 80°C.

[0066] Here, when the object to be surface-treated is immersed in the liquid tank, it is preferable that the object to be surface-treated after the closing step is placed in a basket 4 having a handle 41 and immersed in the surface treatment liquid 5 (the same applies to the subsequent steps). In the method of the present invention, the opening 11 of the cylindrical body 1 is closed by the lid member 3. Therefore, by placing the cylindrical body on the basket 4 so that the lid member 3 becomes the bottom surface, the cylindrical body will not be damaged. Furthermore, since the cover member 3 is formed larger than the opening 11, when the cylindrical bodies 1 are placed on the basket 4, they are less likely to come into contact with each other.

[0067] In this specification, "surface treatment" includes any of chemical conversion treatment, film formation by coating with a liquid agent, and surface treatment by surface processing or modification.

[0068] Examples of chemical conversion treatments include manganese phosphate treatment (phosphate coating treatment), passivation treatment (passivation treatment), sulfurization treatment, chromate treatment, and black dyeing.

[0069] In this specification, manganese phosphate treatment (phosphate coating treatment) refers to a treatment for forming a phosphate film on a metal surface.

[0070] Manganese phosphate treatment (phosphate coating treatment) makes it possible to manufacture a cylindrical body 1 with excellent rust prevention and wear resistance. Therefore, by using manganese phosphate treatment (phosphate coating treatment) as the surface treatment, it is possible to provide a cylindrical body 1 with even better rust prevention and wear resistance. Furthermore, by filling the inside of the cylindrical body 1 with the filling member 2, sealing the opening 11 of the cylindrical body 1 liquid-tightly with the lid member 3, and immersing the cylindrical body 1 in a surface treatment liquid 5 at a temperature higher than the outside air temperature, only the outer surface 12 of the cylindrical body 1 can be manganese phosphate treated (phosphate coating treated), thereby providing a cylindrical body 1 with an even more aesthetically pleasing appearance.

[0071] Examples of film formation by coating with a liquid agent include film formation using a liquid metal, dyeing, silicone film formation, and oil film formation.

[0072] Surface treatments for surface processing and modification include degreasing and polishing.

[0073] Hereinafter, a detailed description will be given of a case where the manufacturing method of the cylindrical body 1 of the present invention is applied to manganese phosphate treatment (phosphate coating treatment) of the cylindrical body 1 (outer ring) for a bearing unit A for a railway vehicle, with reference to Fig. 2. Hereinafter, the cylindrical body 1 after the closing step, filled with the interposing member 2, and fitted with the lid member 3, will also be simply referred to as the surface-treated object after the closing step.

[0074] The manufacturing method of the manganese phosphate treated (phosphate coated) cylindrical body 1 according to this embodiment includes a degreasing operation S21, a water washing operation S22, a surface adjustment operation S23, a phosphate coating formation operation S24, a cooling operation S25, a cleaning operation S26, a drying operation S27, and an oil immersion operation S28 (see FIG. 1).

[0075] Each task will be explained in detail below. Here, in the manufacturing method of the cylindrical body 1 of the present invention, it is not necessary to carry out all of the above steps, and steps can be selected appropriately according to the material and surface condition of the cylindrical body 1. Furthermore, in the present invention, the lid member 3 may be removed as appropriate during the following operations, provided that the effects of the present invention are not impaired. Furthermore, the operations (such as washing with water) may be performed with the lid member 3 removed, provided that the effects of the present invention are not impaired.

[0076] (Degreasing work S21) The degreasing work is a work of degreasing the cylindrical body 1 using a degreasing agent. Here, the degreasing agent may be either an alcohol-based degreasing agent or a petroleum solvent-based degreasing agent.

[0077] Here, the degreasing operation can be performed by immersing the object to be surface-treated after the closing step in a degreasing tank filled with a degreasing agent, thereby degreasing only the outer surface 12 of the object to be surface-treated.

[0078] When immersing in a degreasing tank containing a degreasing agent, the immersion time is preferably 5 minutes or more. By immersing in the degreasing tank for a time longer than the lower limit, it is possible to more reliably degrease only the outer surface 12 of the surface treatment object.

[0079] When the substrate is immersed in a degreasing tank containing a degreasing agent, the immersion time is preferably 15 minutes or less.

[0080] (Water washing work S22) The water washing operation S22 is an operation of washing the cylindrical body 1 with water after the degreasing operation S21. By washing the object to be surface-treated with water after the degreasing operation S21, the degreasing agent and oil remaining on the object to be surface-treated can be removed. Here, a shower can be used for the washing operation.

[0081] (Surface adjustment work S23) The surface conditioning step S23 is a step of conditioning the surface of the cylindrical body 1 after the water washing step S22 using a conditioning treatment liquid before the phosphate coating formation step.

[0082] (Phosphate coating work S24) The phosphate coating formation process is a process in which the object to be surface-treated after the blocking process is immersed in a manganese phosphate treatment (phosphate coating) liquid (surface treatment liquid 5) to perform a manganese phosphate treatment (phosphate coating) on ​​the object to be surface-treated.

[0083] In a preferred embodiment of the present invention, the cylindrical body 1 is subjected to manganese phosphate treatment (phosphate coating treatment) by immersing the object to be surface-treated after the closing step in a liquid tank containing manganese phosphate treatment (phosphate coating treatment) liquid (surface treatment liquid 5).

[0084] When immersing in a liquid tank containing manganese phosphate treatment (phosphate coating treatment) liquid (surface treatment liquid 5), the immersion time is preferably 5 minutes or more. By immersing the object for a time equal to or longer than the lower limit, it is possible to more reliably subject only the outer surface 12 of the object to be surface treated to manganese phosphate treatment (phosphate coating treatment).

[0085] When the substrate is immersed in a liquid tank containing a manganese phosphate treatment (phosphate coating treatment) liquid (surface treatment liquid 5), the immersion time is preferably 60 minutes or less. By immersing the object for a time equal to or less than the upper limit, only the outer surface 12 of the object to be surface treated can be subjected to manganese phosphate treatment (phosphate coating treatment).

[0086] The phosphate coating formation process may be carried out by heating at a temperature equal to or higher than the ambient temperature, more preferably at a temperature equal to or higher than the evaporation temperature of the liquid agent. Heating at a temperature equal to or higher than the lower limit causes convection of the liquid agent. Here, according to the present invention, even when heated at a temperature equal to or higher than the lower limit, the lid member 3 is unlikely to come off.

[0087] Here, the heating temperature of the liquid tank containing the manganese phosphate treatment (phosphate coating treatment) liquid (surface treatment liquid 5) is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher. Heating at a temperature equal to or higher than the lower limit evaporates the water contained in the manganese phosphate treatment (phosphate coating treatment) solution. The evaporation of water causes convection in the solution. Here, according to the present invention, the lid member 3 is unlikely to come off even when heated at a temperature equal to or higher than the lower limit.

[0088] The heating temperature of the liquid tank containing the manganese phosphate treatment (phosphate coating treatment) liquid (surface treatment liquid 5) is preferably 145°C or lower.

[0089] (Cooling work S25) The cooling operation is an operation for cooling the cylindrical body 1 after the phosphate coating forming operation S24. Here, the cooling operation can take the form of immersing the object to be surface treated after the closing step in a water tank to cool the cylindrical body 1.

[0090] (Cleaning work S26) The cleaning operation is an operation for cleaning the cylindrical body 1 after the cooling operation S25. The cleaning operation may include rinsing with water.

[0091] More preferably, the cleaning step includes cleaning with hot water. Here, the cooling operation can take the form of washing the surface-treated object by immersing the surface-treated object after the closing step in a hot water bath.

[0092] (Drying work S27) The drying operation is an operation for drying the outer surface 12 of the object to be surface treated after cleaning. The drying operation can be carried out using an air gun.

[0093] (Oil immersion work S28) The oiling process involves coating the dried surface-treated object with anti-rust oil. Here, the oil immersion work can be performed by immersing the object to be surface treated in an oil tank filled with rust-preventive oil, thereby coating the cylindrical body 1 with the rust-preventive oil.

[0094] A method for manufacturing the railway vehicle bearing unit A using the surface-treated cylindrical body 1 described above will be described below.

[0095] Known methods can be cited (for example, JP 2017-129252 A) as a method for manufacturing a railway vehicle bearing unit A using the above-mentioned cylindrical body 1. More specifically, the method can be a method of manufacturing by combining an inner ring B having a raceway surface, an outer ring (corresponding to the surface-treated cylindrical body in the present invention) having a raceway surface opposing the raceway surface of the inner ring B, and a plurality of rollers that are rollably arranged between the raceway surface of the inner ring B and the raceway surface of the outer ring.

[0096] However, in the present invention, the specific embodiment of the manufacturing method for the railway vehicle bearing unit A using the above-mentioned cylindrical body 1 is not particularly limited, and any known manufacturing method can be adopted. [Example]

[0097] A manganese phosphate-treated (phosphate coating treatment; surface treatment) cylindrical body 1 was manufactured by a manufacturing method including the steps of degreasing operation S21 to oil-soaking operation S28 (see FIG. 1) and varying the above-mentioned conditions.

[0098] Visual inspection of the manufactured cylindrical body 1 revealed that no exposed metal prior to the manganese phosphate treatment (phosphate coating treatment) was found on the outer surface 12 of the cylindrical body. It was also confirmed that the inner surface of the cylindrical body was not subjected to manganese phosphate treatment (phosphate coating treatment). In other words, it was found that by filling the inside of the cylindrical body 1 with the filling member 2 of this embodiment, sealing the opening 11 of the cylindrical body 1 liquid-tightly with the lid member 3, and immersing the cylindrical body 1 in a surface treatment liquid 5 at a temperature higher than the outside air temperature, it is possible to perform manganese phosphate treatment (phosphate coating treatment; surface treatment) on only the outer surface 12. This is because the volume of air remaining in the cylindrical body 1 after the closing step is reduced by filling the inside of the cylindrical body 1 with the interposing member 2 and liquid-tightly closing the opening 11 of the cylindrical body 1 with the lid member 3. Furthermore, it is believed that the reduction in the volume of air remaining in the cylindrical body 1 after the closing step makes it possible to suppress the degree of expansion of the air due to heating, even when the cylindrical body 1 is immersed in the surface treatment liquid 5 whose temperature is higher than the outside air temperature. It was also found that by adopting the above-mentioned configuration, the rolling surface (functional surface) of the cylindrical body 1 can be coated with a surface film without surface treatment. [Industrial Applicability]

[0099] The present invention can be used for surface treatment of the cylindrical body 1. [Explanation of symbols]

[0100] 1 cylinder 11 Opening 12 Outer surface 13 Inner 131 Stenosis 132 Central inner surface 2 Filling material 21 Cone truncated part 211 Reduced diameter part 22 Cylinder 23 Gripping hole 3 Cover member 31 Lid body 32 Occlusion 33 Obstruction means 331 First blocking means 332 Second blocking means 34 Groove 341 First groove 342 Second groove 4 basket 41 Toride 5. Surface treatment liquid A. Bearing units for railway vehicles B. Inner circle C rolling element X Conventional Technology Y Residual air

Claims

1. A method for manufacturing a surface-treated cylindrical body, comprising: a closing step of liquid-tightly closing the opening of the cylindrical body; a surface treatment step of immersing the cylindrical body with the closed opening in a surface treatment solution; and the closing step includes filling the inside of the cylindrical body with an interposing member and liquid-tightly closing the opening of the cylindrical body with a lid member; the surface treatment step is characterized in that the cylindrical body is immersed in a surface treatment liquid having a temperature higher than the ambient temperature, thereby surface-treating the outer surface of the cylindrical body without surface-treating the inner surface of the cylindrical body. A method for manufacturing a surface-treated cylindrical body.

2. the closing step includes filling the interposing member into at least one of the openings of each of the cylindrical bodies, the inner surface of the cylindrical body has a narrowed portion that narrows from the opening side of the cylindrical body toward the center of the cylindrical body, The interposing member has a reduced diameter portion that reduces in diameter to correspond to the narrowed portion of the cylindrical body. A method for manufacturing the surface-treated cylindrical body according to claim 1.

3. The cover member is The lid body and a closing portion that closes the opening by being fitted into the inner surface of the opening of the cylindrical body; and the blocking portion is made of an elastic material; 3. The method for manufacturing a surface-treated cylindrical body according to claim 1, wherein the interposing member is made of a resin material.

4. In a state where the interposing member is filled in the cylindrical body and the opening of the cylindrical body is closed with the lid member, 3. The method for manufacturing a surface-treated cylindrical body according to claim 1, wherein the volume of air remaining in the cylindrical body after the closing step is less than 1 / 200 of the volume of air remaining when the opening of the cylindrical body is closed only by the lid member.

5. The method for manufacturing a surface-treated cylindrical body according to claim 1 or 2, wherein the cylindrical body is a cylindrical body.

6. A method for manufacturing a bearing unit for a railway vehicle, comprising using a surface-treated cylindrical body manufactured by the manufacturing method according to claim 5.

7. A method for manufacturing a rolling bearing, comprising using a surface-treated cylindrical body manufactured by the manufacturing method according to claim 5.

Images