Manufacturing method for resin-bonded steel components

Abstract

To provide a method for continuously and quickly drying and curing a resin solution impregnated in paper bonded to a surface of a steel member.SOLUTION: A method for manufacturing a resin-bonded steel member dries and cures a resin solution impregnated in paper bonded on a surface of a steel member. The steel member is heated on a conveyor using a warm-air heating device, a high-frequency heating device, and a far-infrared heating device in turn in this order. An apparatus for heating a resin-bonded steel member comprises: a conveying device for conveying on a conveyor a steel member bonded on a surface with a paper impregnated with a resin solution; and a plurality of heating devices installed on the conveyor with a warm-air heating device, a high-frequency heating device, and a far-infrared heating device in this order along a conveying direction of the steel member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing resin-bonded steel components and a heating device for resin-bonded steel components. [Background technology]

[0002] It is well known to manufacture resin-coated metal members such as clutch plates by adhering paper that has been impregnated with a resin solution and cured to the surface of the metal member (see, for example, Patent Documents 1 to 3).

[0003] On the other hand, it is known to use a high-frequency heating device to dry a coating film applied to a metal workpiece (see Patent Documents 4 and 5).

[0004] Patent Document 4 describes, "An electrostatic coating method for coating the entire surface of a workpiece having an opening, comprising: a holding step in which a holding jig having a rotating shaft is loosely inserted into the opening of the workpiece and held therein; a position guiding step in which the end of the workpiece loosely inserted in the holding step in the direction of the rotating shaft is kept out of contact with other members; an electrostatic coating step in which the loosely inserted holding jig is rotated around the rotating shaft of the holding jig while electroplating powder to be coated on the workpiece; a temporary curing step in which the powder electrostatically coated on the workpiece is heated and melted by high-frequency induction; and a main curing step in which the insulating coating after the temporary curing step is heated and hardened by irradiating it with far-infrared rays." (Claim 1) It is also shown that the workpiece is transported sequentially by conveyor 9 to electrostatic powder coating section 11, pre-cure heating section (high frequency heating section) 12, and main cure heating section (far infrared heating section) 15 (see Figure 3).

[0005] Patent Document 5 describes, "[Claim 3] A coating drying method for drying a coating film applied to a metal substrate, comprising: a first drying step of heating the coating applied to the substrate with hot air and irradiating the substrate with near-infrared or mid-infrared rays in a wavelength range absorbed by the coating to heat the coating, thereby drying the coating; and a second drying step of heating the substrate with high-frequency induction to dry the coating by heat transfer from the substrate."

[0006] Furthermore, when a workpiece is heated on a conveyor using a high-frequency (microwave) heating device or the like, it is well known to use a belt made of heat-resistant fibers such as glass fiber or aramid fiber that do not easily absorb high-frequency waves (microwaves) (see, for example, claim 1, paragraph

[0031] of Patent Document 6, claim 8, paragraph

[0034] of Patent Document 7, and paragraph

[0017] of Patent Document 8). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 10-103396 [Patent Document 2] Japanese Patent Application Publication No. 11-287274 [Patent Document 3] Patent No. 6685069 [Patent Document 4] Japanese Patent Application Publication No. 2-241563 [Patent Document 5] Japanese Patent Application Publication No. 8-332434 [Patent Document 6] Japanese Patent Application Laid-Open No. 2011-99190 [Patent Document 7] Japanese Patent Application Laid-Open No. 2006-59744 [Patent Document 8] Japanese Patent Application Laid-Open No. 2000-306661 Summary of the Invention [Problem to be solved by the invention]

[0008] Patent documents 1 to 3 describe the production of resin-bonded metal components such as clutch plates by adhering paper that has been impregnated with a resin solution and cured to the surface of a metal component, but do not describe a method for continuously producing resin-bonded steel components by drying and curing the resin impregnated in such paper using a high-frequency heating device or the like. On the other hand, Patent Documents 4 and 5 show the use of a high-frequency heating device to dry paint applied to a metal workpiece, but the objects to be coated are completely different. Patent Documents 6 to 8 describe the use of a glass fiber or aramid fiber conveyor belt to heat a workpiece by high-frequency heating, but do not describe the use of this to manufacture resin-bonded steel components.

[0009] An object of the present invention is to provide a method for continuously and quickly drying and curing a resin solution impregnated in paper adhered to the surface of a steel member. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention employs the following means. (1) A method for manufacturing resin-bonded steel components by drying and hardening a resin solution impregnated in paper adhered to the surface of a steel component, in which the steel component is heated sequentially on a conveyor using a hot air heating device, a high-frequency heating device, and a far-infrared heating device, in that order. (2) A method for manufacturing resin-bonded steel components according to (1), in which a metal belt is used for the conveyor equipped with the hot air heating device, and a glass fiber or aramid fiber belt is used for the conveyor equipped with the high-frequency heating device and the far-infrared heating device. (3) A method for manufacturing resin-bonded steel components according to (1) or (2), wherein the hot air heating device dries the surface of the steel components with hot air generated by a hot air generator and blown into a chamber. (4) In the high-frequency heating device, the foot of an induction heating coil formed by connecting one leg end of two inverted U-shaped conductors arranged in parallel and connecting a power source to the other leg end is placed across the steel member on the conveyor to heat it, in a method for manufacturing resin-bonded steel members described in any of (1) to (3). (5) A heating device for resin-bonded steel components, comprising: a conveying device that conveys steel components having paper impregnated with a resin solution adhered to their surfaces on a conveyor; and a plurality of heating devices arranged on the conveyor in the following order along the conveying direction of the steel components: a hot air heating device, a high-frequency heating device, and a far-infrared heating device. [Effects of the Invention]

[0011] In the present invention, the resin solution impregnated in the paper adhered to the surface of the steel member can be dried and hardened continuously and quickly. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the process of manufacturing resin-bonded steel components on a conveyor according to one embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view showing an example of a drive mechanism for a conveyor on which a high-frequency heating device and a far-infrared heating device are installed. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention (hereinafter referred to as "this embodiment") will be described with reference to FIG. The steel member, with the paper adhered to its surface impregnated with a resin solution, is heated in sequence on conveyors 4a and 4b using a hot air heater 1, a high frequency heater 2, and a far infrared heater 3, in that order. As the steel members are transported on the conveyor 4a, the surface of the paper is heated by the hot air heating device 1, evaporating the solvent of the resin solution on the surface of the paper and drying it. Then, as the steel members are transported on the conveyor 4b, the high-frequency heating device 2 heats the steel members, evaporating the solvent of the resin solution inside the paper (i.e., from the adhesive side of the paper to the surface in the depth direction). The high-frequency heating device 2 is efficient because it heats the paper by rapidly raising the temperature. The paper is then heated by the far-infrared heating device 3. This heating is intended to stabilize the temperature, which has been rapidly raised by the high-frequency heating device 2, at a constant temperature. By heating the sheets in this order, the resin solution impregnated in the paper is hardened, and a resin-bonded steel member can be formed.

[0014] The steel members referred to here include all ordinary steels (carbon steels) and special steels, such as carbon steels such as rolled steels for general structures, steels for low temperatures, steel sheets for nuclear reactors, and iron and steel materials such as cold-rolled steels, hot-rolled steels, hot-rolled steel sheets for automobile structures, and hot-rolled high-tensile steel sheets for automobile processing. Furthermore, the iron and steel materials referred to in the present invention are not limited to the above steel materials, but include, for example, all iron and steel materials standardized by the Japanese Industrial Standards (JIS "SS400") and the like. The paper adhered to the surface of the steel member can be produced by papermaking using, for example, the same fiber components, fillers, etc. as used in the production of ordinary clutch plates.

[0015] The fiber component may be selected from organic fibers such as pulp, polyester fiber, polyamide fiber, polyvinyl chloride fiber, polypropylene fiber, acrylic fiber, phenol fiber, nylon fiber, and cellulose fiber, and inorganic fibers such as glass fiber, rock wool, ceramic fiber, silica fiber, potassium titanate fiber, and carbon fiber. Examples of fillers that may be used include calcium carbonate, magnesium carbonate, silica, barium sulfate, alumina, magnesium oxide, zirconia, diatomaceous earth, silicon carbide, boron carbide, silicon nitride, and boron nitride. Examples of conditioning materials that may be used include cashew dust and graphite. In the papermaking process, a mixed material containing these fiber components, fillers, and conditioning materials is first dispersed in water, and paper is made using a cylinder or fourdrinier papermaking machine, and the paper is then dried to produce paper. The resin solution impregnated into the paper adhered to the surface of the steel member may be, for example, a raw material solution of a thermosetting resin such as phenol resin, melamine resin, urea resin, epoxy resin, polyester resin, or urethane resin.

[0016] In addition, the heating device for resin-bonded steel components according to the present invention comprises the above-mentioned steel components having paper impregnated with a resin solution adhered to their surfaces, a conveying device for conveying the steel components on conveyors 4a and 4b, and a plurality of heating devices 1, 2, and 3 arranged on the conveyors 4a and 4b in the order of a hot air heating device 1, a high-frequency heating device 2, and a far-infrared heating device 3 along the conveying direction (flow direction) of the steel components. The heating device for resin-bonded steel components according to the present invention has the above-described configuration, and therefore can continuously and quickly dry and harden the resin solution impregnated in the paper adhered to the surface of the steel component.

[0017] (Hot air heating device: No. 1) Before high-frequency heating, the surface of the steel member is heated with hot air to evaporate the solvent (organic solvent) in the resin solution on the surface of the paper. Hot air from a hot air generator (not shown) is blown into the chamber of the hot air heating device 1 installed on the conveyor 4a, and the paper surface is heated to a temperature at which the solvent (organic solvent) in the resin solution evaporates. The heating temperature and heating time can be set appropriately depending on the components of the resin solution and solvent (organic solvent) used.

[0018] (High frequency heating device: code 2) After the resin on the surface of the steel member is dried with the hot air heating device 1, the steel member is heated with the high frequency heating device 2 to evaporate and dry the solvent in the resin solution inside the paper (i.e., from the adhesive side of the paper to the steel member in the depth direction to the surface side), thereby making it possible to dry the resin more quickly all the way to the inside when heating with the high frequency heating device 2. The heating temperature and heating time when heating with the high frequency heating device 2 can be set appropriately depending on the components of the resin solution and solvent (organic solvent) used.

[0019] The high-frequency heating device 2 used in this embodiment preferably includes a coil of inverted U-shaped conductors formed by connecting one leg end of two inverted U-shaped conductors arranged in parallel and connecting a power source to the other leg end, as described in Japanese Patent No. 4620486. By heating the steel members on the conveyor 4b with the leg end of the inverted U-shaped conductor of this induction heating coil straddling the steel members, the steel members can be heated efficiently and rapidly to their interiors (deep portions).

[0020] (Far infrared heating device: code 3) After being high-frequency heated, the steel members are heated by a far-infrared heating device 3. This heating is performed by irradiating the steel members, including the paper, with far-infrared rays. This heating is intended to stabilize the temperature, which has been rapidly increased by the high-frequency heating device 2, at a constant temperature. When heating with the far-infrared heating device 3, the heating temperature and heating time can be set appropriately depending on the components of the resin solution and solvent (organic solvent) used. By heating the sheets in this order, the resin solution impregnated in the paper is hardened, and a resin-bonded steel member can be formed.

[0021] (Conveyor) The conveyors 4a and 4b used in this embodiment will be described with reference to FIG. The conveyor 4a on which the hot air heating device 1 is installed has rollers 6a and 6b at both ends of the conveyor body 5a, and an endless belt 7a is stretched between these rollers 6a and 6b to form a conveying path for transporting steel members on the upper surface of the conveyor body 5a. In addition, the conveyor 4a has a conveyor body 5a, which serves as the machine frame, configured as a roughly long band in plan view, with the upper surface side of this conveyor body 5a, i.e., the conveying path, serving as the outgoing path of the endless belt 7a, and the lower surface side of the same conveyor body 5a serving as the return path of the endless belt 7a.

[0022] The endless belt 7a used in the conveyor 4a on which the hot air heating device 1 is installed can be made of metal, and it is preferable to use a stainless steel mesh as the metal. That is, because the endless belt 7a is made of stainless steel mesh, hot air can be blown from above the conveyor 4a as well as below in the hot air heating device 1. Therefore, even if paper impregnated with the resin solution is adhered to both sides of the steel member, the stainless steel mesh allows the hot air to pass through, so that the solvent in the resin solution on the surface side can evaporate on both sides of the paper on the steel member.

[0023] The conveyor 4b, on which the high-frequency heating device 2 and the far-infrared heating device 3 are installed, has rollers 6c and 6d at both ends of the conveyor body 5b, and a first endless belt 7b is stretched between these rollers 6c and 6d, thereby forming a conveying path for transporting steel members on the upper surface of the conveyor body 5b. In addition, the conveyor 4b has a conveyor body 5b, which serves as the machine frame, configured as a roughly long band in plan view, and the upper surface side of this conveyor body 5b, i.e., the conveying path, is configured as the outgoing path of the first endless belt 7b, and the lower surface side of the same conveyor body 6b is configured as the return path of the first endless belt 7b.

[0024] By synchronizing the conveying speed of conveyor 4b with the conveying speed of conveyor 4a, steel components can be smoothly transported from conveyor 4a equipped with hot air heating device 1 to conveyor 4b equipped with high frequency heating device 2 and far infrared heating device 3. The transport speed of the conveyors 4a and 4b can be set appropriately depending on the heating time in the hot air heating device 1, the high frequency heating device 2, and the far infrared heating device 3.

[0025] Legs 8a, 8b, and 8c are provided on both sides of the conveyor body 5a configured as described above near both ends, at the portions supporting the hot air heater 1. In other words, the conveyor body 5a is supported at a predetermined height by six legs. Legs 8d, 8e, 8f, and 8g are provided on both sides near both ends of the conveyor body 5b configured as described above, and at the portions supporting the high-frequency heating device 2 and the far-infrared heating device 3. In other words, the conveyor body 5b is supported at a predetermined height by eight legs.

[0026] The first endless belt 7b used in the conveyor 4b on which the high frequency heating device 2 and the far infrared heating device 3 are installed is preferably made of glass fiber or aramid fiber. Glass fiber and aramid fiber have a heat resistance temperature of 260°C or higher, do not easily absorb high-frequency waves, and do not generate heat themselves due to high-frequency energy, making them ideal materials for the conveyor belt used in high-frequency heating device 2, which dries and hardens steel components bonded to paper impregnated with the resin solution. Furthermore, because the glass fiber and aramid fiber have smooth surfaces, they do not get caught on the first endless belt 7b as it runs, allowing the steel members to be transported smoothly on the first endless belt 7b. When high-frequency heating steel members in the high-frequency heating device 2 is performed in a short time, for example, 20 seconds, everything depends on the passage time, so it is important to prevent the first endless belt 7b from getting caught.

[0027] The first endless belt 7b made of glass fiber or aramid fiber is preferably a mesh made of a fabric woven from glass fiber or aramid fiber. "Made of glass fiber or aramid fiber" does not mean a belt made only of glass fiber or aramid fiber, but also includes a belt made of glass fiber or aramid fiber whose surface is coated with a fluororesin (for example, polytetrafluoroethylene (PTFE)). Also, instead of glass fiber alone, a mixture of glass fiber and PTFE or the like may be used, or a mixture of aramid fiber and other fibers may be used. A glass mat (nonwoven fabric) may also be used instead of a fabric.

[0028] Next, a drive mechanism for a conveyor on which the hot air heating device 1, the high frequency heating device 2, and the far infrared heating device 3 according to one embodiment of the present invention are installed will be described. The drive mechanism of the conveyor on which the hot air heating device 1 is installed is the same as the drive mechanism of a conventional conveyor. When the drive roller is driven by a motor, the endless belt 7a is rotated counterclockwise due to the frictional force generated between it and the outer surface of the drive roller, and the steel members on the endless belt 7a are transported from right to left.

[0029] FIG. 2 shows an example of a drive mechanism for a conveyor equipped with a high-frequency heating device 2 and a far-infrared heating device 3. In the example shown in FIG. 2, the conveyor body 5b is provided on its underside with a rotating roller 9 that comes into contact with the return side of the first endless belt 7b to drive and rotate the belt, and the rotating roller 9, around which the first endless belt 7b is wound, is sandwiched between two driven rollers 11a and 11b on both sides via a second endless belt 10, and a drive roller 12 that comes into contact with the second endless belt 10 to drive and rotate the second endless belt 10 below the driven rollers 11a and 11b is provided as a drive mechanism. The apparatus is provided with a rotating roller 9 that comes into contact with the return side of the first endless belt 7b to drive and rotate the belt 7b, and the first endless belt 7b is wound around the outer periphery of the rotating roller 9, and a second endless belt 10 made of rubber is wound on top of the first endless belt 7b. The second endless belt 10 is brought into surface contact with the first endless belt 7b, and the second endless belt 10 is driven to rotate, thereby driving the rotating roller 9 to rotate.

[0030] As described above, since glass fiber or aramid fiber has a smooth surface, the first endless belt 7b made of glass fiber or aramid fiber does not get caught on parts as it runs, and the steel members on the first endless belt 7b can be transported smoothly, but conversely, slippage may occur between the rotating roller 9 and the first endless belt 7b. Therefore, in this embodiment, it is preferable to adopt the following measures.

[0031] That is, when the second endless belt 10 is driven to rotate by the drive roller 12, the two driven rollers 11a, 11b also rotate in a manner that follows the rotation of the second endless belt 10. Since the two driven rollers 11a, 11b are disposed on both sides of the rotating roller 9 around which the first endless belt 7b is wound, as shown in Fig. 2, the first endless belt 7b and the second endless belt 10 are in surface contact with each other. Therefore, tension is applied to the first endless belt 7b, which can increase the degree of contact between the first endless belt 7b made of glass fiber or aramid fiber and the outer circumferential surface of the rotating roller 9. Here, as mentioned above, the material of the second endless belt 10 is rubber. As the rubber, any ordinary rubber can be used as appropriate.

[0032] 2, the rotating roller 9 is different from a conventional driving roller that is driven by a motor. The driving mechanism for driving the rotating roller 9 will now be described. When the drive roller 12 rotates in the direction of the arrow (clockwise), the second endless belt 10 is rotated clockwise due to the frictional force generated between it and the drive roller 12, and the rotating roller 9, which has two driven rollers 11a and 11b arranged on both sides via the second endless belt 10, is rotated in the direction of the arrow (counterclockwise) due to the frictional force generated between it and the second endless belt 10.

[0033] The first endless belt 7b is rotated counterclockwise by the frictional force generated between it and the outer circumferential surface of the rotating roller 9, and the steel members on the first endless belt 7b are transported from right to left. As described above, the degree of adhesion between the first endless belt 7b made of glass fiber or aramid fiber and the outer surface of the rotating roller 9 can be increased, so that the driving force from the rotating roller 9 can be appropriately transmitted to the first endless belt 7b, enabling the steel members to be transported stably.

[0034] Next, a drive mechanism for driving the drive roller 12 will be described. The drive mechanism for driving the drive roller 12 in this embodiment is the same as the drive mechanism for a conventional drive roller. Two bearings (not shown) with bearings are provided to support the drive roller 12, and the drive roller 12 is horizontally suspended between them and rotatably supported. The drive roller 12 is rotatably supported by inserting a support shaft 12b into the shaft core of a hollow drive roller body 12a, and fitting both ends of this support shaft 12b into the bearings. One end of the support shaft 12b of the drive roller 12 penetrates the bearing portion and protrudes, and a sprocket 12c is attached and fixed to the protruding portion.

[0035] Meanwhile, a drive motor 13 with a speed reducer is installed next to the sprocket 12c of the drive roller 12. A sprocket 13c is provided on the output shaft (not shown) of the reducer, and an endless chain 14 connects the sprocket 13c to the sprocket 12c of the drive roller 12. Therefore, when the drive motor 13 is driven to rotate, the driving force is transmitted to the drive roller 12 via the sprocket 13c, chain 14, and sprocket 12c, driving the drive roller 12 to rotate at a predetermined rotation speed.

[0036] It is preferable to arrange two driven rollers 15a, 15b side by side above the rotating roller 9 with an appropriate gap between them. When the first endless belt 7b rotates as described above, both driven rollers 15a, 15b simultaneously rotate in a manner following the rotation of the first endless belt 7b. The return side of the first endless belt 7b is looped around the two driven rollers 15a, 15b and around the outer periphery of the rotating roller 9, so that the first endless belt 7b contacts the outer periphery of the rotating roller 9 with an appropriate pressing force. Note that when adjusting the tension of the first endless belt 7b, the pressure applied to the outer periphery of the rotating roller 9 can be adjusted by narrowing or widening the gap between the two driven rollers 15a, 15b to increase or decrease the degree of retraction of the first endless belt 7b. [Industrial Applicability]

[0037] The method for manufacturing resin-bonded steel components of the present invention can quickly dry and harden the solvent in the resin solution impregnated in the paper adhered to the surface of the steel component, and therefore can be applied to the manufacture of automobile parts such as clutch plates. [Explanation of symbols]

[0038] 1: Hot air heating device 2: High frequency heating device 3: Far-infrared heating device 4a, 4b: Conveyor 5a, 5b: Conveyor body 6a, 6b, 6c, 6d: Roller 7a: endless belt 7b: First endless belt 8a, 8b, 8c, 8d, 8e, 8f, 8g: Legs 9: Rotating roller 10: Second endless belt 11a, 11b: driven rollers 12: Drive roller 12a: Drive roller body 12b: Support shaft 12c: sprocket 13: Drive motor 13c: sprocket 14: Endless chain 15a, 15b: driven rollers

Claims

1. This is a method for producing resin-bonded steel components by drying and hardening a resin solution impregnated in paper adhered to the surface of a steel component, in which the steel components are heated sequentially on a conveyor using a hot air heating device, a high-frequency heating device, and a far-infrared heating device, in that order, and in the high-frequency heating device, two inverted U-shaped conductors arranged in parallel have one foot end connected to the other foot end to a power source to form an induction heating coil, which is placed across the steel components on the conveyor and heated.

2. 2. The method for manufacturing resin-bonded steel components according to claim 1, wherein a metal belt is used for the conveyor equipped with the hot air heating device, and a glass fiber or aramid fiber belt is used for the conveyor equipped with the high frequency heating device and the far infrared heating device.

3. 3. A method for manufacturing resin-bonded steel components according to claim 1 or 2, wherein in the hot air heating device, the surface of the steel components is dried by hot air generated by a hot air generator and blown into a chamber.

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