Heating coil for high-frequency heaters.

Abstract

DEPCT67 problem The part is arranged as a heating coil for a good high-frequency heater. Excellent cooling performance, allowing for continuous use over extended periods. There was no damage even under high export conditions and allowing for production in the same manner. Along with excellent remanufacturing capabilities in production. Correction Heating coil 1 was constructed using an iterative prototyping method. Layering, melting, solidification, and layering of powders with conductive materials based on three-dimensional data. Heating coil 1 consists of a pair of plate-shaped grounding sections 2a, 2b for... In contact with the poles that generate high-frequency current, a pair of plate-shaped support sections 3a and 3b are positioned upright. The scene is connected to grounding sections 2a and 2b respectively, and an ancillary heating unit 4 is arranged. To connect the far ends of supports 3a and 3b to another sequence of downward flow paths in the center. Cooling systems 6a and 6b are for downstream flow, and the cooling medium is built inside the section. Grounding connections 2a, 2b, support sections 3a, 3b, and heating unit 4, respectively;

Description

Heating coil for high frequency heating equipment

[0001] The present invention relates to a heating coil used in a high-frequency heating device for heating a workpiece by utilizing electromagnetic induction caused by a high-frequency current.

[0002] In order to increase the hardness of the surface of a metal workpiece, the surface of the workpiece is heated to a temperature equal to or higher than the transformation point (austenite transformation point) of the metal and then rapidly cooled (a process known as quenching). A widely used method for quenching is to heat the workpiece by using a high-frequency heating device and bringing a metal member (heating coil) through which a high-frequency current flows close to the surface of the workpiece.

[0003] A conventional heating coil includes a pair of grounding portions that are grounded to a high-frequency power source, an annular coil portion that is fitted around a workpiece, and a pair of connecting portions that connect the grounding portions to the coil portion. Furthermore, in order to suppress heat generation when a high-frequency current is passed through the coil, the conventional heating coil includes a cooling water passage through which a cooling medium such as water flows. For example, Patent Document 1 discloses a heating coil in which a cooling water passage is formed inside the coil portion by stacking coil plates with grooves engraved on the inner surface.

[0004] Furthermore, in a typical heating coil, an insulating plate made of synthetic resin is interposed between a pair of adjacent grounding parts or a pair of connecting parts to prevent dielectric breakdown from occurring between the pair of adjacent grounding parts or between the pair of connecting parts when the output of the high-frequency power supply is increased (Patent Document 2).

[0005] Japanese Patent No. 4358292 Japanese Patent Application Laid-Open No. 2020-115428

[0006] However, the heating coil for the above-mentioned conventional high-frequency heating device must be formed by bonding multiple parts with silver solder or the like to provide a hollow cooling water passage in the coil section, and therefore, if it is used continuously under high output conditions (processing conditions in which a high-voltage high-frequency power source is applied), it is likely to break and cause the cooling medium to leak. Furthermore, since the heating coil for the conventional high-frequency heating device is provided with a cooling mechanism only in the coil section, the cooling efficiency is poor, and if it is used continuously under high output conditions, the grounding section and connecting section are maintained at high temperatures, which causes the insulating plate to carbonize and deteriorate, resulting in insulation breakdown due to surface discharge.

[0007] Furthermore, since the above-mentioned conventional heating coil must be formed by brazing a plurality of parts, it is difficult to reproducibly manufacture coils with identical characteristics during manufacturing, which causes variations in the quality of the workpieces being heated.

[0008] An object of the present invention is to provide a heating coil for a high-frequency heating device that solves the above-mentioned problems of the conventional heating coils for high-frequency heating devices, has good cooling efficiency, can be used for a long period of time even under high output conditions without being damaged, and can be manufactured with good reproducibility to have the same characteristics during manufacturing.

[0009] The invention described in claim 1 of the present invention is a heating coil used in a high-frequency heating device for heating a workpiece by utilizing electromagnetic induction caused by high-frequency current, which is integrally formed using a molding method that repeatedly lays, melts, solidifies, and stacks powder made of a conductive material based on three-dimensional data (hereinafter referred to as a partial deposition lamination method of conductive material powder layers), or a molding method that stacks molten conductive material based on three-dimensional data (hereinafter referred to as a melt extrusion lamination method of conductive material), and is characterized in that it has a pair of plate-shaped grounding portions for abutting against an electrode to which a high-frequency current is passed, a pair of plate-shaped support portions arranged perpendicular to each of the grounding portions, and a ring-shaped heating portion arranged to connect the tips of the support portions, and is characterized in that a series of cooling medium flow paths for flowing a cooling medium are formed inside each of the grounding portions, each of the support portions, and each of the heating portions.

[0010] The invention described in claim 2 is characterized in that, in the invention described in claim 1, an inlet for injecting a cooling medium into the cooling medium flow path and / or an outlet for discharging the cooling medium from the cooling medium flow path are provided in the grounding portion.

[0011] The invention described in claim 3 is characterized in that, in the invention described in claim 1, an inlet for injecting a cooling medium into the cooling medium flow path and / or an outlet for discharging the cooling medium from the cooling medium flow path are provided in the heating section.

[0012] The heating coil for a high-frequency heating device described in claim 1 (hereinafter simply referred to as the heating coil) has a series of cooling medium flow paths formed not only inside the annular heating section but also inside each grounding section and each supporting section for allowing a cooling medium to flow down, so that not only the heating section but also the grounding section and supporting section are cooled simultaneously during the heating treatment of the workpiece, and no part remains at a high temperature for a long period of time. Therefore, the heating coil described in claim 1 is less susceptible to problems such as insulation breakdown due to carbonization or deterioration of the insulating plate or damage due to stress concentration in a specific part, and is therefore highly durable, allowing repeated heating treatment of workpieces for a long period of time even under high output conditions.

[0013] Furthermore, since the heating coil described in claim 1 is formed by a method for partially welding and laminating conductive powder layers based on three-dimensional data or a method for melt extrusion lamination of a conductive material, there is no silver brazing adhesive portion as in conventional heating coils, and therefore the coil does not deform even when the temperature rises during continuous use, and heating treatment (hardening treatment) can be performed according to the standard over a long period of time. Furthermore, since the heating coil described in claim 1 is formed by a method for partially welding and laminating conductive powder layers based on three-dimensional data or a method for melt extrusion lamination of a conductive material, products having the same shape and characteristics can be efficiently manufactured with good reproducibility, regardless of the skill of the manufacturing worker.

[0014] In addition, the heating coil described in claim 1 is integrally formed without brazing by a partial welding lamination method of conductive material powder layers based on three-dimensional data or a melt extrusion lamination method of conductive material, and therefore a series of cooling medium flow paths are formed inside the heating part, each grounding part, and each supporting part, so that there is no need to provide multiple cooling medium supply mechanisms and cooling medium loss (i.e., the situation where the cooling medium is discharged without making a significant contribution to heat exchange) can be reduced.

[0015] The heating coil described in claim 2 has an inlet for injecting the cooling medium into the cooling medium flow path and an outlet for discharging the cooling medium from the cooling medium flow path provided in the grounding portion, so that the mounting portion of the heating coil of the high-frequency heating device can be made space-saving and compact, and it can be easily attached and detached to the main body of the high-frequency heating device.

[0016] The heating coil described in claim 3 has an inlet for injecting the cooling medium into the cooling medium flow path and an outlet for discharging the cooling medium from the cooling medium flow path in the heating section, and can supply low-temperature cooling medium immediately after being introduced from the water source to the heating section, which is most likely to become hot.Therefore, it has extremely excellent cooling efficiency and can be used with a very high-output high-frequency power source applied.

[0017] 4 is a front view of the heating coil; a rear view of the heating coil; a left side view of the heating coil; a plan view of the heating coil (a plan view seen through the internal cooling medium flow path); a perspective view of the heating coil; a cross-sectional view of the grounding part of the heating coil (an end view taken along line A-A in FIG. 4); a cross-sectional view of the support part of the heating coil (an end view taken along line B-B in FIG. 4); an explanatory diagram showing the manufacturing process of the heating coil (a is a plan view, and b is a vertical cross-sectional view); and an explanatory diagram showing a modified example of the heating coil.

[0018] The heating coil according to the present invention must be integrally formed by a modeling method based on three-dimensional data using a three-dimensional printer. Such a modeling method can be a modeling method that involves repeatedly laying, melting, solidifying, and stacking powder made of a conductive material based on three-dimensional data (a method for partially fusing and laminating conductive material powder layers), or a modeling method that involves laminating molten conductive material based on three-dimensional data (a method for melt extrusion and lamination of conductive material). The partial fusing and lamination of conductive material powder layers is preferred as a modeling method for the heating coil, as it allows for the easy manufacture of heating coils with complex shapes and structures.

[0019] In the present invention, the conductive material used as the raw material for shaping refers to a material that is substantially non-magnetic and has good electrical conductivity. Examples of such conductive materials include copper, brass, and silver. Among these conductive materials, copper is preferred because it reduces material costs, enables the heating coil to be manufactured inexpensively and easily using a three-dimensional printer, and provides excellent electrical conductivity, resulting in high heat generation efficiency through electromagnetic induction.

[0020] Furthermore, when copper is used as the conductive material, pure copper can be used, but using an alloy (high-copper alloy) containing copper in a smaller proportion of iron, tin, nickel, titanium, beryllium, zirconium, chromium, silicon, etc. compared to copper is preferable because it can enhance laser absorption and promote temperature rise. Furthermore, among these copper alloys, using a copper-chromium alloy containing chromium in copper is more preferable because it can effectively increase the strength of the heating coil while maintaining high manufacturing efficiency using a three-dimensional printer. An alloy containing chromium and zirconium in a predetermined proportion in copper (C18150, i.e., containing 98.71 to 99.45% by mass of copper, 0.50 to 1.00% by mass of chromium, and 0.05 to 0.25% by mass of zirconium) is particularly preferable.

[0021] When forming the heating coil according to the present invention using the method for partially fusing and laminating conductive material powder layers, it is necessary to melt the laid raw material for the formation (i.e., powder made of conductive material) by irradiating it with a laser or electron beam. As the laser, a semiconductor laser, a carbon dioxide laser, an excimer laser, a YAG laser, a fiber laser, etc. can be suitably used. However, the use of a fiber laser (i.e., a laser using an optical fiber doped with a rare earth element such as Yb as a laser medium) is preferable because it enables a high-output laser beam with a stable optical axis using a small device, and enables the efficient production of heating coils with high dimensional accuracy.

[0022] Furthermore, when forming a heating coil by the partial deposition method of conductive material powder layers, the output power and wavelength of the fiber laser are not particularly limited, but it is preferable to adjust the output power to within the range of 400 to 1,000 W and the wavelength to within the range of 1,000 to 1,100 nm, as this enables efficient forming in a short time. Furthermore, when copper (pure copper) is used as the conductive material, it is also possible to add an absorbent made of a mixed powder of graphite and inorganic oxide to the copper powder in order to improve the laser absorptivity of the copper powder and thereby increase the manufacturing efficiency of the heating coil.

[0023] Furthermore, the heating coil according to the present invention must have a pair of plate-shaped grounding portions for contacting electrodes through which high-frequency current is passed, a pair of plate-shaped support portions arranged perpendicular to the grounding portions, and an annular heating portion provided to connect the tips of the support portions. The heating portions must be annular, but are not limited to being circular and may be non-annular (for example, rectangular in plan view). On the other hand, the shapes of the support portions are not particularly limited as long as they are a pair of plate-shaped (or rod-shaped) support portions arranged perpendicular to the grounding portions, but it is preferable that the corners be chamfered to prevent discharge when power is applied.

[0024] Furthermore, the heating coil according to the present invention must have a series of cooling medium downflow paths formed within each of the grounding portions, support portions, and heating portions for allowing the cooling medium to flow down. The cooling medium downflow path may be a single path connecting the left and right grounding portions, the left and right support portions, and the interior of the heating portion, or two paths may be formed on the left and right sides of the heating coil, connecting the grounding portions, support portions, and interior of the heating portion, respectively. In addition, it is preferable to form the cooling medium downflow path such that the inner wall has no seams or steps of a predetermined height or greater (1.0 mm or greater), or such that the bent portions and connecting portions have a gentle curve (a curve with a curvature radius of 5 mm or greater), because this allows the cooling medium to flow down very smoothly and improves the cooling efficiency of the grounding portions and support portions of the heating coil.

[0025] [Example 1] <Heating Coil Structure> One embodiment of a heating coil according to the present invention will be described in detail below with reference to the drawings. Figures 1 to 7 show a heating coil. The heating coil 1 is composed of a coil body 21 integrally formed from copper (high copper alloy, C18150), an insulating plate 31 formed in a sheet shape from a synthetic resin (fluororesin) having insulating and heat-resistant properties, and a screw member (not shown). The heating coil 1 has dimensions of length (front-to-back) × width (width) × height = 300 mm × 225 mm × 200 mm (the lengths of the maximum points of the length, width, and height).

[0026] The coil body 21 is formed by a modeling method using a three-dimensional printer, which will be described later, and has grounding portions 2a, 2b for contacting the electrodes of a high-frequency power supply, a heating portion 4 for heating a workpiece (workpiece) by induction heating, and support portions 3a, 3b for supporting the heating portion 4 at positions spaced apart from the grounding portions 2a, 2b. Note that, because the coil body 21 is formed by a modeling method using a three-dimensional printer, the entire body is the same color, and the entire surface has the same roughness (surface roughness).

[0027] The ground contact portions 2a, 2b are formed as a pair of flat rectangular parallelepipeds (plates) and are arranged adjacent to each other with one side facing the other and a predetermined distance (approximately 2 mm) apart. Cylindrical drainage pipes 7a, 7b are provided on the upper surfaces of the ground contact portions 2a, 2b, respectively, so as to protrude upward.

[0028] The support portions 3a, 3b are formed as a pair of flat rectangular parallelepipeds (plates) and are arranged adjacent to each other at a predetermined distance (approximately 2 mm) with one plate surface facing the other. The base edges of the support portions 3a, 3b are connected to the inner edges of the left and right ground contact portions 2a, 2b, and the plate surfaces of the support portions 3a, 3b are perpendicular to the plate surfaces of the ground contact portions 2a, 2b.

[0029] On the other hand, the heating unit 4 is designed to heat a workpiece (workpiece) inserted therein. It has a shape in which upper arc-shaped bodies 9a, 9b arranged on the upper side and a lower arc-shaped body 10 arranged on the lower side are connected by vertical connectors 11a, 11b, respectively. The upper arc-shaped bodies 9a, 9b and the lower arc-shaped body 10 are ring-shaped (annular) in plan view. The upper arc-shaped bodies 9a, 9b are arranged adjacent to each other on the left and right sides, separated by a predetermined distance (approximately 2 mm), with their inner plate surfaces facing each other, forming a single arc. Each upper arc-shaped body 9a, 9b is connected to the tip of the left and right support units 3a, 3b via tubular connectors 12a, 12b, respectively.

[0030] The vertical cross section perpendicular to the longitudinal direction of each of the upper arc-shaped bodies 9a, 9b and the lower arc-shaped body 10 has a rectangular shape with rounded corners. An inner injection pipe 13a and an outer injection pipe 13b for injecting a cooling medium from the outside are provided on the upper surface of the left edge of the lower arc-shaped body 10 so as to extend upward along the vertical direction.

[0031] The heating coil 1 has two series of cooling medium flow-down paths 6a, 6b on the left and right sides for allowing a cooling medium (water) to flow down inside the grounding portions 2a, 2b, support portions 3a, 3b, and heating portion 4. That is, the left cooling medium flow-down path 6a runs from the inner injection pipe 13a to the inside of the lower arc-shaped body 10 (the inside above the inner injection pipe 13a), the left connector 11a, the inside of the left upper arc-shaped body 9a, the inside of the left support portion 3a, and the left grounding portion 2a, passing through the left drain pipe 7a.

[0032] Meanwhile, the right-side cooling medium flow down passage 6b extends from the outer injection pipe 13b through the inside of the lower arc-shaped body 10 (the inside below the outer injection pipe 13b), the right-side connector 11b, the inside of the right-side upper arc-shaped body 9b, the inside of the right-side support part 3b, and the right-side grounding part 2b to the right-side drain pipe 7b. Note that both the left-side cooling medium flow down passage 6a and the right-side cooling medium flow down passage 6b first branch into three paths (6α, 6β, 6γ) inside the support parts 3a, 3b, respectively, which are led separately into the left and right grounding parts 2a, 2b and then combined into a single path inside each grounding part 2a, 2b.

[0033] Because the heating coil 1 is integrally formed using a three-dimensional printer, all bends and connecting portions of both the left-side cooling medium flow down channel 6 a and the right-side cooling medium flow down channel 6 b are gently curved (with a curvature radius of 5 mm or more) without any sharp bends. In addition, both the left-side cooling medium flow down channel 6 a and the right-side cooling medium flow down channel 6 b have no seams or steps of a predetermined height (1.0 mm or more) on their inner walls.

[0034] Furthermore, sheet-like insulating plates 31 of a predetermined thickness (approximately 2.0 mm) are sandwiched between the left and right grounding portions 2a, 2b of the coil body 21, between the left and right support portions 3a, 3b, between the left and right upper arc-shaped bodies 9a, 9b of the heating portion 4, and between the left and right connecting bodies 12a, 12b, and in this state, the left and right support portions 3a, 3b and the insulating plate 31 are screwed together with bolts (not shown) inserted through the screw holes 8, 8. Note that these bolts screw together the support portions 3a, 3b and the insulating plate 31 via bushings (not shown) made of insulating and heat-resistant synthetic resin (glass epoxy resin), so that the support portions 3a, 3b are not electrically connected to each other via the bolts.

[0035] 8 shows how the heating coil 1 is formed, and the three-dimensional printer device M for forming the heating coil 1 includes a frame F with a rectangular parallelepiped recessed portion formed in the center, an elevating member that is provided so as to be able to rise and fall relative to the frame F, an irradiation means S for irradiating the laser L, a reflection means R for reflecting the laser, and a drive means (not shown) for raising and lowering the elevating member. The elevating member is provided with a table T having approximately the same area as the opening of the recessed portion of the frame F.

[0036] When manufacturing the heating coil 1 using the three-dimensional printer device M, first, a powder of a copper alloy (C18150 containing 99.3% by mass of Cu, 0.6% by mass of Cr, and 0.10% by mass of Zr) is laid to a predetermined thickness (for example, 30 μm) on the surface of a table T of an elevating member that is in an elevated position (the copper powder is laid to fill the gap between the surface of the table T and the surface of the outer frame of the frame F). Then, a laser (fiber laser) L of a predetermined output is irradiated onto the copper alloy powder in a predetermined shape to melt part of the copper alloy powder, which is then cooled and solidified to form part of the heating coil 1.

[0037] After forming a portion of the heating coil 1 as described above, the table T of the lifting member is lowered by a predetermined height (e.g., 30 μm) by the driving means. Then, at that height, the following operations are repeated: "laying copper alloy powder above the previously formed portion of the heating coil 1 → irradiating the copper alloy powder with the laser L → cooling and solidifying the molten copper alloy (solidification by coagulation)." Then, by repeating the above-described operations of "lowering the table T of the lifting member → laying copper alloy powder → irradiating the copper alloy powder with the laser L → cooling and solidifying the molten copper alloy" a predetermined number of times (e.g., 5,000 times), the heating coil 1 made of copper alloy can be integrally formed.

[0038] <Method of Using the Heating Coil> With the heating coil 1 configured as described above, the left and right grounding portions 2a, 2b are grounded to the electrodes, and a workpiece (workpiece) is inserted inside the annular portion of the heating portion 4 (i.e., the ring formed by the upper arc-shaped bodies 9a, 9b and the lower arc-shaped body 10). An external power source (high-frequency power source) is applied via the electrodes, and the workpiece can be heated using electromagnetic induction. Furthermore, by injecting a cooling medium (water) from the inner injection pipe 13a into the left cooling medium downflow path 6a and draining it through the drain pipe 7a, and injecting a cooling medium from the outer injection pipe 13b into the right cooling medium downflow path 6b and draining it through the drain pipe 7b, the heating portion 4 as well as the grounding portions 2a, 2b and support portions 3a, 3b are efficiently cooled, thereby preventing damage due to melting of the insulating plate 31 and other problems.

[0039] <Effects of the Heating Coil> As described above, the heating coil 1 has a series of cooling medium flow paths 6a, 6b formed not only inside the heating portion 4 but also inside the ground portions 2a, 2b and support portions 3a, 3b for allowing a cooling medium to flow downward. Therefore, during the heat treatment of the workpiece, not only the heating portion 4 but also the ground portions 2a, 2b and support portions 3a, 3b are cooled simultaneously, and a situation in which they are maintained at a high temperature for a long period of time does not occur. Therefore, the heating coil 1 is excellent in durability because it is free from problems such as insulation breakdown due to carbonization or deterioration of the insulating plate 31 or damage due to stress concentration in specific parts, and can repeatedly heat the workpiece for a long period of time even under high output conditions.

[0040] Furthermore, the heating coil 1 is formed by a modeling method using a three-dimensional printer M (i.e., a method of partially fusing and laminating conductive powder layers based on three-dimensional data). Unlike conventional heating coils, there are no adhesive parts such as silver brazing, so it does not deform with continuous use and can be hardened to meet specifications over a long period of time. Furthermore, because the heating coil 1 is formed by a modeling method using a three-dimensional printer M, products with the same shape and characteristics can be efficiently manufactured with good reproducibility, regardless of the skill of the manufacturing worker. In addition, the heating coil 1 has a series of cooling medium flow paths 6a, 6b formed inside the heating portion 4, the grounding portions 2a, 2b, and the support portions 3a, 3b by a modeling method using a three-dimensional printer M without brazing, eliminating the need for multiple cooling water supply mechanisms and reducing cooling water loss.

[0041] Furthermore, the heating coil 1 has outlets 7a, 7b at the grounding portions 2a, 2b for discharging the cooling medium from the cooling medium flow paths 6a, 6b, so that the mounting portion of the heating coil of the high-frequency heating device can be designed to be space-saving and compact, and it is easy to mount and detach it on the main body of the high-frequency heating device.

[0042] Furthermore, the heating coil 1 has inlet ports 13a and 13b in the heating section 4 for injecting the cooling medium into the cooling medium flow paths 6a and 6b, and can supply low-temperature cooling medium immediately after being introduced from a water source to the heating section 4, which is most likely to reach high temperatures. This provides extremely excellent cooling efficiency and allows use with a high-frequency power source applied at a very high output.

[0043] <Evaluation of Durability> Ten heating coils 1 described above were manufactured, and to evaluate durability, 100,000 shots (heating of the workpiece by energizing the high-frequency power source) were repeated under operating conditions of 60 kVA x 10 seconds while cooling was performed using the cooling medium flow paths 6a and 6b (cooling water flow rate = 80 L / min.). However, no insulation breakdown due to carbonization or deterioration of the insulating plate 31 occurred in any of the heating coils. Furthermore, when the surface temperatures of the support portions 3a and 3b of the heating coil 1 were measured during the heat treatment of the workpiece under the operating conditions described above, no significant temperature increase was observed from before the shots began (approximately 30°C). The measurement results of the surface temperatures are shown in Table 1.

[0044] [Comparative Example 1] Using the same raw materials as in Example 1 and a 3D printer M as in Example 1, a heating coil 1' of Comparative Example 1 was manufactured using a molding method with the same three-dimensional printer apparatus M as in Example 1. The heating coil 1' had the same external shape as the heating coil of Example 1, but had no cooling medium flow path formed inside the grounding portion and support portion (the inner injection pipe 13a and the outer injection pipe 13b were connected inside the heating portion 4 to form a cooling medium flow path along the route "inner injection pipe 13a → heating portion 4 → outer injection pipe 13b"). Using the heating coil 1' of Comparative Example 1, shots were repeatedly performed for approximately 30 minutes under operating conditions of 60 kVA x 10 seconds while cooling only the heating portion 4 (cooling water flow rate = 80 L / min). The surface temperatures of the support portions 3a and 3b of the heating coil 1' were then measured. The results showed that the temperature had risen significantly from before the shots began. The surface temperature measurement results are shown in Table 1.

[0045]

[0046] <Modifications of the heating coil> The heating coil according to the present invention is not limited to the above-described embodiments, and the materials, shapes, structures, and other configurations of the grounding portion, supporting portion, and heating portion can be appropriately modified as needed without departing from the spirit of the present invention.

[0047] For example, the heating coil according to the present invention is not limited to the above embodiment in which an annular heating portion is formed by an upper arc-shaped body and a lower arc-shaped body, but may be a simple annular heating portion as shown in Fig. 9, and the shapes of the heating portion, ground portion, and support portion can be any shape for the purpose of adapting them to the shape of the workpiece. Furthermore, the heating coil according to the present invention is not limited to the above embodiment in which a plurality of cooling medium flow paths are provided, but may be modified to a single cooling medium flow path (for example, as in the heating coil 1 of Fig. 9, a cooling medium flow path extends from an injection pipe 14 on one side to a ground portion 2a' and a support portion 3a' to the heating portion 4, and from the heating portion 4 to a support portion 3b' and a ground portion 2b' to the injection pipe 15 on the other side).

[0048] In addition, the heating coil according to the present invention is not limited to the above embodiment in which the pair of grounding portions and the pair of supporting portions are insulated by an insulating plate made of a fluororesin (PTFE, PFA, FEP, ETFE, PCTFE, ECTFE, PVDF), but can also be changed to a configuration in which the pair of grounding portions and the pair of supporting portions are insulated by an insulating plate made of another synthetic resin having insulating properties and heat resistance, such as polyacetal (POM), polyphenylene sulfide (PPS), or polyether ether ketone (PEEK).

[0049] The heating coil according to the present invention has the excellent effects as described above, and can therefore be suitably used as a member for heating a workpiece by utilizing electromagnetic induction.

[0050] 1, 1'... Heating coil 2a, 2b, 2a', 2b'... Grounding part 3a, 3b, 3a', 3b'... Supporting part 4, 4'... Heating part 6a, 6b, 6'... Cooling medium flow path 7a, 7b... Discharge pipe 13a... Inner injection pipe 13b... Outer injection pipe 14... Injection pipe 15... Discharge pipe

Claims

DEPCT671. Heating coils used for high-frequency heaters are designed to heat materials by electromagnetic induction using high-frequency current. The heating coils are integrated using prototyping methods that repeat the layering, melting, solidification, and layering of conductive powder materials based on three-dimensional data, or prototyping methods that melt conductive material layers based on three-dimensional data. The heating coil consists of: a pair of plate-shaped grounding sections for contact with the terminals through which the high-frequency current flows; a pair of plate-shaped support sections positioned perpendicular to the grounding sections, respectively; and an ancillary heating unit positioned to connect the far ends of the supports to one another, where a sequence of cooling medium flow paths is created inside each of the grounding sections, each of the supports, and the heating unit.Heating coils for high-frequency heaters under claim 1, where the grounding section is provided with an injection port for injecting the cooling medium into the cooling medium flow and / or an outlet port for releasing the cooling medium from the cooling medium flow; 3. Heating coils for high-frequency heaters under claim 1, where the heating unit is provided with an injection port for injecting the cooling medium into the cooling medium flow and / or an outlet port for releasing the cooling medium from the cooling medium flow.

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