JPS6310559B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an electromagnetic induction heating coil that can improve the heating efficiency of a heated object and a method for manufacturing the same. (Prior Art) Heating is generally incorporated into the manufacturing process of products depending on the purpose, and one example is heating for drying in the painting process. This heating is to fix the paint after painting, and is carried out in a drying oven using a heating lamp, hot air, or the like. In this type of heating, the shape of the object to be heated is simple,
And suitable for large objects. When the object to be heated is small and has a complicated shape, electromagnetic induction heating is used to obtain uniform temperature distribution. This electromagnetic induction heating method has been proposed by the applicant. Patent application shown in Figures 11 and 12 in 1983-
No. 166973, an electromagnetic induction heating coil and its manufacturing method. Furthermore, there is an electromagnetic induction heating coil disclosed in Utility Model Application No. 59-181168, shown in FIGS. 13 and 14, which is an improvement on the above invention. The heating coil 20 described above has an uneven inner surface that matches the surface shape of the object to be heated.
A wooden mold 21 formed in the shape of the object to be heated is assembled with a fixing plate 22 having a hole corresponding to this wooden mold 21, and after applying a release agent to the surface of the wooden mold 21 and adhering a cloth, Connect the conductor 23 while solidifying it with adhesive.
It is manufactured by winding the paper and removing the wooden mold 21 after drying. (Problems to be Solved by the Invention) In the above-mentioned heating coil for electromagnetic induction, the object to be heated is of a single shape, and there is room for improvement in order to expand the application. The negative effects on heating due to abnormal heating and interference of the excitation magnetic field must be improved. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems by providing a heat detection means in an external heating coil that surrounds each divided part of an object to be heated, and an internal heating coil that is inserted into the hollow of the object to be heated. To provide an electromagnetic induction heating coil that has high thermal efficiency, accurate heating, durability, versatility, and is easy to manufacture, by inserting a cooling pipe into the coil and inserting an interference prevention member, and a method for manufacturing the same. That's true. (Means for Solving the Problems) In order to achieve the above object, the first invention of the present invention provides a shape that is approximated according to the shape of the object to be heated, and a shape that is approximated according to the shape of the object to be heated. An external heating coil is provided with a heat detection means in a bobbin large enough to surround each heating point, and a cooling pipe made of a non-magnetic material is installed inside a rod-shaped bobbin large enough to be inserted into the hollow part of the object to be heated. The structure consists of an internal heating coil into which an interference prevention member for the excitation magnetic field is inserted.
The second invention is to apply a base to a bobbin that approximates the shape of the divided parts of the object to be heated, and then wind the conductive wire according to the surface of the bobbin while fixing it with adhesive. This is a method of spraying heat-resistant reinforcement after drying. (Function) By the external heating coil and internal heating coil of the electromagnetic induction heating coil of the first invention manufactured by the method of the second invention, for example, a heated object shaped like a shock absorber can be heated. When heated, the temperature rise rate to the required temperature is high, and the thermal efficiency is high.
A heating coil that is durable and easy to manufacture can be realized. (Example) The following will mainly explain the electromagnetic induction heating coil of the first invention manufactured by the method according to the second invention of the invention. An electromagnetic induction heating coil (hereinafter referred to as a heating coil) includes an outer shell 2, which is an object to be heated, as shown in FIG. 5, and a spring seat 3.
and a shock absorber 5 consisting of a bracket 4.
The shape is for heating. The heating coil 1a shown in FIG. 1 is located at a position corresponding to the state in which the heating coil 1a is inserted as shown in FIG. A conductive wire 8 is appropriately wound around a bobbin 7a on which a ring body 6 is formed. The surface of the ring body 6 on which the conducting wire 8 is not wound faces one surface of the spring seat 3 of the shock absorber 5. By making the outer diameter of the ring body 6 10 to 15 mm smaller than the outer diameter of the spring seat 3, the shape prevents heat concentration on the outer peripheral end of the spring seat 3. A hole 9 is bored between the conductive wire 8 located in the cylinder of the bobbin 7a and the wheel body 6, and a thermocouple 10 serving as a heat detection means is attached to the hole 9. The heating coil 1b shown in FIG. 2 is similarly positioned corresponding to the location shown in FIG. When the bracket 4 is fixed to the outer shell 2, a half-split heating coil 1c as shown in FIG. 3 is used in combination. In both of these, as described above, the conductive wire 8 is wound around the outer surface of the bobbins 7b and 7c, and the thermocouple 10 is attached between them. The heating coil 1d shown in FIG. 4 has a shape that can be inserted into the hollow outer shell 2 as shown in FIG. It's wrapped. Two cooling pipes 11 made of non-magnetic material are inserted through the opening of the bobbin 7d to prevent induction heating, and to forcibly cool the heat generated by thermal radiation.
Cooling water can be circulated. Further, in order to prevent interference of the excitation magnetic field, a ferrite or aluminum foil serving as an interference prevention member 12 is inserted, and the opening of the bobbin 7d is sealed with a well-known heat-resistant sealing material. Each heating coil 1a, 1 shown in FIGS. 1 to 3
Although not shown, the terminals of the thermocouples 10 provided at b and 1c are connected to a microcomputer via an intermediate control device so that voltage, current, frequency, etc. can be controlled. Heating coils 1a, 1b, 1c, 1d described above
Although the shape has been described as an example of use in the shock absorber 5, it has versatility so that it can be used in other shock absorbers 5 having different dimensions. In order to further expand versatility, it is conceivable to prepare heating coils of various shapes. Next, the manufacturing order will be explained. First, the shock absorber 5 shown in FIG. 5 is divided into three parts as shown in FIG. 6, and the bobbin 7 is made of a material with high magnetic permeability.
a, 7b, 7c, and 7d (same as those shown in FIGS. 1 to 4) are prepared. Taking as an example the heating of the outer shell 2 shown in FIG. 2, a base material 13 such as resin is applied to the surface of the bobbin 7b as shown in FIG. The conductive wire 8 is wound around the outer surface of the bobbin 7b while being fixed with the adhesive 14 and dried. After drying,
As shown in FIG. 9, it is completed by spraying a heat-resistant reinforcing material 15 such as ceramic or Teflon as appropriate. The heating coils 1c, 1d are not limited to the winding shape of the conducting wire 8 as shown in FIGS. 3 and 4, but the conducting wire 8 is shaped in advance into a flat shape corresponding to the surface area of the bobbins 7c, 7d. Wind it around.
Thereafter, it may be attached to the bobbins 7c, 7d, and the direction of winding may be a constant direction. In the above process, a plurality of twisted heat-resistant enameled wires are used as the conducting wire 8. In this way, the current flowing through each conductor 8 can be made uniform,
Also, the lines of magnetic force can be made denser. Furthermore, the heating coil naturally cools down faster than a single wire, making it cost-effective. Each heating coil 1a manufactured in this way,
1b, 1c, and 1d are inserted into the outer periphery of the shock absorber 5, and when energized, a magnetic field is generated and heated. Here, for the heating coil of the present invention,
The above-mentioned Japanese Patent Application No. 59-166973, the heating coil A shown in FIGS. 11 and 12 of the invention, and the Utility Application No. 59-166
Table 1 shows the results of an experiment comparing heating coil B shown in Figures 13 and 14 of the invention in No. 181168. In this table, the evaluation that satisfies each experimental item is set as 100, and other values are expressed. As another result of the above experiment, a graph showing the change in temperature of the shock absorber 5 is shown in FIG. The measurement points are the outer shell 2 and spring 3 of the shock absorber 5, and are represented by curves B ₂ and B ₃ for the heating coil B (FIG. 14) corresponding to the numbers, and the curves E ₂ and E ₃ of the present invention are It was expressed as

[Table] As is clear from the table, in the heating coil of the present invention, based on the temperature distribution results for the shock absorber 5, thermocouples 10 are attached to the heating coils 1a, 1b, and 1c, and the current, voltage of each heating coil,
It shows that uniform heating is possible because the frequency can be controlled and unnecessary heat radiation can be eliminated through forced cooling.The heating time shows that the heating coil 1 is compatible with the above control and the shape of the shock absorber 5.
a, 1b, 1c, and 1d, so as is clear from Figure 10, the rate of temperature rise up to the required temperature is 2 to 3 times higher, and as for the required temperature, as also shown in Figure 10, , Since the interference prevention member was inserted, the thermal efficiency is around 20%, and the current value is 10A.
This shows that it has been improved from 12A to 12A.
Moreover, in terms of structure, the heating coils 1a, 1b,
Since the wires 1c and 1d are divided into shapes that can be placed at various locations on the shock absorber 5, manufacturing is easy, and the conductor wire 8 is located on the surface of the bobbins 7a, 7b, 7c, and 7d, giving it a versatile shape. When inserting the heating coil into the spring, damage to the coating surface of the shock absorber 5, and reduction in thermal efficiency due to inappropriate gaps between the inner surfaces of the heating coils 1a, 1b, 1c and the coating surface are eliminated. Since the diameter of the ring 6 of the heating coil 1a shown in FIG. 1 facing the seat 2 is made 10 to 15 mm smaller than the diameter of the spring seat 3, heat concentration is eliminated and thermal efficiency is good. Since the cooling pipe 11 is inserted through the heating coil 1d inserted into the inside of the shock absorber 5, the heating coils 1a, 1b, 1
The lifespan of c and 1d becomes longer. (Effects of the Invention) As explained above, the present invention is a heating coil and its manufacturing method, so the temperature rise rate to the required temperature is high, the thermal efficiency with respect to the applied voltage and current is high, and accurate heating is possible. Since a durable heating coil can be realized, it is easy to manufacture, and it is versatile, the efficiency of drying work by heating can be improved, high quality drying can be achieved, and the manufacturing cost can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of the external heating coil of the present invention, Fig. 2 is a perspective view showing an example of the external heating coil of the invention, and Fig. 3 is a perspective view showing an example of the external heating coil of the invention. 4 is a perspective view showing an example of the internal heating coil of the present invention, FIG. 5 is a perspective view showing a shock absorber as an object to be heated, and FIG. 6 is a perspective view showing the shock absorber shown in FIG. A schematic side view of the heating coil inserted into the absorber, FIG. 7 is a perspective view of the bobbin with a base coated, FIG. 8 is a perspective view of the bobbin with the conductor wound around it, and FIG. 9 is a perspective view of the bobbin with the conductor wound around it. Figure 10 is a perspective view of the heat-resistant reinforcing material sprayed after turning.
A graph showing the experimental results comparing the heating coil of the present invention and a conventional one. FIG. 11 is a perspective view showing the manufacturing process of the conventional heating coil. FIG. 12 is a graph showing the manufacturing process of another conventional heating coil. Perspective view shown, 13th
The figure is a perspective view showing a conventional heating coil manufacturing process, and FIG. 14 is a perspective view showing a conventional heating coil manufacturing process. 1a, 1b, 1c: external heating coil, 1d: internal heating coil, 5: heated object (shock absorber), 7a, 7b, 7c, 7d: bobbin, 10:
Heat detection means (thermocouple), 11: Cooling pipe, 1
2: Interference prevention member.

Claims (1)

[Scope of Claims] 1. A heat detection means is provided on a bobbin having a shape approximated according to the shape of the object to be heated and having a size that surrounds each of the divided heating points of the object to be heated. an external heating coil, and an internal heating coil in which a cooling pipe made of a non-magnetic material is inserted into the inside of a rod-shaped bobbin having a size that can be inserted into the hollow part of the object to be heated, and an interference prevention member for the excitation magnetic field is inserted. An electromagnetic induction heating coil comprising: 2. After applying a base to a bobbin that approximates the shape of the divided parts of the object to be heated, the conductor is wound according to the surface of the bobbin while being fixed with adhesive, then dried, and after drying, a heat-resistant reinforcing material is applied. A method for manufacturing an electromagnetic induction heating coil, characterized by thermal spraying.