JP5606133B2 - Heating device - Google Patents

Description

  The present invention relates to a heating device for heating a zinc hot dipping bath.

  Conventionally, a combustion method using a burner has been adopted for heating the zinc hot dip plating tank. However, since the heating by the burner is local heating, the zinc hot dipping bath cannot be heated uniformly. Moreover, since the adjustment of the thermal power is gradual, it is not suitable for precise temperature control. Therefore, in recent years, an attempt has been made to induction-heat a zinc hot dipping plating tank. For example, Patent Document 1 below discloses that a high-frequency heating device is disposed on a side wall of a zinc hot dipping bath to inductively heat the zinc hot dipping bath (see FIG. 38 in the literature). Patent Document 2 below describes that induction heating is performed by sharing a zinc hot dipping plating tank using a plurality of high-frequency heating devices.

JP 2008-95207 A

JP-A-8-13111

  In order to uniformly heat the galvanized plating bath, it is necessary to narrow the interval between the induction heating coils (high-frequency heating devices). However, when the arrangement interval of the induction heating coils is narrowed, there is a problem that the magnetic flux generated by each induction heating coil interferes (specifically, the leakage magnetic flux interferes with the magnetic flux of the adjacent induction heating coil). The temperature of the zinc hot dipping bath and plating bath cannot be controlled.

  In order to solve this, for example, as shown in FIG. 15, it is conceivable to prevent magnetic flux leakage by disposing a magnetic shield plate 8 made of ferrite in correspondence with each induction heating coil 7. However, since ferrite is a sintered body, if it is to be made into a single large plate shape, there is a problem that distortion and cracking occur when it is heat-treated and hardened, and it is difficult to mold. Therefore, the cost becomes high.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a heating device having high temperature control capability and low cost.

The present invention is a heating apparatus for heating a zinc hot dipping bath, and includes a plurality of induction heating coils arranged along the surface of the side wall of the zinc hot dipping bath, and the induction heating coils. On the other hand, a magnetic shield member that is arranged on the back surface side and covers the back surface of each induction heating coil, and is divided by a plurality of ferrite plate pieces that cover and cover the back surface of the induction heating coil. And a power supply device that is provided exclusively for each induction heating coil and applies a high-frequency AC voltage to the induction heating coil, and a partition plate that partitions the inner space of the frame into front and back sides, and the induction heating coil is provided on the surface side. An outer frame that houses each ferrite plate piece constituting the magnetic shield member on the back side, and the induction heating coil is a square planar coil, The plurality of ferrite plate pieces include a cross-shaped ferrite plate piece and an L-shaped ferrite plate piece, and the cross-shaped ferrite plate piece and the L-shaped ferrite plate piece are arranged adjacent to each other. The ferrite plate pieces are characterized in that they are arranged on the outer frame body so that the gaps between the ferrite plate pieces are substantially equal in length and width .

Since ferrite is a sintered body, when it is formed into a plate shape, distortion and cracking occur when heat-treated and baked. In the present invention, the magnetic shield member is divided by a plurality of ferrite plate pieces. With such a configuration, the cost can be reduced because it is much easier to make than a single plate of ferrite. Moreover, since the ferrite plate pieces arranged adjacent to each other are arranged so that the gaps are substantially uniform in the vertical and horizontal directions, the leakage of magnetic flux produced by the induction heating coil can be covered both in the vertical and horizontal directions. Further, by providing a gap between the ferrite plate pieces, it becomes difficult for heat to be accumulated, and the heat dissipation effect is enhanced.

  As an embodiment of the present invention, the following configuration is preferable.

The ferrite plate pieces are individually covered and a ferrite cover made of an insulating material is provided. In this way, breakage and cracking of each ferrite plate piece can be prevented.

A temperature sensor is provided corresponding to each induction heating coil in the zinc hot dipping bath, and the power supply device of each induction heating coil is individually controlled based on the output of each temperature sensor. In this way, precise temperature control of the hot dip galvanizing tank and the plating bath becomes possible.

  According to the present invention, it is possible to provide a heating device with high temperature control capability and low cost.

The perspective view of the zinc hot dipping plating tank concerning one embodiment of the present invention. Plan view showing the relationship between the hot-dip galvanizing tank and the furnace body (furnace body is shown in cross section) Coil unit perspective view Exploded perspective view of coil unit Coil holder perspective view Front view of coil unit (viewed from the front) Diagram showing the shape of the ferrite plate piece (showing the ferrite cover removed) Diagram showing shape of L-shaped ferrite plate piece (showing the state of ferrite cover) Diagram showing the shape of a cross-shaped ferrite plate piece (showing the ferrite cover attached) Diagram showing the assembly structure of the ferrite cover to the ferrite plate Rear view of coil unit (view from back side) Diagram showing shape of ferrite holder Sectional drawing which shows the state which made the accommodating part accommodate the coil unit Block diagram showing the electrical configuration of the heating device Diagram showing shielding effect by magnetic shield plate

<One Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
1. Overall Structure As shown in FIG. 1, a zinc hot dip plating tank 10 that is a heating container is made of iron and has a horizontally long bathtub type (horizontally long box type). As shown in FIG. 2, the zinc hot dipping bath 10 is surrounded on four sides by a furnace body 15. The furnace body 15 uses a heat-resistant brick or an indeterminate castable refractory, and has an accommodating portion 16 provided on the inner wall surface facing the plating tank 10.

  The accommodating portion 16 is provided in each of five chambers along the surfaces of the side walls 10 </ b> A and 10 </ b> B on the long side of the zinc hot dipping plating tank 10, and the coil unit 50 is accommodated in each of the accommodating portions 16. The accommodating portion 16 is provided with a short distance in the longitudinal direction of the zinc hot dipping bath 10, and the induction heating coils 71 of the coil units 50 are provided on almost the entire side walls 10 </ b> A and 10 </ b> B of the zinc hot dipping bath 10. It is the structure which faces evenly.

2. Description of the structure of the coil unit 50 The coil unit 50 constitutes a heating device M for induction heating of the galvanized hot dip bath 10 together with a power supply device 30 and the like described later. As shown in FIGS. 3 and 4, the coil unit 50 mainly includes an outer frame body 61, a partition plate 65, an induction heating coil 71, and a magnetic shield member 81. The outer frame 61 has a rectangular frame shape and is made of an insulating material (specifically, mica material). The outer frame 61 is partitioned into a front surface side and a back surface side by a partition plate 65 made of an insulating material (specifically, mica material).

  An induction heating coil 71 is attached to the surface side of the outer frame body 61 (the lower side in FIGS. 3 and 4). The induction heating coil 71 is a copper pipe processed into a spiral shape. The induction heating coil 71 is a rectangular rectangular planar coil, and the entire coil is configured to fit within the frame of the outer frame body 61. A cross-shaped coil holder 75 is assembled on the front surface side of the outer frame body 61 so that the end portion is fitted in a fixing groove formed on the inner wall of the outer frame body 61.

  As shown in FIG. 5, the coil holder 75 is a combination of square bars in a cross shape. The coil holder 75 has support grooves 76 formed at regular intervals, and the induction heating coil 71 is fitted into the support grooves 76. As a result, the induction heating coil 71 is configured to be held uniformly on all sides as shown in FIG. 6 and supported on the outer frame 61 without rattling.

  Next, a magnetic shield member 81 is attached to the back side of the outer frame body 61 (the upper side in FIGS. 3 and 4). The magnetic shield member 81 is made of ferrite and prevents leakage of magnetic flux produced by the induction heating coil 71. As shown in FIG. 7, the magnetic shield member 81 is divided into a plurality of ferrite plate pieces 91 and 95. The ferrite plate pieces 91 and 95 have a flat plate shape, and are composed of two types: a ferrite plate piece 91 having a cross shape and a ferrite plate piece 95 having an L shape.

  These ferrite plate pieces 91 and 95 are covered with a ferrite cover 97 as shown in FIGS. The ferrite cover 97 is made of an insulating material, specifically, a fired mica material (powder mica hardened with a binder). As shown in FIG. 10, the ferrite cover 97 has a strip shape with the tip cut off in a tapered shape. For the L-shaped ferrite plate piece 91, two L-shaped ferrite covers 91 are used. These four sides are covered, and the four crossed ferrite plate pieces 95 are used to cover the four sides of the cross.

  Each ferrite cover 97 is formed with an opening window 98 in the center of the cover, and the ferrite plate pieces 91 and 95 are exposed through the opening window 98. That is, the ferrite cover 97 is configured to cover only the peripheral portions of the ferrite plate pieces 91 and 95. Each of the ferrite plate pieces 91 and 95 is configured to be assembled to the outer frame body 61 so that the ends thereof are fitted in the mounting grooves 62 formed on the inner wall of the outer frame body 61.

  Next, the arrangement of the ferrite plate pieces 91 and 95 with respect to the outer frame body 61 will be described. As shown in FIGS. 7 and 11, the cross-shaped ferrite plate piece 91 is disposed at the center of the outer frame body 61, and is configured to cross the space inside the outer frame body 61 in a cross shape. On the other hand, three L-shaped ferrite plate pieces 95 having different sizes are prepared and arranged in order of size (in ascending order) from the corner side of the outer frame 61 toward the center of the cross.

  Each L-shaped ferrite plate piece 95 is arranged in the same direction with a certain distance from the adjacent ferrite plate pieces 91 and 95. Here, “align the direction” means aligning the directions of the two pieces of the ferrite plate piece 95 so that the two pieces are directed in the vertical direction and the horizontal direction, respectively. In this embodiment, as shown in FIG. 7, the gaps D between adjacent ferrite plate pieces are set to be equal in length and width. Thus, the ferrite plate pieces 91 and 95 can uniformly cover the back surface of the induction heating coil 71 having a square shape. Therefore, the entire surface of the induction heating coil 71 can be shielded evenly, and a structure that does not cause magnetic flux leakage is obtained. Further, by providing a gap between the ferrite plate pieces 91 and 95, it becomes difficult for heat to be accumulated, and the heat dissipation effect is enhanced.

  7 is a view for explaining the arrangement of the ferrite plate pieces 91 and 95 with respect to the outer frame body 61, and is a view in which the ferrite cover 97 is omitted.

  A ferrite holder 85 having a lattice shape is assembled on the back surface side of the outer frame body 61 so that the end portion is fitted in a fixing groove 63 formed on the inner wall of the outer frame body 61.

  As shown in FIG. 12, the ferrite holder 85 is a combination of square bars in a lattice shape. The ferrite holder 85 has support grooves 86 formed at regular intervals, and the ferrite plate pieces 91 and 95 are fitted into the support grooves 86. As a result, the ferrite plate pieces 91 and 95 are configured to be supported by the outer frame body 61 without rattling as shown in FIG.

  As shown in FIG. 13, the coil unit 50 configured as described above has the surface of the furnace body 15 with the surface on which the induction heating coil 71 is attached facing the side walls 10 </ b> A and 10 </ b> B of the zinc hot dipping plating tank 10. It is configured to be attached to the accommodating portion 16.

  Next, the electrical configuration of the heating device M will be described with reference to FIG. The heating device M includes the coil unit 50, the power supply device 30, the temperature sensor 40, and the control device 20.

  The power supply device 30 is a so-called inverter power supply (frequency converter), and applies a high-frequency AC voltage to the induction heating coil 71 of the coil unit 50. The power supply device 30 is provided individually corresponding to the induction heating coil 71 of each coil unit 50.

  The temperature sensor 40 detects the temperature of the zinc hot dipping bath 10 and is attached along the inner wall of the zinc hot dipping bath 10. The temperature sensor 40 is individually provided corresponding to each induction heating coil 71, and the output line is connected to the control device 20.

  The control device 20 gives a control signal to each power supply device 30 to control the output of each power supply device 30 (the amount of power applied to the induction heating coil 71), thereby increasing the strength of the alternating magnetic flux of each induction heating coil 71. It has a function to control.

  In this embodiment, as a result of the control device 20 individually adjusting the output of each power supply device 30 based on the output value of each temperature sensor 40, the temperature of the zinc hot dipping bath 10 and the plating bath is the target temperature. It is configured to be automatically controlled at a certain 670 degrees.

3. Description of effect (1) Effect seen from temperature control surface The heating device M employs an induction heating method. With the induction heating method, the strength of the alternating magnetic flux of the induction heating coil 71, that is, the amount of heat generated can be continuously adjusted steplessly by adjusting the output of the power supply device 30. And since the power supply device 30 is provided separately, the strength of the alternating magnetic flux of each induction heating coil 71 can be individually controlled. From the above, precise temperature control becomes possible, and the temperature of the zinc hot dipping bath 10 and the plating bath can be accurately controlled to a desired temperature.

  In the present embodiment, the induction heating coils 71 are arranged side by side along the side walls 10 </ b> A and 10 </ b> B of the zinc hot dip plating tank 10 without any gaps. Therefore, the side walls 10A and 10B of the zinc hot dipping bath 10 can be heated uniformly over the entire surface in the longitudinal direction, and the temperatures of the zinc hot dipping bath 10 and the plating bath can be made constant over the entire surface. It is.

  On the other hand, when the induction heating coils 71 are arranged side by side, there is a problem of mutual interference of magnetic fluxes. If the magnetic flux generated by the induction heating coil 71 interferes between the coils, the intended amount of heat generation cannot be obtained, and temperature control becomes unstable. In this regard, in this embodiment, the magnetic shield member 81 is provided corresponding to each induction heating coil 71. Therefore, it is possible to minimize the leakage of magnetic flux generated by each coil 71 (see FIG. 15), and there is no level of mutual interference that affects control. From the above, it becomes possible to exhibit a high temperature control capability.

(2) Effect Seen from Cost In the present embodiment, the magnetic shield member 81 is divided by a plurality of ferrite plate pieces 91 and 95. With such a configuration, it is much easier to make than in the case where the ferrite is a single plate. Therefore, it becomes possible to provide the heating device M having a high temperature control capability at low cost, which is effective.

  Moreover, in this thing, the power supply device 30 is provided for every induction heating coil 71 individually. With such a configuration, the power supply device 30 may have a small output as compared with the case where the induction heating coil 71 is driven by a single power supply device 30. Therefore, for example, a general-purpose power supply device (IH power supply device) used for a commercial electromagnetic cooker can be used for the power supply device 30, and the equipment cost can be suppressed.

(3) Other Effects In this embodiment, the induction heating coil 71 and the magnetic shield member 81 are fixed to the outer frame body 61 and the whole is assembled as the coil unit 50. Therefore, it becomes the structure excellent in handling. In this embodiment, the ferrite plate pieces 91 and 95 are covered with the ferrite cover 97. Therefore, cracking and breakage of the ferrite plate pieces 91 and 95 can be prevented.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above embodiment, an example in which the coil units 50 are arranged in one stage is illustrated, but the number of stages of the coil units 50 is not limited to one, and is multi-stage (for example, upper and lower two stages). Of course, it is good even if it is the structure arranged to.

DESCRIPTION OF SYMBOLS 10 ... Lead hot dip bath 20 ... Control device 30 ... Power supply device 40 ... Temperature sensor 50 ... Coil unit 61 ... Outer frame 65 ... Partition plate 71 ... Induction Heating coil 75 ... Coil holder 81 ... Magnetic shield member 85 ... Shield member cover 91, 95 ... Ferrite plate piece 97 ... Ferrite cover

Claims (3)

A heating device for heating a zinc hot dipping bath,
A plurality of induction heating coils arranged side by side along the surface of the side wall of the zinc hot dipping bath;
A magnetic shield member that is arranged on the back side of each induction heating coil and covers the back side of each induction heating coil, and is divided by a plurality of ferrite plate pieces that share and cover the back side of the induction heating coil A magnetic shield member configured;
A power supply device that is provided exclusively for each induction heating coil and applies a high-frequency AC voltage to the induction heating coil ;
It comprises a partition plate that partitions the inner space of the frame into front and back, the induction heating coil is accommodated on the front surface side, and the outer frame body that accommodates each ferrite plate piece constituting the magnetic shield member on the back surface side,
The induction heating coil is a square planar coil,
The plurality of ferrite plate pieces include a cross-shaped ferrite plate piece and an L-shaped ferrite plate piece, and the cross-shaped ferrite plate piece and the L-shaped ferrite plate piece are arranged adjacent to each other. The heating device is characterized in that it is arranged on the outer frame body so that the gaps between the ferrite plate pieces are substantially equal in length and width . The heating apparatus according to claim 1 , further comprising a ferrite cover that individually covers each of the ferrite plate pieces and is made of an insulating material. A temperature sensor is provided corresponding to each induction heating coil in the zinc hot dipping bath, and the power supply device of each induction heating coil is individually controlled based on the output of each temperature sensor. The heating apparatus according to claim 1 or 2 .

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