JP7614493B2 - Oxidation prevention treatment device, heating device, oxidation prevention treatment method, and method for manufacturing molded product - Google Patents

Description

The present invention relates to an oxidation suppression treatment device, a heating device, an oxidation suppression treatment method, and a method for manufacturing molded products.

In order to optimize the dimensional accuracy or strength required for a molded product, a workpiece formed by joining multiple components together by welding or other methods may be heated and processed to produce the molded product. In addition, in order to improve the corrosion resistance of the molded product, the multiple components that make up the workpiece may have a plated coating.

The plated coating may contain components that dissolve into the welded area during welding, thereby affecting the strength of the welded area. In this case, the plated coating is removed from the welded area and its vicinity. However, depending on the atmosphere in the heating furnace, this may result in the formation of scale (oxide coating) in the area where the plated coating has been removed. Such scale may reduce the adhesion of the coating, making it necessary to remove it in a subsequent process.

Therefore, it is necessary to suppress the generation of scale at the welded parts. For example, the following Patent Document 1 describes a technology in which a sealed replacement gas holding section is formed at a part that is oxidized by welding or brazing, and a replacement gas such as an inert gas is supplied to the replacement gas holding section.

In addition, the following Patent Documents 2 and 3 describe a technique for suppressing oxidation around the weld by controlling the dew point temperature and composition of the shielding gas supplied to the weld during welding.

Furthermore, the following Patent Document 4 describes a technique for applying a decarburization prevention agent to the side of a slab before it is heated in a heating furnace by varying the amount of decarburization prevention agent liquid sprayed onto the side of the slab.

Japanese Patent Application Publication No. 5-177388 JP 2008-183565 A Japanese Patent Application Publication No. 6-155029 JP 2001-79604 A

However, the techniques described in Patent Documents 1 to 3 attempt to suppress the generation of scale at the welded portion by controlling the atmosphere during welding. The technique described in Patent Document 4 applies a decarburization inhibitor to the entire surface of the side of the slab, which is the open surface during transport before being placed in the heating furnace, to suppress decarburization due to subsequent heating. Here, in order to suppress the generation of scale at the welded portion when heating a workpiece having a welded portion, it is possible to apply an antioxidant to the welded portion before placing the workpiece in the heating furnace. On the other hand, if it is sufficient to apply the antioxidant to the extent that it is possible to suppress the generation of scale at the welded portion, it is preferable to apply the antioxidant only as close to the welded portion as possible and not to spread it to other areas.

The present invention has been made in consideration of the above problems, and the object of the present invention is to provide an oxidation inhibition treatment device, a heating device, an oxidation inhibition treatment method, and a method for manufacturing a molded product that can apply an antioxidant to the vicinity of the welded part before the workpiece is placed in the heating furnace, and at the same time, can prevent the antioxidant from scattering to areas other than the welded part.

In order to solve the above problem, according to one aspect of the present invention, there is provided an oxidation inhibition treatment device that sprays an antioxidant along a weld of a workpiece having a linear weld between one member and another member, at least one of which is made of a plate material having a plating coating, the oxidation inhibition treatment device comprising a supply unit that supplies a mixed gas containing atomized antioxidant to the weld, a recovery unit that recovers a portion of the mixed gas supplied to the weld, and a header unit shaped to fit the weld and in which the supply unit and the recovery unit are arranged.

At least one of the supply section and the recovery section may be provided in multiples.

The supply sections and recovery sections may be arranged alternately.

The supply section and the recovery section may comprise a pair of header sections that face each other at a sandwiched position, and the supply section and the recovery section of one of the pair of header sections may face the recovery section and the supply section of the other header section, respectively, at a position sandwiching the weld section.

The oxidation suppression treatment device may move relatively along the welded portion.

To solve the above problem, according to another aspect of the present invention, a heating device is provided that includes the oxidation suppression treatment device, a heating furnace that heats the workpiece to which the antioxidant has been sprayed, and a transport mechanism that transports the workpiece from the oxidation suppression treatment device into the heating furnace.

The conveying mechanism is arranged outside the heating furnace and includes a table roller section including a plurality of table rollers, the table rollers having a first table roller section and a second table roller section spaced apart in the longitudinal direction of the table roller, the table roller section including a row of spaced sections formed by the spaced sections between the first table roller section and the second table roller section on each of the plurality of table rollers, and the row of spaced sections may have a shape following the header section.

The heating device may include a tray on which the workpiece is placed and transported by the transport mechanism, and the header portion may be provided on the tray.

In order to solve the above problems, according to another aspect of the present invention,
Provided is an oxidation inhibition treatment method for spraying an antioxidant along a weld of a workpiece having a linear weld between one member and another member, at least one of which is made of a plate material having a plating coating, the oxidation inhibition treatment method comprising: a supply section that supplies a mixed gas containing atomized antioxidant to the weld and a recovery section that recovers a portion of the mixed gas supplied to the weld, and while supplying the mixed gas to the weld, the mixed gas is recovered by a supply section that supplies the mixed gas containing atomized antioxidant to the weld and a recovery section that recovers a portion of the mixed gas supplied to the weld, wherein at least a plurality of the supply sections and the recovery sections are provided and arranged alternately along the weld, and the suction flow rate of gas sucked in to recover the mixed gas in each of the recovery sections is equal to or more than half the sum of the supply flow rates of the mixed gas supplied by the supply sections adjacent to both sides of the recovery section.

The antioxidant is sprayed onto the welded portion from both sides of the workpiece, and the supply section and recovery section on one side face each other with the recovery section and supply section on the other side sandwiching the welded portion of the workpiece, and the supply flow rate of each of the supply sections on one side may be less than or equal to 1/2 (>0) of the sum of the supply flow rates of the supply sections adjacent to both sides of the recovery section on the other side facing the supply section on the one side.

The plating film may be an Al-based alloy film.

The first and second members may be made of materials having different tensile strengths.

The first member and the second member may have different thicknesses.

In order to solve the above problem, according to another aspect of the present invention, there is provided a method for manufacturing a molded product in which a workpiece having a weld between one member and another member, at least one of which is made of a plate material having a plating coating, is molded into a molded product of a predetermined shape, the method including the steps of spray-applying the antioxidant to the weld of the workpiece by the oxidation suppression treatment method, heating the workpiece to which the antioxidant has been applied, and hot forming the heated workpiece.

As described above, the present invention provides an oxidation inhibition processing device, a heating device, an oxidation treatment inhibition method, and a method for manufacturing a molded product, which can apply an antioxidant near the welded part before the workpiece is placed in the heating furnace and can prevent the antioxidant from scattering to areas other than the welded part, thereby preventing the antioxidant from affecting subsequent processes.

1 is a side view showing a schematic configuration of a heating device according to a first embodiment of the present invention. FIG. 2 is a plan view showing a schematic configuration of the heating device according to the embodiment. 5 is a schematic diagram provided for explaining a welding process of a workpiece according to the embodiment; FIG. 2 is a schematic diagram showing a schematic configuration of an oxidation suppression treatment device according to the embodiment; FIG. 2 is a schematic diagram showing a schematic configuration of an oxidation suppression treatment device according to the embodiment; FIG. 13 is a partial enlarged view for explaining the arrangement of the lower header portion according to the embodiment. FIG. 13 is a partial enlarged view for explaining the arrangement of the lower header portion according to the embodiment. FIG. 13 is a partial enlarged view for explaining the arrangement of the lower header portion according to the embodiment. FIG. 4 is a flowchart showing an example of an oxidation suppression treatment method in the embodiment. 4 is a flowchart showing an example of a method for manufacturing a molded product according to the embodiment. FIG. 4 is a partial enlarged view for explaining the arrangement of a hearth roller unit according to the embodiment. 13 is a plan view showing a schematic configuration of a header portion according to a modified example of the embodiment. FIG. FIG. 4 is a side view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 13 is a plan view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 5 is a side view showing a schematic configuration of a heating device according to a second embodiment of the present invention. FIG. 2 is a plan view showing a schematic configuration of the heating device according to the embodiment. FIG. 2 is an external perspective view of the tray according to the embodiment. FIG. 4 is a side view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 13 is a plan view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 13 is a plan view showing a schematic configuration of a heating device according to another modified example of the embodiment. FIG. 11 is a side view showing a schematic configuration of a heating device according to a third embodiment of the present invention. FIG. 2 is a plan view showing a schematic configuration of the heating device according to the embodiment. FIG. 2 is an external perspective view of the tray according to the embodiment. FIG. 4 is a side view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 13 is a plan view showing a schematic configuration of a heating device according to a modified example of the embodiment. FIG. 13 is a plan view showing a schematic configuration of a heating device according to another modified example of the embodiment. FIG. 13 is a side view illustrating a schematic configuration of a heating device according to a fourth embodiment of the present invention. FIG. 2 is a plan view illustrating a schematic configuration of the heating device according to the embodiment. FIG. 13 is a side view illustrating a schematic configuration of a heating device according to a fifth embodiment of the present invention. FIG. 2 is a plan view illustrating a schematic configuration of the heating device according to the embodiment. FIG. 13 is a diagram illustrating a schematic configuration of a welding head and an oxidation suppression treatment device according to a sixth embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of an oxidation suppression treatment device according to a modified example of the embodiment. FIG. 13 is a side view showing a modified example in which a hat-shaped workpiece is heated. 13 is a partial enlarged view for explaining the arrangement of a lower header portion according to a modified example of the header portion that follows the welded portion. FIG. 13 is a partial enlarged view for explaining the arrangement of a lower header portion according to a modified example of the header portion that follows the welded portion. FIG.

The preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. Note that in this specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals to avoid redundant description.

First Embodiment
1. Configuration of the heating device
First, a schematic configuration of a heating device 100 according to a first embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a side view showing a schematic configuration of the heating device 100 according to the present embodiment. Fig. 2 is a plan view showing a schematic configuration of the heating device 100 according to the present embodiment.

As shown in Figs. 1 and 2, the heating device 100 according to this embodiment includes a heating furnace 101. The heating furnace 101 heats the workpiece W inside. In this embodiment, the heating furnace 101 has a tunnel structure that is connected along the Y direction in Fig. 1, and the workpiece W is heated as it passes continuously through the tunnel structure.

The heating device 100 includes a plurality of heating sections 110, a transport mechanism 120, and an oxidation suppression treatment device 130. The plurality of heating sections 110 are provided inside the heating furnace 101, and heat the workpiece W under predetermined heating conditions. As an example, the heating sections 110 are panel-shaped electric heaters. As shown in FIG. 1, the plurality of heating sections 110 are arranged separately above and below the workpiece W. The plurality of heating sections 110 on the upper and lower sides are arranged side by side in the transport direction of the workpiece W. An example of the atmosphere inside the furnace is air. An example of the temperature inside the furnace is about 700 to 900°C.

The transport mechanism 120 transports the workpiece W inside and outside the heating furnace 101. As shown in FIG. 1, the transport mechanism 120 is a roller-type transport mechanism. Specifically, the transport mechanism 120 includes a hearth roller section 121 provided inside the heating furnace 101 and a table roller section 122 in front of the heating furnace 101 that transports the workpiece W to the hearth roller section 121. The hearth roller section 121 has multiple hearth rollers 121A. The table roller section 122 has table rollers 122A. With the workpiece W placed on the multiple table rollers 122A or the multiple hearth rollers 121A, the table rollers 122A or hearth rollers 121A rotate by the power supplied from a drive source (not shown), thereby transporting the workpiece W.

Here, the workpiece W that is the main object to be heated in the heating device 100 according to this embodiment will be described with reference to FIG. 3. FIG. 3 is a schematic diagram provided for explaining the welding process of the workpiece W according to this embodiment.

For the sake of convenience, the following description will be given with an example in which the workpiece W is plate-shaped, but the workpiece W is not limited to being a flat member, and may be a member having a three-dimensional shape due to processing. An example of the workpiece W is a structural member formed into a predetermined cross-sectional shape, such as a hat shape. Specifically, an example of the workpiece W is a B-pillar of an automobile frame part, or an intermediate molded product thereof. Cases in which the workpiece W has a three-dimensional shape will be described later.

As an example, the workpiece W is a so-called tailored-welded blank (TWB) formed by joining multiple metal plate-shaped members. That is, the workpiece W is formed by welding a first plate-shaped member T1 and a second plate-shaped member T2. Specifically, as shown in the top part of FIG. 3, the end face of the first plate-shaped member T1 and the end face of the second plate-shaped member T2 are butted together and welded. As a result, the base metals melt together to form a welded portion W1 in the workpiece W (second from the top in FIG. 3). The welding method is not particularly limited, but one example is laser welding.

The first plate-shaped member T1 and the second plate-shaped member T2 that form the workpiece W are, as an example, steel plates. In particular, the first plate-shaped member T1 and the second plate-shaped member T2 may be hot forming steel plates. Furthermore, the first plate-shaped member T1 and the second plate-shaped member T2 may be made of different metals. For example, the first plate-shaped member T1 may be a steel plate, and the second plate-shaped member T2 may be a plate material made of a metal other than steel.

As described above, the workpiece W is a tailored blank material, and is formed by appropriately combining multiple members according to the strength required for the workpiece W. For example, the first plate-shaped member T1 and the second plate-shaped member T2 may have different tensile strengths. Also, as shown in FIG. 3, the first plate-shaped member T1 and the second plate-shaped member T2 may have different plate thicknesses.

Here, the workpiece W may be required to have further improved corrosion resistance. In this case, as a method for improving corrosion resistance, there is a method of improving corrosion resistance by providing a plated coating L on the surface of the workpiece W as shown in FIG. 3. An example of the plated coating L is an Al-based alloy coating or a Zn-based alloy coating. However, since the workpiece W is a tailored blank material as described above, plate-shaped members having the plated coating L are welded together. If the plated coating L remains at the welded portion of the plate-shaped member, the alloy component in the plated coating L may dissolve into the welded portion W1. Specifically, the Al component in the plated coating L may dissolve into the welded portion W1. In this case, since a hard and brittle plated intermetallic compound phase remains at the boundary between the welded portion W1 and the heat-affected portion, the fatigue strength of the welded portion W1 decreases when the welded portion W1 is subjected to repeated loads, and the welded portion W1 is more likely to break. In other words, the durability of the workpiece W and the molded product formed from the workpiece W may decrease. Furthermore, the Al component in the plated coating L may dissolve into the welded portion W1. This may result in a decrease in corrosion resistance. In other words, the durability of the workpiece W and the molded product formed from the workpiece W may decrease.

In order to suppress the above phenomenon, the plating film L may be partially reduced or removed before welding. However, in this case, when the workpiece W is put into the heating furnace 101 after welding, an oxide film (scale S) may be generated on the surface of the workpiece W at the portion where the plating film L was removed (i.e., the welded portion W1 and its surroundings) depending on the atmosphere in the heating furnace 101 (third from the top in FIG. 3). Such scale S may reduce the adhesion of the coating film, and may need to be removed in a later process. Furthermore, since the scale S grows in the thickness direction of the plate material by heating, the plate material becomes thinner when the scale S is generated (bottom part of FIG. 3). In this case, the portion of the plate material where the plate thickness is reduced becomes a stress concentration portion SC, and stress is concentrated in the vicinity of the welded portion W1, and the breaking load during press forming at the welded portion W1 and the breaking load of the formed member may decrease. In addition, physical methods for removing the scale S include shot blasting, cutting, grinding, etc. In addition to physical methods, chemical methods may also be used to remove the scale S. Chemical methods for removing scale S include, for example, pickling and etching.

On the other hand, coating with an antioxidant may be considered to suppress the generation of scale S. However, when a liquefied antioxidant is sprayed onto the workpiece W, it is expected that the scattering will have an impact on the surrounding environment inside and outside the furnace. For example, if an excessive amount of antioxidant is scattered and remains inside the furnace, it may change the adjusted atmosphere inside the furnace or cause malfunctions of the furnace mechanisms.

The inventors conducted extensive research and came up with the oxidation suppression treatment device of the present invention. The oxidation suppression treatment device 130 according to an embodiment of the present invention is described below.

2. Configuration of the oxidation suppression treatment device
4 and 5 are schematic diagrams showing a schematic configuration of the oxidation suppression treatment device 130 according to this embodiment. As shown in Fig. 4 and Fig. 5, the oxidation suppression treatment device 130 includes a supply section 131, a recovery section 132, and a header section 133. In the header section 133, the supply section 131 and the recovery section 132 are provided along the longitudinal direction of the welded section W1. In other words, the header section 133 integrates the multiple supply sections 131 and the recovery sections 132. In the example shown in Fig. 4 and Fig. 5, the oxidation suppression treatment device 130 includes a pair of header sections 133, an upper header section 133A and a lower header section 133B, which are arranged above and below the workpiece.
The supply unit 131 supplies the gas mixture containing the antioxidant supplied by the antioxidant supply device 141 and atomized to the welded zone W1. The antioxidant is not particularly limited as long as it can suppress the generation of scale S at the welded zone W1, and examples thereof include particulate metal oxides. Such metal oxide particles are suspended in a solvent, making it possible to atomize the liquid containing the antioxidant.

The recovery section 132 recovers a portion of the mixed gas supplied to the welded portion W1 by the supply section 131. The recovery section 132 does not recover all of the mixed gas supplied to the welded portion W1, but rather recovers only enough to suppress the formation of an oxide film and to prevent the antioxidant from scattering to the surrounding area. In order to suppress the spread of the spray range due to the expansion of the flow (jet) of the mixed gas supplied from the supply section 131, and to promote the recovery of the mixed gas containing the antioxidant that has diffused without adhering to the workpiece W, it is desirable to make the opening area of the recovery section 132 larger than the opening area of the supply section 131.

The mixed gas flow supplied from the supply unit 131 collides with the welded portion W1 of the workpiece W and its surrounding area, and is then collected by the collection unit 132, changing the direction of the airflow. Specifically, as shown in Figs. 4 and 5, the mixed gas flow supplied from the supply unit 131 collides with the workpiece W and then turns back toward the collection unit 132. In this way, the mixed gas flow is controlled to prevent the antioxidant from diffusing to the surrounding area. As a result, the mixed gas containing the antioxidant is localized, and there is a fixed area through which the mixed gas supplied to and collected from the welded portion W1 flows, so that the application range of the antioxidant applied to the welded portion W1 is limited, and excessive scattering of the antioxidant to the surrounding area is prevented.

The mixed gas containing the antioxidant supplied from the supply unit 131 is collected by the opposing collection unit 132 in an area where it does not collide with the workpiece W (for example, an area on the outer side of the workpiece W), so that a linear gas flow of the mixed gas is formed on the side of the workpiece W. This further prevents the antioxidant from scattering around the welded portion W1.

(Header section)
As shown in FIG. 4, the header section 133 may have a substantially rectangular parallelepiped housing shape. A plurality of supply sections 131 and a plurality of recovery sections 132 are provided along the longitudinal direction of the housing. Here, the longitudinal direction of the header section 133 is along the extension direction of the welded section W1. For example, when the welded section W1 is formed linearly, the longitudinal direction of the header section 133 is along the longitudinal direction of the welded section W1. The supply sections 131 and the recovery sections 132 are alternately arranged in the longitudinal direction of the header section 133. In other words, when the welded section W1 is linear, the supply sections 131 and the recovery sections 132 are alternately arranged along the longitudinal direction of the welded section W1 formed linearly. Specifically, as shown in FIG. 4, a plurality of openings are provided inside the header section 133, and these openings function as the supply sections 131 or the recovery sections 132. As shown in FIG. 4, these openings are connected to a supply duct 135A and a recovery duct 135B, respectively (see the blowing portion (cross-sectional view) in FIG. 4), thereby realizing the supply and recovery of a mixed gas containing an antioxidant.

The header section 133 may also be arranged so that its longitudinal direction is aligned with the transport direction of the workpiece W (as shown in FIG. 2). In other words, the supply section 131 and the recovery section 132 in the header section 133 may be arranged along the transport direction of the workpiece W.

4 and 5, as described above, the oxidation suppression treatment device 130 has an upper header portion 133A and a lower header portion 133B. The upper header portion 133A and the lower header portion 133B face each other with the workpiece W before being transported into the heating furnace 101 in between. Furthermore, the upper header portion 133A is provided at a position facing the front surface of the welded portion W1 of the workpiece W, and the lower header portion 133B is provided at a position facing the back surface of the welded portion W1 of the workpiece W. As a result, the mixed gas containing the antioxidant is supplied to and collected at the front and back sides of the welded portion W1 by the supply portion 131 and the recovery portion 132 of each of the upper header portion 133A and the lower header portion 133B provided at positions facing the front and back surfaces of the welded portion W1, respectively.

Specifically, as shown in FIG. 1, the upper header section 133A is attached upstream in the conveying direction from the insertion opening of the heating furnace 101. On the other hand, the lower header section 133B is provided on the table roller section 122 upstream in the conveying direction from the insertion opening of the heating furnace 101.

The arrangement of the table roller portion 122 and the lower header portion 133B will be described below with reference to Figures 6 to 8. Figure 6 is a partial enlarged view (viewed in the Y direction) for explaining the arrangement of the lower header portion 133B. Also, Figure 7 is a partial enlarged view (viewed in the Z direction) for explaining the arrangement of the lower header portion 133B. Also, Figure 8 is a partial enlarged view (viewed in the X direction) for explaining the arrangement of the lower header portion 133B.

In the table roller section 122, as shown in Figs. 6 and 7, the multiple table rollers 122A have a first table roller section 122B and a second table roller section 122C that are spaced apart from each other in a direction perpendicular to the conveying direction of the workpiece W of the table roller 122A (the X direction in Fig. 6, i.e., the longitudinal direction along the rotation axis of the table roller 122A). That is, the table roller 122A has a spaced section 122E between the first table roller section 122B and the second table roller section 122C. The first table roller section 122B and the second table roller section 122C are connected by a core rod member 122D for transmitting a rotational force. The table roller section 122 has a spaced section row 122F composed of the spaced sections 122E of the multiple table rollers 122A. The lower header section 133B is arranged in the spaced section row 122F of the table roller section 122.

The outer diameter of the core rod member 122D is smaller than the outer diameters of the first table roller portion 122B and the second table roller portion 122C. As a result, a space is formed surrounded by the workpiece W, the core rod member 122D, the first table roller portion 122B, and the second table roller portion 122C. In the table roller portion 122, such spaces are formed in a row in the transport direction of the workpiece W, and a part of the lower header portion 133B is provided within this space. As shown in Figures 6 and 8, the portion of the lower header portion 133B that is arranged in the above-mentioned space is smaller than the other portions of the lower header portion 133B.
As shown in FIG. 11, the hearth roller 121A in the heating furnace 101 shown in FIG. 1 may also be configured to have a first hearth roller portion 121B and a second hearth roller portion 121C spaced apart from each other in the longitudinal direction of the table roller 122A (in other words, in a direction perpendicular to the transport direction of the workpiece W), similar to the table roller 122A of the table roller portion 122 in front of the heating furnace 101.
That is, in the hearth roller unit 121, the multiple hearth rollers 121A may have a first hearth roller unit 121B and a second hearth roller unit 121C spaced apart from each other in a direction perpendicular to the conveying direction of the workpiece W (i.e., the longitudinal direction along the rotation axis of the hearth roller 121A) as shown in Fig. 11. That is, the hearth roller 121A may have a spaced apart portion 121E between the first hearth roller unit 121B and the second hearth roller unit 121C. The first hearth roller unit 121B and the second hearth roller unit 121C may be connected by a core rod member 121D for transmitting a rotational force.

(Supply and recovery system)
As shown in FIG. 5, the oxidation suppression treatment device 130 includes a supply recovery system 140 for supplying the mixed gas containing the antioxidant to the header section 133 and recovering it. That is, the oxidation suppression treatment device 130 includes an antioxidant supply device 141, an air blower 142, an exhaust blower 143, and a filter 144. The antioxidant supply device 141 includes, for example, a valve 141A that atomizes the liquid antioxidant and mixes it with the carrier gas sent from the air blower 142. The mixed gas mixed by the valve 141A is supplied to the header section 133. The filter 144 is a dust recovery device that removes excess antioxidant from the recovered mixed gas. The exhaust blower 143 may or may not be provided. When the exhaust blower 143 is omitted, the filter 144 and the air blower 142 may be connected by a circulation path 145, and the gas filtered by the filter 144 may be circulated by the air blower 142. With the above-described configuration, a mixed gas obtained by mixing the antioxidant supplied from the antioxidant supply device 141 and the carrier gas sent from the air blower 142 is supplied from the supply unit 131 toward the welded portion W1 of the workpiece W. In addition, the mixed gas containing the supplied antioxidant is collected via the collection unit 132.

(Control Unit)
As shown in FIG. 1, the heating device 100 has a furnace control unit 170. The furnace control unit 170 controls the operation of the multiple heating units 110 and the transport mechanism 120, etc., to control the heating conditions in the heating furnace 101. Furthermore, the heating device 100 has a control unit 160 (oxidation suppression control unit). The control unit 160 may be either integrated with the heating furnace control unit 170 or separate from it. The control unit 160 controls the operation of the oxidation suppression treatment device 130 (the opening degree of the valve 141A of the antioxidant supply device 141, the rotation speeds of the air blower 142 and the exhaust blower 143, etc.). By controlling the opening degree of the valve 141A of the antioxidant supply device 141, the supply amount of the antioxidant, and therefore the concentration of the antioxidant, are adjusted, and by controlling the rotation speeds of the air blower 142 and the exhaust blower 143, the supply flow rate and the recovery flow rate of the mixed gas are adjusted.

The function of the heating furnace control unit 170 is realized, for example, by cooperation between a CPU (Central Processing Unit), memory, storage, etc. That is, the CPU functions as the heating furnace control unit 170 by executing, on the memory, a heating control program set for each work type of the heating device 100 stored in the storage. Similarly, the function of the control unit 160 is realized, for example, by cooperation between a CPU, memory, storage, etc. That is, the CPU functions as the control unit 160 by executing, on the memory, a control program for the supply and recovery of mixed gas, the supply amount of antioxidant, and the operating time set for each work type of the heating device 100 stored in the storage.

Next, the functions of the heating device 100 and the oxidation suppression treatment device 130 according to this embodiment will be described. The workpiece W is transported to the heating furnace 101 by the transport mechanism 120. When the workpiece W is placed in a predetermined position before being inserted into the heating furnace 101, the oxidation suppression treatment device 130 is provided at a position facing the welded portion W1 of the workpiece W. A mixed gas containing an antioxidant is supplied from the oxidation suppression treatment device 130 toward the welded portion W1 of the workpiece W. As a result, the antioxidant contained in the mixed gas adheres to and is applied to the welded portion W1, and the welded portion W1 and its surrounding areas are coated with this antioxidant. The workpiece W is then transported into the furnace and heated under predetermined heating conditions. During and after the heating of the workpiece W, the welded portion W1 and its surrounding areas are covered with the antioxidant, so that the generation of scale S at the welded portion W1 and its surrounding areas is suppressed. After heating under the specified conditions is completed, the workpiece W is removed from the heating furnace 101 by the transport mechanism 120 and transported to the subsequent process.

(Oxidation suppression treatment method)
Next, an oxidation suppression treatment method according to this embodiment will be described with reference to Fig. 9. Fig. 9 is a flow chart of a heating method according to this embodiment. As shown in Fig. 9, first, a workpiece W is placed at a predetermined position (S101). Next, a mixed gas containing an antioxidant is supplied to a welded portion W1 of the workpiece W (S103). In step S103, the welded portion W1 and its surroundings are covered with the antioxidant. Furthermore, in parallel with step S103, a portion of the supplied mixed gas is recovered (S105).
In these steps S103 and S105, the supply parts 131 and the recovery parts 132 are alternately arranged along the longitudinal direction of the linearly formed welded part W1, and the recovery flow rate of the gas by each recovery part 132 is set to be equal to or more than 1/2 of the total supply flow rate of the mixed gas by the supply parts 131 adjacent to both sides of the recovery part 132. The gas sucked from each recovery part 132 may contain the surrounding atmosphere (e.g., air) in addition to the mixed gas supplied from the supply part. The gas intake flow rate of each recovery part 132 is a flow rate including such an atmosphere. The adjacent supply parts 131 on both sides of the recovery part 132 include the case where the supply part 131 is only on one side of the recovery part 132. In this case, the supply flow rate of the mixed gas by the supply part 131 on this one side is set to be the total supply flow rate of the mixed gas by the adjacent supply parts 131 on both sides of the recovery part 132.
Such a control method is realized, for example, by providing a constant flow control valve in each system of the supply unit 131 in Fig. 5, providing a flow adjustment valve in each system of the collection unit 132, and setting the flow adjustment valve of the collection unit 132 based on the set flow rate of each constant flow control valve. In this case, the flow adjustment of the collection unit 132 is set to 1/2 or more of the total supply flow rate of the mixed gas by the supply unit 131 adjacent to the collection unit 132, for example, within 10% of 1/2 of the total (i.e., in the range of 50 to 55% of the total). If the pressure in the supply duct 135A in Fig. 4 can be maintained uniform and the flow rate distribution of each supply unit 131 can be equalized, the flow rate may be adjusted in two systems, the collection unit 132 located at the end of the header unit 133 in the longitudinal direction and the other collection units 132.
In steps S103 and S105, the mixed gas is supplied and collected by the supply unit 131 and the collection unit 132 facing the welded portion W1 at a supply flow rate and a collection flow rate that generate an airflow from the supply unit 131 at the longitudinal end of the welded portion W1 toward the longitudinal center of the welded portion W1. Such a control method is realized, for example, by providing a gas suction tube for measuring the concentration of the antioxidant at the outer edge of the supply unit 131 located at both longitudinal ends (front and rear ends) of the welded portion W1, and adjusting the flow rate of the collection unit 132 located inside the supply unit 131 at both longitudinal ends so that the antioxidant is equal to or lower than a predetermined concentration. The concentration of the antioxidant may be adjusted, for example, by the flow rate of the mixed gas and the spray amount of the antioxidant sprayed and atomized (nozzle diameter of the atomized portion of the spray, liquid pressure). The concentration of the antioxidant is the ratio of the antioxidant in the mixed gas, and may be the mass or number of particles per unit flow rate.
The concentration of the antioxidant is adjusted based on the relationship (previously determined) between the concentration of the antioxidant, the flow rate, and the amount of application. The concentration of the antioxidant is adjusted by adjusting the flow rate based on the concentration of the antioxidant (by a particle size meter, etc.) rather than the oxygen concentration.
Furthermore, in steps S103 and S105, the supply flow rate of the mixed gas by the supply section 131 of one of the upper header section 133A and the lower header section 133B provided at positions facing the front and back surfaces of the welded zone W1 is set to be equal to or less than half (>0) of the sum of the supply flow rates of the mixed gas by the supply sections 131 adjacent to both sides of the recovery section 132 of the other header section facing the supply section 131. Such a control method is realized, for example, by setting the flow rate of the upper supply section 131 to a predetermined value, and then adjusting the flow rate of the lower supply section 131 facing the supply section 131 by the flow rate adjustment valve of the lower supply section 131 in accordance with the set flow rate of the constant flow valve of the upper supply section 131 adjacent to both sides of the upper recovery section 132 facing the lower supply section 131. Similarly, such a control method is realized, for example, by setting the flow rate of the lower supply unit 131 to a predetermined value, and then adjusting the flow rate of the upper supply unit 131 opposite the lower supply unit 131 by the flow rate adjustment valve of the lower supply unit 131 according to the set flow rate of the constant flow valve of the lower supply unit 131 adjacent to both sides of the lower recovery unit 132 opposite the upper supply unit 131. In this case, the supply units 131 adjacent to both sides of the recovery unit 132 of the other header unit opposite the supply unit 131 of one header unit include a case where the supply unit 131 is located only on one side of the recovery unit 132. In this case, the supply flow rate of the mixed gas of the supply unit 131 on this side is set to the sum of the supply flow rates of the mixed gas by the adjacent supply units 131 on both sides of the recovery unit 132. In this way, when there is a supply section 131 on only one side of the recovery section 132 of one header section opposite the supply section 131 of the other header section, the flow rate of the supply section 131 of one header section is determined according to the set flow rate of the constant flow valve of the supply section 131 adjacent to one side of the recovery section 132.

Next, in step S107, it is determined whether the oxidation suppression process satisfies a termination condition. An example of the termination condition is whether the mixed gas has been supplied and collected for a predetermined time. If the determination is positive, the oxidation suppression process is terminated. In this termination process, the supply of the mixed gas is stopped, and the supply and collection are continued. Then, when a certain time has elapsed using a timer, or when the concentration of the antioxidant is determined and the concentration of the oxidizer falls below a standard, the supply and collection are stopped. The reason for this termination process is to prevent unnecessary diffusion of the antioxidant to the surroundings. On the other hand, if the determination is negative, the oxidation suppression process returns to step S103. Above, the oxidation suppression process method according to this embodiment has been described.

(Production method)
Next, a method for manufacturing a molded product according to this embodiment will be described with reference to FIG. 10. FIG. 10 is a flow chart of the method for manufacturing a molded product according to this embodiment. As shown in FIG. 10, first, oxidation inhibition treatment is performed on the welded portion W1 of the workpiece W using the oxidation inhibition treatment method shown in FIG. 9 (S110). Next, the workpiece W is transported to a heating furnace. Then, the workpiece W is heated (S120). Then, the workpiece W is transported to a press machine (S130). The transport time is, for example, several seconds to about 20 seconds. Then, the heated workpiece W is hot formed into a predetermined shape (S140). The method for manufacturing a molded product according to this embodiment has been described above.

(Action and Effect)
According to this embodiment, in the heating of the workpiece W, the oxidation suppression treatment device 130 supplies a mixed gas containing an antioxidant to the welded portion W1 of the workpiece W to apply the antioxidant to the welded portion W1, and the mixed gas is collected, thereby suppressing the generation of scale S at the welded portion W1 of the workpiece W and its surroundings, and suppressing the influence of the scattering of the antioxidant. That is, when the plated coating L is removed from the periphery of the welded portion W1 when the workpiece W is formed by welding a member having the plated coating L, in the portion where the plated coating is removed, scale S may be generated at the welded portion W1 of the workpiece W and its surroundings in the subsequent heating process depending on the atmosphere in the heating furnace. At this time, since the scale S progresses in the thickness direction of the plate material, even when such scale S is removed, a locally thinned portion may be generated around the welded portion W1, and a stress concentration portion SC may be generated. Conversely, if the scale S remains, it may affect painting in the subsequent process. Therefore, by supplying a mixed gas containing an antioxidant to the welded portion W1 and exhausting the mixed gas, the generation of scale S is suppressed while the area in which the mixed gas containing the antioxidant flows is localized to suppress the scattering of the antioxidant.

Therefore, according to this embodiment, contamination inside the heating furnace 101 due to splashes (dust) of the antioxidant can be suppressed, and the effects on subsequent processes due to splashes of the antioxidant to areas other than the welded part W1 (specifically, unstable molding due to fluctuations in the sliding characteristics during press molding, the occurrence of surface contamination of the molded product, etc.) can be suppressed.

In addition, according to this embodiment, by supplying the mixed gas from multiple locations and then recovering the mixed gas from multiple locations, it is possible to more efficiently suppress the generation of scale S while more locally localizing the application area of the antioxidant near the weld.

In addition, according to this embodiment, the supply sections 131 and the recovery sections 132 are arranged alternately, which makes it easier to form a flow of mixed gas, and more efficiently suppresses the generation of scale S while more localizing the application range of the antioxidant to the vicinity of the welded part.

In addition, according to this embodiment, the supply unit 131 and the recovery unit 132 are arranged opposite each other with the workpiece W in between, which makes it easier to form a flow of mixed gas, and can localize the antioxidant while further suppressing the generation of scale S. Furthermore, in cases where the workpiece W is not present between the supply unit 131 and the recovery unit 132 or in locations where the workpiece W is not present, an airflow that covers the sides of the workpiece W can be created, thereby suppressing the scattering of the antioxidant.

In addition, according to this embodiment, the supply section 131 and the recovery section 132 are aligned along the transport direction, so that the antioxidant can be controlled even while the workpiece W is being transported.

In addition, according to this embodiment, the table roller unit 122 in front of the heating furnace, which transports the workpiece W to the hearth roller unit 121, has a first table roller unit 122B and a second table roller unit 122C that are spaced apart from each other in a direction perpendicular to the transport direction of the workpiece W, and a header unit 133 is provided between the first table roller unit 122B and the second table roller unit 122C. As a result, even if the table roller unit 122 is provided as the transport mechanism 120, the oxidation suppression treatment device 130 can supply and recover a mixed gas containing an antioxidant.

In addition, according to this embodiment, the plating film L is an Al-based alloy film. Therefore, when the plating film L is an Al-based alloy, it may be necessary to remove more of the Al-based film around the welded portion W1 in order to avoid a decrease in strength due to the penetration of the Al component into the welded portion W1. At this time, more scale S may be generated around the welded portion W1 of the workpiece W in the subsequent heating process. Therefore, by supplying a mixed gas containing an antioxidant to the welded portion W1 and recovering the mixed gas, it is possible to suppress the generation of scale S while localizing the area where the mixed gas containing the antioxidant flows and suppressing the scattering of the antioxidant.

In addition, according to this embodiment, the first plate-shaped member T1 and the second plate-shaped member T2 are made of materials with different tensile strengths. Therefore, by forming the workpiece W by welding members with different strengths, stress optimization is realized and the weight of the workpiece W is reduced. On the other hand, in the heating process for such workpiece W, scale S may be generated at the welded portion W1. Since such scale S progresses in the thickness direction of the plate material, even if the scale S is removed, the plate material thickness is reduced, and a stress concentration portion may be generated around the welded portion W1. Therefore, by supplying a mixed gas to the welded portion W1 and recovering the mixed gas, the generation of scale S is suppressed, while the area where the mixed gas containing the antioxidant flows is localized and the antioxidant is prevented from scattering.

In addition, according to this embodiment, the first plate-like member T1 and the second plate-like member T2 have different plate thicknesses. Therefore, by forming the workpiece W by welding members of different plate thicknesses, stress optimization is realized and the weight of the workpiece W is reduced. On the other hand, in the heating process for such workpiece W, scale S may be generated at the welded portion W1. Since the scale S progresses in the thickness direction of the plate material, even if the scale S is removed, the plate thickness is reduced, and a stress concentration area may be generated around the welded portion W1 (especially on the thin plate side). Therefore, by supplying the mixed gas to the welded portion W1 and recovering the mixed gas, the generation of scale S can be suppressed while localizing the area where the mixed gas containing the antioxidant flows and suppressing the scattering of the antioxidant.

In addition, this embodiment can prevent contamination inside the heating furnace 101 due to splashes of the antioxidant into the furnace.

In the above embodiment, the header portion 133 may be replaceable. That is, the header portion 133 is attached so as to be removable. For example, multiple types of header portions 133 may be prepared according to the type of workpiece W or the position, size, or shape of the welded portion W1 in the workpiece W, and the header portions 133 may be replaced as appropriate. For example, as shown in FIG. 12, the arrangement of the header portions 133 and the arrangement of the supply portion 131 and the recovery portion 132 may be appropriately set according to the shape, number, and welded portion W1 of the workpiece W, and each header portion 133 may be connected by a connecting portion 134 to form an oxidation suppression treatment device 130. In addition, when the workpiece W has multiple welded portions W1, the upper header portion 133A and the lower header portion 133B in FIG. 1 may be arranged in multiple rows. The spacing portion rows 122F of the table roller portion 122 may be arranged in multiple rows in a shape following the multiple rows of the lower header portions 133B.

Furthermore, in the above embodiment, an example was given in which the table roller 122A is composed of the first table roller portion 122B and the second table roller portion 122C which are separate bodies, but the present invention is not limited to such an example. For example, the first table roller portion 122B and the second table roller portion 122C may be an expanded diameter portion of an integrated table roller 122A. In this case, the lower header portion 133B is disposed in the space formed between the reduced diameter portion between the first table roller portion 122B and the second table roller portion 122C and the welded portion W1 of the workpiece W.

(Variation 1)
Next, some modified examples of the first embodiment of the present invention will be described with reference to Figures 13 to 14. In the following description of the modified examples, the description of the configuration common to the above embodiment may be omitted.

In one variation of this embodiment, the configuration of the heating furnace 101 is different from that of the above embodiment. As shown in FIG. 13, in this variation, the heating furnace 101 is a heating furnace that is open only in one direction along the Y direction in FIG. 13. An openable furnace lid 101A is attached to the opening. The workpiece W is placed in the heating furnace 101 and heated under predetermined conditions.

As shown in FIG. 14, the oxidation suppression treatment device 130 is attached to a position facing the workpiece W on the upstream side of the insertion port of the heating furnace 101 in the transport direction. The welded portion W1 of the workpiece W is covered with the mixed gas supplied from the oxidation suppression treatment device 130. This suppresses the generation of scale S at the welded portion W1 of the workpiece W. Furthermore, by recovering the mixed gas by the oxidation suppression treatment device 130, the antioxidant is prevented from scattering to the surroundings and affecting the surrounding environment. It is preferable that the hearth roller 121A in the heating furnace 101 shown in FIG. 14 is configured to have a first hearth roller portion 121B and a second hearth roller portion 121C, similar to the table roller 122A of the table roller portion 122 in front of the heating furnace 101. In addition, when the oxidation suppression treatment device 130 has a header portion 133, in FIG. 14, the header portion 133 is arranged such that its longitudinal direction is aligned with the transport direction of the workpiece W. The header section 133 may be arranged so that its longitudinal direction is perpendicular to the transport direction of the workpiece W.

<<Second embodiment>>
A heating device 200 according to a second embodiment of the present invention will be described with reference to FIGS. 15 to 17. FIG. 15 is a side view showing a schematic configuration of the heating device 200 according to this embodiment. FIG. 16 is a plan view showing a schematic configuration of the heating device 200 according to this embodiment. FIG. 17 is an external perspective view of a tray 250 according to this embodiment. As an example, the tray 250 has a structure in which a plurality of bars are provided inside an outer frame, and has a plurality of openings (slits). These multiple openings are provided to maintain the heating efficiency of the workpiece W in the heating furnace 101 (promoting radiant heat input from the heating section 110 on the lower side and stabilizing the overall atmosphere in the gas circulation furnace). The tray 250 may also be in a mesh or lattice shape, or may be punched metal, etc.

This embodiment is different from the first embodiment in that the workpiece W is placed on a tray 250 and transported by the transport mechanism 120. In the description of this embodiment, the description of the configuration common to the first embodiment may be omitted.
In the conveying mechanism 120 of this embodiment which conveys the tray 250, the row of spaced portions 122F of the table roller section 122 and the row of spaced portions 121F of the hearth roller section 121 may be omitted, and the table roller 122A and the hearth roller 121A may be normal rollers without the spaced portions 122E of the table roller 122A and the spaced portions 121E of the hearth roller 121A.

As shown in Figures 15 and 16, the oxidation suppression treatment device 130 according to this embodiment has a pair of upper and lower header sections 133 (upper header section 133A and lower header section 133B). The upper header section 133A is attached upstream in the conveying direction from the insertion opening of the heating furnace 101. Meanwhile, the lower header section 133B is provided on a tray 250, which will be described later.

The tray 250 is transported by the transport mechanism 120 while supporting the workpiece W. The transport mechanism 120 includes a hearth roller section 121 in the heating furnace and a table roller section 122 in front of the heating furnace, as in the first embodiment. In this embodiment, the tray 250 is transported by so-called pitch feed, in which the tray 250 stops at a predetermined position during the transport process, as described later. As shown in FIG. 17, the tray 250 includes a plate-shaped main body section 251 having multiple openings and a pin-shaped support section 253 protruding from the main body section 251. The support section 253 supports the workpiece W by abutting its tip against the workpiece W. The lower header section 133B is attached to the main body section 251. The lower header section 133B is attached at a position facing the welded section W1 of the workpiece W when the workpiece W is supported by the support section 253.

As shown in FIG. 17, the lower header section 133B has a supply section 131 and a recovery section 132. Furthermore, the lower header section 133B has a connection pipe 235. The connection pipe 235 can be connected to the supply and recovery duct 237 when the tray 250 is in a predetermined position. Specifically, as shown in FIG. 16, the connection pipe 235 and the supply and recovery duct 237 are connected at a position where the lower header section 133B faces the upper header section 133A. Although not shown in the figure, the connection pipe 235 and the supply and recovery duct 237 have two systems for supplying and recovering the mixed gas. As a result, the supply and recovery duct 237 supplies and recovers the mixed gas containing the antioxidant, and the supply section 131 and recovery section 132 of the lower header section 133B supply and recover the mixed gas to the welded section W1.

(Action and Effect)
According to this embodiment, even when there is a tray 250 on which the workpiece W is placed, the oxidation suppression treatment of the welded portion W1 can be achieved by the oxidation suppression treatment device 130. In particular, since the tray 250 and the lower header portion 133B of the oxidation suppression treatment device 130 are integrated, the positional relationship between the workpiece W and the lower header portion 133B does not change, and the oxidation suppression treatment can be achieved.

(Variation 2)
Next, some modified examples of the second embodiment of the present invention will be described with reference to Figures 18 to 20. In the following description of the modified examples, the description of the configuration common to the above embodiment may be omitted.

In one variation of this embodiment, the configuration of the heating furnace 101 is different from the above embodiment. As shown in Figures 18 and 19, in this variation, the heating furnace 101 is a heating furnace that is open only in one direction along the Y direction in Figure 18. The upper header portion 133A of the oxidation suppression treatment device 130 is attached to a position facing the welded portion W1 of the workpiece W, upstream of the insertion port of the heating furnace 101 in the transport direction.

The lower header section 133B is provided on the tray 250. When the tray 250 is in the position before being inserted into the furnace, the connection pipe 235 of the lower header section 133B is connected to the supply and recovery duct 237. This allows the mixed gas to be supplied and recovered from the supply section 131 and recovery section 132 of the lower header section 133B. Thus, according to this modified example, the same effect as the above embodiment can be achieved even when the heating furnace 101 is a heating furnace that is open on only one side.

(Variation 3)
In addition, in another modification of this embodiment, the arrangement of the oxidation suppression treatment device 130 in the heating device 200 is different from that of the above embodiment. As shown in FIG. 20, when the oxidation suppression treatment device 130 includes a header section 133, the oxidation suppression treatment device 130 is arranged so that the longitudinal direction of the header section 133 is perpendicular to the transport direction of the workpiece W. That is, the supply section 131 and the recovery section 132 are arranged so as to be aligned along a direction perpendicular to the transport direction of the workpiece W (X direction in FIG. 20). The lower header section 133B of the oxidation suppression treatment device 130 is also arranged on the tray 250 so as to be aligned along a direction perpendicular to the transport direction of the workpiece W (X direction in FIG. 20). Thus, according to this modification, the same effect as the above embodiment is achieved even when the longitudinal direction of the header section 133 is arranged perpendicular to the transport direction in the heating device 200.

<<Third embodiment>>
A heating device 300 according to a third embodiment of the present invention will be described with reference to Figs. 21 to 23. Fig. 21 is a side view showing a schematic configuration of the heating device 300 according to this embodiment. Fig. 22 is a plan view showing a schematic configuration of the heating device 300 according to this embodiment. Fig. 23 is an external perspective view of a tray 350 according to this embodiment. As an example, the tray 350 has a structure in which a plurality of bars are provided inside an outer frame, and has a plurality of openings (slits). The tray 350 may alternatively be in a net or lattice shape, or may be made of punched metal, etc.

This embodiment differs from the first and second embodiments in that the workpieces W are placed on a tray 350, and a structure 333 of the oxidation suppression treatment device 130 is attached to the tray 350. In the description of this embodiment, the description of the configuration common to the first and second embodiments may be omitted.
In the conveying mechanism 120 of this embodiment which conveys the tray 350, the row of spaced portions 122F of the table roller section 122 and the row of spaced portions 121F of the hearth roller section 121 may be omitted, and the table roller 122A and the hearth roller 121A may be normal rollers without the spaced portions 122E of the table roller 122A and the spaced portions 121E of the hearth roller 121A.

21 and 22, the upper header portion 333A and the lower header portion 333B of the oxidation suppression treatment device 130 according to this embodiment are attached to the tray 350. Specifically, as shown in FIG. 23, the upper header portion 333A and the lower header portion 333B are connected by a connecting portion 333C to form a structure 333, and the structure 333 is attached to the tray 350. The upper header portion 333A and the lower header portion 333B face each other, and are provided at a position facing the welded portion W1 when the workpiece W is placed on the tray 350. The connecting portion 333C connects one end of the upper header portion 333A and the lower header portion 333B in the longitudinal direction. In addition, a duct for supplying and recovering the mixed gas is housed inside the connecting portion 333C.

The structure 333 also has a connecting pipe 235. As shown in FIG. 22, when the tray 350 is in a predetermined position before being inserted into the heating furnace 101, the connecting pipe 235 of the structure 333 is connected to the supply and recovery duct 237. This allows the mixed gas to be supplied and recovered from the supply section 131 and recovery section 132 of the lower header section 333B. Furthermore, the mixed gas is also supplied and recovered to the upper header section 333A via the connecting section 333C.

According to this embodiment, by providing the upper header portion 333A and the lower header portion 333B on the tray 350, changes in the positional relationship between the workpiece W and the upper header portion 333A and the lower header portion 333B are suppressed, and effective oxidation suppression processing can be achieved.

(Variation 4)
Next, some modified examples of the third embodiment of the present invention will be described with reference to Figures 24 to 26. In the following description of the modified examples, the description of the configuration common to the above embodiment may be omitted.

In one variation of this embodiment, the configuration of the heating furnace 101 is different from that of the above embodiment. As shown in Figures 24 and 25, in this variation, the heating furnace 101 is a heating furnace that is open only in one direction along the Y direction in Figure 24.

The upper header section 333A and the lower header section 333B of the oxidation suppression treatment device 130 are provided on a tray 350. When the tray 350 is inserted into the furnace and positioned forward, the connection pipe 235 is connected to the supply and recovery duct 237. This allows the mixed gas to be supplied and recovered from the supply section 131 and the recovery section 132 of the lower header section 333B. In this way, according to this modified example, the same effect as the above embodiment can be achieved even when the heating furnace 101 is a heating furnace that is open on only one side.

(Variation 5)
In addition, in another modification of this embodiment, the arrangement of the oxidation suppression treatment device 130 in the heating device 300 is different from that of the above embodiment. As shown in Fig. 26, when the oxidation suppression treatment device 130 includes an upper header portion 333A and a lower header portion 333B, the oxidation suppression treatment device 130 is arranged so that the longitudinal directions of both header portions 333A, 333B are perpendicular to the transport direction of the workpiece W. That is, the supply section 131 and the recovery section 132 are arranged so as to be aligned along a direction (X direction in Fig. 26) perpendicular to the transport direction of the workpiece W. Thus, according to this modification, the same effect as the above embodiment can be obtained even when the longitudinal directions of the upper header portion 333A and the lower header portion 333B are arranged perpendicular to the transport direction in the heating device 300.

<<Fourth embodiment>>
A heating device 400 according to a fourth embodiment of the present invention will be described with reference to Figs. 27 and 28. Figs. 27 and 28 are side cross-sectional views that typically show an example of the configuration of the heating device 400 according to this embodiment. This embodiment is different from the first to third embodiments in that the workpiece W is placed on a tray 450, and the upper header portion 133A and the lower header portion 133B of the oxidation suppression treatment device 130 are provided upstream of the insertion port in the conveying direction. In the description of this embodiment, the description of the configuration common to the first to third embodiments may be omitted.
In the conveying mechanism 120 of this embodiment which conveys the tray 450, the row of spaced portions 122F of the table roller section 122 and the row of spaced portions 121F of the hearth roller section 121 may be omitted, and the table roller 122A and the hearth roller 121A may be normal rollers without the spaced portions 122E of the table roller 122A and the spaced portions 121E of the hearth roller 121A.

As shown in FIG. 27, the upper header portion 133A and the lower header portion 133B are provided upstream of the insertion opening of the heating furnace 101 in the conveying direction. The support portion 253 provided on the tray 450 is partially not provided to avoid interference with the lower header portion 133B. In particular, the support portion 253 is not provided around the welded portion W1 of the workpiece W. The upper header portion 133A and the lower header portion 133B face each other, and are provided in a position facing the welded portion W1 when the tray 450 is positioned before being inserted into the furnace. Thus, according to this embodiment, oxidation suppression processing is achieved even when the header portion 133 is not provided on the tray 450.

<<Fifth embodiment>>
A heating device 500 according to a fifth embodiment of the present invention will be described with reference to Figs. 29 and 30. Figs. 29 and 30 are side cross-sectional views that typically show an example of the configuration of the heating device 500 according to this embodiment. This embodiment is different from the first to fourth embodiments in that the heating device 500 is a heating device that includes a manipulator 521 as a transport mechanism 520. In the description of this embodiment, the description of the configuration common to the first to fourth embodiments may be omitted.

As shown in Figures 29 and 30, the workpiece W is transported between the inside and outside of the furnace by a manipulator 521 serving as a transport mechanism 520 according to this embodiment. Specifically, after oxidation inhibition treatment of the welded portion W1 of the workpiece W by a pair of header portions 133 provided upstream of the insertion port of the heating furnace 101 in the transport direction, the workpiece W is gripped by the gripping portion 521A of the manipulator 521, and the workpiece W is inserted into the furnace. Finally, the workpiece W is placed on a plurality of supports 554 provided in the furnace.

The upper header section 133A and the lower header section 133B are provided upstream of the insertion port of the heating furnace 101 in the transport direction. The workpiece W is gripped by the gripping section 521A of the manipulator 521 and placed on the multiple supports 553. The upper header section 133A and the lower header section 133B face each other, and are provided in positions facing the welded section W1 with the workpiece W placed on the multiple supports 553. Thus, according to this embodiment, even when the transport of the workpiece W is achieved by the manipulator 521, oxidation suppression treatment is achieved for the welded section W1 of the workpiece W.

<<Sixth embodiment>>
An oxidation inhibition treatment method according to a sixth embodiment of the present invention will be described with reference to Fig. 31. Fig. 31 is a diagram that illustrates a schematic diagram of an oxidation inhibition treatment method according to this embodiment. In this embodiment, oxidation inhibition treatment of the welded portion W1 by an oxidation inhibition treatment device 630 is performed before the workpiece W is transported to a heating furnace. In the description of this embodiment, description of configurations common to the configurations of the first to fifth embodiments may be omitted.

The oxidation suppression treatment method shown in FIG. 31 suppresses oxidation of the welded portion W1 formed by welding the first plate-shaped member T1 and the second plate-shaped member T2 (see FIG. 3) by the welding head 603. Specifically, the welded portion W1 is formed by irradiating the area where the first plate-shaped member T1 and the second plate-shaped member T2 are butted together with laser light H from the welding head 603 to fuse the base metal together. As a result, the first plate-shaped member T1 and the second plate-shaped member T2 are integrated to form the workpiece W, which is a tailored blank material.

The welding head 603 is moved by a drive mechanism (not shown) to perform welding along the area where the first plate-shaped member T1 and the second plate-shaped member T2 are butted together. As a result, a linear weld W1 is formed. When laser welding the workpiece W, the workpiece W is clamped at a position several mm from the edge of the plate to suppress changes in the welding gap caused by heat input, and a tunnel-shaped space surrounded by the clamp fixing part is formed on the back side of the workpiece W.

31, in the oxidation suppression treatment device 630, the upper header portion 133A and the lower header portion 133B are changed to a front header portion 633A and a back header portion 633B in the first embodiment. The front header portion 633A is a header provided on the same side of the workpiece W as the welding head 603, and the back header portion 633B is a header provided on the opposite side (i.e., the back side) of the workpiece W from the side on which the front header portion 633A is provided. The front header portion 633A and the back header portion 633B are connected to the supply and recovery system 140 by the supply and recovery hose 637A and the supply and recovery hose 637B, respectively. As a result, a mixed gas containing an antioxidant is sprayed from the supply portion 631 toward the welded portion W1. As a result, the surface of the welded portion W1 is covered with the antioxidant SB. In addition, a part of the mixed gas containing the antioxidant is recovered from the recovery portion 632. Furthermore, as will be described in detail later, the front header portion 633A is connected to the welding head 603 and moves together with it.

As shown in FIG. 31, the front side header portion 633A moves along the welded portion W1. Specifically, the front side header portion 633A is provided rearward of the welding head 603 in the movement direction of the welding head 603, and moves together with the welding head 603. Specifically, the front side header portion 633A is connected to the welding head 603 by a connecting member 605, rearward in the movement direction of the welding head 603. This allows the front side header portion 633A to move together with the welding head 603.

The connecting member 605 is a rod-shaped member, and both ends of the connecting member 605 are fixed at a predetermined angle to the welding head 603 and the front header portion 633A, respectively. By adjusting the length or mounting angle of the connecting member 605, the distance between the front header portion 633A and the welding head 603, or the distance between the front header portion 633A and the welded portion W1 can be adjusted.

The welding head control unit 607 controls the operation of the welding head 603. Specifically, it controls the moving speed of the welding head 603, the distance to the workpiece W, the output of the laser light H, and the like. The welding head control unit 607 also controls the pressure or flow rate of the shielding gas. Furthermore, the welding head control unit 607 controls the operation of the supply and recovery system 140.
31, the rear header portion 633B sprays the mixed gas containing the antioxidant from the supply portion 631 toward the welded portion W1. As a result, the rear surface of the welded portion W1 is covered with the antioxidant SB. Also, a part of the mixed gas containing the antioxidant is collected from the collection portion 632. Furthermore, the rear header portion 633B is movable in accordance with the movement of the welding head 603. Specifically, the rear header portion 633B is provided with a drive wheel 639. A drive force is supplied to the drive wheel 639 from a drive source (not shown), so that the rear header portion 633B moves in accordance with the movement of the welding head 603.

In the oxidation suppression treatment method according to this embodiment, after welding by the welding head 603 and oxidation suppression treatment by the oxidation suppression treatment device 630, the workpiece W is transported to a heating process, where the workpiece W is subjected to a heat treatment. For example, the workpiece W is placed in a heating furnace and heated under predetermined heating conditions.

According to this embodiment, the front header portion 633A and the back header portion 633B move together with the welding head 603, so that the antioxidant can be supplied to the welded portion W1 on the front side of the workpiece W, and the process of suppressing the generation of scale S during the heating process can be completed before the workpiece is subjected to the heating process. As a result, the generation of scale S during the heating process can be further suppressed.

(Variation 6)
Next, a modified example of the sixth embodiment of the present invention will be described with reference to Fig. 32. This modified example differs from the above embodiment in that only the front header portion 633A moves in accordance with the welding head 603. In the following description of the modified example, description of configurations common to the above embodiment may be omitted.

In this modified example, as shown in FIG. 32, the rear header portion 633B is provided on the opposite side (i.e., the rear side) of the workpiece W from the side on which the front header portion 633A is provided. The rear header portion 633B is connected to the supply and recovery system 140 by the supply and recovery hose 637B. The rear header portion 633B injects the mixed gas containing the antioxidant toward the space between the workpiece W and the shielding body spaced a predetermined distance from the workpiece W, which is formed on the rear side of the workpiece W during laser welding as described above. Specifically, as shown in FIG. 32, the rear header portion 633B is arranged so that the direction along the movement direction of the welding head 603 is the injection direction of the mixed gas containing the antioxidant. The supply portion 631 of the rear header portion 633B sprays the mixed gas containing the antioxidant toward the space. The injected mixed gas remains in the space, and the antioxidant SB contained in a part of the mixed gas adheres to the surface of the welded portion W1. In addition, the mixed gas containing the excess antioxidant is collected by the collection section 632. Note that the form of supply and collection of the antioxidant on the back side described here is a reference example of the present invention.

In the above embodiment, an example has been described in which the front header portion 633A moves while connected to the welding head 603, but the present invention is not limited to such an example. For example, a drive mechanism (not shown) that moves the front header portion 633A may be configured to control the travel of the front header portion 633A independently of the welding head 603 so that the positional relationship between the front header portion 633A and the welding position can be set and maintained.

Although several preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, the present invention is not limited to these examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified examples or application examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, an example is shown in which an electric heater is used as the heat source in the heating furnace, but the present invention is not limited to such an example. For example, the type of heating furnace may be a gas furnace or a hot air heating furnace. In addition, the heating method is not limited to heating by radiant heat, and the workpiece W may be directly heated by a method such as induction heating or resistance heating.

In the above embodiment, the welded portion W1 is linear and extends in a direction along the conveying direction or in a direction perpendicular to the conveying direction, but the present invention is not limited to such an example. For example, the welded portion W1 may be linear and extend in a direction that forms a predetermined angle with the conveying direction. The welded portion W1 may also be curved. Furthermore, the welded portion W1 may be discontinuous linear or dot-shaped.

In addition, in the above embodiment, the workpiece W is described as being welded by butting the first plate-shaped member T1 and the second plate-shaped member T2 together, but the present invention is not limited to such an example. For example, the workpiece W may be welded in a state in which the second plate-shaped member T2 is superimposed on the first plate-shaped member T1.

In the above embodiment, the multiple heating sections 110 are arranged on the upper and lower furnace walls of the heating furnace, i.e., above and below the workpiece W, but the multiple heating sections 110 may be arranged not only on the upper and lower sides, but also on the left and right furnace walls of the heating furnace, i.e., on the left and right sides, or may be arranged side by side in the width direction of the heating furnace and divided in the width direction of the workpiece W.

In the above embodiment, the workpiece W is a flat member, but the workpiece W may be a member having a three-dimensional shape due to processing. For example, FIG. 33 shows an example of heating a hat-shaped workpiece W. In the oxidation suppression treatment device 130 of the heating device 700 shown in FIG. 33, the upper header portion 133A and the lower header portion 133B are changed to a shape that conforms to the hat shape of the workpiece W, compared to the first embodiment. In addition, the lower header portion 733B has a fixed lower header portion 733B1 and a lifting lower header portion 733B2. The fixed lower header portion 733B1 is positioned opposite the flange portion of the workpiece W when the workpiece W is transported above the lower header portion 733B1. The upper header section 733A and the lower header section 733B2 are liftable, and when the workpiece W is transported between the upper header section 733A and the lower header section 733B2, they are moved to a vertically withdrawn position as shown by the two-dot chain line, and when the workpiece W is transported between the upper header section 733A and the lower header section 733B2, they are moved to a position closer to the workpiece W as shown by the solid line.

As another example of heating a hat-shaped workpiece W, the oxidation suppression treatment device 130 may have an upper header section 733A and a lower header section 733B shaped to match the hat shape of the workpiece W, the lower header section 733B mounted on a tray, and the upper header section 733A may be of a lifting type, which is moved to a retracted position above when the workpiece W placed on the tray is transported below the upper header section 733A, and which is lowered to approach the workpiece W when the workpiece W is transported below the upper header section 733A.

In the above embodiment, an example was given in which the header portion 133 extends linearly, but depending on the shapes of the workpiece W and the welded portion W1, the header portion 133 may be a member having a shape that curves to match the welded portion W1. For example, in the example shown in Figures 34 and 35, in contrast to the first embodiment, the header portion 833 is formed to match the shape of the curved welded portion W1. In Figure 34, the spacing portion row 122F formed in the table roller portion 122 is formed to match the shape of the lower header portion 833B.

Furthermore, the gap between the spaced portion row 122F may be increased to an extent that does not interfere with the transport of the workpiece W. As shown in Fig. 35, the spaced portion row 122F formed in the table roller portion 122 may be formed following the extending direction of the lower header portion 833B.
Also, when the spaced portion row 121F is formed in the hearth roller portion 121, the spaced portion row 121F may be formed in the hearth roller portion 121, like the spaced portion row 122F formed in the table roller portion 122 shown in Figure 35.

100, 200, 300, 400, 500, 600, 700 Heating device 101 Heating furnace 110 Heating section 120, 520 Transport mechanism 121 Hearth roller section 121A Hearth roller 121B First hearth roller section 121C Second hearth roller section 122 Table roller section 122A Table roller 122B First table roller section 122C Second table roller section 122D Core rod member 122E Separation section 122F Separation section row 130, 630 Oxidation suppression treatment device 131 Supply section 132 Recovery section 133, 633, 733, 833 Header section 333 Structure 133A, 333A, 733A Upper header section 133B, 333B, 733B, 833B Lower header section 140 Supply and recovery system 160 Control unit 250, 350, 450, 550 Tray 521 Manipulator 603 Welding head 633A Front header portion 633B Back header portion L Plating film T1 First plate-shaped member T2 Second plate-shaped member W Workpiece W1 Welding portion S Scale

Claims (14)

An oxidation inhibition treatment device for spraying an antioxidant along a weld of a workpiece having a linear weld between one member and another member, at least one of which is made of a plate material having a plating film, the device comprising:
a supply section that supplies a gas mixture containing an atomized antioxidant to the weld;
a recovery section that recovers a portion of the mixed gas supplied to the welding portion;
a header portion in which the supply portion and the recovery portion are arranged and which is shaped to conform to the welded portion;
Oxidation suppression treatment device. The oxidation suppression treatment device according to claim 1, wherein the header section is provided with a plurality of at least one of the supply sections and the recovery sections. The oxidation suppression treatment device according to claim 2, wherein the header section has the supply sections and the recovery sections arranged alternately. a pair of the header portions opposed to each other with the weld portion interposed therebetween;
The oxidation suppression treatment device according to any one of claims 1 to 3, wherein the supply section and the recovery section of one of the pair of header sections are opposed to the recovery section and the supply section of the other header section, respectively, at a position across the welded section. The oxidation suppression treatment device according to any one of claims 1 to 4, wherein the oxidation suppression treatment device is movable along the welded portion. The workpiece heating device,
The oxidation suppression treatment device according to any one of claims 1 to 5,
a heating furnace for heating the workpiece to which the antioxidant has been sprayed;
a transport mechanism for transporting the workpiece from the oxidation suppression treatment device into the heating furnace;
Heating device. The transport mechanism includes:
a table roller unit disposed outside the heating furnace and including a plurality of table rollers;
The table roller has a first table roller portion and a second table roller portion spaced apart in a longitudinal direction of the table roller,
the table roller section includes a row of spaced portions formed by spaced portions between the first table roller section and the second table roller section in each of the plurality of table rollers,
The spaced portion row has a shape conforming to the header portion.
The heating device according to claim 6. The heating device includes a tray on which the workpiece is placed and which is transported by the transport mechanism,
The heating device according to claim 6 , wherein the header portion is provided on the tray. 1. An oxidation suppression treatment method for a workpiece having a linear weld between one member and another member, at least one of which is made of a plate material having a plating film, comprising spraying an antioxidant along the weld,
a supply section that supplies a gas mixture containing an atomized antioxidant to the weld;
a recovery section that recovers a portion of the mixed gas supplied to the welding section,
The mixed gas is collected while the mixed gas is supplied to the welding portion,
The supply section and the recovery section are alternately arranged along the welded section,
an intake flow rate of the gas sucked in to recover the mixed gas in the recovery unit is set to ½ or more of a total of supply flow rates of the mixed gas by the supply units adjacent to both sides of the recovery unit;
Oxidation inhibition treatment method. The antioxidant is sprayed onto the weld from both sides of the workpiece,
The supply unit and the recovery unit on one surface side face each other with the recovery unit and the supply unit on the other surface side sandwiching the welded portion of the workpiece;
The supply flow rate of each of the supply parts on the one surface side is set to ½ or less of the total supply flow rate of the supply parts adjacent to both sides of the recovery part on the other surface side opposite to the supply part on the one surface side.
The oxidation suppression treatment method according to claim 9. The oxidation suppression treatment method according to any one of claims 9 to 10, wherein the plating film is an Al-based alloy film. The oxidation suppression treatment method according to any one of claims 9 to 11, wherein the one member and the other member are made of materials having different tensile strengths. The oxidation suppression treatment method according to any one of claims 9 to 12, wherein the first member and the second member have different plate thicknesses. A step of spraying the antioxidant onto the welded portion of the workpiece by the oxidation inhibition treatment method according to any one of claims 9 to 13;
Heating the workpiece to which the antioxidant has been applied;
hot forming the heated workpiece;
A method for producing a molded article, comprising: