TW202331176A - Heat treatment furnace - Google Patents

Abstract

The present invention provides a heat treatment furnace capable of supplying gas toward a target position even in an environment where a gas supplying pipe is deformed by heat. The heat treatment furnace includes a ceramic muffle 11 in which a heat treatment space S for the workpiece W is formed, and a metallic gas supplying pipe 15 that is arranged in the heat treatment space S and supplies gas to the heat treatment space S. The bottom portion 21 of the muffle 11 has a flat upper surface 21a, and the gas supplying pipe 15 is arranged to extend along the upper surface 21a.

Description

Heat treatment furnace

The invention relates to a heat treatment furnace.

Conventionally, a heat treatment furnace is known in which a workpiece is loaded into a muffle furnace and heat treated in a heat treatment space within the muffle furnace. Such a heat treatment furnace is provided with a gas supply pipe for supplying a predetermined ambient atmosphere gas into the muffle furnace. For example, in the heat treatment furnace described in Patent Document 1 below, gas supply pipes extending in the longitudinal direction of the muffle furnace are attached to the inner surfaces of the side walls and the ceiling of the muffle furnace. [Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 10-267544

(Problem to be solved by the invention)

In the case where the muffle furnace is made of metal, in order to install the gas supply pipe on the side wall and top of the muffle furnace, for example, it is conceivable to weld a plurality of supporting metal parts to the side wall at intervals along the length direction of the muffle furnace. etc., the gas pipe is supported by a plurality of supporting metal parts. On the other hand, when the material of the muffle furnace is a non-metallic heat-resistant material such as ceramics, since it is impossible to weld and support metal parts, it is considered to support both ends of the gas supply pipe on the outside of the muffle furnace, for example. .

However, if both ends of the gas supply pipe are supported on the outside of the muffle furnace, there is a possibility that the gas supply pipe will sag significantly due to thermal deformation inside the muffle furnace. If the gas supply pipe sags, the position of the gas ejection port changes, and there is a possibility that the gas cannot be supplied to the target position.

An object of the present invention is to provide a heat treatment furnace capable of supplying gas toward a target position even in an environment where a gas supply pipe is deformed by heat. (technical means to solve the problem)

(1) The heat treatment furnace of the present invention includes: a muffle furnace made of ceramics, in which a heat treatment space for workpieces is formed; and a gas supply pipe made of metal, which is arranged in the heat treatment space and supplies gas toward the heat treatment space; The bottom of the muffle furnace has a flat upper surface, and the gas supply pipe is arranged along the upper surface.

In addition, in the above-mentioned configuration, "the way of being along the upper surface" means that the gas supply pipe is arranged along the upper surface (approximately in parallel) near the upper surface of the bottom, and the gas supply pipe can be in contact with the upper surface. It may float slightly from the upper surface within a range that does not greatly affect the positional fluctuation of the ejection port when the gas is supplied to the workpiece.

According to the above configuration, since the gas supply pipe is arranged along the upper surface of the bottom of the muffle furnace, the upper surface can prevent or suppress the sag of the gas supply pipe due to heat. . Therefore, it is possible to suppress the variation in the position of the ejection port formed in the gas supply pipe, and supply the gas toward the target position.

(2) It is preferable that the gas supply pipe is arranged between the workpiece and the side wall of the muffle furnace. With such a configuration, especially for workpieces stacked in the vertical direction, gas can be supplied from the lateral direction toward the gap between the workpieces, thereby contributing to uniform gas supply to the workpieces.

(3) Preferably, the workpieces are arranged in a plurality of rows, and the gas supply pipes are arranged between adjacent rows of the workpieces. With such a configuration, even when there are a plurality of rows of workpieces, it is possible to contribute to uniform gas supply toward the workpieces.

(4) Preferably, the heat treatment furnace has a restricting member capable of restricting movement of the gas supply pipe in a radial direction of the gas supply pipe along the direction of the upper surface. According to this configuration, even if the gas supply pipe is deformed due to heat, the movement of the gas supply pipe in the direction along the bottom upper surface in the radial direction of the gas supply pipe can be restricted by the restricting member, so that the gas ejection port can be suppressed. changes.

(5) Preferably, the bottom portion is formed by arranging a plurality of divided bodies in the longitudinal direction of the gas supply pipe, and the restricting member is sandwiched between the adjacent divided bodies. According to this configuration, the restricting member can be fixed to the bottom of the muffle furnace by sandwiching the restricting member between adjacent divided bodies. In addition, even in the case where the bottom of the muffle furnace and the restricting member are dissimilar materials that cannot be welded, it is possible to fix the restricting member to the bottom.

(6) Preferably, the gas supply pipe includes a first gas supply pipe and a second gas supply pipe, the first gas supply pipe and the second gas supply pipe are disposed so as to sandwich the workpiece, and the restricting member has : a first restricting part, which restricts the movement of the first gas supply pipe; a second restricting part, which restricts the movement of the second gas supply pipe; and a connecting part, which is sandwiched between the adjacent divisions, The above-mentioned first restricting part and the above-mentioned second restricting part are connected. When the restricting member is sandwiched between the adjacent split bodies, a gap corresponding to the thickness of the restricting member is generated between the two split bodies, and there is a possibility that gas may leak through the gap. In the above structure, since the connecting portion is clamped by the adjacent split bodies between the first restricting portion and the second restricting portion, between the first restricting portion and the second restricting portion, the gap between the two split bodies There will be no gap between. Therefore, gas leakage from the muffle furnace between the first restricting part and the second restricting part can be suppressed. (compared to the effect of previous technology)

According to the present invention, gas can be supplied toward a target position even in an environment where deformation of the gas supply pipe occurs due to heat.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram of a heat treatment furnace according to one embodiment of the present invention. Fig. 2 is a sectional view of line A-A of Fig. 1 . Fig. 3 is the sectional view of the muffle furnace of the B-B line of Fig. 2. The heat treatment furnace of this embodiment is a continuous heat treatment furnace 10 . The continuous heat treatment furnace 10 performs heat treatment while transferring a plurality of workpieces W sequentially. In addition, in the following description, the conveying direction of the workpiece W is represented by the symbol X, the width direction of the muffle furnace 11 perpendicular to the conveying direction X of the workpiece W is represented by the symbol Y, and the width direction of the muffle furnace 11 perpendicular to the directions X and Y is represented by the symbol Z. up and down direction.

The continuous heat treatment furnace 10 has a muffle furnace 11, a transfer device 12, a heat insulating wall 13, a heating device 14, a gas supply pipe 15, and the like. The muffle furnace 11 is formed in a cylindrical shape and has a heat treatment space S inside. The muffle furnace 11 is formed to be long in the transfer direction X of the workpiece W, and the heat treatment space S also extends in the same direction X. Therefore, the workpiece W is conveyed in the longitudinal direction of the muffle furnace 11 . In the following description, the longitudinal direction of the muffle furnace 11 may be marked with a symbol X in some cases.

The muffle furnace 11 has a bottom 21 , a pair of side walls 22 and a top 23 . The space surrounded by the bottom 21 , the side wall 22 , and the top 23 is defined as a heat treatment space S.

The bottom 21 of the muffle furnace 11 has a flat upper surface 21a. The pair of side wall portions 22 linearly extend upward from both end portions of the bottom portion 21 in the width direction Y of the muffle furnace 11 . The top portion 23 is provided so as to straddle the upper ends of the pair of side wall portions 22 .

The side wall portion 22 and the top portion 23 of the muffle furnace 11 of this embodiment are integrated, and they are formed separately from the bottom portion 21 . The lower ends of the pair of side wall portions 22 are in contact with the upper surface 21 a of the bottom 21 . In addition, the muffle furnace 11 of the present embodiment is formed of ceramics which is a non-metallic heat-resistant material. The muffle furnace 11 of the present embodiment is constituted by a plurality of split bodies 11A, 11B. The divided bodies 11A and 11B are formed of a first divided body 11A constituting the bottom 21 and a second divided body 11B constituting the side wall portion 22 and the top portion 23 .

The transfer device 12 transfers the workpiece W along the longitudinal direction X of the muffle furnace 11 while supporting the workpiece W in the heat treatment space S in the muffle furnace 11 . Therefore, the transfer device 12 also functions as a support device that supports the workpiece W in the heat treatment space S. As shown in FIG. In the present embodiment, a plurality of (for example, three) conveying devices 12 are arranged side by side at intervals in the width direction Y of the muffle furnace 11 .

The conveyor device 12 of this embodiment is a chain type conveyor provided with a conveyor chain 12a, sprockets 12b, 12c, and a rail 12d. The chain 12 a moves on a rail 12 d provided on the upper surface 21 a of the bottom 21 of the muffle furnace 11 . The chain 12a is wound around the driving sprocket 12b and the driven sprocket 12c, and moves in the longitudinal direction X in the muffle furnace 11. The rail 12d extends along the conveyance direction X of the workpiece W. As shown in FIG. A tray T on which a workpiece W is placed is provided on the chain 12a. In the present embodiment, a plurality of trays T are stacked at intervals in the vertical direction Z, and workpieces W are placed on each tray T. As shown in FIG. The conveying device 12 may also be other types of devices such as a belt conveyor or a roller conveyor.

As described above, the workpiece W (actually, the group of workpieces on the tray T) is conveyed in a plurality of lines by the plurality of conveyance devices 12 . However, the workpiece W may be conveyed in one line by one conveying device 12 .

As shown in FIG. 2 , the heat insulating wall 13 has a lower heat insulating wall 13a disposed below the muffle furnace 11, side heat insulating walls 13b disposed on both sides in the width direction Y of the muffle furnace 11, and a heat insulating wall disposed The upper insulating wall 13c above the muffle furnace 11. The muffle furnace 11 is arranged in a space surrounded by the lower heat insulating wall 13a, the side heat insulating wall 13b, and the upper heat insulating wall 13c. The heat insulating wall 13 is made of ceramics. The so-called ceramics refer to non-metallic/inorganic solid materials, equivalent to materials other than metal materials such as iron, aluminum, copper, and organic materials such as plastic or wood. More specifically, as ceramics, old ceramics such as ceramics, refractories (refractory bricks), glass, and cement, or new ceramics (fine ceramics) are representative.

The heating device 14 has a heater arranged below the muffle furnace 11 . The heating device 14 heats the muffle furnace 11 from the outside to raise the temperature of the heat treatment space S in the muffle furnace 11 to a predetermined temperature. As the heating device 14, a resistance heating type device or a gas combustion heating type device can be used. The arrangement and form of the heating device 14 are not particularly limited, for example, it may also be arranged on the side of the muffle furnace 11 in the width direction Y or above the muffle furnace 11 . The heating device 14 may also be embedded in the heat insulating wall 13 .

Fig. 4 is a perspective view showing a gas supply pipe and a restricting member. The gas supply pipe 15 generates a predetermined ambient atmosphere by supplying gas into the muffle furnace 11 . In this embodiment, nitrogen gas is used, for example. The gas supply pipe 15 is arranged along the upper surface 21 a of the bottom 21 of the muffle furnace 11 . Specifically, the gas supply pipe 15 is placed on the upper surface 21a of the bottom 21, and is supported from below by the upper surface 21a.

The gas supply pipe 15 extends along the conveyance direction X of the workpiece W. As shown in FIG. The gas supply pipes 15 are respectively provided on both outer sides of the conveying devices 12 in the width direction Y of the muffle furnace 11 and between adjacent conveying devices 12 . Therefore, in this embodiment, a total of four gas supply pipes 15 are provided in the muffle furnace 11 . On the outer peripheral surface of the gas supply pipe 15, a discharge port 15a for discharging gas is formed. A plurality of ejection ports 15a are formed at intervals in the conveyance direction X of the workpiece W. As shown in FIG. In the gas supply pipes 15 disposed on both sides of the conveying device 12 in the width direction Y of the muffle furnace 11 , ejection ports 15 a are formed so as to eject gas obliquely upward toward the workpiece W located on the inner side in the same direction Y. Each of the gas supply pipes 15 arranged between the adjacent conveying devices 12 is provided with an ejection port so as to eject gas obliquely upward toward the workpiece W arranged on both sides of the muffle furnace 11 in the width direction Y. 15a. By blowing the gas obliquely upward from the gas supply pipe 15 as described above, the gas can be blown uniformly to the workpieces W on the stacked plurality of trays T. As shown in FIG. However, the discharge port 15a may discharge the gas in a direction that does not directly blow the gas to the workpiece W. As shown in FIG.

The gas introduction pipe 16 is arranged adjacent to the gas supply pipe 15 which is one of the two gas supply pipes 15 arranged between the adjacent conveying devices 12 . In this embodiment, two gas introduction pipes 16 are adjacently arranged on both sides of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 . In order to detect the concentration of a predetermined gas in the muffle furnace 11 , the gas introduction pipe 16 is used to introduce the gas in the muffle furnace 11 and send it out of the muffle furnace 11 .

A restricting member 30 is provided at the bottom 21 of the muffle furnace 11 . This restricting member 30 restricts the movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 . The restricting member 30 is made of heat-resistant metal, such as a plate made of nickel alloy (Inconel (registered trademark) 601 or the like), and has a base 30a, a restricting piece 30b, and a supporting piece 30c.

The base 30 a of the restricting member 30 is fixed to the bottom 21 of the muffle furnace 11 . Specifically, as shown in FIG. 3 , the base 30 a is fixed to the bottom 21 by being sandwiched between the divided bodies 11A constituting the bottom 21 of the muffle furnace 11 . The base portion 30 a has a length in the same direction Y as the gas supply pipe 15 across both ends in the width direction Y of the muffle furnace 11 . Specifically, as shown in FIG. 2 , the base portion 30 a is formed to have substantially the same length as the length L of the heat treatment space S in the muffle furnace 11 . The so-called substantially the same length naturally includes a case where it matches the length L of the heat treatment space S, and also includes a case where it falls within the range of dimensional errors (or tolerances). In addition, the base portion 30a may also have the same or greater length than the bottom portion 21 in the width direction Y of the muffle furnace 11 .

Fig. 5 is a perspective view of a restricting member. Fig. 6 is an enlarged view of part C of Fig. 2 . As shown in FIGS. 4 to 6 , the restricting piece 30 b of the restricting member 30 protrudes upward from the upper edge of the base 30 a. In the present embodiment, a pair of restriction pieces 30b are arranged on both sides of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 . The pair of restricting pieces 30 b is arranged with a slight gap between them and the gas supply pipe 15 , or the pair of restricting pieces 30 b is arranged in a state of being in contact with the gas supply pipe 15 . Therefore, movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 is restricted. In this embodiment, the pair of restricting pieces 30b and a portion of the base 30a connecting the pair of restricting pieces 30b are referred to as “restricting portion 31 ” that restricts movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 . For the two gas supply pipes 15 arranged at both ends in the width direction Y of the muffle furnace 11, the restricting member 30 also has a pair of restricting pieces 30b (restricting portions 31) in the form shown in FIG. 6 .

Fig. 7 is an enlarged view of part D of Fig. 2 . As shown in Fig. 4, Fig. 5 and Fig. 7, for the gas supply pipe 15 adjacent to the two gas introduction pipes 16, a pair of restricting pieces 30b are arranged to be separated from the gas introduction pipe 16 by a gap, or a The counter-regulating piece 30 b is arranged in a state of being in contact with the gas introduction pipe 16 . Therefore, the movement of each gas introduction pipe 16 toward one side in the width direction Y of the muffle furnace 11 is respectively restricted by the pair of restriction pieces 30b, and two of the gas introduction pipes 16 are indirectly restricted by the pair of restriction pieces 30b. Movement of the gas supply pipe 15 between the gas introduction pipes 16 in the width direction Y of the muffle furnace 11 . The pair of restricting pieces 30b and a portion of the base portion 30a connected to the pair of restricting pieces 30b also constitute a restricting portion 31 that restricts the movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 .

The restricting member 30 is provided with the restricting part 31 which has a pair of restricting pieces 30b at four places at intervals in the width direction Y of the muffle furnace 11. As shown in FIG. Adjacent restricting portions 31 are connected to each other by a part of the base portion 30a. In the present embodiment, a portion of the base portion 30a connecting adjacent restricting portions 31 is referred to as a "connecting portion 32".

As described above, the restricting member 30 has a plurality of restricting portions 31 and a connection portion 32 connecting adjacent restricting portions 31 .

Fig. 8 is an enlarged view of part E of Fig. 3 . As shown in FIG. 4 , FIG. 5 and FIG. 8 , the support piece 30 c of the restricting member 30 protrudes from the lower edge of the base portion 30 a in the conveying direction X of the workpiece W. As shown in FIG. The support piece 30c of this embodiment is formed by bending along the conveyance direction X of the workpiece|work W from the lower edge of the base part 30a. Specifically, the support piece 30c includes a portion bent to one side in the conveyance direction X of the workpiece W and a portion bent to the other side in the conveyance direction X. As shown in FIG. The support piece 30c is disposed along the lower surface of the bottom 21 of the muffle furnace 11 . The bottom 21 of the muffle furnace 11 is supported by the upper surface of the support platform 17 formed by bricks or the like. The supporting piece 30c of the restricting member 30 is sandwiched between the upper surface of the supporting table 17 and the lower surface of the bottom 21 of the muffle furnace 11 . The movement of the restriction member 30 in the vertical direction Z is restricted by the support piece 30c, thereby preventing the base 30a from protruding from the upper surface 21a of the bottom 21 or the restriction piece 30b from sinking downward.

The continuous heat treatment furnace 10 of this embodiment described above has: a muffle furnace 11 in which a heat treatment space S for the workpiece W is formed; and a gas supply pipe 15, which is arranged in the heat treatment space S, and supplies the ambient atmosphere gas to the heat treatment space S. The muffle furnace 11 is made of non-metal, that is, ceramics. The bottom 21 of the muffle furnace 11 has a flat upper surface 21a. Furthermore, the gas supply pipe 15 is arranged along the upper surface 21 a of the bottom 21 . Thus, when the muffle furnace 11 is made of non-metal, it is impossible to install the gas supply pipe 15 made of metal to the muffle furnace 11 by welding or the like. In the present embodiment, the gas supply pipe 15 is arranged along the upper surface 21 a of the bottom 21 . Thereby, when the gas supply pipe 15 is deformed due to heat, since the gas supply pipe 15 is supported by the upper surface 21a of the bottom 21, it is possible to prevent the gas supply pipe 15 from sagging downward or about to sag downward. suppressed less. Therefore, it is possible to suppress variation in the position of the discharge port 15 a formed in the gas supply pipe 15 .

In the above embodiment, the gas supply pipe 15 extends in the conveying direction X of the workpiece W, and the plurality of conveying devices 12 are arranged in line in the width direction Y of the muffle furnace 11, and in the width direction Y of the muffle furnace 11, The gas supply pipe 15 is arranged between adjacent conveying devices 12 . In other words, the workpieces W are arranged in a plurality of rows, and the gas supply pipe 15 is arranged between rows of adjacent workpieces W. FIG. Therefore, it is possible to easily spread the gas between rows of adjacent workpieces W. FIG. In addition, gas may be blown from between adjacent conveying devices 12 to the workpiece W conveyed by the conveying device 12 . In addition, in the present embodiment, since the gas supply pipe 15 is also provided on the outside in the same direction Y of the conveying device 12 arranged at both ends of the width direction Y of the muffle furnace 11, it is possible to efficiently use the muffle furnace. The whole inside the Furnace 11 is set to a predetermined ambient atmosphere.

In the above embodiment, the transfer device 12 is arranged on the upper surface 21 a of the bottom 21 of the muffle furnace 11 , and the gas supply pipe 15 is arranged on the side of the transfer device 12 in the width direction Y of the muffle furnace 11 . Furthermore, in the up-down direction Z, the conveying device 12 and the gas supply pipe 15 are arranged at overlapping heights. Therefore, it is possible to arrange the gas supply pipe 15 along the upper surface 21 a of the bottom 21 at a position where the workpiece W conveyed by the conveying device 12 is not too far apart in the vertical direction. Therefore, it is possible to blow gas to the workpiece W from the gas supply pipe 15 . In addition, since the gas supply pipe 15 and the conveying device 12 are arranged at overlapping heights, and the gas supply pipe 15 is arranged at a lower position than the workpiece W on the conveying device 12, even if the gas supply pipe 15 is deformed, it is almost It will not come into contact with the workpiece W.

In the above-mentioned embodiment, the gas supply pipe 15 extends along the conveying direction X of the workpiece W, and the continuous heat treatment furnace 10 is provided with the restricting member 30 which restricts the gas supply pipe 15 in the width direction Y of the muffle furnace 11 (in other words, The radial direction of the gas supply pipe 15 and the direction along the upper surface 21 a of the bottom 21 ). Therefore, even if the gas supply pipe 15 is deformed by heat, since the movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11 is restricted by the restricting member 30, it is possible to suppress the jet formed in the gas supply pipe 15. Changes to exit 15a.

In the above embodiment, the bottom 21 of the muffle furnace 11 has a plurality of split bodies 11A made of non-metal or ceramics. ) arrangement. Also, the restricting member 30 is sandwiched between the adjacent divided bodies 11A. Thereby, it is possible to fix the restricting member 30 made of heat-resistant metal such as nickel alloy to the bottom 21 of the muffle furnace 11 made of ceramics.

In the above embodiment, the restricting member 30 has: one restricting portion (first restricting portion) 31 that restricts the movement of one gas supply pipe (first gas supply pipe) 15 in the width direction Y of the muffle furnace; other restricting part (second restricting part 31), which restricts the movement of other gas supply pipe (second gas supply pipe) 15 in the width direction Y of muffle furnace 11; and connecting part 32, which is sandwiched between adjacent Between the divided bodies 11A, the first restricting portion 31 and the second restricting portion 31 are connected. Therefore, even if the restricting member 30 is sandwiched by the adjacent segmented bodies 11A, between the first restricting portion 31 and the second restricting portion 31 , there will not be a gap corresponding to the thickness of the restricting member 30 between the adjacent segmented bodies 11A. Clearance. In addition, in the present embodiment, since all (four) restricting parts 31 are connected by the connecting part 32, most of the width direction Y of the muffle furnace 11 is not separated between adjacent divided bodies 11A. There will be a gap. Therefore, it is possible to suppress the leakage of ambient atmosphere gas from between the adjacent divided bodies 11A.

In addition, in the above embodiment, since one restricting member 30 has a plurality of restricting portions 31 , by attaching one restricting member 30 to the muffle furnace 11 , it is possible to restrict movement of a plurality of gas supply pipes 15 .

In each restricting portion 31, although the lower ends of the pair of restricting pieces 30b are connected by the base portion 30a, the upper ends are not connected, and the pair of restricting pieces 30b is opened upward. Therefore, although the restricting part 31 restricts the movement of the gas supply pipe 15 in the width direction Y of the muffle furnace 11, it does not restrict the upward movement. Therefore, the gas supply pipe 15 can be easily detached upward from the restricting portion 31 , and maintenance such as replacement of the gas supply pipe 15 can be easily performed.

In addition, the muffle furnace 11 of the present invention does not interfere with the installation of the gas supply pipe 15 on the side wall portion 22 or the top portion 23 . The mounting structure of the restricting member 30 to the bottom 21 of the muffle furnace 11 as described above can also be applied to the side wall portion 22 or the top 23 . That is, by clamping the restricting member (support member) that supports the gas supply pipe 15 and restricts its movement between the adjacent divided bodies 11B (side wall portion 22, top 23), the restricting member can be fixed to the muffle. Furnace 11.

Thus, the heat treatment furnace 10 of the said embodiment has the following structures. That is, the heat treatment furnace 10 includes: a muffle furnace 11 in which a heat treatment space S for the workpiece W is formed; a gas supply pipe 15 arranged in the heat treatment space S to supply gas to the heat treatment space S; member) 30, which restricts the movement of the gas supply pipe 15; the muffle furnace 11 is formed by arranging a plurality of split bodies 11A, 11B in the longitudinal direction of the gas supply pipe 15 (the longitudinal direction X of the muffle furnace 11), The restricting member 30 is sandwiched between the adjacent divided bodies 11A, 11B. With such a configuration, the restricting member 30 can be appropriately fixed regardless of any part of the muffle furnace 11 (the bottom 21 , the side wall 22 , or the top 23 ). In addition, even if the muffle furnace 11 and the restricting member are dissimilar materials that cannot be welded, the restricting member can be fixed to the muffle furnace 11 .

The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the invention described in the claims. For example, the number of conveyance devices 12 in the muffle furnace 11 is not limited, and may be one or two, or four or more.

The gas supply pipe 15 may also be arranged in a state of being slightly lifted from the upper surface 21 a of the bottom 21 of the muffle furnace 11 . For example, the upper edge of the base 30a of the restricting member 30 can be made slightly higher than the upper surface 21a of the bottom 21, and the gas supply pipe 15 is floated from the upper surface 21a of the bottom 21 by lifting the gas supply pipe 15 with the restricting member 30. . Alternatively, a partially protruding pedestal may be provided in advance on the upper surface 21 a of the bottom 21 , and the gas supply pipe 15 may be placed on the pedestal to float from the upper surface 21 a of the bottom 21 . However, when the gas supply pipe 15 is floated from the upper surface 21a of the bottom 21, there is deformation caused by heat so that the gas supply pipe 15 hangs down until it comes into contact with the upper surface 21a of the bottom 21, and the gap between the ejection ports 15a There is a possibility of increasing the amount of variation, and there is a possibility of stress concentration on the portion supported by the gas supply pipe 15 , so it is preferable to directly place the gas supply pipe 15 on the upper surface 21 a of the bottom 21 . When the gas supply pipe 15 is floated from the upper surface 21a, it is preferable to set it to such an extent that the gas supply from the ejection port 15a will not be hindered even if it hangs down (for example, the gas can be uniformly supplied to the workpiece W). degree) height. In addition, when the gas supply pipe 15 is floated from the upper surface 21a of the bottom 21, it is preferable to suppress the air supply pipe 15 by narrowing the distance between the support members such as the restricting member 30 in the conveyance direction X of the workpiece W. 15 variants.

In the muffle furnace 11, a part where the gas supply pipe is not arranged may be partly formed of a heat-resistant material other than ceramics. For example, the side walls 22 and top 23 of the muffle furnace 11 may be made of ceramics and the bottom 21 may be made of metal, or the side walls 22 and top 23 may be made of metal and the bottom 21 may be made of ceramics. The entire muffle furnace 11 may be made of ceramics, and a part of the inner surface may be provided as a metal layer (plate) for the purpose of oxygen adsorption.

The gas supply pipes 15 are respectively provided on both outer sides of the conveying device 12 in the width direction Y of the muffle furnace 11 and between adjacent conveying devices 12 , but they may be provided on only one of them.

10: Heat treatment furnace 11: muffle furnace 11A: split body 12: Conveying device 12a: chain 12b: sprocket (drive sprocket) 12c: sprocket (driven sprocket) 12d: track 13: Insulation wall 13a: Lower insulation wall 13b: Side insulation wall 13c: Upper insulating wall 14: Heating device 15: Gas supply pipe 15a: Jet outlet 16: Gas inlet tube 17: Support table 21: Bottom 21a: upper surface 22: side wall 23: top 30: Restricted components 30a: base 30b: Restricted film 30c: support piece 31: Restricted Department 32: Connecting part L: Length S: heat treatment space T: Tray W: Workpiece

Fig. 1 is a schematic diagram of a heat treatment furnace according to one embodiment of the present invention. Fig. 2 is a sectional view of line A-A of Fig. 1 . Fig. 3 is the sectional view of the muffle furnace of the B-B line of Fig. 2. Fig. 4 is a perspective view showing a gas supply pipe and a restricting member. Fig. 5 is a perspective view of a restricting member. Fig. 6 is an enlarged view of the gas supply pipe and the restricting member in part C of Fig. 2 . Fig. 7 is an enlarged view of a gas supply pipe and a restricting member in part D of Fig. 2 . Fig. 8 is an enlarged view of the gas supply pipe and the restricting member in part E of Fig. 3 .

11: muffle furnace

12: Conveying device

12a: chain

13: Insulation wall

13a: Lower insulation wall

13b: Side insulation wall

13c: Upper insulating wall

14: Heating device

15: Gas supply pipe

16: Gas inlet tube

21: Bottom

21a: upper surface

22: side wall

23: top

30a: base

30b: Restricted film

30c: support piece

L: Length

S: heat treatment space

T: Tray

W: Workpiece

Claims (6)

A kind of heat treatment furnace, it has: A muffle furnace made of ceramics forming a heat treatment space for workpieces inside; and a metal gas supply pipe disposed in the heat treatment space, and supplies gas to the heat treatment space; The bottom of the above-mentioned muffle furnace has a flat upper surface, The gas supply pipe is arranged along the upper surface. Such as the heat treatment furnace of claim 1, wherein, The gas supply pipe is disposed between the workpiece and a side wall of the muffle furnace. Such as the heat treatment furnace of claim 1 or 2, wherein, The above artifacts are configured on plural lines, The said gas supply pipe is arrange|positioned between the adjacent said workpiece|work row. Such as the heat treatment furnace of claim 1 or 2, wherein, The heat treatment furnace has a restricting member that restricts movement of the gas supply pipe in a radial direction of the gas supply pipe along the direction of the upper surface. Such as the heat treatment furnace of claim 4, wherein, The bottom part is formed by arranging a plurality of divided bodies in the longitudinal direction of the gas supply pipe, The restriction member is sandwiched between the adjacent divided bodies. Such as the heat treatment furnace of claim 5, wherein, The gas supply pipe includes a first gas supply pipe and a second gas supply pipe, The first gas supply pipe and the second gas supply pipe are disposed so as to sandwich the workpiece, The aforementioned limiting member has: a first restricting portion that restricts movement of the first gas supply pipe; a second restricting portion that restricts movement of the second gas supply pipe; and The connecting portion is sandwiched between the adjacent divided bodies, and connects the first restricting portion and the second restricting portion.