Degreasing furnace

Abstract

The present invention comprises: a furnace main body 6 that has openings 61, 62; lids 71, 72 attached to the openings 61, 62; and a sealing structure for providing an airtight seal for the openings 61, 62 by using the lids 71, 72. The sealing structure is configured so as to comprise: an outside annular packing member 82 and an inside annular packing member 81 that are interposed between facing surfaces 62a, 72a that are provided in the peripheral edges of the lids 71, 72 and the openings 61, 62; and a depressurizing mechanism 83 that reduces pressure in a space S1 formed by being surrounded by each facing surface 62a, 72a and each annular packing member 81, 82. As a result, airtightness in a heating furnace for degreasing can be reliably maintained by a simple structure.

Description

[Technical field]

[0001] The present invention relates to a degreasing furnace for degreasing objects such as ceramic materials. [Background technology]

[0002] This type of degreasing furnace (hereinafter also simply referred to as a "heating furnace"), as shown in Patent Document 1, accommodates an object to be treated, heats it, and degreases it.

[0003] This heating furnace is provided with an opening for putting in and taking out the object to be treated, and a lid for sealing this opening. This lid functions as a door and can be opened and closed, and conventionally, a seal member such as a heat-resistant packing or an O-ring is interposed between the periphery of the opening and the lid, and the lid is pressed against the furnace body using multiple fastening members such as clamp mechanisms or cylinders to clamp the seal member and ensure airtightness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-43704 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there may be cases where a predetermined level of airtightness cannot be maintained due to variations in the fastening force of each fastening member or differences in the fastening order, etc., which may result in a non-uniform load acting on the seal member.

[0006] The present invention has been made to find and solve such problems, and is intended to make it possible to reliably maintain airtightness in this type of degreasing heating furnace with a simple structure. [Means for solving the problem]

[0007] That is, the degreasing furnace according to the present invention includes a furnace body having an opening for inserting and removing an object to be treated, a lid body attached to the opening, and a seal structure for air-tightly sealing the opening with the lid body. The sealing structure is characterized by comprising an outer annular packing member and an inner annular packing member interposed between opposing surfaces provided on the lid body and the peripheral portion of the opening, respectively, and a pressure reducing mechanism for reducing the pressure in the space formed by each of the opposing surfaces and each annular packing member. Effect of the Invention

[0008] According to the above configuration, the negative pressure generated by the pressure reducing mechanism and the atmospheric pressure differential draw the opposing surfaces together, crushing each annular packing member evenly, thereby enabling the opening provided in the furnace body to be reliably sealed by the lid body. [Brief description of the drawings]

[0009] [Figure 1] 1 is an overall schematic diagram of a degreasing device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic perspective view of the heating furnace in the embodiment. [Diagram 3] FIG. 2 is a schematic rear view of the heating furnace in the embodiment. [Figure 4] FIG. 2 is a schematic front view of the heating furnace in the embodiment. [Diagram 5] 4 is a schematic diagram of a second cover and an annular groove in this embodiment as viewed from the inner surface. FIG. [Figure 6] 3A is a cross-sectional view showing a sealing structure of the heating furnace in the embodiment, and FIG. 3B is a schematic diagram showing the connection of a pressure reducing mechanism and the like. [Figure 7] FIG. 11 is a cross-sectional view showing an annular packing member and a circumferential groove in another embodiment of the present invention. [Figure 8] FIG. 4 is a perspective cross-sectional view showing an annular packing member and a circumferential groove in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] As shown in FIG. 1, the degreasing apparatus 100 of this embodiment includes a heating furnace 1 in which the object to be treated W is housed, a heater 2 for heating the heating furnace 1, a gas supply pipe 3 for supplying a degreasing gas into the heating furnace 1, a gas exhaust pipe 4 for exhausting volatile decomposition gases and the like released from the object to be treated W together with the degreasing gas outside the heating furnace 1, and a fan 5 for circulating the degreasing gas within the heating furnace 1. The heating furnace 1, which is a characteristic feature of the degreasing apparatus 100, will be described in detail below.

[0012] 1, 2, etc., the heating furnace 1 is made of metal and has a roughly rectangular parallelepiped shape, and includes a furnace body 6 having openings 61, 62 formed on the front side and the rear side opposite thereto, respectively, and covers 71, 72 for sealing the openings 61, 62. The reference symbol T shown in Figs. 1 and 2 denotes the front panel of a housing provided further outside the heating furnace 1. Next, each part of the heating furnace 1 will be described. The opening 61 on the front side (hereinafter also referred to as the first opening 61) is for inserting and removing the treatment object W into and from the furnace body 6 and has, for example, a rectangular shape.

[0013] The cover 71 (hereinafter also referred to as the first cover 71) that seals the first opening 61 has a rectangular shape that is slightly larger than the first opening 61, and is supported by a hinge member P1 attached to the furnace body 6 so as to be rotatable around one side edge between a closed position and an open position, as shown in Figures 2 and 3. In addition, first fasteners Q1, for example of a handle rotation type, that press and fasten the first cover 71 against the furnace body 6 in the closed position, are provided at the four corners of the first cover 71. The opening 62 on the rear side (hereinafter also referred to as the second opening 62) has, for example, a rectangular shape.

[0014] The cover 72 (hereinafter, also referred to as the second cover 72) that seals the second opening 62 is rectangular and slightly larger than the second opening 62, and is attached to the furnace body 6 by a toggle clamp type second fastener Q2, as shown in Figs. 2 and 4. The second opening 62 is usually closed by the second cover 72, and functions as a safety valve that is opened by the release of the second fastener Q2 only when the pressure inside the heating furnace 1 increases abnormally. The second fastener Q2 is set to have a weaker holding force than the first fastener Q1, and when the pressure inside the heating furnace increases, the second fastener Q2 is released before the first fastener Q1, and the second cover 72 is forced to open before the first cover 71.

[0015] Each of these openings 61, 62 is hermetically sealed by the lid bodies 71, 72, respectively. However, since the sealing structure between the first opening 61 and the first lid body 71 in this embodiment and the sealing structure between the second opening 62 and the second lid body 72 have a common structure, the following will explain the sealing structure between the second opening 62 and the second lid body 72 with reference to Figures 5, 6, etc.

[0016] As shown in Figures 1, 2, 5, and 6, rectangular annular flange portions 621, 721 of a predetermined thickness are provided on the peripheral portion of the second opening 62 in the furnace body 6 and the peripheral portion of the second lid body 72, and in the closed position, these flange portions 621, 721 are configured to face each other.

[0017] An inner annular packing member 81 and an outer annular packing member 82 made of elastic resin and forming an endless ring are sandwiched between the opposing surfaces 62a, 72a of these flange portions 621, 721, so that the second opening 62 can be air-tightly sealed by the second lid body 72.

[0018] In this embodiment, inner and outer circumferential grooves 81a, 82a are formed on the opposing surface 72a of the lid body 72, and the inner annular packing member 81 and the outer annular packing member 82 are fitted into these circumferential grooves 81a, 82a, respectively.

[0019] Further, as shown in FIG. 6, this seal structure includes a pressure reducing mechanism 83 for reducing the pressure in a space S1 defined by the outer annular packing member 82, the inner annular packing member 81 and the opposing surfaces 62a, 72a.

[0020] The decompression mechanism 83 includes a suction pump 831 connected to the space S1. More specifically, a communication hole 83a is provided penetrating the flange portion 621 of the furnace body 6 in the thickness direction to communicate the space S1 with the outside, and the suction pump 831 is connected to the communication hole 83a via a piping member 83b.

[0021] In addition, this embodiment further includes a pressure sensor 91 that directly or indirectly measures the pressure in the space S1, and a monitoring device 92 that monitors the pressure measured by the pressure sensor 91 and reports the fluctuation of the pressure when the fluctuation of the pressure exceeds a predetermined range.

[0022] The pressure sensor 91 is attached to a flow path system between the space S1 and the suction pump 831, for example, the piping member 83b, and measures the pressure therein. Alternatively, the pressure of the communication hole 83a may be measured, or the pressure in the space S1 may be directly measured.

[0023] The monitoring device 92 is, for example, a computer equipped with a CPU, memory, AD converter, etc., which receives a measurement signal from the pressure sensor 91 and sequentially records the measured pressure in memory, and, as described above, notifies the user of the fact by displaying a message on a screen or by voice, etc., when the fluctuation mode of the measured pressure exceeds a predetermined range. Specific examples of the fluctuation mode of the measured pressure exceeding a predetermined range include the measured pressure increasing above a predetermined value, or the fluctuation range of the measured pressure exceeding a predetermined range.

[0024] This sealing structure is also provided with a cooling mechanism for cooling the inner annular packing member 81. The inner annular packing member 81 is closer to the internal space of the heating furnace 1 than the outer annular packing member 82, and may exceed its heat-resistant temperature due to the heat, so this is to prevent this. The cooling mechanism here is configured to flow a cooling medium such as water in a circular flow path R provided in the vicinity of the inner annular packing member 81, more specifically, in the flange portion 62 and directly below the inner annular packing member 81, as shown in Fig. 6.

[0025] 1, a flange 611 is also provided on the periphery of the first opening 61 in the furnace body 6, and a flange 711 is also provided on the periphery of the first lid 62 that closes it. As described above, a similar seal structure and associated pressure sensors and monitoring devices are provided between these flanges 611, 711.

[0026] In this embodiment, the gap between the inner annular packing member 81 and the outer annular packing member 82 on the second opening 62 side is configured to be smaller than the gap between the inner annular packing member and the outer annular packing member in the sealing structure on the first opening 61 side.

[0027] Next, an example of a procedure for closing the openings 61, 62 with the lids 71, 72 will be described. When closing the second opening 62, first, the second cover 72 is attached using the second fasteners Q2. In this state, the annular packing members 81, 82 are crushed to a certain extent, and the space S1 is sealed (FIG. 6(a)). Then, the suction pump 831 is operated to reduce the pressure in the space S1 to create a vacuum. As a result, atmospheric pressure acts to draw the opposing surfaces 62a, 72a toward each other, and the annular packing members 81, 82 are crushed to a predetermined extent, and the second opening 62 is airtightly sealed by the second cover 72. This state is shown in FIG. 6(b). The first opening 61 is similar, except that the first lid 72 is attached by the first fastener Q1.

[0028] According to the above-described configuration, the opposing surfaces 62a, 72a are attracted to each other by the differential pressure between the negative pressure (vacuum) generated by the pressure reducing mechanism 83 and atmospheric pressure, and the annular packing members 81, 82 are evenly crushed, so that the openings 61, 62 provided in the furnace body 6 can be reliably sealed by the lid bodies 71, 72.

[0029] In addition, since sealing is achieved by operating the suction pump 831, the work is made easier and leaks can be prevented more reliably than in the conventional structure in which all fasteners must be tightened according to specifications.

[0030] Furthermore, if the sealing performance deteriorates due to aging, damage, or the like, pressure rise and pressure vibrations will occur in the space S1. Since the monitoring device 92 monitors these pressure fluctuations, it becomes possible to predict leaks in advance and detect them immediately after they occur, thereby improving maintainability and safety.

[0031] In addition, the gap between the outer annular packing member 82 and the inner annular packing member 81 on the rear side is set smaller than that on the front side, in other words, the area of ​​the space S1 on the front side when viewed from the front-rear direction is set larger than that on the rear side, so that the holding force on the second cover body 72 is smaller than the holding force on the first cover body 71. As a result, for example, when the pressure inside the furnace abnormally increases, the second cover body 72 is opened first to reduce the pressure inside the furnace, and the first cover body 71 on the side where the operator works can be prevented from coming off unexpectedly, thereby improving safety.

[0032] The present invention is not limited to the above-described embodiment. The pressure in the space S1 is preferably closer to a vacuum because the force holding the lid bodies 71, 72 is stronger and the sealing performance is improved. However, if the force holding the lid bodies 71, 72 is insufficient or the crushing force of the annular packing members 81, 82 is insufficient even when the pressure in the space S1 is made a vacuum, the pressing force of the fasteners Q1, Q2 may also be added. The circumferential grooves 81a, 82a may be provided in the flange portion of the furnace body 6, and a communication hole that communicates the space S1 with the suction pump 92 may be provided in the flange portions of the lids 71, 72. The flange portion that forms the opposing surface is not necessarily required. The shapes of the heating furnace 1, the openings 61, 62, and the lids 71, 72 can also be modified in various ways.

[0033] The annular packing members 81, 82 are not limited to solid members having a circular or elliptical cross section, but may also have a cavity formed therein. An example of this will be described with reference to Figures 7 and 8. In the following, components corresponding to those in the above embodiment are given the same reference numerals.

[0034] In this example, as shown in Figs. 7 and 8, the circumferential grooves 81a and 82a are dovetail grooves having an isosceles trapezoidal cross section with a bottom width greater than an opening width. In this example, the annular gasket members 81, 82 are made of elastic resin (here, silicone rubber) and consist of fitting portions 812, 822 that fit almost tightly into the circumferential grooves 81a, 82a, and protruding portions 811, 821 that protrude integrally from the openings of the circumferential grooves 81a, 82a.

[0035] As shown in FIG. 7, in a natural state in which no external force is substantially applied, the fitting portions 812, 822 have a cross-sectional contour shape that is an isosceles trapezoid that is substantially equal to the cross-sectional shape of the circumferential grooves 81a, 82a. Cavities 812a, 822a extending in the circumferential direction are formed in the fitting parts 812, 822. The cavities 812a, 822a have shapes in cross section that are roughly similar to the contour shapes of the fitting parts 812, 822, and are configured so that the wall thickness between the cavities 812a, 822a and the outer circumferential surfaces of the fitting parts 812, 822 is roughly equal. Furthermore, grooves 812b, 822b having a semicircular cross section and extending in the circumferential direction are formed in the bottom surfaces of the fitting portions 812, 822.

[0036] The contour shape of the protruding portions 811 and 821 in cross section is a tunnel shape that combines a rectangle with a semi-ellipse or a semi-circle. The protruding portions 811, 821 also have cavities 811a, 821a formed therein, which extend in the circumferential direction and have shapes roughly similar to the contour shapes of the protruding portions 811, 821 in cross section, so as to extend in the circumferential direction. The protruding height of the protruding portions 811, 821 is approximately equal to the depth of the circumferential grooves 81a, 82a.

[0037] According to such annular packing members 81, 82, the fitting portions 812, 822 and the protruding portions 811, 821 have cavities 812a, 822a and cavities 811a, 821a, respectively, so that a large crushing allowance can be provided. Furthermore, when the furnace body 6 and the lid body 72 (71) are fastened together and the opposing surfaces 62a, 72a are brought close to each other and in close contact with each other, the fitting portions 812, 822 come into close contact with the inner surfaces of the peripheral grooves 81a, 82a, and the protruding portions 811, 821 come into close contact with the opposing surface 62a in a wide area.

[0038] Therefore, compared to the solid gasket member having a circular or elliptical cross section described in the above embodiment, sufficient airtightness can be ensured even if the fastening force of the clamping mechanism or cylinder is reduced, and even if the structures including the furnace body 6 and the lid bodies 71 and 72 are deformed due to heat, etc.

[0039] Also, in this example, grooves 812b, 822b are formed in the bottom surfaces of fitting portions 812, 822 to make the thickness of fitting portions 812, 822 smaller at these portions than at other portions and to make them easier to deform. Therefore, by curving or bending the bottom portions of annular packing members 81, 82 about grooves 812b, 822b, they can be easily fitted into circumferential grooves 81a, 82a.

[0040] Furthermore, since the fitting portions 812, 822 are fitted into the dovetail-shaped peripheral grooves 81a, 82a with almost no gap, there is an effect that the annular packing members 81, 82 are unlikely to come off even when the lids 71, 72 are opened and closed.

[0041] The shape of this annular packing member is not limited to the above. The shape of the fitting portion can be changed to match the cross-sectional shape of the circumferential groove, and the protruding portion can be other shapes such as semicircular or semi-elliptical. The cross-sectional shape of the cavity can also be variously modified, and the cavity can be formed across the protruding portion and the fitting portion. A groove can be provided on the bottom surface of the cavity of the fitting portion, and the shapes of the outer annular packing member and the inner annular packing member can be made different.

[0042] In addition, the present invention may be modified within the scope of the invention, for example by combining parts of the above-mentioned modifications. The features of the present embodiment described above can be summarized as follows.

[0043] (1) This heating furnace 1 comprises a furnace body 6 having openings 61, 62, cover bodies 71, 72 attached to the openings 61, 62, and a sealing structure for air-tightly sealing the openings 61, 62 with the cover bodies 71, 72, and the sealing structure comprises an outer annular packing member 82 and an inner annular packing member 81 interposed between opposing surfaces 62a, 72a provided on the periphery of the cover bodies 71, 72 and the openings 61, 62, respectively, and a pressure reducing mechanism 83 for reducing the pressure in a space S1 formed by being surrounded by the opposing surfaces 62a, 72a and the annular packing members 81, 82.

[0044] (2) If a pressure sensor 91 for measuring the pressure in the space S1 is further provided, deterioration of the sealing property due to aging or damage and the resulting gas leakage from the heating furnace 1 to the outside can be detected by monitoring the pressure fluctuations in the space S1.

[0045] (3) More specifically, it is preferable to further include a monitoring device 92 that monitors the pressure measured by the pressure sensor 91 and notifies the user when the measured pressure exceeds a predetermined range.

[0046] (4) If two openings 61, 62 are provided, one of which, the first opening 61, is for loading and unloading the degreasing treatment object W into the heating furnace 1, and the other, the second opening 62, is opened when the pressure inside the heating furnace 1 exceeds a predetermined value, the front lid 71 operated by the user will not open accidentally, thereby improving safety.

[0047] (5) To achieve this, for example, the sealing structures are provided between each of the openings 61, 62 and the cover bodies 71, 72 attached to the openings 61, 62, respectively, and the distance between the outer annular packing member and the inner annular packing member in the sealing structure on the first opening 61 side is set larger than the distance between the outer annular packing member and the inner annular packing member in the sealing structure on the second opening 62 side.

[0048] (6) A cooling mechanism for cooling the inner annular packing member is further provided. The inner annular packing member 81 is close to the internal space of the heating furnace 1, and may exceed its heat-resistant temperature due to the heat. Therefore, by providing the cooling mechanism, deterioration of the inner annular packing member can be suppressed.

[0049] (7) The pressure reduction mechanism includes a suction pump connected to the space, and a communication hole is provided through the flange portion of the furnace body in the thickness direction to connect the space to the outside, and the suction pump is connected to the communication hole.

[0050] (8) A circumferential groove 81a, 82a into which the annular packing members 81, 82 are fitted is formed on one of the opposing surfaces 72a (62a), The annular packing members 81, 82, in a natural state in which no force is applied from the other opposing surface 62a (72a), consist of fitting portions 812, 822 which fit into the circumferential grooves 81a, 82a with almost no gap, and protruding portions 811, 821 which protrude from the openings of the circumferential grooves 81a, 82a, and the fitting portions 812, 822 and protruding portions 811, 821 are provided with cavities 812a, 822a and cavities 811a, 821a extending circumferentially, respectively. With such a structure, the annular packing members 81, 82 can be crushed to a large extent and their flexibility when crushed can be maintained, so that the fastening force can be reduced and sealing performance can be ensured even when the structure is deformed by heat or the like.

[0051] (9) Grooves 812b, 822b are formed in the bottom surfaces of the fitting portions 812, 822 of the annular packing members 81, 82, extending in the circumferential direction. With this, the annular packing members 81, 82 can be easily fitted into the circumferential grooves 81a, 82a. [Industrial Applicability]

[0052] The negative pressure generated by the pressure reducing mechanism and the atmospheric pressure differential draw the opposing surfaces together and crush the annular packing members evenly, so that the opening in the furnace body can be reliably sealed by the lid. [Explanation of symbols]

[0053] 100 Degreasing equipment W: Processing object 1...Heating furnace 6 Furnace body 61...First opening 62...Second opening 71...First cover 72 Second cover 62a, 72a: opposing surfaces 82...Outer annular packing member 81...Inner annular packing member 83 Pressure reducing mechanism 91 Pressure sensor 92...Monitoring device S1...Space 812, 822...Inset part 811, 821...Protruding part 812a, 822a, 811a, 821a...Cavity 812b, 822b...Groove

Claims

1. A furnace body having an opening; A cover attached to the opening; a seal structure for air-tightly sealing the opening with the lid, The seal structure is an outer annular packing member and an inner annular packing member interposed between opposing surfaces provided on the lid body and the peripheral portion of the opening, respectively; a pressure reducing mechanism for reducing a pressure in a space surrounded by each of the opposing surfaces and each of the annular packing members, This degreasing furnace has two openings, one of which, a first opening, is for loading and unloading the object to be degreased into the heating furnace, and the other opening, a second opening, is opened when the pressure inside the heating furnace exceeds a predetermined value.

2. 2. The degreasing furnace according to claim 1, further comprising a pressure sensor for measuring the pressure in the space.

3. 3. The degreasing furnace according to claim 2, further comprising a monitoring device for monitoring the pressure measured by said pressure sensor and for notifying the user when said measured pressure exceeds a predetermined range.

4. A furnace body having an opening; A cover attached to the opening; a seal structure for air-tightly sealing the opening with the lid, The seal structure is an outer annular packing member and an inner annular packing member interposed between opposing surfaces provided on the lid body and the peripheral portion of the opening, respectively; a pressure reducing mechanism for reducing a pressure in a space surrounded by each of the opposing surfaces and each of the annular packing members, the two openings are provided, one of which, a first opening, is for loading and unloading the object to be degreased into and from the heating furnace, and the other of which, a second opening, is opened when the pressure in the heating furnace exceeds a predetermined value; the seal structure is provided between each of the openings and a cover attached to each of the openings, A degreasing heating furnace, in which the distance between the outer annular packing member and the inner annular packing member in the sealing structure on the first opening side is set larger than the distance between the outer annular packing member and the inner annular packing member in the sealing structure on the second opening side.

5. The degreasing furnace according to claim 1 , further comprising a cooling mechanism for cooling the inner annular packing member.

6. The pressure reducing mechanism includes a suction pump connected to the space, 6. A degreasing heating furnace as described in any one of claims 1 to 5, wherein a communication hole is provided through a flange portion provided on the peripheral portion of the opening of the furnace body or a flange portion provided on the peripheral portion of the lid body in the thickness direction to communicate the space with the outside, and the suction pump is connected to the communication hole.

7. A furnace body having an opening; A cover attached to the opening; a seal structure for air-tightly sealing the opening with the lid, The seal structure is an outer annular packing member and an inner annular packing member interposed between opposing surfaces provided on the lid body and the peripheral portion of the opening, respectively; a pressure reducing mechanism for reducing a pressure in a space surrounded by each of the opposing surfaces and each of the annular packing members, A circumferential groove into which the annular packing member is fitted is formed on one of the opposing surfaces, A degreasing heating furnace in which the annular packing member consists of an insertion portion that fits into the circumferential groove with almost no gap and a protruding portion that protrudes from the opening of the circumferential groove, and in which a cavity extending in the circumferential direction is provided in each of the insertion portion and the protruding portion.

8. 8. A degreasing furnace according to claim 7, wherein a groove extending in a circumferential direction is formed on a bottom surface of the fitting portion of said annular packing member.

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