JP2003113414A - Thermal-expansion absorbing device for continuous vacuum carburizing furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous vacuum furnace with the long life for carburizing iron alloy, which has several heat treatment chambers from an upstream side to a downstream side, does not require a repairing cost, because the heat treatment chambers and particularly, the connected parts absorb a large thermal expansion caused by exposure to a temperature as high as 1,000 deg.C, and are not thermally deformed. SOLUTION: The continuous vacuum carburizing furnace having temperature- raising chambers 2 consisting of the several heat treatment chambers, several carburization diffusion chambers 3, 4 and 5, a temperature-lowering chamber 6, a quenching chamber 7 and a carrying out chamber 8, arranges a pit 10 which can accommodate all of the several heat treatment chambers 2, 3, 4, 5, and 6 located in the upstream side of the quenching chamber 7 that are adjacent to the floor 9 of the quenching chamber 7, arranges frames 12 in each space between the bottom 1 of the pit 10 and each bottom of the heat treatment chambers 2, 3, 4, 5, and 6 in the upstream side, and arranges rollers 14 movable to an upstream direction, between the bottom of the heat treatment chambers 2, 3, 4 and 5, and the frames 12, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thermal expansion absorption in a continuous vacuum carburizing furnace for iron alloy parts having a plurality of heat treatment chambers including a temperature raising chamber, a carburizing chamber and a diffusion chamber, or a carburizing diffusion chamber, a descending greenhouse and a quenching chamber. Regarding the improvement of the device.

[0002]

2. Description of the Related Art A conventional continuous carburizing furnace is operated by a gas carburizing method.
-6364, etc., outlines the equipment. However, in such a continuous furnace, the total length of the furnace becomes long and the inside of the metal furnace body is covered with a heat insulating material, but since the inside is heated up to about 1,000 ° C, the temperature rise of the furnace body is unavoidable and the furnace body heats up. Expands. Therefore, it is better to raise the heat insulation effect so that heat is not transmitted to the furnace body, but there are problems that a large amount of heat insulating material is required and the furnace body becomes large, but in the gas carburizing method even if the treatment atmosphere is under reduced pressure. Leakage caused by deformation of the furnace body due to thermal expansion, which is relatively close to atmospheric pressure, is not a serious problem.
The above-mentioned JP-A No. 11-1759 and JP-A No. 62-6364 do not disclose or suggest the thermal expansion. JP
The 2000-297985 publication describes the thermal expansion of the muffle in the continuous sintering furnace, but does not disclose or suggest the thermal expansion of the furnace body.

The applicant has filed a patent application shown in a schematic side sectional view in FIG.
In the case of the hearth roller type continuous furnace, which is a continuous vacuum carburizing furnace proposed in 2001-032184 and undisclosed, rollers for transferring between rooms are required to transfer trays or baskets, but it interferes with the partition door. A roller raising / lowering device was required, and the roller raising / lowering device therefor protruded below the furnace body.
The protrusions are often stored in the pit due to the tray or basket pass line. In the case of oil quenching, it is necessary to install a large number of pits for the quenching oil tank and the pits for the roller up-down device between the chambers, and further, a considerably larger pit is required for maintenance and disassembly of each device.
Each pit requires a lifting means such as stairs or a ladder and a drainage device. These heat treatment chambers are exposed to a high temperature of about 1000 ° C and undergo a large thermal expansion.

[0004]

The continuous vacuum carburizing furnace of FIG. 4 is a continuous vacuum carburizing furnace capable of bright quenching by processing an iron alloy under a reduced pressure of about 10 KPa, but maintaining a reduced pressure of about 10 KPa. It is necessary to. Therefore, it is necessary to suppress leakage caused by deformation due to thermal expansion that occurs when the furnace body is heated. Furthermore, each pit is maintained,
If the size is increased for disassembly, it is assumed that the furnace body support part will hit the pit, and if it is avoided, the furnace body support will become unbalanced. Since the lower part of the transition roller elevating device was housed in a pit dug down from the ground, each of the plurality of heat treatment chambers and especially the connection part could not absorb such a large thermal expansion and was thermally deformed, which required repair costs, It had a short life. The subject of the present invention is a continuous vacuum carburizing furnace for iron alloy parts having a plurality of heat treatment chambers including a temperature raising chamber, a carburizing chamber and a diffusion chamber, or a carburizing diffusion chamber, a descending greenhouse, and a quenching chamber. Even if exposed to a high temperature such as ° C, each of the plurality of heat treatment chambers and especially the connection portion absorbs such a large thermal expansion, does not undergo thermal deformation, and does not require repair cost, and provides a long-life continuous carburizing furnace. is there.

[0005]

Therefore, the present invention provides an iron alloy part having a plurality of heat treatment chambers including a temperature raising chamber, a carburizing chamber and a diffusion chamber, or a carburizing diffusion chamber, a greenhouse chamber, and a quenching chamber from upstream to downstream. In a continuous vacuum carburizing furnace, a pit adjacent to the floor of the quenching chamber and capable of continuously accommodating a plurality of heat treating chambers upstream from the quenching chamber is provided, and the bottom face of the pit and the plurality of upstream heat treating chambers are provided. A thermal expansion absorber for a continuous vacuum carburizing furnace is provided, in which a gantry is provided between the lower part of each chamber and a roller movable in the upstream direction between each of the lower parts of the chambers and each gantry. By doing so, the problems of the conventional products described above were solved.

[0006]

With such a structure, a pit is provided which can continuously accommodate all of the plurality of heat treatment chambers upstream from the quenching chamber having the floor of the quenching chamber as the bottom, and the bottom of the pit and the lower portion of each of the plurality of heat treatment chambers upstream. Each of the plurality of heat treatment chambers has a temperature of 1000 ° C, because each of the plurality of heat treatment chambers moves upstream because the pedestals are provided in each and the rollers that can move in the upstream direction are arranged between each chamber and each pedestal. Even when exposed to high temperatures, each of the multiple heat treatment chambers and connections absorbs such a large thermal expansion,
It provides a long-lived continuous vacuum carburizing furnace that does not undergo thermal deformation and requires no repair costs.

Preferably, a guide for guiding in a direction orthogonal to the upstream direction and a guide roller guided by the guide are arranged between the lower portion of each chamber and each gantry, and each chamber in a direction orthogonal to the upstream direction is arranged. Was regulated so that the large thermal expansion applied to each of the plurality of heat treatment chambers and the connecting portion was reliably absorbed, and thermal deformation was prevented.

[0008]

1 is a schematic side sectional view showing a thermal expansion absorber for a continuous vacuum carburizing furnace for iron alloy parts according to an embodiment of the present invention. In the embodiment of the present invention, the arrow A
The heating chamber 2 and the carburizing and diffusing chambers, which are a plurality of heat treatment chambers following the filling chamber 1 from the upstream side to the downstream side, respectively.
3, 4 and 5 (may be formed by a carburizing chamber and a diffusion chamber), a descending greenhouse 6, a quenching chamber 7, and an unloading chamber 8. In the present invention,
The quenching chamber 7 is provided with a pit 10 adjacent to the floor surface 9 and capable of accommodating all of the plurality of heat treatment chambers 2, 3, 4, 5, 6 which are upstream of the quenching chamber 7. Between the heat treatment chambers 2, 3, 4, 5, 6 under
Was set up. As shown in FIG. 2 (a), which is an enlarged view of the lower part of the greenhouse 6 in FIG. 1, the greenhouse 6 and a plurality of heat treatment chambers 2 in the upstream,
A roller 14 movable in the upstream direction indicated by an arrow B is arranged between a pedestal 13 (which may not be provided) supporting the lower surfaces 3, 4, and 5 and each pedestal 12. Each heat treatment room 2, 3,
The connecting portion 15 provided between 4, 5, and 6 is provided with a lifting device 17 for the door 16 of each heat treatment chamber, and between the feed rollers 18 of each heat treatment chamber according to the lifting and lowering of the door 16 by the door lifting device 17. And a transition roller ascending / descending device 19 for connecting the above.

In this embodiment, the inside of the temperature raising chamber 2 and the plurality of carburizing diffusion chambers 3, 4 and 5 is at about 1,000 ° C., and the descending greenhouse 6 is at about 850 ° C.
Each is heated to ° C. Quenching oil is about 200 ℃ in the quenching chamber 7.
However, the quenching chamber 7 itself is not heated. The quenching chamber 7 is fixed to the floor 9 of the quenching chamber, and the quenching chamber 6 descends from the insertion chamber 1.
The chambers up to are sealed and connected by a flange of a furnace body (not shown). A partition door 16 is provided between the chambers and is raised when the tray or basket W is conveyed to the next chamber. that time,
The transport roller 18 for the tray or basket W rises from the lower part. The transfer roller raising / lowering device 19 of the transport roller 18 projects downward. The quenching chamber 7 is housed in a pit in view of the transfer height of the tray or basket W, and the transition roller raising / lowering device 19 projects downward so that it must be a pit capable of maintenance and disassembly.

As shown in FIG. 2 (b), which is a partial sectional view taken along line bb of FIG. 2 (a), a plurality of upstream heat treatment chambers are provided.
Between the pedestal 13 supporting the 2, 3, 4, 5, 6 chambers and each pedestal 12, a guide 20 for guiding in the direction indicated by the arrow C orthogonal to the upstream direction indicated by the arrow B and a guide guided by the guide 20. A roller 21 is arranged to regulate the movement of each heat treatment chamber 2, 3, 4, 5, 6 in a direction indicated by an arrow C orthogonal to the upstream direction. As can be seen clearly in FIG. 3, which is a partially enlarged view of the portion surrounded by the one-dot chain line indicated by c in FIG. 2 (b), the shaft fixed to the pair of flanges 22 fixed to the lower surface of the pedestal 13 of the greenhouse 6
A roller 14 is rotatably supported by 23. Further, a guide roller 27 is rotatably supported by a shaft 24 fixed to a pair of plates 25 fixed to one of the flanges 22, and the guide roller 27 is guided by a guide surface 26 of a guide 20 fixed to the pedestal 12. The movement of the falling greenhouse 6 in the direction indicated by the arrow C is restricted.

[0011]

EFFECTS OF THE INVENTION With this configuration, a plurality of heat treatment chambers are provided.
Even when exposed to a high temperature such as 1000 ° C, each heat treatment chamber and connection portion absorbs a large thermal expansion applied via rollers between the pedestal and the pedestal supporting the heat treatment chamber, and does not undergo thermal deformation.
It has become a long-lived continuous vacuum carburizing furnace with no repair cost.

Preferably, a guide which guides in a direction orthogonal to the upstream direction and a guide roller which is guided by the guide are arranged between the lower parts of the plurality of heat treatment chambers and the pedestals.
Since the movement of each chamber in the direction orthogonal to the upstream direction is regulated and the movement of each heat treatment chamber in the direction orthogonal to the upstream direction is regulated, a plurality of upstream heat treatment chambers are orthogonal to the upstream direction. It became to prevent it from being transformed into.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing a thermal expansion absorber of a continuous vacuum carburizing furnace according to an embodiment of the present invention.

2 (a) is an enlarged partial sectional view of a lower part of the greenhouse in FIG. 1, and (b) is a partial sectional view taken along line bb of FIG. 2 (a).

FIG. 3 is a partially enlarged view of a portion surrounded by a chain line indicated by c in FIG. 2 (b).

FIG. 4 is a schematic side sectional view of a hearth roller type continuous furnace which is an undisclosed continuous vacuum carburizing furnace proposed by the applicant in Japanese Patent Application No. 2001-032184.

[Explanation of symbols]

2 ・ ・ Raising room (heat treatment room) 3, 4, 5 ・ ・
Carburizing diffusion room (heat treatment room) 6 ... falling greenhouse (heat treatment room) 7 ... quenching room (heat treatment room) 9 ... quenching room floor 10 ... pit 11 ... pit bottom 12 ... frame 14 ... roller 20 ・ ・ Guide 27 ・ ・ Guide roller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Murakami             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai (72) Inventor Sueo Takashima             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai (72) Inventor Yoshiyuki Iwakami             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai (72) Inventor Koichi Fukuda             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Akio Tamura             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 4K028 AA01 AB01 AC03 AC04                 4K034 AA18 CA05 GA18                 4K050 AA02 BA02 CA12 DA00

Claims (2)

[Claims] 1. A continuous vacuum carburizing furnace for iron alloy parts having a plurality of heat treatment chambers including a temperature raising chamber, a carburizing chamber and a diffusion chamber, or a carburizing diffusion chamber, a descending greenhouse, and a quenching chamber from upstream to downstream. Adjacent to the entrance floor surface, a pit is provided which can continuously accommodate all of the plurality of heat treatment chambers upstream of the quenching chamber, and a gantry is provided between the bottom surface of the pit and the lower portion of each of the upstream heat treatment chambers. A thermal expansion absorber for a continuous vacuum carburizing furnace, wherein a roller movable in an upstream direction is arranged between each of the lower parts of the chambers and each of the mounts. 2. A guide that guides in a direction orthogonal to the upstream direction and a guide roller that is guided by the guide are arranged between the lower part of each chamber and each gantry.
A thermal expansion absorber of the continuous vacuum carburizing furnace described.