JP3490791B2 - Multi-chamber heat treatment furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for heat treating a processed member.

[0002]

2. Description of the Related Art When carburizing and quenching steel-worked members, a series of steps such as pre-cleaning, carburizing, oil-quenching, post-cleaning, and tempering are performed. When vacuum quenching a mold member or the like, gas cooling is performed subsequent to vacuum heating. When sintering powder metallurgical members such as metals and ceramics,
A series of steps including binder burn-off, heating, slow cooling, and cooling are performed. In carrying out these series of steps,
As the heat treatment equipment that has been conventionally used, each batch type processing device for carrying out each step or two steps is independently arranged, or each processing chamber is continuously operated to carry out a series of these steps. There is continuous processing equipment connected in series.

A batch type carburizing and quenching furnace is provided with a front chamber and a heating chamber, and a quenching oil tank provided with an elevating means at the lower part of the front chamber, and the temperature of the carburized and diffused treated member is lowered to the quenching temperature. Then, after being soaked and maintained in the heating chamber for a predetermined time, it is carried out to the previous chamber and immediately oil-quenched. After the oil-cooled member to be processed is lifted up by the elevating means above the quenching oil tank and drained in the front chamber,
It is carried out of the equipment. Then the member to be processed is additionally washed removed is loaded into the installed washed flight quenching oil, are transported after being dried, is being input to the separately installed tempering furnace, where it undergoes a tempering treatment.

The single-chamber vacuum quenching furnace is equipped with a heating mechanism and a gas cooling device in the single chamber, and members heated at a quenching temperature for a predetermined time immediately cool the gas in the same chamber.

In the case of batch sintering equipment, there are one in which all steps from burn-off to sintering and cooling are performed in the same chamber, and one in which a burn-off furnace and a sintering furnace are separately installed. In the latter case, the member to be processed enters the cooling process in the same chamber immediately after the completion of the sintering process. Unlike the above two examples, the cooling rate after sintering does not depend on the characteristics of the object to be processed, so that it is not usually a problem.

In the case of continuous processing equipment, each process is assigned to a different processing room or processing area and a passing time or a staying time of each room, and like a batch processing type equipment, a plurality of processes are performed in the same processing room. The process is never performed.

[0007]

In the case of the conventional batch type carburizing and quenching furnace, it is necessary to increase the number of furnaces installed in order to increase the throughput, but the number of quenching oil tanks also automatically increases. However, the time required for oil quenching / oil removal is usually significantly shorter than the time for carburizing / diffusion / soaking. In other words, the utilization efficiency of the quenching oil tank is extremely low. Therefore, it was a facility with poor investment efficiency. The same applies to the transport mechanism related to the antechamber, the lifting means, the gas pipe, the exhaust pipe, the exhaust system such as the vacuum pump, the control valve such as the solenoid valve, and the measuring device such as the pressure gauge. In addition, since loading and unloading between a plurality of batch devices is performed by a track trolley that travels in front of each device, not only equipment cost but also a large installation area, it is dangerous if an operator neglects to pay attention to traveling of the trolley,
There was a problem such as.

In the case of a conventional single-chamber vacuum quenching furnace, two means having mutually opposite functions, that is, a heating and sealing heat insulating means composed of a heater and a heat insulating material, a gas introduction pipe, a fan, and a gas cooler are provided in the same chamber. It was necessary to have a third means for accommodating the circulating cooling means and for switching both functions depending on the process. For this reason, the internal structure of the device becomes complicated, the size of the device becomes large, and the cost must be increased. In addition, when increasing the production volume with this device, the number of installed units will be increased, but considering that the heating time is longer than the gas cooling time for quenching, the circulation cooling means and the switching means are changed for the same reason as above. There was a problem of low utilization efficiency. Furthermore, during cooling, not only the member to be treated but also the heat insulating means are cooled at the same time, so in order to achieve the constant cooling rate required by the object to be treated, it is necessary to employ a cooling means with a large capacity. Not only that, but in the heat treatment of the next batch, it was necessary to compensate the heat storage loss of the heat insulating member due to cooling, and extra energy was required.

In the case of a single-chamber sintering furnace, the binder atmosphere and the forming lubricant volatilized from the powder metallurgy member at the time of burn-off do not contaminate the furnace members such as the high temperature sintering member and the heat insulating material in the furnace atmosphere. A special configuration that takes into consideration the flow and exhaust path is required, which is one of the factors contributing to the high device cost. Nevertheless, in particular because the contamination of the furnace material at a low temperature portion can not be avoided, have to devolatilization to baking to contaminate the equipment at a high temperature for each or every certain number of uses certain period in between operating there were. Therefore, there is a problem that productivity is not increased and extra energy is required.

In order to solve the above-mentioned problem of including components and functions with low utilization efficiency, which becomes apparent when a plurality of batch furnaces or single-chamber furnaces are operated, a continuous processing facility is considered. Was given. That is, in the continuous processing apparatus, the capacity and residence time of each series of processing chambers are designed according to the preset processing amount. Therefore, it does not include components and functions with low utilization efficiency such as batch furnaces and single chamber furnaces. Utilization efficiency is 100% in all parts during steady operation. further,
Each treatment chamber or treatment area may have a configuration capable of exhibiting a necessary and sufficient action for each treatment, such as a batch furnace or a single-chamber furnace, in which two different functions that do not act at the same time coexist. Since there is no need to take the cost, it is possible to design without waste.

However, the continuous processing apparatus has the following problems. If the throughput is reduced from the original plan, that is, the equipment design standard, the equipment utilization rate decreases linearly after the last charging of the processed products, and becomes zero when the processing of the final processed products is completed. become, therefore thereafter ing that operation of the apparatus is temporarily stopped. Next, in order to restart the operation of the device again, in order to achieve a long-term continuous operation with high utilization efficiency,
A stockpile of the products to be processed is required, thus causing a considerable waiting time, that is, a device downtime. Therefore, in such a production situation, the utilization efficiency of the continuous processing apparatus, which should have been high originally, becomes conspicuously low as compared with the case of the batch furnace or the single chamber furnace. Therefore, the continuous processing device is not suitable for small-lot production of a wide variety of products, which is difficult to collect and has many kinds of objects to be processed.

The present invention has been made in order to solve the above-mentioned drawbacks of the conventional apparatus, and an object thereof is a heat treatment suitable for high-mix low-volume production with high utilization efficiency of the apparatus constituent parts. To provide a furnace.

[0013]

The heat treatment furnace of the present invention includes a plurality of processing chambers, a vacuum purging front chamber for loading and unloading objects to be processed, and a rotatable vertical axis. And a main transfer chamber accommodating main transfer means for transferring an object to be processed between the processing chamber and the front chamber, the plurality of processing chambers and front chambers being perpendicular to the main transfer chamber. coaxial with the axis of rotation of the same cylindrical surface in the circumferential contact as disposed access port to replaceable in parallel connected arranged Then Tomo
In addition, in the main transfer chamber, between the cooling unit and the cooling unit to be processed
The multi-chamber heat treatment furnace is characterized in that a means for raising and lowering an object is added .

[0014]

[0015] invention of claim 2 is characterized in the provision of the pushing mechanism of the workpiece to the main transport chamber prior Symbol treatment chamber.

Further, in the main transport chamber, and a cooling unit, footprint becomes in <br/> of are added and means for raising and lowering the object to be processed, it enables 3-dimensional arrangement between the cooling unit Can be saved.
In addition, it is possible to quickly transfer the object to be processed between the processing chamber and the cooling chamber.

According to the second aspect of the present invention, the object to be processed is extruded directly onto the elevating means of the main transfer chamber by the extruding mechanism provided in the processing chamber, so that the object to be processed can be quickly transferred.

[0018]

Embodiments of the present invention will now be described with reference to the drawings.

[0019]

[Embodiment 1] FIG. 1 shows a plane arrangement of a multi-chamber heat treatment furnace of the present invention, which is configured for vacuum sintering.
The object to be processed is taken in and out from the vacuum purge chamber (1). Then, after vacuum purging and restoring the pressure with nitrogen gas, they are transferred into the main transfer chamber (2). The main transfer means (3) of the main transfer chamber (2) is rotatable in a horizontal plane and can be stopped at a position facing any of the surrounding chambers. A fork type that can be carried into another chamber is preferable. Further, each chamber and the main transfer chamber are separated by a door (not shown) so that the door is opened only when it is necessary to transfer the object to be processed. The object transferred into the main transfer chamber (2) is transferred to the main transfer chamber (2) in the order of the burn-off chamber (4), the first vacuum sintering chamber (5) and the cooling chamber (7). After completing the first predetermined process consisting of dewaxing, vacuum sintering, and cooling, when returning to the main transfer chamber (2) again, finally it passes through the vacuum purge chamber (1). Then, it is carried out of the furnace. Usually, cooling is performed by a combination of natural cooling and gas cooling, but it is not limited to this.

Similarly, the second object to be treated is carried in, the burn-off chamber (4), the second vacuum sintering chamber (6), and the cooling chamber (7).
In that order, after passing through the main transfer chamber (2) and completing the second predetermined process, the second transfer process is carried out through the main transfer chamber (2) and the vacuum purge chamber (1) to the outside of the furnace. Similarly, the third, fourth, ... Processing objects are processed. In this example, two vacuum sintering chambers (5) for relatively long process time sintering
A vacuum purge chamber (1), a burn-off chamber (4), and a cooling chamber (7) are provided for each of (6) to balance the process capability. The combination can be set freely. The main transfer chamber (2) and the main transfer means (3) are shared by the above-mentioned five chambers to further improve the utilization efficiency. Further, depending on the case, the number of rooms can be reduced. As described above, the first and second objects to be processed do not always receive the same processing. Furthermore, for example, the first vacuum sintering chamber (5) may be operated with temporally changing parameters. The same applies to the other rooms. Unlike in the case of a continuous furnace, since the processing chambers are arranged in parallel, the degree of freedom in changing the processing conditions is high even when performing a series of processing continuously.

[0021]

Embodiment 2 FIG. 2 shows the main transfer chamber (2) of the multi-chamber heat treatment furnace of the present invention, the main transfer means (3), the quenching chamber (8) above the main transfer chamber (2), and the first transfer chamber. It is an elevation view which shows the structure which arranged the raising / lowering means (9). The first object to be processed is sintered in the first vacuum sintering chamber (5) and then transferred to the first elevating means (9) waiting in advance in the main transfer chamber (2) and immediately quenched. The chamber (8) is lifted and cooling is started. During the cooling of the first object to be processed, the vacuum sintering chamber (5) transfers the second object to be processed in the burn-off chamber (4) through the main transfer chamber (2) to the main transfer means (2). Receive from 3) and start a new sintering process. The same applies to the second vacuum sintering chamber (6). The cooling chamber (7) can be replaced with another processing chamber, or can be left as it is and used as two independent cooling chambers. On arrangement, quench chamber (8) is suitable for gas cooling especially. Of course, the quenching chamber (8) may be replaced with a normal cooling chamber.

[0022]

[Embodiment 3] FIG. 3 shows a planar arrangement of a multi-chamber heat treatment furnace of the present invention for carburizing and quenching. It includes a vacuum purge chamber (1), a main transfer chamber (2), and a main transfer means. (3), first carburizing and quenching chamber (10), second carburizing and quenching chamber (11), cleaning chamber (14), and tempering chamber (1
5) is shown. In addition, FIG. 4 shows the same configuration example.
Main transfer means (3), main transfer chamber (2) in main transfer chamber (2)
FIG. 3 is an elevational view showing a configuration in which a quenching oil tank (12) and a second elevating means (13) are arranged in the lower part of the. The object to be processed is transferred to the main transfer chamber (2) through the vacuum purge chamber (1), and then the first carburizing and quenching chamber (10) or the second carburizing and quenching chamber (11) and the quenching oil tank (12). , Main transfer chamber (2), cleaning chamber (14), tempering chamber (15) in order, carburizing / diffusion / soaking, oil quenching, oil removal, degreasing cleaning,
After a series of steps consisting of tempering is finished, finally it is carried out to the outside again via the vacuum purge chamber (1).

Now, returning to the description of the operation during quenching,
Carburized and diffused in the first carburizing and quenching chamber (10),
Next, the first object to be treated, which has been kept at the quenching temperature for a predetermined time, is the second elevating means (1) waiting in advance in the main transfer chamber.
3) It is conveyed to the upper side and immediately lowered into the quenching oil tank (12) for oil quenching. At this time, an extruding mechanism (not shown) provided in the carburizing and quenching chamber (10) is used to quickly convey the object to be processed to the main transport chamber (2). Quenching in oil needs to be carried out quickly, but if this is done by the main transport means (3), it is necessary to move the object to be carburized and quenched into the carburizing and quenching chamber (10), which is more difficult than the extrusion mechanism. This is because it takes extra time. During the oil quenching of the first object to be processed, the first carburizing and quenching chamber (10) waits for the second object to be processed in the vacuum purge chamber (1) via the main transfer chamber (2). Received from the main transport means (3), a new carburizing and quenching process is started. The same applies to the second carburizing and quenching chamber (11). This configuration is particularly suitable for rapid quenching in oil and quenching in water. In some cases, injection quenching with water or oil may be performed. In that case, a liquid injection quenching chamber (not shown) may be used instead of the quenching oil tank (12) below the main transfer chamber (2).

For the above reason, in the case of this example,
The main transfer means (3) does not necessarily have to be of the fork type, but rather has a push-out mechanism, and the carburizing and quenching chamber (10)
Not only (11) but also cleaning room (14) and tempering room (15)
It goes without saying that the vacuum purge chamber (1) and the vacuum purge chamber (1) may each be provided with an extrusion mechanism. The above is the case of the carburizing and quenching furnace, but the same applies to the case of the vacuum gas cooling quenching furnace. That is, although not shown, the object to be treated that has been uniformly heated to the quenching temperature in the vacuum heating chamber is quickly transferred to the first elevating means of the main transfer chamber by the extrusion mechanism provided in the vacuum heating chamber, It is pushed up to the quenching room and immediately gas cooled and quenched. The quenching gas quenching chamber is not limited to the upper part of the main transfer chamber, but lower parts or upper and lower parts may be provided separately.

Next, based on a carburizing furnace having an effective size in the furnace of 24 inches width × 36 inches depth × 24 inches height, the floor space occupied by the furnace of the present embodiment is equivalent to that of a conventional batch furnace. Compare with the one in line. In the case of the conventional batch furnace line, the occupied floor area is 84 square meters, whereas in the configuration of this embodiment, it is 41 square meters. That is, in the case of this configuration, it is possible to install equipment having a capacity of two lines of the conventional batch furnace in the same floor area.

[0026]

[Embodiment 4] FIG. 5 shows a plane arrangement when two units A and B are connected, as one example of an extension of the multi-chamber heat treatment furnace of the present invention. That is, A and B are connected to each other by a connecting chamber (16), and each of A and B has a vacuum purge chamber (1). In this configuration, for example, the vacuum purge chamber (1) of A is used as the inlet of the object to be processed and that of B is used as the outlet, and the arrangement of each processing chamber
It is possible to aim for so-called sequential use, in which a series of processing is completed while moving from B to B. It is also possible to simply make the arrangement of the processing chambers equal to A and B and simply aim for parallel use. The point to be noted here is that even in the case of a strong sequential arrangement,
Since it is parallel in each A and B, it is possible to operate with a much higher degree of freedom than the conventional continuous furnace.
On the contrary, even in the case where the parallelism is strong, A, B
Compared to the case of operating independently without connecting
Therefore, as compared with the conventional multiple batch furnaces, the degree of freedom in processing is greatly increased. As a result, processing can be performed with more combinations, and the utilization efficiency of the entire device can be further increased. Although not shown, if the number of connections is increased, the layout can be linear, annular, mesh-like, or any shape.

Here, the connection chamber (16) is optionally thermally insulated. For example, heat insulation is necessary when the object to be processed heated to a high temperature is transported between AB. Also, the number and position of the entrances and exits can be freely selected. For example, instead of one vacuum purging chamber (1) in each of FIGS. 5A and 5B, a suitable processing chamber is installed, and instead of the connecting chamber (16), one long side face and two other side faces are provided. Another type of vacuum purge chamber with doors that can be opened on each side (not shown)
By arranging, the object to be processed can be exchanged with the outside world through one long side door.

[0028]

EFFECTS OF THE INVENTION According to the present invention, it is possible to realize a safe and clean heat treatment furnace which has a lower equipment cost, higher utilization efficiency, a smaller occupied floor area, and a load fluctuation of the object to be treated. It is possible to provide a heat treatment furnace which can be flexibly dealt with and which is particularly suitable for high-mix low-volume production. In addition, the processing chambers can be combined and connected freely, and the optimum equipment configuration according to the purpose can be achieved.

Further , the object to be treated is provided between the cooling section and the cooling section.
Means for raising and lowering the
Therefore, not only the occupied floor area can be further saved, but also rapid quenching becomes possible.

According to the second aspect of the present invention, rapid transportation is possible, and quenching is further ensured.

[0031]

[Brief description of drawings]

FIG. 1 is a plan layout view showing a first embodiment of the present invention.

FIG. 2 is an elevational view showing a second embodiment of the present invention.

FIG. 3 is a plan layout view showing a third embodiment of the present invention.

FIG. 4 is an elevational view of an essential part of a third embodiment of the present invention.

FIG. 5 is a plan layout view showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 Vacuum purge chamber 2 Main transport room 3 Main transport means 4 Burn-off room 5 First vacuum sintering chamber 6 Second vacuum sintering chamber 7 Cooling chamber 8 quenching room 9 First lifting means 10 First carburizing and quenching room 11 Second carburizing and quenching room 12 Quenching oil tank 13 Second lifting means 14 Washing room 15 Tempering room 16 connecting rooms

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Maeda, 229 Kahata-cho, Tenri-shi, Nara Koyo Lindbergh Co., Ltd. (56) Reference JP-A-6-244124 (JP, A) (58) (Int.Cl. ⁷ , DB name) F27B 5/02 F27B 5/04 F27B 5/12

Claims (2)

(57) [Claims] 1. A plurality of processing chambers, an antechamber capable of vacuum purging for loading and unloading an object to be treated, and a processing chamber or anterior chamber rotatable about a vertical axis. Including a main transfer chamber containing a main transfer means for transferring the processed material,
Said plurality of processing chambers and the front chamber, the relative vertical shaft and connecting port disposed in contact circumference on the same cylindrical surface coaxial to replaceable in parallel connected respectively disposed with respect to the main carrier chamber Along with the main transfer chamber, a cooling unit and a cooling unit
A multi-chamber heat treatment furnace, characterized in that a means for raising and lowering an object to be processed is added between the heat treatment furnace and the heat treatment furnace. 2. A multi-chamber heat treatment furnace according to claim 1, characterized in that a pushing mechanism of the workpiece to the main transport chamber to the process chamber.