JP5167640B2 - Heat treatment equipment - Google Patents

Description

  The present invention relates to a heat treatment facility that is a batch furnace, has good productivity, and can perform heat treatment such as carburizing and quenching of metals with various heat patterns.

In general, batch-type furnaces are inferior in productivity as compared with continuous furnaces. Therefore, in the heat treatment equipment shown in the following Patent Document 1 relating to the applicant's patent application, the batch furnace is processed by a transfer unit equipped with a heat insulation chamber. The product can be transported and the processed product can be delivered to the processing chamber. This makes it suitable for high-mix low-volume production and can achieve productivity or thermal efficiency equivalent to that of a continuous furnace while being a batch furnace. At the same time, it realized a heat treatment facility that had batch-type advantages, such as thinning operation and partial maintenance that were impossible with a continuous furnace.
JP 2006-63363 A

By the way, in order to improve the strength of the treated product as compared with the conventional carburized product, it is often necessary to have a two-step heating heat pattern that is once cooled after heating (carburizing) and then reheated. The conventional heat treatment equipment disclosed in Patent Document 1 has a problem in that it cannot respond to a request for heat treatment such as carburizing and quenching a metal with such various heat patterns.
If the two-stage heating pattern is to be executed intentionally in the heat treatment facility disclosed in Patent Document 1, the treated product must be submerged in a cooling oil tank, but if this is the case, the oil adhered to the treated product before reheating is performed. It is not practical because the processing efficiency becomes extremely poor.

In order to solve the above problems, the heat treatment equipment according to the present invention includes a plurality of batch heat treatment chambers arranged in parallel on one side of a linear rail, and each of the heat treatment chambers is provided with a heater for heating a processed product. The transfer unit forms a heat insulation chamber and a delivery chamber in a straight line with an airtight and heat insulating door between them, and supports the heat insulation chamber and the delivery chamber on the carriage so that it can run on the rail. provided, the receiving pass chamber provided delivery mechanism to pass by and between the heat insulation chamber of the previous SL thermal processing chamber treated products, forcing the heater and the cooling gas in-holding temperature chamber incubating the treated product gas cooling means for cooling is provided a treated product by circulating, move and stopped by entering the receiving pass chamber prior to any thermal processing chamber said transport unit The treated product is charged into the heat treatment chamber and the treated product is heated to a predetermined heat treatment temperature in the heat treatment chamber, and then the treated product is moved into the heat retaining chamber through the delivery chamber. The processed product is cooled to a required temperature in the heat retaining chamber by forced circulation of the cooling gas by the gas cooling means, and the processed product after cooling is charged into the heat treatment chamber again through the delivery chamber. It is characterized by being reheated .

  According to the heat treatment facility according to the present invention, the processed product can be efficiently heat-treated with various heat patterns.

  FIG. 1 is a plan view of a heat treatment facility according to an embodiment of the present invention. In the figure, 1 and 1 are two parallel rails arranged in a straight line, and 2a to 2c are batch-type heat treatment chambers in which one side of the rail is arranged with its opening facing the rail side, 3 is a transfer unit provided to run on the rail, 4 is a charging table arranged next to the heat treatment chamber 2a, and 5 is a cooling oil tank arranged next to the heat treatment chamber 2c. . FIG. 1 shows a state where the transfer unit 3 is stopped so as to face the heat treatment chamber 2b.

  As shown in the longitudinal sectional view of FIG. 2, the batch type heat treatment chambers 2a to 2c form a processing chamber 7 surrounded by a heat insulating material 6 in a pressure-resistant furnace shell formed in a cylindrical shape. The processing product W is placed on the gantry 8 provided in the, and 9 is an opening through which the processing product W is taken in and out of the processing chamber. The opening is provided with an airtight opening / closing door 10 in which a heat insulating material 6 is attached to the inner surface, and the opening / closing door is operated at the opening edge of the chamber by operating a cylinder 11 provided horizontally above the opening / closing door. The opening 9 can be opened and closed by laterally sliding along the inner surface of the flange 12 provided. Reference numeral 13 denotes a heater provided on the processing chamber wall for heating the processed product W, and reference numeral 14 denotes a fan provided in the processing chamber. The fan stirs the gas in the processing chamber by driving the motor 15. Reference numeral 16 denotes an air inlet formed to connect the heat treatment chambers 2a to 2c to a vacuum pump (not shown). By sucking air in the heat treatment chamber from the air inlet, the inside of the chamber (the processing chamber 7) is drawn. (Inside) is in a vacuum state (reduced pressure state). Reference numeral 17 denotes a gas supply port for supplying a carburizing gas such as acetylene into the chamber (inside the processing chamber 7). The gas supply port is connected to a gas source (not shown) of the carburizing gas by a pipe.

  On the other hand, as shown in the longitudinal sectional view of FIG. 3, the transport unit 3 linearly couples the heat retaining chamber 20 and the delivery chamber 21 with the flange 22 therebetween, and can run on the rails 1 and 1. By placing the roller 24 on the provided carriage 23 and supporting the heat retaining chamber 20 on the roller 23, the heat retaining chamber 20 and the delivery chamber 21 are slightly advanced and retracted in a direction perpendicular to the traveling direction of the carriage 23. Supports to be movable. Reference numeral 46 denotes a cylinder provided on the carriage in order to make the heat retaining chamber 20 and the delivery chamber 21 advance and retract minutely. 1 is a vacuum pump fixed on one side of the heat retaining chamber 20 of the transport unit 3, and 41a and 41b are vacuum exhaust valves which are electromagnetic valves provided on the intake pipe of the vacuum pump. It is.

  As shown in FIG. 4, the heat insulation chamber 20 forms a processing chamber 26 surrounded by a heat insulating material 25 in a pressure-resistant furnace shell formed in a cylindrical shape, and a processed product W is placed in the processing chamber. And a heater 28 for heat insulation are provided on the walls of the processing chamber, and vent holes 29 and 30 are formed on the upper and lower walls of the processing chamber 26, respectively. Cylinders 31 and 32 are provided at the vent holes, respectively. The heat insulating doors 33 and 34 are provided so that they can be opened and closed. A fan 44 is arranged to be rotated by a motor 45 provided at the upper part of the upper ventilation port 29 in order to forcibly circulate the gas in the furnace. Reference numeral 37 denotes a cooling water pipe provided on the vent hole 29 in order to prevent the fan 44 from overheating. Reference numerals 38 and 38 denote gas cooling means composed of a pair of heat exchangers disposed on both sides of the processing chamber 26, and the heat exchanger is kept at a low temperature by passing cooling water through the heat exchanger. Be drunk. Reference numeral 39 denotes an opening / closing door provided at the boundary with the delivery chamber 21, and the opening / closing door slides laterally along the inner surface of the flange 22 by operating a cylinder 40 provided horizontally at the upper portion. A heat insulating material 25 is also attached to the inner surface of the open / close door 39. For this reason, the heat insulation chamber 20 is kept airtight and heat-insulating with the delivery chamber 21 by closing the door 39. Reference numeral 42 denotes an intake port, which is connected to a vacuum exhaust valve 41a of the vacuum pump 41, and the inside of the heat retaining chamber can be decompressed by sucking gas from the intake port. Reference numeral 43 denotes a gas supply port formed for supplying an inert gas such as nitrogen gas into the heat retaining chamber. The gas supply port is connected to a gas source (not shown) via a flexible hose (not shown). ).

  The delivery chamber 21 has a substantially cylindrical shape and is pressure resistant. One end of the delivery chamber 21 is fixed to the outer surface of the flange 22 by a bolt 50, and the other end is fixed with a frame-like packing 51. When the delivery chamber 21 is moved forward together with the heat retaining chamber 20, as shown in FIG. 5, the frame-like packing 51 can be brought into airtight contact with the outer surface of the flange 12 provided in the openings of the heat treatment chambers 2a to 2c. I have to. Reference numeral 52 denotes a delivery mechanism provided at the inner bottom of the delivery chamber 21. As shown schematically in FIG. 6, the delivery mechanism has a fork 53 on which the processed product W can be placed on the horizontal slide members 54a and 54b. The fork 53 is moved back and forth in the heat treatment chambers 2a to 2c and the heat retaining chamber 20 by moving the horizontal slide member forward and backward by a drive source such as a motor, and the processed product W on the mounts 8 and 27 is supported. Can be transferred onto the fork 53. Also, 55 is an intake port formed to connect the delivery chamber 21 to the vacuum exhaust valve 41b of the vacuum pump 41, and 56 is formed to supply an inert gas such as nitrogen gas into the delivery chamber. At the gas supply port, the gas supply port is connected to an air supply source (not shown) via a flexible hose (not shown).

  The cooling oil tank 5 shown in FIG. 1 contains quenching cooling oil in a container, an opening having a flange 63 is formed on the front surface of the container facing the rails 1 and 1, and a cylinder is formed in the opening. A sliding door type door 60 that automatically opens and closes by actuating 65 is provided, an opening having a flange 64 is formed on the back surface thereof, and a sliding door type that automatically opens and closes by operating a cylinder 66 in the opening. The door 61 is provided.

  In the heat treatment equipment configured in this way, as shown in FIG. 7, for example, the processed product W is heated to 950 ° C., soaked, carburized and diffused, and then cooled to 100 ° C. to 650 ° C. Next, a procedure for heat-treating the processed product W in a two-step heating pattern in which the temperature of the processed product W is raised to 850 ° C., soaked, carburized and diffused, kept at 850 ° C., and then oil cooled will be described. First, the processed product W on the charging table 4 is carried into one of the batch heat treatment chambers 2 a to 2 c by the transport unit 3. For this purpose, the transport unit 3 runs on the rails 1 and 1 and stops in front of the loading table 4 and operates the delivery mechanism 52 to receive the processed product W on the loading table on the fork 53 and deliver it. Place in chamber 21. Then, the transfer unit 3 is moved and stopped before any one of the heat treatment chambers, and the cylinder 46 is operated to press the frame packing 51 of the delivery chamber 21 against the outer surface of the flange 12 of the heat treatment chamber, and then the vacuum exhaust valve 41b is opened and the inside of the delivery chamber 21 is evacuated by the vacuum pump 41. After completion of evacuation, the heat treatment chamber opening / closing door 10 is opened, and the fork 53 is advanced to load the processed product W into the heat treatment chamber.

  The heat treatment chamber is preheated to about 850 ° C. to 950 ° C., and after the processing product W is charged, the temperature raising process of the processing product W is continuously performed. At this time, for the purpose of shortening the rate of temperature rise particularly in a low temperature region of 650 ° C. or less, nitrogen gas may be introduced to about atmospheric pressure and radiation heating and convection heating may be used in combination. Once the processed product W has been raised to the carburizing temperature (here, 950 ° C.), the nitrogen gas in the heat treatment chamber is once evacuated again, and then a predetermined amount of the carburizing gas is introduced to perform the carburizing / diffusion process. . The carburizing gas is introduced intermittently according to preset conditions. In the meantime, the heat retaining chamber 20 and the delivery chamber 21 are waiting to receive the processed product W while the vacuum exhaust valves 41a and 41b are opened and the vacuum pump 41 is evacuated. After the carburizing / diffusion process is completed, the doors 10 and 39 are opened, the fork 53 of the delivery mechanism 52 is advanced into the heat treatment chamber, the processed product W is received on the fork, and the fork 53 is retracted to directly The fork 53 is advanced into the heat insulation chamber 20, and the processed product W taken out from the heat treatment chamber is placed on the gantry 27 in the heat insulation chamber. Then, after opening and closing the doors 10 and 39 and further closing the vacuum exhaust valve 41a, nitrogen gas is introduced from the gas supply port 43, the inside of the heat retaining chamber 20 is pressurized to a predetermined pressure, and the heat as gas cooling means The cooling water is passed through the exchanger 38, and the fan 44 is rotated so that the gas in the heat retaining chamber 20 passes through the ventilation openings 29 and 30 and the heat exchangers 38 and 38 and the processed product as indicated by arrows in FIG. The processed product W is gas-cooled by forced circulation to W. Thereby, the processed product W is cooled to a required temperature of 100 ° C. to 650 ° C.

  After the cooling, the processed product W is inserted into the heat treatment chambers 2a to 2c again through the delivery chamber 21, reheated in the heat treatment chamber, heated to 850 ° C. and soaked, and then the carburized gas is introduced. Then, the second carburizing / diffusion process is performed. During this time, the heat retaining chamber is preheated to 850 ° C. by energizing the heater 28, and is waiting to receive the processed product W again. After completion of the carburizing / processing step, the processed product W is again transported from the heat treatment chamber to the heat retaining chamber by the same procedure as the previous time, and is maintained at 850 ° C. in the heat retaining chamber. After moving and stopping in front of the cooling oil tank 5 from the heat treatment chamber and operating the cylinder 46, the frame packing 51 of the delivery chamber 21 is brought into pressure contact with the outer surface of the flange 63 of the cooling oil tank 5, and then the vacuum exhaust valve 41b is set. The delivery chamber 21 is once evacuated by the vacuum pump 41, and then the evacuation valve 41 is closed, the supply gas port 56 is opened and nitrogen gas is introduced, and the delivery chamber 21 is filled with atmospheric nitrogen gas. To be filled with. After a predetermined holding time has elapsed, the vacuum exhaust valve 41a is closed, the gas supply port 43 is opened, nitrogen gas is introduced, the interior of the heat retaining chamber 20 is filled with nitrogen gas at atmospheric pressure, and the open / close doors 60 and 39 are opened. Then, the fork 53 of the delivery mechanism 52 is advanced into the heat insulation chamber 20 to receive the processed product W, and the fork 53 is advanced to advance into the cooling oil tank 5 as it is. The taken out processed product W is placed on a frame in the cooling oil tank 5. By closing the open / close doors 60 and 39 and lowering the frame in the cooling oil tank 5 in the oil tank, the processed product W is immersed in the quenching oil, and a quenching process is performed. The processed product W that has been subjected to the series of heat treatments in this way is extracted by opening the door 61 provided on the back surface of the cooling oil tank 5.

  The transport unit 3 is moved while the processed product W is being cooled in the heat retaining chamber 20, and the next processed product W prepared on the charging table 4 is charged into the empty heat treatment chambers 2 a to 2 c. In addition, the processed product W that has been reheated in the heat treatment chambers 2 a to 2 c can be taken out of the heat treatment chamber and transferred to the cooling oil tank 5. For this reason, although the heat treatment equipment of the present invention is a batch type, the processed product W can be efficiently heat-treated from one to the next, and high productivity can be maintained.

  In addition, in the present invention, the opening chamber of the delivery chamber 21 is supported by supporting the heat retaining chamber 20 and the delivery chamber 21 of the transport unit 3 on the carriage 23 so that they can be moved forward and backward in a direction perpendicular to the traveling direction. Can be brought into close contact with the openings of the batch-type heat treatment chambers 2a to 2c, and the heat insulation chamber 20 is provided with a gas cooling means, so that the processed product W can be removed from the heat treatment chamber without being exposed to external air. Since the processed product W can be gas-cooled by moving it to 20 and forcibly circulating the cooling gas, various processed products depend on the characteristics of the metal as in the two-stage heating shown in this embodiment. It is possible to meet the demand for heat treatment by a heat pattern.

  In this embodiment, three heat treatment chambers 2a to 2c are provided on one side of the rail. However, the number of heat treatment chambers can be increased or decreased according to the demand for production capacity. Further, two or more transport units 3 may be run on the rail. The delivery mechanism 52 is configured to move the fork 53 forward and backward in this embodiment, but the delivery mechanism is not limited to such a configuration, and may be a roller type or other mechanism.

The top view of the heat processing equipment which shows embodiment of this invention. The longitudinal cross-sectional view of the batch type heat processing chamber of FIG. FIG. 2 is a longitudinal sectional view of the transport unit in FIG. 1. AA line sectional view of Drawing 3. FIG. 3 is a sectional view taken along line BB in FIG. 1. The schematic diagram of the delivery mechanism which shows the embodiment of the present invention. The heat pattern figure of the processed goods by the heat processing equipment of this invention.

Explanation of symbols

W treated product 1 Rail 2a to 2c Batch type heat treatment chamber 3 Transfer unit 4 Loading table 5 Cooling oil tank 9 Opening portion 10 Opening / closing door 13 Heater 16 Intake port 17 Gas supply port 20 Heat insulation chamber 21 Delivery chamber 23 Cart 24 Roller roller 28 Heater 29 , 30 Ventilation port 38 Gas cooling means (heat exchanger)
39 Opening / closing door 41 Vacuum pump 42 Intake port 43 Gas supply port 44 Fan 52 Delivery mechanism 55 Intake port 56 Gas supply port

Claims (1)

A plurality of batch-type heat treatment chambers are arranged in parallel on one side of the straight rail, each of the heat treatment chambers is provided with a heater for heating a processed product, and the transfer unit is provided with an airtight and heat insulating door. linearly and-holding temperature chamber and delivery chamber so as to form provided to be run on said rails by supported on the dolly, the receiving pass chamber processing products pre Symbol heat and insulation chamber and delivery chamber Te A delivery mechanism for delivering to and from the processing chamber is provided, and a heater for keeping the processed product and a gas cooling means for cooling the processed product by forcibly circulating the cooling gas are provided in the insulated chamber. are, formulation either the treated product to move and stopped by placed into receiving pass chamber prior to the heat treatment chamber the transport unit was charged into the heat treatment chamber After the product is heated to a predetermined heat treatment temperature in the heat treatment chamber, the treated product is moved into the heat insulation chamber through the delivery chamber, and in the heat insulation chamber by forced circulation of the cooling gas by the gas cooling means. A heat treatment facility characterized in that the treated product is cooled to a required temperature, and the treated product that has been cooled is reheated by being inserted into the heat treatment chamber again through the delivery chamber .

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