JP3197270B2 - Oxygen-free forging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a forging product manufacturing line, which performs forging in a forging room in the manufacturing line, heat treatment in a heat treatment room, and conveyance by each conveying means. The present invention relates to an oxygen-free forging apparatus that can be all performed under a nitrogen gas atmosphere and can eliminate generation of defective products due to rust.

[Conventional technology]

Conventionally, forged products are manufactured by a manufacturing line as shown in FIG. This production line includes a material supply device 31 having a belt conveyor, a conveying means 32 having a roller conveyor, an induction heating furnace 33, a forging chamber 34, a forging machine (not shown),
Processed product transfer means 35 such as forklift, roller conveyor 3
A forged product 2 is manufactured in the following manner, including a heat treatment chamber 37 provided with 6 and a shot blast chamber 38.
That is, the material 1 is conveyed to the front of the induction heating furnace 32 by the belt conveyor of the material supply device 31 and transferred to the roller conveyor of the conveyance device 32, and thereafter, is carried into the induction heating furnace 33 by the roller conveyor and heated. After that, forging room 34
Transported to The material 1 is forged in the forging chamber 34 and is taken out of the forging chamber 35 as a forged product 2 after processing. The forged product 2 taken out is conveyed to the front of the heat treatment chamber 37 by a forklift 35 or the like, transferred to the roller conveyor 36, and then carried into the heat treatment chamber 37 for heat treatment (annealing, normalizing). ) Is done. In such a production line, heating in the induction heating furnace 33 is performed in a nitrogen gas atmosphere,
Forging and heat treatment are performed in the air because it is not necessary to use a nitrogen gas atmosphere. Then, as a final stage of the production line, the forged product 2 annealed and normalized in the heat treatment chamber 37 is carried into the shot blast chamber 38, and the forged product 2 is set in the shot blast chamber 38. On the surface, rust formed before or forging is removed.

[Problems to be solved by the invention]

However, when a forged product is manufactured by the above-described manufacturing line, the material 1 is transported by the transport means 32 in the atmosphere, and the forging chamber 34 is in an atmospheric atmosphere. As described above, the material 1 is partially rusted during the transportation and while waiting for forging in the forging chamber 34, and the material 1 is forged in a state where the rust remains. Further, even after the forging, the forged product 2 is transported by the forklift 35 or the like, and annealing in the heat treatment chamber 37 is performed.
Since the normalization is performed in the atmosphere, the forged product is thinly rusted during the above-mentioned transportation and during annealing and normalizing in the heat treatment chamber 37. For this reason, on the surface of the forged product, the rusted portion appears in a convex pattern due to the forging of the above partially rusted portion, and rust floats as a whole due to rust after forging. I have. In order to flatten the surface of the forged product 2 by removing such a convex pattern due to rust and rust on the entire surface,
A shot blast chamber 38 is provided following the heat treatment chamber 37 for heat-treating the forged product 2. However, by removing rust in the shot blast chamber 38, rust generated after forging can be removed, but rust in a convex pattern generated in the forging process cannot be removed. That is, this rust is partially or entirely embedded in the interior due to the impact during forging, and cannot be completely removed by a shot blast. Therefore, in reality, a considerably defective product is produced due to the presence of the convex rust. Further, in the above-described method, it is necessary to provide the shot blasting chamber 38 following the heat treatment chamber 37 as described above, so that the production line becomes longer and the equipment cost increases.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide an oxygen-free forging apparatus capable of reducing defective products due to rusting, shortening the entire production line, and reducing equipment costs.

[Means for solving the problem]

In order to achieve the above object, the oxygen-free forging apparatus of the present invention includes a heating furnace for heating a material under a nitrogen gas atmosphere, a conveyance unit for conveying the material heated from the heating furnace to a forging chamber, and a conveyance unit. A forging machine having a forging machine for forging a forged material, a heat treatment chamber for heat-treating the forged product, and a forging device provided with a workpiece conveying means for conveying the forged product from the forging chamber to the heat treatment chamber, wherein the conveying means And a sealing means for sealing the workpiece transfer means and the heat treatment chamber, a nitrogen gas supply means for setting the sealed space by the sealing means to a nitrogen gas atmosphere, and a forging die in the forging chamber of the following (A) or (B): A cooling liquid supply pipe for spraying a cooling liquid is provided.

(A) A cooling liquid composed of a liquefied gas mixture of nitrogen, argon and carbonic acid.

(B) A cooling liquid composed of liquefied carbon dioxide.

[Action]

That is, the oxygen-free forging apparatus of the present invention includes a means for setting a transfer path for transferring a material heated under a nitrogen gas atmosphere in a heating furnace to a nitrogen gas atmosphere, and a method for transferring nitrogen, argon, and carbon dioxide to a forging mold in a forging chamber. Since a cooling liquid supply pipe for spraying a cooling liquid composed of a mixed liquefied gas or a cooling liquid composed of liquefied carbonic acid is provided, by spraying the cooling liquid on the forging die, a mixed gas of nitrogen, argon and carbonic acid is formed in the forging chamber. Since the atmosphere or carbon dioxide atmosphere can be used, the material does not rust before forging. In addition, since a means for setting the conveying path of the forged product to a nitrogen gas atmosphere and a means for setting the heat treatment chamber to a nitrogen gas atmosphere are provided, the forged product does not rust even after forging.

Next, the present invention will be described in detail based on embodiments.

〔Example〕

FIG. 1 shows a production line according to an embodiment of the present invention. Reference numeral 1 denotes a prepared iron-based material. The material 1 is conveyed by a belt conveyor of a material supply device 3 and further transferred onto a heat-resistant roller conveyor of a conveyance device 4 to be preheated by a preheating furnace 5 and a first connection chamber 6. , An induction heating furnace 7, a second connection chamber 8, a forging chamber 9, a third connection chamber 11, and a heat treatment furnace 12 are sequentially transferred. The preheating furnace 5, the first connection chamber 6, the induction heating furnace 7, the second connection chamber 8, the forging chamber 9, the third connection chamber 11, and the heat treatment furnace 12 communicate with each other in series in a substantially sealed state. It is formed in a nitrogen gas atmosphere. In order to form this nitrogen gas atmosphere, the preheating furnace 5 is sealed from the outside with a dome-shaped furnace material (a curtain is provided at the entrance), and the first connection chamber 6 is formed from a metal dome and the inside is sealed. Have been. Further, the induction heating furnace 7, the forging chamber 9, and the heat treatment furnace 12 are also sealed with a dome-shaped furnace material, and the second connection chamber 8 and the third connection chamber 11 are also made of a metal dome similarly to the first connection chamber. Is sealed. Each of them is provided with a nitrogen gas supply device 5a, 6a, 7a, 8a, 9a, 11a, 12a, and each nitrogen gas supply device 5a, 6a, 7a, 8a, 9a, 11a, 12a has the same nitrogen gas supply device. It is connected to a gas supply tank (not shown). Each of the connection chambers 6, 8, and 11 is equipped with a heat-resistant roller conveyor. More specifically, during the transportation, the material 1 is first placed in a preheating furnace 5 (nitrogen gas atmosphere).
Preheating at a temperature of 500 to 900 ° C. for 10 minutes, and an induction heating furnace
(Nitrogen gas atmosphere) and heated at 1200 ° C. for 2-3 minutes. The heated material 1 is carried into the forging chamber 9 via the second connection chamber 8 in which the inside is in a nitrogen gas atmosphere. As shown in FIG. 2, the forging chamber 9 is also formed in a nitrogen gas atmosphere by nitrogen gas supplied from a nozzle 18 of a nitrogen gas supply device 9a attached to the ceiling.
In addition, in order to enable all operations in the forging chamber 9 to be controlled from the outside, a first manipulator 15 and a second manipulator 17 that can be controlled from the outside are provided in the forging chamber 9 in addition to the forging machine 13. ing. That is, the material 1 transferred from the second connection chamber 8 by the roller conveyor of the transfer device 4
From the entrance 9a opened in the wall of the forging chamber 9, the cover 9b swingably attached to the entrance 9a is pushed away to enter the forging chamber 9, and is fed onto the heat-resistant roller conveyor 14. The fed material 1 has a high temperature of 900 to 1000 ° C., is transferred from the roller conveyor 14 to the forging machine 13 by the first manipulator 15, and is forged by the upper die 16 a and the lower die 16 b of the forging machine 13. Thus, a forged product 2 is formed. Upper die 16 heated by forging
For a, cooling is performed by spraying a cooling liquid (water) from a cooling liquid supply pipe (not shown). In this case, since the room is in a nitrogen gas atmosphere, rusting caused by spraying water is prevented. The forged product 2 thus formed is transferred onto the heat-resistant roller conveyor of the workpiece transfer device 10 by the second manipulator 17, and from the outlet 9 c opened in the wall of the forging chamber 9, the outlet 9 c The cover 9d, which is swingably attached, is pushed away and is conveyed to the third connection chamber 11. The third connection chamber 11 is also formed in a nitrogen gas atmosphere by the nitrogen gas supply device 11a. The forged product 2 is in the third connection room 11
Via the heat treatment furnace (heat treatment room) 12.
As shown in FIG. 3, the heat treatment furnace 12 is divided into an annealing furnace 26 and a normalizing furnace 27 by a partition wall 12g. The annealing furnace 26 has a burner 19 and a first nozzle of a nitrogen gas supply device 12a. 21 and a nozzle 23a of the titanium gas supply device 23 are provided. The normalizing furnace 27 is provided with a burner 20 and a second nozzle 22 of the nitrogen gas supply device 12a. The annealing furnace 26 and the normalizing furnace 27 are formed in a nitrogen gas atmosphere by the nitrogen gas supplied from the nozzles 21 and 22. The forged product 2 conveyed from the third connection chamber 11 by the roller conveyor 10 is moved from the inlet 12a opened in the wall of the annealing furnace 26 by pushing the cover 12b swingably attached to the inlet 12a. Enter 26, roller conveyor 24
Will be transferred above. The forged product 2 is annealed by the conveyer 24 with a 900 ° C. flame from the burner 19 in a nitrogen gas atmosphere while moving through the annealing furnace 26. The nozzle 23a of the titanium gas supply device 23 is provided in the annealing furnace 26.
Titanium gas is supplied from the
Titanium is deposited on the surface of the forged product 2 using the residual heat of the flame of 0 ° C. Further, the forged product 2 is pushed from the communication port 12c opened in the partition wall 12g to the cover 12d which is swingably attached to the communication port 12c, enters the normalization furnace 27, is placed on the roller conveyor 25, and is standardized. While moving through the furnace 27, it is normalized by a flame of 500 ° C. from the burner 21 under a nitrogen gas atmosphere. After normalizing, the forged product 2 exits to the normalizing furnace 27
From 12e, the cover 12 that is swingably attached to this outlet 12e
f is pushed out and is discharged as a product outside the normalizing furnace 12. The cover 12b attached to the inlet 12a of the annealing furnace 26, the cover 12d attached to the communication port 12c of the partition wall 12g, and the cover 12f attached to the outlet 12e of the normalizing furnace 27,
The mixed gas atmosphere of the nitrogen gas and the titanium gas in the inside is easily maintained independently (not mixed) with the nitrogen gas atmosphere in the third connection chamber 11 and the nitrogen gas atmosphere in the normalizing furnace 27. In addition, the nitrogen gas atmosphere inside the normalizing furnace 27 is easily maintained independently of the atmosphere outside the normalizing furnace 27. The speed of the roller conveyors 24 and 25 can be controlled, so that the annealing time by the annealing furnace 26 and the normalizing time by the normalizing furnace 27 can be controlled.

In this configuration, heating of the material 1 in the heating furnace 5, heating of the material 1 in the induction heating furnace 7, forging of the material 1 in the forging room 9, heat treatment of the forged product 2 in the heat treatment room 12, and each transport Is carried out in a nitrogen gas atmosphere, so that the material 1 does not rust before being forged and the forged product does not rust after forging, and the forged product 2 has irregularities on its surface. Absent. Accordingly, defective products due to rusting are eliminated, and a shot blasting chamber for eliminating the irregularities can be omitted, so that the production line is small and inexpensive.

Incidentally, instead of the forging machine 13 used in the above embodiment,
It is preferable to use a special forging machine 13 having a cooling liquid supply pipe 28 shown in FIG. In the forging machine 13, a coolant is blown from the coolant supply pipe 28 to the upper die 16a of the forging machine 13, and the sprayed coolant is nitrogen gas (80 Wt%), argon gas (5 Wt%) and carbon dioxide gas ( 15 Wt%) is used. Thus, the inside of the forging chamber 9 can be set to a mixed gas atmosphere of nitrogen gas, argon gas and carbon dioxide gas, so that the nitrogen gas supply device 9a attached to the forging chamber 9 can be omitted. Further, since liquid argon and liquid carbonic acid are mixed in addition to liquid nitrogen, the surface of the iron-based material is prevented from being nitrided by N in nitrogen gas and hardened more than necessary. Moreover, in the above embodiment, water was used as the cooling liquid,
a), rust is formed on the upper mold 16a in some cases, and becomes oxidized scale during forging, and the lower mold 16b
In addition, there is a disadvantage that the coolant escape hole 29 provided on the lower mold 16b is accumulated on the lower mold 16b. However, according to the special forging machine 13, such inconvenience does not occur. When the liquid nitrogen is sprayed from the cooling liquid supply pipe 28 of the special forging machine 13, the nitrogen gas supply device 9a can be omitted, and the nitriding treatment can be performed simultaneously on the iron-based material that requires nitriding. become. Further, by using liquefied carbon dioxide instead of the above-mentioned cooling gas, snow-like carbon dioxide gas (dry ice) can be sprayed from the nozzle onto the mold and cooled efficiently.

〔The invention's effect〕

As described above, the oxygen-free forging apparatus according to the present invention includes a means for setting a conveying path of a material heated under a nitrogen gas atmosphere in a heating furnace to a nitrogen gas atmosphere, and a method in which a forging die in a forging chamber includes nitrogen, argon, and carbon dioxide. A cooling liquid supply pipe for spraying a cooling liquid composed of a mixed liquefied gas or a cooling liquid composed of liquefied carbon dioxide. By spraying the cooling liquid on the forging die, a mixture of nitrogen, argon, and carbonic acid is formed in the forging chamber. Since the atmosphere can be a gas atmosphere or a carbon dioxide gas atmosphere, materials such as iron do not rust before forging. In addition, even after forging, the forged product does not rust because it has a means for setting the conveying path of the forged product to a nitrogen gas atmosphere and a means for setting the heat treatment chamber to a nitrogen gas atmosphere. Therefore, a convex pattern or the like due to rust does not appear on the surface of the forged product, and the generation of defective products due to rust can be greatly suppressed. Moreover, conventionally, a shot blasting chamber for eliminating the convex pattern is required,
Since this can be omitted in the present invention, the production line can be shortened, and at the same time, the equipment cost can be reduced accordingly. In particular, when the cooling liquid is composed of a liquefied gas mixture of nitrogen, argon and carbonic acid, the forging chamber can be made into a mixed gas atmosphere of nitrogen, argon and carbonic acid by spraying the cooling liquid onto the forging die. The surface is prevented from being hardened more than necessary by being nitrided. Also, when the cooling liquid is liquefied carbon dioxide, the forging chamber can be made to have a carbon dioxide gas atmosphere by spraying the cooling liquid onto the forging die, and a snow-like carbon dioxide gas (dry ice) is blown onto the forging die. The forging die can be efficiently cooled.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a production line according to an embodiment of the present invention, FIG. 2 is an explanatory view of a forging chamber used in this production line, FIG. 3 is an explanatory view of a heat treatment furnace used in the production line,
FIG. 4 is a sectional view of a main part of the forging machine, and FIG.
FIG. 3 ... material supply device, 4 ... conveying means, 5 ... preheating furnace,
7 ... Induction heating furnace, 9 ... Forging room, 10 ... Work transfer means, 12 ... Heat treatment room, 13 ... Forging machine

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21J 17/00 B21K 27 / 00,29 / 00 C21D 1/74

Claims (1)

(57) [Claims] 1. A forging chamber having a heating furnace for heating a material in a nitrogen gas atmosphere, conveying means for conveying the material heated from the heating furnace to a forging chamber, and a forging machine for forging the conveyed material. And a heat treatment chamber for heat-treating the forged product, and a forging apparatus having a workpiece transfer means for transporting the forged product from the forging chamber to the heat treatment chamber, wherein the transport means and the workpiece transfer means and the heat treatment chamber are sealed. A sealing means, a nitrogen gas supply means for converting a sealed space by the sealing means into a nitrogen gas atmosphere, and a cooling liquid supply pipe for spraying a cooling liquid of the following (A) or (B) to a forging die in a forging chamber are provided. An oxygen-free forging device characterized by the above-mentioned. (A) A cooling liquid composed of a liquefied gas mixture of nitrogen, argon and carbonic acid. (B) A cooling liquid composed of liquefied carbon dioxide.