JP6002111B2 - Heating device and hot forging device - Google Patents

Description

  The present invention relates to a heating device that heats a material to be heated and a hot forging device that forges the material to be heated.

  In forging that is formed by forging a metal material, hot forging is known in which forging is performed after the metal material is heated. In hot forging, an induction heating apparatus that heats a metal material by applying high-frequency power to the metal material is widely used.

  In such an induction heating apparatus, a rod-shaped metal material is cut into a predetermined length, and the cut material to be heated is continuously conveyed to the heating coil, thereby passing the heating coil to a desired temperature. The structure which raises to is known (refer patent document 1).

Japanese Patent Laid-Open No. 5-38545

  The prior art described in Patent Document 1 is configured to efficiently raise the temperature of many materials to be heated by continuously conveying the materials to be heated in the feeding direction.

  By the way, in such a heating apparatus, since the materials to be heated are continuously conveyed in a stacked state, the materials to be heated in a heated state may be bonded to each other with adjacent materials to be heated. If adjacent materials to be heated are joined, it will cause a choke stop or failure of the forging device.

  The present invention has been made in view of such problems, and provides a heating device and a hot forging device capable of preventing the heated materials from joining when the heated materials are continuously heated. With the goal.

According to an aspect of the present invention, there is provided an induction heating apparatus for heating a material to be heated, the first heating unit and the second heating unit for heating the material to be heated, and the material to be heated continuously to the first heating unit. The transporting material is provided between the inlet transporting unit, the first heating unit, and the second heating unit, and the materials to be heated that have come out of the first heating unit are separated one by one and transported to the second heating unit. An intermediate conveyance unit, and the intermediate conveyance unit conveys the material to be heated to the second heating unit at a speed higher than a speed at which the inlet conveyance unit conveys the material to be heated to the first heating unit. It is characterized by.

  According to the above aspect, in the intermediate conveyance unit, the heated materials that have come out of the first heating unit are separated one by one and conveyed to the second heating unit, so that the heated material that has been once heated to a predetermined temperature Is temporarily exposed to the outside air, so that an oxide film is generated on the surface and the adjacent heated materials can be prevented from joining.

It is explanatory drawing which shows the structure of the hot forging apparatus of embodiment of this invention. It is explanatory drawing which shows the structure of the induction heating apparatus of embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Drawing 1 is an explanatory view showing the composition of hot forging device 1 of the embodiment of the present invention.

  The hot forging device 1 according to the present embodiment heats the billet 50 formed of a metal material, and hits and presses the billet 50 that has been heated to a target temperature, thereby forming a predetermined shape.

  The hot forging device 1 includes a cutting device 5 that forms a billet 50 that is a material to be heated, an induction heating device 10 that raises the billet 50 to a target temperature, and an intermediate material 90 by forging the billet 50 that has been heated. And a forging device 80 for forming.

  The cutting device 5 forms the billet 50 by cutting the rod-shaped metal material 51 with a predetermined length (or a predetermined weight). The cutting device 5 cuts the metal material 51 by shear cutting or cutting with a circular saw, a band saw, or the like.

  The induction heating device 10 includes a heating unit 11 and allows the billet 50 to pass through the inside thereof, thereby raising the temperature of the billet 50 to a target temperature (eg, 1200 ° C.) for hot forging in the forging device 80.

  The forging device 80 performs forging by hitting and pressurizing the billet 50 that has been heated to the target temperature with a mold, and forms the intermediate material 90.

  FIG. 2 is an explanatory diagram showing the configuration of the induction heating apparatus 10 according to the embodiment of the present invention.

  The induction heating apparatus 10 includes a heating unit 11, an inlet transport unit 20, an intermediate transport unit 30, and a controller 60. The induction heating device 10 heats the billet 50, which is a material to be heated, to a predetermined temperature. The heated billet 50 is sent to the forging device 80 in the next step.

  The inlet transport unit 20 transports the billet 50 into the heating unit 11. The inlet transport unit 20 is configured by a pinch roller that sandwiches the billet 50 and transports it in the feed direction when a pair of opposed rollers rotate. The inlet transport unit 20 continuously transports the billet 50 to the inside of the heating unit 11 so that the billet 50 is stacked and transported in the feed direction.

  The heating unit 11 includes a plurality of heating coils 14 (14a, 14b, 14c, 14d) from the inlet side toward the outlet side.

  The heating coil 14 is formed around the billet 50 to be transported, generates eddy current inside the billet 50 when high-frequency power is applied, and performs induction heating to heat the billet 50 by Joule heat due to the eddy current. . The heating coil 14 has a hole having a shape slightly larger than the outer diameter of the billet 50 inside, and the billet 50 is conveyed while sliding inside the heating coil 14. As will be described later, inside the heating coil 14, the billet 50 is continuously conveyed in contact with the front and rear billets.

  By configuring in this way, the billet 50 is heated while being shielded from the outside air (oxygen) in the heating coil 14, so that the formation of an oxide film on the surface of the billet 50 is suppressed.

  The billet 50 has a low temperature (substantially the same temperature as the ambient environment temperature) in the vicinity of the inlet of the heating unit 11, and a large amount of electric power is required to raise the billet 50 to the target temperature (1200 ° C.) at once. Therefore, the heating coil 14 of the heating unit 11 is divided into a plurality of parts, and the billet 50 is sequentially passed through the plurality of heating coils 14 to raise the temperature stepwise to the target temperature. In the example shown in FIG. 2, four heating coils 14 (14a, 14b, 14c, 14d) are provided from the inlet side toward the outlet side.

  The controller 60 controls the current applied to the heating coil 14 (14 a, 14 b, 14 c, 14 d) and the operations of the inlet transport unit 20 and the intermediate transport unit 30.

  By the way, the induction heating apparatus 10 configured as described above has the following problems.

  The inlet transport unit 20 transports the billet 50 into the heating coil 14. The billet 50 passes through the inside of the heating coil 14 while being pressed by the billet 50 on the rear side in the transport direction while being in contact with the front and rear billets 50. Billets 50 passing through the heating coil 14 are in contact with the front and rear billets 50 at their cut surfaces.

  At this time, the billet 50 to be heated may be joined to the front and rear billets 50.

  When the billet 50 is heated, the movement of iron atoms constituting the billet 50 increases. As the movement of the iron atoms increases, the iron atoms jump over the cut surface and move to the adjacent billet 50. The billets 50 adjacent to each other on the cut surface of the billet 50 may be joined by the moving iron atoms (diffusion joining). When the billet 50 is joined, it causes a yield in the forging device 80 in the next step.

  In particular, when cutting with a circular saw or the like is performed, the perpendicularity of the cut surface is large, so that the possibility that the billets 50 are joined to each other increases.

  Therefore, in the embodiment of the present invention, the adjacent billet 50 is suppressed from being joined by the following configuration.

  In the embodiment of the present invention, as shown in FIG.

  The heating unit 11 includes two parts, a first heating unit 101 including heating coils 14a and 14b and a second heating unit 102 including heating coils 14c and 14d. An intermediate unit 15 is configured between the first heating unit 101 and the second heating unit 102.

  In the intermediate unit 15, an intermediate transport unit 30 is provided between the first heating unit 101 and the second heating unit 102.

  The intermediate conveyance unit 30 exposes the billet 50 to the outside of the heating unit 11 in order to temporarily expose the billet 50 to the outside air (oxygen atmosphere). Further, the intermediate transport unit 30 is set so that the billet 50 is fed faster than the entrance transport unit 20.

  The embodiment of the present invention obtains the following operation by such a configuration.

  The billet 50 cut to a predetermined length is stacked and transported in the feed direction by the inlet transport unit 20 to the first heating unit 101. In the first heating unit 101, each billet 50 is heated to a predetermined temperature. The predetermined temperature raised by the first heating unit 101 is about 1000 ° C., for example.

  The billet 50 that has passed through the first heating unit 101 is exposed to the outside of the heating unit 11 at the intermediate unit 15. In the intermediate unit 15, the billets 50 are separated and conveyed one by one to the second heating unit 102 by the intermediate conveyance unit 30. The intermediate transport unit 30 is configured to transport the billet at a transport speed faster than the transport speed of the entrance transport unit 20. Thereby, the billets 50 transported from the first heating unit 101 are separated one by one in the intermediate transport unit 30 and then transported to the second heating unit 102.

  In the intermediate unit 15, the billet 50 is separated one by one by the intermediate transport unit 30 transporting the billet 50 to the second heating unit 102 at a speed faster than the speed at which the entrance transport unit 20 transports the billet 50. The Thereby, the surface (especially cut surface) of the billet 50 is exposed to outside air. By exposing the surface of the billet 50 to the outside air, an oxide film is generated on the cut surface of the billet 50.

  The billet 50 having an oxide film formed on the surface is transported by being stacked in the feed direction by the intermediate transport unit 30 to the second heating unit 102. The second heating unit 102 raises the billet 50 to the target temperature.

  In the second heating unit 102, the billet 50 is conveyed while being in contact with the front and rear billets 50, but the oxide film formed on the cut surface prevents the iron atoms from moving to the adjacent billet 50. In this way, adjacent billets 50 are prevented from joining.

  The billet 50 heated to the target temperature is sent to the forging device 80 in the next process.

  As described above, in the embodiment of the present invention, in the induction heating apparatus 10 that heats the billet 50 that is the material to be heated for hot forging, between the first heating unit 101 and the second heating unit 102. The intermediate transport unit 30 is provided for separating the billet 50 transported continuously one by one and transporting the billet 50 to the second heating unit.

  In the embodiment of the present invention, an oxide film can be generated on the surface of the billet 50 by temporarily exposing the billet 50 to the outside air in the intermediate conveyance unit 30 with such a configuration. By forming an oxide film on the surface of the billet 50, it is possible to prevent adjacent billets 50 from being bonded to each other. This effect corresponds to claim 1.

  Since the intermediate transport unit 30 transports the billet 50 to the second heating unit 102 at a speed faster than the speed at which the entrance transport unit 20 transports the billet 50, the cut surface of the billet 50 transported from the first heating unit 101. Can be exposed to the open air. Thereby, an oxide film is formed on the surface of the billet 50, and it is possible to prevent the adjacent billets 50 from joining each other. This effect corresponds to claim 2.

  The first heating unit 101 and the second heating unit 102 constituting the heating unit 11 perform induction heating that heats the billet 50 when a high-frequency current is applied to the heating coil 14. The induction heating can easily control the temperature of the material to be heated by the control of the controller 60 and has high energy conversion efficiency, so that power saving can be achieved. This effect corresponds to the third aspect.

  And since this embodiment prevents the billets 50 from joining together as mentioned above in the hot forging device 1 comprised from the cutting device 5, the induction heating device 10, and the forging device 80, the forging device 80 It is possible to eliminate a choke stop or failure in This effect corresponds to claim 4.

  In addition, since the oxide film produced | generated on the surface of the billet 50 may have an influence, such as scratching the metal mold | die of the forging apparatus 80, in the intermediate part 15, gold | metal | money is such that the billet 50 does not join. It is desirable to use a minimum oxide film as long as it does not affect the mold.

  As an example, the minimum oxide film can be generated by exposing the billet 50 heated to about 1000 ° C. by the first heating unit 101 to the outside air for about 10 seconds.

  The embodiment of the present invention has been described above, but the above embodiment is merely a part of an application example of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  In the above embodiment, the billet 50 is separated one by one and transported to the second heating unit 102 by increasing the speed of the intermediate transport unit 30 than the entrance transport unit 20. Absent. For example, the intermediate unit 15 may be configured such that the cut surface of the billet 50 is exposed to the outside air by moving the temporary billet 50 in a direction perpendicular to the conveyance direction of the billet 50.

  Moreover, in the said embodiment, although the induction heating which heats the billet 50 by applying high frequency electric power to the heating coil 14 was demonstrated to the example, it is not restricted to this. It may be combustion heating with fossil fuel, or resistance heating in which a current is directly supplied to the billet 50.

  Moreover, it is good also considering places other than the intermediate conveyance part 30 as inert gas atmosphere, such as argon, so that an oxide film may not be produced | generated on the surface of the billet 50 more than necessary.

DESCRIPTION OF SYMBOLS 1 Hot forging apparatus 5 Cutting apparatus 10 Induction heating apparatus 11 Heating part 14 Heating coil 15 Intermediate | middle part 20 Inlet conveyance part 30 Intermediate conveyance part 40 Control apparatus 50 Billet 60 Controller 80 Forging apparatus 101 1st heating part 102 2nd heating part

Claims (3)

A heating device for heating a material to be heated,
A first heating unit and a second heating unit for heating the material to be heated;
An inlet transport unit that continuously transports the material to be heated to the first heating unit;
An intermediate conveyance unit that is provided between the first heating unit and the second heating unit, and that separates the material to be heated from the first heating unit one by one and conveys the material to the second heating unit; ,
Equipped with a,
The intermediate transport unit transports the heated material to the second heating unit at a speed faster than the inlet transport unit transports the heated material to the first heating unit. A heating device characterized by that. The heating apparatus according to claim 1, wherein the first heating unit and the second heating unit include a heating coil, and the material to be heated is induction-heated by applying a current to the heating coil .   A cutting device for cutting the metal material to form the material to be heated having a predetermined shape;
  The heating device according to claim 1 or 2,
  A forging device forging the heated material heated by the heating device;
  A hot forging device comprising:

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