JP2018176172A - Method for cooling main roll for ring rolling and method for manufacturing ring rolling body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cooling a mail roll by which strengths of a shaft body of the mail roll and peripheral parts thereof are sufficiently assured, maintenance of the main roll can be easily performed, and the shaft body of the main roll and the peripheral parts thereof can be efficiently cooled, and a method for manufacturing a ring rolling body by which a ring roll body having a high quality can be manufactured.SOLUTION: This invention relates to a method for cooling a main roll 1 for ring rolling by which the main roll 1 is cooled in the state that one side in a rotation axis direction thereof is directed upward, and a method for manufacturing a ring rolling body including the same. In the cooling method, liquid W is poured into reception parts 13, 17 which are concaved from an upper end surface 12c of a metal mold 12 of the main roll 1 directed to one side in the rotation axis direction and surround a shaft body 11 of the main roll 1, thereby cooling the shaft body 11. In the method for manufacturing a ring rolling body, the metal mold 12 is heated by an induction heating mechanism 6 and the shaft body 11 is cooled by the above cooling method, and further a ring material M is drafted between the main roll 1 and a mandrel 2, thereby manufacturing the ring rolling body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of cooling a main roll used for ring rolling, and further, the present invention uses a mold of the main roll to produce a substantially ring-shaped rolled body (hereinafter referred to as "ring rolled body"). Ring rolling which cools the shaft of the main roll by the above-mentioned cooling method while heating, and further reduces the substantially ring-shaped material (hereinafter referred to as "ring material") in the radial direction between the main roll and the mandrel It relates to the method of manufacturing the body.

  Parts in a substantially ring shape (hereinafter referred to as “ring parts”) are used for gears used in various industrial fields, rotating bodies of rotating mechanisms, etc. (hereinafter referred to as “ring parts”) It is made by doing. The ring-rolled body is manufactured by subjecting a ring material to ring rolling, and a rolling apparatus such as a ring rolling mill is used for ring rolling.

  The rolling mill is provided with a forming roll for pressing the ring material so as to form a ring rolling body, and examples of the forming roll include main rolls and a mandrel for pressing the ring material between its inner and outer circumferences . The forming rolls are exposed to a high temperature environment during ring rolling, in particular during hot ring rolling. Therefore, it may be required to cool the forming roll in order to protect the forming roll, accurately control the temperature of the forming roll, and enhance the quality of the ring-rolled body produced using the forming roll. . Therefore, various forming roll cooling techniques have been proposed.

  As an example of a cooling technique, a technique of spraying a cooling solvent such as cooling water on a processing portion provided so as to surround a rotating shaft in a forming roll has been proposed. Further, as another example of the above-described cooling technology, a technology has been proposed in which a water channel extending from one end to the other end of the forming roll in the rotation axis direction is provided along the rotation axis of the forming roll to flow cooling water in the water path See, for example, Patent Document 1 and Patent Document 2).

JP 58-025834 Japanese Patent Application Laid-Open No. 54-101757

  However, in ring rolling as in one example of the above-described cooling technique, the cooling medium is sprayed on the processing portion of the forming roll in contact with the ring material, so the temperature of the processing portion of the forming roll may decrease. Therefore, in ring rolling, there is a possibility that problems such as cracking of the ring material in contact with the processing portion of the forming roll and deformation defects may occur. In particular, in the case where the ring material is made of a difficult-to-process metal material such as a Ni-based super alloy, a Co-based alloy, etc., there is a high possibility that a failure of the ring material will occur. In the example of the above-mentioned cooling technology, there is also a problem that it is difficult to cool the rotation shaft of the forming roll and the peripheral portion thereof among the forming rolls.

  Furthermore, in addition to the mechanism which pours a cooling water into a water channel, the mechanism which rotates a forming roll is installed in the rotating shaft of a forming roll, and its periphery part in another example of the said cooling technology. Therefore, the structure of the rolling mill becomes complicated in order to install these mechanisms, and as a result, it is difficult to secure the strength of the main roll of the rolling mill, in particular, the rotation axis of the main roll and its peripheral portion. Maintenance may be difficult.

  In particular, when applying one example of the above-mentioned cooling technology and another example to the main roll of a ring rolling mill, the above-mentioned problem becomes remarkable. Therefore, in the method of cooling the main roll of the ring rolling mill, maintenance of the main roll is facilitated while securing sufficient strength of the main roll shaft and its peripheral portion, and the main roll shaft and its peripheral portion It is desirable to efficiently cool the Further, in the method of manufacturing a ring rolling body, the mold of the main roll, in particular, the processing portion of the mold in contact with the ring material is heated while the shaft of the main roll and the peripheral portion thereof are efficiently cooled. It is desirable to produce a high-quality ring-rolled body by using a temperature-controlled main roll appropriately.

  In order to solve the problem, according to the method of cooling a main roll according to one aspect of the present invention, a shaft body extending along the rotation axis of the main roll, and a mold arranged to surround the shaft body A method of cooling a main roll having the main roll used for ring rolling with one side in the direction of the rotational axis facing upward, the main roll facing one side in the direction of the rotational axis The shaft of the main roll is cooled by injecting a liquid into a receiving portion which is recessed from the upper end surface of the die and surrounds the shaft of the main roll. Furthermore, the shaft of the main roll and its peripheral portion are cooled.

  According to the method of manufacturing a ring-rolled body according to an aspect of the present invention, the ring-rolled body is manufactured by rolling the ring material, and the method of heating the mold of the main roll by the heating mechanism. Temperature control step of cooling the shaft of the main roll by the main roll cooling method according to one aspect of the present invention, and the ring material by the main roll and mandrel whose temperature is controlled in the temperature control step And a rolling process for reducing the pressure between the inner and outer peripheries.

  According to the method of cooling the main roll according to one aspect of the present invention, the strength of the shaft of the main roll and the peripheral portion thereof can be sufficiently ensured, the main roll can be easily maintained, and the shaft of the main roll and its periphery The part can be cooled efficiently. Further, according to the method of manufacturing a ring-rolled body according to one aspect of the present invention, the mold of the main roll, in particular, the processed portion of the mold contacting the ring material is heated while the shaft of the main roll and the periphery thereof A high-quality ring-rolled body can be produced by using a main roll properly temperature-controlled so as to cool the part efficiently.

It is a perspective view showing roughly the rolling device used for the cooling method of the main roll concerning a 1st embodiment of the present invention, and the manufacturing method of a ring rolling object. It is a top view which shows roughly a shaft and a metallic mold of a main roll of a rolling mill in a 1st embodiment of the present invention. It is the sectional view on the AA line of FIG. It is a flowchart for demonstrating the cooling method of the main roll which concerns on 1st Embodiment of this invention. It is a flowchart for demonstrating the manufacturing method of the ring rolling body which concerns on 1st Embodiment of this invention. It is sectional drawing which shows roughly the state which cut | disconnected the axial body and metal mold | die of the main roll in 2nd Embodiment of this invention along the line corresponded to the AA of FIG. It is sectional drawing which shows roughly the state which cut | disconnected the axial body and metal mold | die of the main roll in 3rd Embodiment of this invention along the line corresponded to the AA of FIG.

  The method of cooling the main roll according to the first to fourth embodiments of the present invention, the method of manufacturing a substantially ring-shaped rolled body (hereinafter referred to as "ring rolled body"), and the rolling apparatus will be described below. In the method of cooling the main roll, the shaft of the main roll of the rolling mill and the peripheral portion thereof are mainly cooled. Further, in the method of manufacturing a ring-rolled body, while heating the machined portion of the outer peripheral surface of the die of the main roll, particularly the die in contact with a substantially ring-shaped material (hereinafter referred to as "ring material") The cooling method mainly cools the shaft of the main roll and its peripheral portion, and further presses the ring material between the main roll and the mandrel. In addition, the cooling method of a main roll is also applicable to the manufacturing method of the ring rolling body other than 1st-4th embodiment of this invention.

  In the first to fourth embodiments of the present invention, the ring-rolled body is used to produce a substantially ring-shaped component (hereinafter referred to as "ring component"). As an example, the ring component may be a gear used in various industrial fields, a rotating body of a rotating mechanism, etc. Furthermore, the ring component needs strict dimensional control, in particular, a gas turbine, steam It is preferable that it is a turbine disc used for a turbine, jet engine of an aircraft, etc. Moreover, as an example, it is preferable that the largest diameter of the outer periphery of a ring rolling body is about 600 mm or more and about 2000 mm or less. However, the present invention is not limited to this, and the maximum diameter of the outer periphery of the ring rolling body may be smaller than about 600 mm and larger than about 2000 mm depending on the ring component manufactured using the ring rolling body. .

  Furthermore, in the first to fourth embodiments of the present invention, the ring-rolled body is shaped by subjecting a ring material to ring rolling. In particular, the ring material may be manufactured using a metal material that is excellent in high temperature strength, high temperature toughness, etc. For example, the ring material is Ni base alloy, Fe base alloy, Co base alloy which is excellent in high temperature strength, high temperature toughness etc. It is good to be produced using a metal material selected from Ti-based alloys and the like.

First Embodiment
A method of cooling a main roll, a method of manufacturing a ring-rolled body, and a rolling apparatus according to a first embodiment of the present invention will be described.

[About rolling equipment]
First, with reference to FIG. 1, a rolling apparatus used in the method of cooling the main roll 1 and the method of manufacturing a ring-rolled body according to the present embodiment will be described. The rolling mill is configured to be capable of mounting a ring material M formed substantially rotationally symmetric with respect to the central axis C, and the rolling mill is configured to perform ring rolling on the ring blank M mounted thereon There is.

  Specifically, the rolling mill comprises the main roll 1 and the mandrel 2 as described above. The main roll 1 and the mandrel 2 contact the outer peripheral surface m1 and the inner peripheral surface m2 of the ring material M, respectively, and press the ring material M in the radial direction (hereinafter referred to as "ring radial direction") between them. Do. The rolling mill also comprises a pair of axial rolls 3,4. The pair of axial rolls 3, 4 contact the upper end face m3 and the lower end face m4 in the direction of the central axis C in the ring material M (hereinafter referred to as "ring axial direction") and ring material M between them Press down in the axial direction.

  The rolling mill also has a liquid supply mechanism 5 for supplying water W for cooling the main roll 1. As an example, the temperature of water W is preferably normal temperature. Furthermore, the rolling mill includes an induction heating mechanism 6 configured to inductively heat the main roll 1. In ring rolling, the ring material M abuts on the main roll 1 induction-heated by the induction heating mechanism 6.

  However, the present invention is not limited to this, and the rolling mill may be configured as follows. The rolling mill may be configured not to include a pair of axial rolls. If the main roll can be cooled, the liquid supply mechanism may supply a liquid other than water. In particular, the liquid may have flame retardancy and high fluidity, for example, the liquid may be silicone oil or the like. The rolling mill may have a heating mechanism other than the induction heating mechanism as long as it can heat the main roll. For example, the heating mechanism may be a gas burner or the like.

[About main roll and mandrel]
The main roll 1 and the mandrel 2 will be described with reference to FIG. The main roll 1 and the mandrel 2 are rotatable around rotational axes 1a and 2a, respectively. Each of main roll 1 and mandrel 2 is arranged so that one side of the direction of its rotation axis 1a, 2a (hereinafter referred to as “rotational axis direction” in each of main roll 1 and mandrel 2) is directed upward. .

  Each of the main roll 1 and the mandrel 2 has shafts 11 and 21 extending along the rotation axes 1a and 2a, and molds 12 and 22 surrounding the shafts 11 and 21, respectively. The shafts 11 and 21 and the dies 12 and 22 are separate members, and the dies 12 and 22 are attached to the shafts 11 and 21. However, the present invention is not limited thereto, and the shaft and the mold may be integrated in at least one of the main roll and the mandrel.

  The molds 12 and 22 of the main roll 1 and the mandrel 2 respectively have outer peripheral surfaces 12a and 22a formed substantially rotationally symmetric with respect to the rotation axes 1a and 2a, respectively, and these outer peripheral surfaces 12a and 22a are respectively rings It contacts the outer peripheral surface m1 and the inner peripheral surface m2 of the material M. The outer peripheral surfaces 12a and 22a of the dies 12 and 22 of the main roll 1 and the mandrel 2 have a shape corresponding to the shape of the ring-rolled body to be manufactured. As an example, the ring material M shown in FIG. 1 has one convex portion m5 that protrudes from the outer peripheral surface m1 and extends along the circumferential direction of the ring material M (hereinafter referred to as "ring circumferential direction") The outer peripheral surface 12a of the mold 12 of the main roll 1 is formed to have one recessed portion 12b corresponding to one convex portion m5 and extending along the circumferential direction of the main roll 1. However, the present invention is not limited to this, and the outer peripheral surface of the ring material may be formed other than the shape having one convex portion, and the outer peripheral surface of the mold of the main roll is the outer periphery of such a ring material. It may be formed corresponding to the surface.

  Preferably, at least one of the main roll 1 and the mandrel 2 can be rotationally driven by a drive mechanism (not shown). In this case, the drive mechanism comprises at least one shaft 11 or 21 of the main roll 1 and the mandrel 2 It should be attached. If necessary, the rotational speeds of the main roll 1 and the mandrel 2 should be controllable. In particular, it is preferable that only the main roll 1 can be rotationally driven. The main roll 1 and the mandrel 2 may also be movable in the ring radial direction according to the expansion of the ring radial direction of the ring material M.

  The ring material M is pressed in the ring radial direction between the outer peripheral surfaces 12 a and 22 a of the dies 12 and 22 of the main roll 1 and the mandrel 2 while rotating in the ring circumferential direction as the main roll 1 and the mandrel 2 rotate. Be done. In the method of manufacturing a ring-rolled body to be described later, the main roll 1 rotates to one side (indicated by arrow R1) in the rotation direction and the mandrel 2 rotates to one side (indicated by arrow R2) in the rotation direction. The case where the ring material M rotates toward one side (indicated by the arrow F) in the ring circumferential direction along with these rotations will be described.

  Furthermore, while the main roll 1 can be heated by the induction heating mechanism 6, it should be a size that is difficult to heat by a heating furnace, gas burner, etc. In particular, the maximum diameter of the outer peripheral surface 12a of the mold 12 in the main roll 1 is And preferably about 1000 mm or more. However, the present invention is not limited thereto, and the maximum diameter of the outer peripheral surface of the mold in the main roll may be smaller than about 1000 mm, as long as the main roll can be appropriately heated.

[Main roll cooling structure]
The cooling structure of the main roll 1 will be described with reference to FIGS. 2 and 3. The mold 12 of the main roll 1 has a receiving portion 13 recessed downward from the upper end face 12c. The receiving portion 13 is opened at the upper end surface 12 c of the mold 12 and extends in the circumferential direction of the main roll 1 so as to surround the shaft 11. The receiver 13 receives the water W supplied from the liquid supply mechanism 5.

  The mold 12 of the main roll 1 also has a plurality of fluid passages 14 extending from the receiving portion 13 toward the other side in the rotational axis direction, and the plurality of fluid passages 14 are spaced from one another in the circumferential direction of the main roller 1. It is empty. As one example, the mold 12 shown in FIGS. 2 and 3 has four fluid passages 14. However, the present invention is not limited thereto, and the mold may have two or more liquid passages, and in particular, the mold preferably has three or more liquid passages.

  Furthermore, the mold 12 has a mounting hole 15 penetrating therethrough so as to allow the shaft 11 to be inserted. The mounting hole 15 extends from the bottom surface 13 b of the receiving portion 13 to the lower end surface 12 d of the mold 12 along the rotation axis 1 a of the main roll 1. The shaft 11 is attached to the mold 12 in a state of being inserted into the attachment hole 15.

  In the cooling structure of the main roll 1, the receiving portion 13 has an opening edge 13a located on the upper end surface 12c of the mold 12, a bottom surface 13b opposite to the opening edge 13a, and the outside of the opening edge 13a and the bottom surface 13b. An inner circumferential surface 13c extending between the peripheral edges is formed.

  In consideration of preventing temperature decrease in the processed portion of the outer peripheral surface 12a of the mold 12 in contact with the ring material M and preventing reduction in strength of the mold 12, the bottom surface 13b of the receiving portion 13 is the mold 12 It is preferable to be located above the processing part of As an example, since the centrifugal force is applied to the liquid such as water W in the receiving portion 13 when the main roll 1 rotates, the bottom surface 13b has a depth of the receiving portion 13 which can be held in the receiving portion 13 It may be formed to give The bottom surface 13 b may be formed in a substantially flat shape along the horizontal direction.

  Also, in view of preventing temperature decrease of the outer peripheral surface 12 a of the mold 12 and preventing strength reduction of the peripheral portion of the shaft body 11 in the mold 12, the receiving portion 13 from the rotation axis 1 a of the main roll 1 The maximum distance to the inner peripheral surface 13c of the main roll 1 is preferably 3/4 or less of the minimum distance from the rotation axis 1a of the main roll 1 to the outer peripheral surface 12a of the mold 12, and furthermore, 1/2 of the minimum distance It is preferable that it is the following. The inner circumferential surface 13c is formed along the vertical direction. However, the present invention is not limited thereto, and the inner circumferential surface may be inclined relative to the vertical direction, for example, the inner circumferential surface is formed to be tapered from the bottom surface of the receiving portion toward the opening edge May be

  Furthermore, in the cooling structure of the main roll 1, each liquid passage 14 has an inlet 14 a opening at the receiving portion 13 and an outlet 14 b opening at the lower end surface 12 d of the mold 12. Each fluid passage 14 may also communicate with the mounting hole 15 in the radial direction of the main roll 1. In particular, each fluid passage 14 is preferably formed so as to be recessed from the inner circumferential surface 15 a of the mounting hole 15, and each fluid passage 14 preferably extends along the shaft 11. However, the present invention is not limited to this, and at least one of the plurality of fluid paths may be spaced from the mounting hole 15 in the radial direction of the main roll.

[About liquid supply mechanism]
The liquid supply mechanism 5 of the rolling mill will be described with reference to FIG. The liquid supply mechanism 5 has a supply pipe 51 through which the water W can pass, and a valve 52 disposed in the supply pipe 51. A supply port 51 a for supplying the water W to the receiving unit 13 is formed at the tip of the supply pipe 51, and the supply port 51 a is located above the receiving unit 13. The valve 52 can be opened and closed so as to switch between a state in which the water W flows out from the supply port 51 a and a state in which the outflow of the water W is stopped. In particular, it is preferable that the valve 52 be adjustable in its opening / closing amount so as to adjust the amount of water W supplied from the supply port 51a.

  The liquid supply mechanism 5 also has a temperature detection unit 53 capable of detecting the temperature of the receiving unit 13 of the main roll 1. The temperature detection unit 53 preferably detects the temperature of the receiving unit 13 in a non-contact manner. For example, the temperature detection unit 53 may be a radiation temperature sensor or the like. However, the present invention is not limited to this, and the temperature detection unit may be able to detect the temperature of water discharged from the outlet of the mold.

  The liquid supply mechanism 5 also has a control unit 54 that can control the supply of the water W from the supply pipe 51 to the receiving unit 13. The control unit 54 is electrically connected to the valve 52 and the temperature detection unit 53. The control unit 54 receives the temperature detection value of the receiving unit 13 from the temperature detection unit 53. Furthermore, the control unit 54 controls the opening and closing of the valve 52 in accordance with the temperature detection value. In particular, the control unit 54 is preferably capable of controlling the opening and closing amount of the valve 52. In addition, as an example, the control unit 54 may be a control unit including an electric component such as a CPU, an electric circuit, and the like.

[About induction heating mechanism]
The induction heating mechanism 6 of the rolling mill will be described. Although not particularly illustrated, the induction heating mechanism 6 includes an induction heating coil having a winding wound at least once. In the induction heating mechanism 6, a magnetic flux line for induction heating is generated by passing an alternating current through the winding of the induction heating coil.

  As shown in FIG. 1, the induction heating mechanism 6 is provided around the outer peripheral surface 12 a of the mold 12 in the main roll 1 so as to inductively heat the processed portion (including the recess 12 b) of the outer peripheral surface 12 a of the mold 12. It is arranged. In particular, the induction heating mechanism 6 rotates the main roll 1 around the outer peripheral surface 12 a of the mold 12 with respect to the reduction area between the main roll 1 and the mandrel 2 (hereinafter referred to as “inner and outer reduction area”). It is preferable to arrange | position to the area | region (henceforth "the area | region just before inner and outer peripheral pressure reduction") adjacent to the other side of the. As an example, it is preferable that the region immediately before the inner and outer peripheral pressure reduction be located within a range of length obtained by dividing the entire circumferential length of the main roll 1 into four from the inner and outer peripheral pressure reduction region toward the other side of the rotation direction of the main roll 1. However, the present invention is not limited to this, and the induction heating mechanism may inductively heat the edge shape contact portion of the main roll that contacts the edge shape portion formed on the outer peripheral surface of the ring material.

[About the main roll cooling method]
The cooling method of the main roll 1 which concerns on this embodiment is demonstrated with reference to FIG.1 and FIG.4. Initially, the valve 52 is closed, and the supply of the water W from the supply pipe 51 is stopped (step S1). A temperature detection value of the receiver 13 is obtained by the temperature sensor 52 (step S2). The control unit 54 determines whether the temperature detection value of the receiving unit 13 is larger than a predetermined upper temperature threshold (step S3).

  If the temperature detection value of the receiving unit 13 is less than or equal to the upper temperature threshold (NO), the process returns to the operation of obtaining the temperature detection value of the receiving unit 13 by the temperature sensor 52 before the determination (step S2). On the other hand, when the temperature detection value of the receiver 13 is larger than the upper temperature threshold (YES), the valve 52 is opened to supply the water W from the supply pipe 51 to the receiver 13 (step S4). Before the water W is supplied to the receiving portion 13, the water W may be subjected to a pretreatment to prevent the generation of the scale. Next, the temperature detection value of the receiver 13 is obtained again by the temperature sensor 52 (step S5). It is determined whether the temperature detection value of the receiver 13 is smaller than the temperature lower limit threshold (step S6).

  If the temperature detection value of the receiver 13 is equal to or higher than the lower temperature threshold (NO), the supply of the water W to the receiver 13 is continued (step S4). If the temperature detection value of the receiver 13 is smaller than the lower temperature threshold (YES), the valve 52 is closed to stop the supply of the water W to the receiver 13 (step S7). Note that the supply rate of water W to the receiver 13 may be adjusted according to the temperature detection value of the receiver 13.

  The above operation may be repeatedly performed in a situation where the die 12 of the main roll 1 is induction-heated by the induction heating mechanism 6, whereby the temperature distribution of the shaft 11 of the main roll 1 and the die 12 is properly controlled Good to be done. Such a cooling method is suitable to be carried out in the rotation state of the main roll 1 but can also be carried out in the rotation stop state of the main roll 1. Note that at least one of the cooling method operations may be performed manually by the operator.

  In the cooling method, the upper temperature threshold and the lower temperature threshold may be determined as follows. The upper temperature threshold is preferably about 150 ° C., and the lower temperature threshold is preferably about 40 ° C. That is, it is preferable that the temperature detection value of the receiving portion 13 be maintained between about 40 ° C. or more and about 150 ° C. or less.

  However, the present invention is not limited thereto, and the temperature upper limit threshold is larger than the temperature lower limit threshold, and the temperature upper limit threshold is a bearing portion based on the heat conduction condition from the receiving portion of the mold to the bearing portion of the shaft. It may be less than the temperature of the receiving part determined corresponding to the heat resistance temperature of the above.

[About the manufacturing method of the ring rolling body]
The manufacturing method of the ring rolling body which concerns on this embodiment is demonstrated with reference to FIG.1 and FIG.5. In the manufacturing method, a step of managing the temperature of the main roll 1 so as to cool the mold 11 of the main roll 1 while cooling the shaft body 11 of the main roll 1 and its peripheral portion (hereinafter, “temperature control step”) A step (hereinafter, referred to as a “rolling step”) of performing ring rolling on the ring material M that has been heated in advance and is heated in advance is performed. In the rolling process, the temperature of the preheated ring material M is preferably about 850 ° C. or more and about 1150 ° C. or less. However, the temperature of the ring material is not limited to this, and can be adjusted according to the type of metal material used for the ring material so as to produce a high-quality ring-rolled body.

  The temperature control process is implemented first. Specifically, the main roll 1 is rotated (step P1). The operation of induction heating of main roll 1 by induction heating mechanism 6 (hereinafter referred to as “induction heating operation”) and the operation of cooling main roll 1 by the above cooling method (hereinafter referred to as “cooling operation”) are started ( Process P2). Thereafter, if the temperature distribution of the shaft body 11 of the main roll 1 and the mold 12 is properly controlled (process P3), the induction heating operation and the cooling operation are ended (process P4). Furthermore, rotation of the main roll 1 is stopped (process P5). In addition, it is good to stop the supply of the water W from the liquid supply mechanism 5 to the receiving portion 13 when problems such as electrical grounding occur while the induction heating mechanism 6 is energized.

  Next, the rolling process is performed. Specifically, the ring material M heated in advance is attached to a rolling mill (process P6). The main roll 1 and the mandrel 2 are rotated, and the pair of axial rolls 3 and 4 are rotated. With these rotations, the ring material M heated in advance is one of the ring circumferential directions around its central axis C. Rotate toward the side (indicated by arrow F) (process P7). The induction heating operation is started again (process P8). The work of pressing the ring material M in the ring radial direction by the main roll 1 and the mandrel 2 and the work of pressing the ring material M in the ring axial direction by the pair of axial rolls 3 and 4 ) (Step P9). At this time, the main roll 1 and the mandrel 2 are relatively moved in the ring radial direction with reference to the radial center of the ring material M, thereby deforming the ring material M so as to enlarge its diameter. it can. If the ring material M is deformed into the desired shape (Step P10), the pressing operation is ended, and at the same time, the induction heating operation for the main roll 1 is ended (Step P11). Thereafter, the rotation of the ring material M is stopped (process P12). During the transition from the temperature control process to the rolling process, the induction heating operation may be continued without stopping once. A cooling operation may be performed during the reduction operation. Further, after the end of the rolling process, particularly when the shaft body 11 of the main roll 1 and its peripheral portion have preheating, it is preferable to further carry out a cooling operation.

[About the details of induction heating work]
Here, the details of the induction heating operation will be described. As described above, the induction heating operation is performed almost continuously from the start to the start of the reduction operation, and is also performed during the reduction of the ring material M. Before the reduction work, the induction heating work is performed for a predetermined temperature (hereinafter, referred to as “reduction of pressure” on the processed portion of the outer peripheral surface 12 a of the mold 12 in the main roll 1 for a predetermined time (hereinafter referred to as “heating before reduction”). The preheating temperature is referred to as "). During the reduction operation, the induction heating operation is performed so that the processed portion of the outer peripheral surface 12a of the die 12 of the main roll 1 has a predetermined temperature (hereinafter, referred to as "heating temperature during reduction").

  The pre-reduction heating time, the pre-reduction heating temperature, and the during-reduction heating temperature may be as follows. Considering that the mold 12 of the main roll 1 is sufficiently heated before the reduction work so as to efficiently enhance the quality of the ring rolling body to be produced, and that the induction heating is also performed during the reduction work, The preheating heat treatment time should be about 3 minutes or more, and the preheating heat treatment temperature should be about 100 ° C. or more, preferably about 150 ° C. or more, and more preferably about 300 ° C. or more.

  On the other hand, in consideration of preventing the main roll 1 from being softened and preventing a reduction in the production efficiency of the ring-rolled body, the pre-shutdown heating time should be about 1 hour or less, and the pre-shutdown heating temperature Should be less than the softening temperature of the material of the main roll 1. Specifically, when the material of the outer peripheral surface 12a of the die 12 in the main roll 1 is a steel for hot die specified in JIS G4404 or its improved steel, the heating temperature before rolling is less than the tempering temperature The softening temperature may be the tempering temperature. When strength and heat resistance are required for the material of the main roll 1, a Ni-based super heat-resistant alloy may be used, and in this case, the pre-reduction heating temperature may be less than the solution treatment temperature. That is, it is preferable that the softening temperature be a solution treatment temperature.

  Furthermore, the heating temperature during pressure reduction may be in the range of about 300 ° C. or more and the temperature of the ring material M to be preheated. The upper limit value may be set according to the material of the main roll 1 and the like, and in particular, the upper limit value may be set to a temperature at which the softening of the main roll 1 can be prevented. That is, the heating temperature during the pressure reduction may be less than the softening temperature of the material of the mold 12 in the main roll 1 as the heating temperature before the pressure reduction.

  Moreover, the temperature of induction heating by the induction heating mechanism 6 can efficiently control the temperature distribution in the radial direction of the ring material M within an appropriate temperature range while suppressing heat removal of the ring material M within the above range. It should be adjusted to As one example, the temperature of induction heating by the induction heating mechanism 6 may be adjusted to make the temperature distribution in the radial direction of the ring material M uniform.

  However, this invention is not limited to this, The manufacturing method of a ring rolling body may become as follows. The induction heating operation may end before or after the end of the reduction operation. The timing of resuming the induction heating operation after interrupting the start of the ring material pressing operation can be either immediately before, at the start of, or after the start of the ring material pressing operation. In particular, the interruption time of the induction heating operation should be set in such a range that the temperature of the main roll can be maintained so as to efficiently improve the quality such as the dimensional accuracy of the ring rolling body to be produced. In addition, the pressing operation may be performed in a state in which the induction heating operation is stopped. In this case, the pre-pressurization heating time may be about 15 minutes or more and about 2 hours or less, and more preferably about 30 minutes or more and about 1 hour or less.

[Action and effect]
As described above, according to the method of cooling the main roll 1 according to the present embodiment, the receiving portion 13 recessed from the upper end surface 12 c of the mold 12 of the main roll 1 and surrounding the shaft body 11 of the main roll 1 receives the water W Since the main roll 1 is cooled by the water W in the receiving portion 13, the shaft body 11 can be cooled efficiently. On the other hand, since the receiving portion 13 is separated from the processing portion (including the recess 12b) of the outer peripheral surface 12a of the mold 12 contacting the ring material M, the processing portion of the mold 12 and the ring material M contacting it Can be effectively prevented. Therefore, the shaft 11 of the main roll 1 and the peripheral portion thereof can be cooled efficiently. The receiving portion 13 opens wide toward the outside of the main roll 1 at the upper end surface 12 c of the mold 12, so the inside of the receiving portion 13 can be easily cleaned from the opening. Therefore, the main roll 1 can be easily maintained. Since the receiving portion 13 is formed in the mold 12, the cooling structure of the main roll 1 can prevent the strength of the shaft 11 from being reduced. Therefore, the strength of the rotation support structure of the main roll 1 can be sufficiently secured.

  According to the method of cooling the main roll 1 according to the present embodiment, the water W injected into the receiving portion 13 is extended from the receiving portion 13 by the mold 12 toward the other side in the rotational axis direction. The fluid flows into a plurality of fluid passages 14 spaced from each other in the circumferential direction. Therefore, the water W is stored in the receiving portion 13, and thereafter, the water W in the receiving portion 13 is sent to the plurality of liquid paths 14. As a result, water W remains in the main roll 1 so that the main roll 1, in particular, the shaft 11 can be cooled efficiently. Further, since the plurality of liquid paths 14 provided in the main roll 1 in addition to the receiving portion 13 are spaced from each other in the circumferential direction of the main roll 1, the strength of the main roll 1 is increased by the plurality of additional liquid paths 14 Can be suppressed. That is, the strength of the main roll 1 can be sufficiently secured.

  According to the method of cooling the main roll 1 according to the present embodiment, the water W having flowed into the liquid path 14 is made to the outside of the main roll 1 from the outlet 14 b of the liquid path 14 opened at the lower end face 12 d of the mold 12. Exhausted. Therefore, since the water W in the main roll 1 can be replaced, the main roll 1 can be cooled efficiently.

  According to the method of manufacturing a ring-rolled body according to the present embodiment, even when the mold 12 of the main roll 1 is heated, the shaft body 11 of the main roll 1 can be efficiently cooled by the cooling method. Heating the main roll 1 which maintains a fixed shape makes temperature management in hot ring rolling easier, as compared to heating the ring material M deformed during ring rolling directly. That is, while cooling the shaft 11 which needs to be prevented from being exposed to high temperature, the temperature of the processed portion of the mold 12 which performs hot ring rolling on the ring material M can be accurately managed. Therefore, a high-quality ring-rolled body can be produced by hot ring rolling using the main roll 1 that enables accurate temperature control as described above.

Second Embodiment
A method of cooling a main roll, a method of manufacturing a ring-rolled body, and a rolling apparatus according to a second embodiment of the present invention will be described. The method of cooling the main roll and the method of manufacturing the ring-rolled body according to the present embodiment are the same as those according to the first embodiment. The rolling mill according to the present embodiment is the same as that according to the first embodiment except for the liquid passage in the cooling structure of the main roll.

[About the liquid passage in the cooling structure of the main roll]
The liquid passage 16 in the cooling structure of the main roll 1 will be described with reference to FIG. The mold 12 of the main roll 1 of this embodiment has a plurality of fluid passages 16 formed in a blind hole shape instead of the plurality of fluid passages 14 penetrating as in the first embodiment. Each fluid passage 16 has an inlet 16 a opening at the receiving portion 13 and a bottom 16 b located at the lower end thereof. The other configuration of the fluid passage 16 is the same as that of the fluid passage 14 of the first embodiment.

[Action and effect]
As described above, according to the method of cooling the main roll 1 according to the present embodiment, instead of the functions and effects provided by the plurality of liquid paths 14 penetrating in the method of cooling the main roll 1 according to the first embodiment, the following Action and effect can be obtained. That is, since the water W having flowed into the blind hole-shaped liquid passage 16 is stored above the bottom 16b of the liquid passage 16, the water W is evaporated in the main roll 1, and the heat of vaporization associated with the main roll 1, and in particular, the shaft body 11 of the main roll 1 and its peripheral portion can be cooled efficiently. The other operations and effects based on the method of cooling the main roll 1 according to the present embodiment and the operations and effects based on the method of manufacturing the ring-rolled body are the same as those according to the first embodiment.

Third Embodiment
A method of cooling a main roll, a method of manufacturing a ring-rolled body, and a rolling apparatus according to a third embodiment of the present invention will be described. The method of cooling the main roll and the method of manufacturing the ring-rolled body according to the present embodiment are the same as those according to the first embodiment. The rolling mill according to the present embodiment is the same as that according to the first embodiment except for the receiving portion in the cooling structure of the main roll.

[About the receiving part in the cooling structure of the main roll]
The receiving part 17 in the cooling structure of the main roll 1 is demonstrated with reference to FIG. The mold 12 of the main roll 1 of the present embodiment has a receiving portion 17 recessed downward from the upper end surface 12 c thereof, and the receiving portion 17 is opened at the upper end surface 12 c of the mold 12 and the shaft 11 is It extends in the circumferential direction of the main roll 1 so as to surround it. The receiving unit 17 receives the water W supplied from the liquid supply mechanism 5.

  The receiving portion 17 has an opening edge 17a formed on the upper end surface 12c of the mold 12, a bottom surface 17b opposite to the opening edge 17a, and an inner circumferential surface 17c located between outer edges of the opening edge 17a and the bottom surface 17b. Have. The bottom surface 17 b is formed in a concave shape so as to be tapered toward the inflow port 14 a of the fluid passage 14. Therefore, the water W in the receiving part 17 can be efficiently guide | induced to the liquid path 14 by the bottom face 17b. Further, in the upper area of the inner circumferential surface 17c, a projection 17d is formed which protrudes toward the rotation axis 1a of the main roll 1 with respect to the lower area thereof. Therefore, the projection 17 d can prevent the water W in the receiving portion 17 from leaking from the opening of the receiving portion 17 to the outside when the main roll 1 rotates.

  The bottom surface 17b of the receiving portion 17 is also preferably located above the processed portion of the outer peripheral surface 12a of the mold 12 as in the first embodiment. As an example, as in the first embodiment, since the centrifugal force is applied to the liquid such as water W in the receiving portion 17 when the main roll 1 rotates, the bottom surface 17b can be held in the receiving portion 17 It is good to form so that depth of receiving part 17 may be given. Furthermore, the maximum distance from the rotation axis 1a of the main roll 1 to the inner circumferential surface 17c of the receiving part 17 is also the same as in the first embodiment, from the rotation axis 1a of the main roll 1 to the outer circumferential surface 12a of the mold 12 The distance is preferably 3/4 or less of the minimum distance, and more preferably 1/2 or less of the minimum distance.

Fourth Embodiment
Among them, the method for cooling the main roll and the method for manufacturing the ring-rolled body in the method for manufacturing the ring-rolled body according to the fourth embodiment of the present invention are the same as those in the second embodiment. It is similar to the one concerned. Further, the rolling mill according to the present embodiment is the same as that according to the second embodiment except that the mold of the main roll has the same receiving portion as the third embodiment.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the present invention can be modified and changed based on the technical idea thereof.

  For example, as a first modification of the present invention, a mold of the main roll in the first to fourth embodiments includes a liquid passage which penetrates as in the first and third embodiments, and the second and fourth embodiments. As such, it may have a plurality of fluid passages comprising blind hole shaped fluid passages.

  As a second modification of the present invention, the mold of the main roll in the first to fourth embodiments can also be configured not to have a liquid path.

  Reference Signs List 1 main roll, 1a rotation axis, 11 shaft, 12 molds, 12c upper end face, 12d lower end face, 13 receiving portion, 13b bottom surface, 14 fluid passage, 14b outlet, 16 fluid passage, 16b bottom, 17 receiving portion, 17b bottom surface, 2 mandrels, M ring material, m1 outer peripheral surface, m2 inner peripheral surface, W water, S1 to S6 steps, P1 to P12 steps, R1, R2, F arrow

Claims (5)

The main roll having a shaft extending along the rotation axis of the main roll and a mold disposed so as to surround the shaft, and using the main roll used for ring rolling, with one side in the rotation axis direction upward A method of cooling a main roll that cools in a directed state, comprising:
A main roll that cools the main roll shaft by injecting a liquid into a receiving portion that is recessed from the upper end surface of the main roll mold that faces one side in the rotation axis direction and that surrounds the main roll shaft. Cooling method.   The liquid injected into the receiving portion flows from the receiving portion to the other side in the rotational axis direction in the mold and flows to a plurality of liquid paths spaced from each other in the circumferential direction of the main roll. A method of cooling a main roll according to claim 1.   The liquid that has flowed into at least one of the plurality of liquid paths is discharged from the outlet of the at least one liquid path that opens at the lower end surface of the mold located on the other side in the rotational axis direction The method for cooling a main roll according to claim 2, wherein the main roll is discharged to the outside of the roll.   The main roll cooling according to claim 2, wherein the liquid that has flowed into at least one of the plurality of liquid paths is stored above the bottom formed in the at least one liquid path having a blind hole shape. Method. A method for producing a ring-rolled body, wherein a ring-rolled body is produced by rolling a ring material,
A temperature control step of heating the die of the main roll by the heating mechanism and cooling the shaft of the main roll by the method of cooling the main roll according to any one of claims 1 to 4;
And a rolling process for reducing the pressure between the inner and outer peripheries of the ring material by the main roll and the mandrel whose temperature is controlled in the temperature control step.

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