JP2001150027A - Method and device to adjust metal plated ring's average diameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method to adjust a ring material 1 whose base material 2 is covered outside with a metal plate 3 by shrinking them slightly. SOLUTION: Keeping a ring material 1 rotating, a heating device 10 heats a ring material 1 through its circumferential part and raises the ring 1's temperature to a predetermined degree and keep it during the time specified and then cool it down to the normal temperature. Such heating and cooling operation shrinks the ring's diameter a little. Since the shrinking amount is determined by the temperature to which the ring material is heated and kept, a choice of the temperature makes a ring material's diameter shrink in a requested amount to be a requested size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting an average diameter of a ring material which finely corrects the average diameter of the ring material having a metal coating layer on an outer peripheral surface, an inner peripheral surface or an end surface so as to have a desired diameter. It relates to the equipment used.

[0002]

2. Description of the Related Art Recently, a hard metal coating layer is formed on an outer peripheral surface, an inner peripheral surface, or an end surface of a large diameter ring-shaped base material having a diameter of 1 to 3 m in order to improve physical properties such as wear resistance. A ring material having such a configuration has been required. Therefore, the present inventors,
As a method of manufacturing a ring material having this configuration, first, a ring material having a predetermined shape and dimensions is manufactured from a base material such as steel, and then a metal such as a self-fluxing alloy is formed on an outer peripheral surface, an inner peripheral surface, or an end surface of the ring material. A method for forming a hard metal coating layer by spraying a material for forming the coating layer to form a sprayed layer, and then heating and melting the sprayed layer was developed.

[0003]

However, the ring material manufactured by this method has an average diameter of the ring material before formation of the metal coating layer (average of the entire circumference of the outer diameter, inner diameter, etc., ie, the circumference length).
Even if machining was performed so that π) became a desired value, there was a phenomenon that the amount was reduced by a small amount due to the melting treatment of the thermal sprayed layer. Therefore, it is conceivable to set the average diameter of the ring material before forming the metal coating layer large in anticipation of the reduction amount of the average diameter at the time of the melting treatment. It is not always constant, possibly due to the influence of the melting process conditions, the temperature and humidity of the environment, etc. Therefore, the ring material cannot be made to have a desired diameter, and a deviation of about 0.02 to 0.2% of the diameter occurs. May have occurred. When the ring material is composed of only a base material such as steel, the ring material may be made larger and machined such as grinding to correct the diameter to a desired diameter. In the formed ring material, since the metal coating layer is thin (typically, about 1 to 5 mm), the metal coating layer cannot be modified to have a desired average diameter by machining. For this reason, the ring material after forming the metal coating layer needs to be finely modified to have a desired average diameter without using mechanical processing.

The present invention has been made in response to such a demand, and an object of the present invention is to provide a method capable of finely adjusting the average diameter of a ring material provided with a metal coating layer and an apparatus used therefor.

[0005]

Means for Solving the Problems The inventors of the present invention have intensively studied a method of finely correcting the average diameter of a ring material provided with a metal coating layer, and as a result, a small section in the circumferential direction of the ring material is heated by a heating device. The average diameter of the ring material is reduced by heating and moving the ring material relative to the heating device to heat the ring material to an appropriate temperature over its entire circumference, and then cool the ring material. The present inventors have found that the amount of reduction in the average diameter can be reduced by keeping a proper load applied outward to the ring material during the operation, and that it is possible to further expand the diameter, and completed the present invention. .

That is, in the mean diameter correcting method according to the first invention of the present application, the ring material having the metal coating layer is heated by heating a small section in the circumferential direction of the ring material with the heating device. The ring material is relatively moved in the circumferential direction to heat the ring material over the entire circumference, is heated to a predetermined temperature, and is then cooled. When such a heating / cooling operation is applied to the ring material, a phenomenon occurs in which the average diameter of the ring material is reduced. The average diameter of the ring material can be reduced and corrected to a desired value by appropriately setting them.

In the mean diameter correcting method according to the second invention of the present application, an outward load is applied to a plurality of load application points circumferentially separated from each other in a ring material, and in that state, the load application point is separated from the load application point. Heating the ring material over the entire circumference by moving the ring material relative to the heating device in the circumferential direction while heating a small section in the circumferential direction of the ring material in the region set by the heating device. In some cases, the temperature is raised to a predetermined temperature and then cooled. As described above, the diameter of the ring material is reduced by applying a heating / cooling operation to the ring material,
At this time, by applying an outward load to the ring material, it becomes possible to cause plastic deformation in the radially expanding direction in the heating region of the ring material and expand the diameter. In combination with the diameter reduction operation adjustment by the above condition selection, the degree of freedom of the reduction / expansion adjustment is increased, and the average diameter can be corrected to a desired value.

An average diameter correcting apparatus according to the present invention comprises a ring material supporting and rotating device for supporting and rotating a ring material to be processed in such a manner that the outer diameter of the ring material is not increased, and a circumferential direction of the ring material. It is configured to include a heating device for heating a small section. With this configuration, while heating a small section in the circumferential direction of the ring material with the heating device, the ring material can be relatively moved in the circumferential direction with respect to the heating device and heated over the entire circumference, The average diameter of the ring material can be corrected to a desired value by implementing the above-described average diameter correction method of the first invention of the present application. Also, during this heating operation, the ring material tends to expand outward due to thermal expansion, but the ring material supporting / rotating device does not prevent the ring material from expanding outward, which may cause abnormal deformation of the ring material. And a ring material having a good shape can be obtained.

An average diameter correcting apparatus according to another aspect of the present invention is a ring for supporting and rotating a ring material to be processed while applying a load outward at a plurality of load application points on an inner peripheral surface. The apparatus is provided with a material supporting rotating device and a heating device for heating a small section in the circumferential direction of the ring material. With this configuration, the ring material is circumferentially moved relative to the heating device while a small section in the circumferential direction of the ring material is heated by the heating device in a state where an outward load is applied to the ring material. It can be moved and heated over the entire circumference, and the average diameter correcting method of the second invention of the present application described above is implemented.
The average diameter of the ring material can be modified to a desired value. Also, during this heating operation, the ring material tends to expand in the outer diameter direction due to thermal expansion, but since the ring material supporting / rotating device is pushing the ring material outward from the inside, it is difficult to prevent the ring material from expanding to the outer diameter. Therefore, abnormal deformation does not occur in the ring material, and a ring material having a good shape can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, any ring material whose average diameter is to be corrected is arbitrary as long as a metal coating layer is formed on the surface of a base material having a generally hollow cylindrical shape. For example, like a ring material 1 shown in FIG. 1, a metal coating layer 3 for improving physical properties of a base material is provided on an outer circumferential surface of a base material 2 having a simple cylindrical inner and outer peripheral surfaces. Examples thereof include those formed and those having a metal coating layer formed on the inner surface of the base material 2. If the average diameter of the ring material of this configuration after performing the melting treatment of the metal coating layer deviates from the dimension required for the final product, there is a thin metal coating layer on the outer peripheral surface or the inner peripheral surface. It is impossible to correct the average diameter by grinding the surface of the metal coating layer greatly,
Therefore, it is effective to correct the average diameter to a predetermined size by the average diameter correction method of the present invention.

The ring material for which the average diameter is to be corrected is not limited to this structure, but may be modified such as providing grooves or steps on the outer peripheral surface, inner peripheral surface, end surface, etc. of the base material 2 or forming a flange. Alternatively, the formation position of the metal coating layer can be appropriately changed. The base material constituting the ring material is arbitrary as long as it is a metal material.Specifically, carbon steel, low alloy steel, stainless steel, cast steel, cast iron, Ni-based alloy, Cu-based alloy, Al-based alloy, etc. Can be mentioned. The metal coating layer is also arbitrary as long as it can improve the physical properties of the surface as desired. For example, a Ni-based alloy, a Co-based alloy, or a hard material such as WC, Cr ₃ C ₂ , TiB _2, etc. And the like in which fine particles are blended. Although the dimensions of the ring material are not particularly limited, those having a large diameter, for example, a large diameter such as an outer diameter of 1 to 3 m, have a large deviation from a desired value when the average diameter changes,
The merit of applying the present invention is great.

Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a schematic perspective view showing a state in which the average diameter of a ring material is corrected using the average diameter correction device for a ring material according to one embodiment of the present invention. FIG. It is a schematic side view which shows the relationship of. The average diameter correcting device of this embodiment includes a ring material supporting and rotating device 8 that supports and rotates the ring material 1 to be processed in a manner that does not hinder the expansion of the outer diameter of the ring material, and a circumference of the ring material 1. A heating device 10 for heating a small section in the direction is provided.

The ring material supporting / rotating device 8 includes a ring material 1
Can be supported and rotated as long as it does not hinder the expansion of the outer diameter of the ring material, but in this embodiment, the axis is vertical and rotatable in this embodiment. Three support rollers 11A, 11 provided in
B, 11C, and a receiving roller 12 provided horizontally. Here, three support rollers 11A, 11B, 1
Of the 1C, two support rollers 11A and 11B are provided so as to rotate at a fixed position, while the remaining support rollers 11C are provided so as to be movable in a direction perpendicular to the axis and in the direction indicated by arrow A. Have been. Further, a pressing means (not shown) such as an air cylinder is connected to the support roller 11C so as to press the support roller 11C against the inner surface of the ring material 1 with an appropriate pressure. Thus, the ring material 1 is arranged so as to surround the three support rollers 11A, 11B, and 11C, and the support roller 11C is pushed in the direction of arrow A to press against the inner peripheral surface of the ring material 1. Two support rollers 1 whose faces are arranged at fixed positions
The ring material 1 is pressed against the support rollers 1A and 11B, and can be positioned and supported at a predetermined position determined by the two support rollers 11A and 11B.

Thus, the movable support roller 11C
When three support roller systems including
When the support roller 11C is retracted in the direction opposite to the arrow A when setting the ring material 1, the setting of the ring material 1 can be performed very easily, and regardless of the inner diameter of the ring material 1, Material 1 is divided into two support rollers 1
The effect of being able to be positioned and supported at a predetermined position determined by 1A and 11B is obtained. Note that the support rollers 11A, 1
It is preferable that the arrangement interval of 1B can be easily changed. The number of support rollers used here is not limited to three as shown, but may be two or four or more. For example, when two pieces are used, one is provided in a fixed position and the other is movable, so that the ring member 2 is positioned so that the two support rollers are positioned on the diameter of the ring member 2. be able to. When four pieces are used, two pieces are provided at fixed positions and the remaining two pieces are movable, so that the ring member can be positioned at a position determined by the two fixed positions.

A drive means (not shown) for rotating the support roller is connected to one support roller 11A, and the ring material 1 is rotated by rotating the support roller 11A. be able to. The pressing force for pressing the support roller 11C against the inner peripheral surface of the ring material 1 is a frictional force capable of restraining the ring material 1 from rattling in the radial direction and transmitting the rotation of the support roller 11A to the ring material 1. , But is set low so as not to deform the ring material 1. The number of support rollers rotated by the driving means is not limited to one, and may be two or all. Increasing the number of the rotationally driven support rollers reduces the frictional force required to rotate the ring material 1, and therefore reduces the pressing force of the support rollers against the ring material 1 required to rotate the ring material 1. It becomes possible.

The receiving roller 12 supporting the ring material 1 is
The receiving roller 12 is merely provided to receive the weight of the ring member 1 and the receiving roller 12 is also rotatably provided so as not to hinder the rotation of the ring member 1. The means for rotatably supporting the ring material 1 is not limited to the receiving roller 12, but may be changed as appropriate. Further, the ring member 1 may be rotated by rotating the receiving roller 12, and the supporting rollers 11A, 11B, and 11C may be configured to simply support the ring member 1 rotatably.

As described above, the ring material supporting / rotating device 8 of the present embodiment comprises the ring material by the support rollers 11A, 11B, 11C disposed inside the ring material 1 and the receiving roller 12 supporting the lower end of the ring material 1. Since the ring member 1 is configured to be rotated while being supported, the ring member 1 can be supported in a form that does not prevent the outer diameter of the ring member 1 from expanding. Therefore, the ring member 1 is heated by the heating device 10 to cause thermal expansion. Even in such a case, the diameter of the entire ring material can be increased, and local abnormal deformation does not occur.

The heating device 10 is optional as long as it can heat a small section in the circumferential direction of the ring material 1. An inductor is provided as the heating device 10 and a high-frequency alternating current is applied to the inductor. It is preferable to use the induction heating method since the amount of heat input can be increased and the amount of heat input can be easily controlled. For this reason, in this embodiment, an inductor is provided. Heating width w of the ring material in the circumferential direction by the heating device 10
(See FIG. 2) varies depending on the amount by which the ring material 1 is to be reduced in diameter, the heating temperature, the rotation speed of the ring material 1, and the like, but is usually set to about 20 to 100 mm. If the dimension d is smaller than 20 mm, the heating area is too small, so that induction heating with large heat input becomes difficult, and the rotation speed of the ring material 1 must be reduced. On the other hand, if it is larger than 100 mm, the size of the inductor and the power supply equipment increases. In consideration of these, the above-mentioned size range is preferable.

The method for correcting the average diameter of the ring material using the apparatus having the above-described structure is performed as follows. That is, as shown in FIG.
A, 11B, 11C support to rotate at a fixed position,
While heating a small section of the ring material 1 in the circumferential direction by the heating device 10, the ring material 1 is rotated to heat the ring material 1 over the entire circumference. By continuing the heating and the rotation of the ring member 1, the temperature of the ring member 1 is gradually increased as shown by the characteristic curve 14 in the graph of FIG.
a) When the temperature reaches a predetermined temperature, the temperature is maintained for a predetermined time (straight line 14b), and thereafter, heating and rotation of the ring material 1 are stopped, and cooling is performed (curve 14c). In addition, the ring material 1
When a small section in the circumferential direction is heated by the heating device 10 while rotating the ring member 1, the ring material 1 is rotated in the circumferential direction, and the curve 1 shown in FIG.
A temperature distribution as shown in FIG. That is, in the region heated by the heating device 10, the temperature rises as shown by the curve 15a, and in other regions, the temperature gradually falls as shown by the curve 15b. The temperature in the graph shown in FIG. 4 indicates the temperature (point 16 in FIG. 3) of the region of the ring material 1 immediately after leaving the heating device 10 as an index.

As described above, when heating the ring material 1, as shown by the curve 14 in FIG.
Is heated, held and cooled. In the heating step, the heating rate is kept low so that the ring material 1 does not crack. That is, since the base material 2 and the metal coating layer 3 constituting the ring material 1 have slightly different coefficients of thermal expansion, a film crack occurs when the temperature of the ring material 1 is increased and the thermal expansion is suddenly performed. Set the heating rate to such an extent that film cracking does not occur. For example, when the base material 2 is S20C and the metal coating layer 3 is a Ni—Cr-based self-fluxing alloy,
Set to about ° C / min. The rotational speed of the ring material 1 is preferably faster in order to heat the entire circumference of the ring material 1 as uniformly as possible. However, if it is too fast, the power required for rotation increases and the amount of heat dissipation increases, resulting in a large energy loss. Because the following disadvantages occur, the peripheral speed of the ring
It is preferable to be about 50 mm / sec.

The heating temperature (holding temperature) of the ring material 1 is usually set to about 500 to 1000 ° C. As a result of confirmation by the present inventors, it has been found that the holding temperature affects the diameter reduction ratio of the ring material. Therefore, the holding temperature is set according to a desired diameter reduction ratio. If the holding time is short, the effect of diameter reduction tends to be low and the diameter reduction rate tends to be unstable.

Even at the time of cooling, if the temperature lowering rate is high, the film is cracked. Therefore, it is desirable to cool slowly, and it is preferable to perform cooling slowly or gradually cooling by wrapping in a heat insulating material.

When the heating, holding, and cooling of the ring material 1 are performed as described above, the diameter of the ring material 1 is reduced, and the average diameter is reduced. Although the reason for this diameter reduction cannot be determined, it is thought to be due to the difference in cooling behavior between the outer peripheral surface side and the inner peripheral surface side of the ring material in the cooling process after heating and maintaining the temperature. In other words, the temperatures on the outer peripheral surface side and the inner peripheral surface side generally change in the heating / temperature maintaining process, but in the cooling process,
Both the radiant cooling and the convective cooling act strongly on the outer peripheral surface side, so that the temperature on the outer peripheral surface side is lower than that on the inner peripheral surface side. As for the force relationship, the heat shrinkage of the outer peripheral surface advances ahead of the inner peripheral surface, the outer peripheral surface exerts a compressive force on the inner peripheral surface, and the inner peripheral surface exerts a tension force on the outer peripheral surface. The cooling proceeds with the deformation resistance on the outer peripheral surface side being higher than that on the inner peripheral surface side. As a result, in the cooling process, the inner peripheral surface side having a low deformation resistance (soft) is compressively yielded by the compressive force exerted from the outer peripheral surface side and undergoes plastic deformation with reduced diameter, and the diameter of the inner peripheral surface side when thermally contracted to room temperature. (For example, the inner diameter dimension) becomes smaller than the original diameter. At this time, the outer peripheral surface side imitates the diameter of the inner peripheral surface side in such a manner that mutually minute elastic deformation force is exerted between the inner peripheral surface side and dimensional alignment. In other words, the plastic deformation on the inner peripheral surface side controls the diameter of the entire ring material after cooling.

As a result of examining factors affecting the diameter reduction ratio when the diameter is reduced by the above-described method, it was found that not only the holding temperature but also the heating width by the inductor and the rotation speed of the ring material are present. . For example, Table 1 shows the results obtained by measuring the relationship between the heating holding temperature and the diameter reduction ratio under the following conditions. (1) Sample ring material material Base material 2: S20C metal coating layer 3; Ni-Cr based self-fluxing alloy (2) Sample ring material size Outer diameter: 1845mm Inner diameter; 1840mm width; 80mm Metal coating layer thickness: 2.5mm ( 3) Heating / rotation conditions Ring material peripheral speed; 15 mm / sec Inductor heating width w; 40 mm Heating rate; 5 to 7 ° C / min Holding time; 2 hours Cooling method: Cooling by covering with heat insulating material (gradual cooling) )

[0025]

[Table 1]

Table 2 shows the results obtained by measuring the relationship between the heating width of the inductor and the diameter reduction ratio under the following conditions. (1) Sample ring material material Base material 2: S20C metal coating layer 3; Ni-Cr based self-fluxing alloy (2) Sample ring material size Outer diameter: 1845mm Inner diameter; 1840mm width; 80mm Metal coating layer thickness: 2.5mm ( 3) Heating and rotation conditions Ring material peripheral speed; 15 mm / sec Heating rate; 6 ° C / min Holding temperature; 800 ° C Holding time; 2 hours Cooling method: Cover with heat insulating material and allow to cool (gradual cooling)

[0027]

[Table 2]

Table 3 shows the results obtained by measuring the relationship between the rotation speed of the ring material and the diameter reduction ratio under the following conditions. (1) Sample ring material material Base material 2: S20C metal coating layer 3; Ni-Cr based self-fluxing alloy (2) Sample ring material size Outer diameter: 1845mm Inner diameter; 1840mm width; 80mm Metal coating layer thickness: 2.5mm ( 3) Heating condition Inductor heating width w; 30 mm Heating rate; 6 ° C / min Holding temperature; 800 ° C Holding time; 2 hours Cooling method: Cover with heat insulating material and allow to cool (slow cooling)

[0029]

[Table 3]

As described above, the diameter reduction ratio of the ring material 1 varies depending on the holding temperature, the heating width by the inductor, and the rotation speed of the ring material. By obtaining a condition for a desired diameter reduction ratio from the characteristics and performing a diameter reduction operation under the condition, the ring material 1 can be corrected to a desired diameter.

In the above-described embodiment, the pressing force of the support roller 11C, which is disposed so as to be in contact with the inner peripheral surface of the ring member 1, against the ring member 1 is restricted to such an extent that the ring member 1 does not rattle in the radial direction. At the same time, a frictional force capable of transmitting the rotation of the support roller 11A to the ring material 1 can be ensured, but is set low so as not to deform the ring material 1. Therefore, the heating operation is performed without applying a substantial load to the ring material 1. However, the present invention is not limited to this case, and the heating operation is performed in a state in which a diametrically outward load is applied to the ring material 1, thereby reducing the diameter reduction amount or further expanding the diameter. It is also possible. Hereinafter, an embodiment in this case will be described.

FIG. 5 is a schematic plan view showing an embodiment in this case. The average diameter correcting device used in this embodiment also includes a ring material supporting / rotating device 18 for supporting and rotating the ring material 1 to be processed, and a heating device 10 for heating a small circumferential section of the ring material 1. ing. The ring material supporting and rotating device 18 includes a support roller 21 disposed at a fixed position.
A and a supporting roller 21B pressed by pressing means (not shown) such as an air cylinder in a direction away from the supporting roller 21A.
Ring material 1 is set so as to surround
By pressing 1B in the direction indicated by arrow A by pressing means,
The two support rollers 21A and 21B can apply a load radially outward to two load application points C on the inner surface of the ring member 1 on the diameter. A rotation mechanism is connected to one support roller 21A, and the ring material 1 can be rotated by rotating the support roller 21A.
The heating device 10 heats a small section in the circumferential direction of the ring material 1, and the same device as the heating device of the embodiment shown in FIG. 1 is used. The heating device 10 is arranged to heat the ring material 1 at an intermediate position between the support rollers 21A and 21B.

In this embodiment, the support rollers 21A, 21A
The rotation and heating of the ring material 1 are performed in a state where a load is applied to the ring material 1 in the diametrically outward direction by B. The same is done. As a result, the ring material 1 tends to be reduced in diameter as described in the above embodiment.

On the other hand, since a radially outward load is applied to the two load application points C sandwiching the center of the ring material 1, this causes the ring material 1 to be plastically deformed to a small extent, and the ring material is deformed. Acts to expand the diameter. Hereinafter, this point will be described.

As shown in FIG. 6, the radius of the ring member 1 is R, the heating point of the ring member 1 is B, the points where a load acts on the ring member 1 are C and C, and the load is F. Due to this load F, the ring material 1 is deformed into an elliptical shape as shown in an exaggerated manner, and at the load application point C, a bending moment Mc acts in a direction to reduce the radius of curvature of the ring material 1, and the application points C and C A bending moment Mb acts on the heating point B at an intermediate point in the direction of increasing the radius of curvature of the ring material 1. These bending moments Mb and Mc are expressed by Equations 1 and 2, respectively.

[0036]

(Equation 1)

[0037]

(Equation 2)

Where k is the section modulus of the curved beam,
If the thickness of the ring material 1 in the radial direction is smaller than the radius R, it is considerably smaller than 1 and can therefore be omitted. Therefore, when the magnitude of the bending moment is calculated by omitting k, Mb = 0.182FR Mc = 0.318FR The stress generated in the ring material 1 by this bending moment is as follows: σ (point B) = Mb / Z = 0.182 FR / Z σ (point C) = Mc / Z = 0.318FR / Z. Therefore, the ratio between the two is σ (point C) / σ (point B) = 1.75, and a larger stress is generated at the load application point.

The stress σ (point B) generated in the ring material 1 by the bending moment Mb acting on the heating point B
When the plastic deformation stress .sigma.f of the ring member 1 in the above is exceeded, the ring member 1 plastically deforms at the heating point B in a direction in which the radius of curvature increases, whereby the ring member 1 tends to expand in diameter. On the other hand, the stress σ (C point) generated in the ring material 1 by the bending moment Mc acting on the load application point C is
When the plastic deformation stress .sigma.f of the ring material 1 at the load application point C is exceeded, the ring material 1 plastically deforms at the load application point C in a direction in which the radius of curvature is reduced. I do. Therefore, by increasing the plastic deformation at the heating point B and suppressing or eliminating the plastic deformation at the load application point C, it is possible to provide the ring member 1 with a diameter expanding action. Incidentally, as described above, the stress generated at the heating point B and the load application point C are not the same, and the stress at the load application point C is 1.75 times larger than the stress at the heating point B. Therefore, if the plastic deformation stress σf at the heating point B and the load application point C are the same, the plastic deformation at the load application point C is 1.75 times as large as the plastic deformation at the heating point B, and the diameter expansion occurs. Absent. Therefore, the heating point B
In order to make the plastic deformation at the load application point C larger than that at the load application point C, the ratio of the plastic deformation stress at the heating point B and the load application point C may be set as in the following equation. σf (point C) / σf (point B)> σ (point C) / σ (point B) = 1.75 (1)

The plastic deformation stress σf of the ring material changes depending on the temperature. For example, the temperature characteristic of the plastic deformation stress of S20C (normalized carbon steel) is as shown in the graph of FIG. Decreases as the value rises. FIG.
As shown in the figure, a temperature distribution is generated in the ring material 1 in the circumferential direction. This temperature distribution can be changed by changing the rotation speed of the ring member 1 or by blowing air onto the ring member 1 in a region exiting the heating device 10 to cool it. Therefore, by appropriately setting the temperature distribution in the ring material 1, the plastic deformation resistance σf (B
Point) and the plastic deformation resistance σf at point of load application point C (point C)
Can be set to a value that satisfies the above expression (1), whereby the ring member 1 can have a diameter expanding action. Explaining specific numerical values, assuming that the heating point B is 850 ° C., the plastic deformation resistance σf (point B) is 522 kg from FIG.
/ Cm ² , the plastic deformation stress σf (point C) at the load application point C is σf (point C)> 522 × 1.75 = 914 kg / cm ² from the above equation (1). The temperature corresponding to this value of plastic deformation resistance is shown in FIG.
Since the temperature at the load application point C is set to 660 ° C. or lower, the diameter expansion action can be caused. The lower the temperature, the larger the diameter expansion amount.

As described above, the ring material 1 is
When performing the operation of rotating while heating in the ring material 1
By applying a load F to the outside in the diametric direction and providing an appropriate temperature difference between the heating point B and the load application point, the ring member 1 can be provided with a diameter expansion action. The diameter expansion amount generated by this diameter expansion action increases as the load F increases and as the temperature difference increases. On the other hand, as described above, the ring material 1 is rotated while being heated, and then cooled.
Is reduced in diameter. Therefore, the diameter expansion effect due to the load and the heating
By appropriately adjusting the diameter reduction effect by the cooling operation, the ring material can be expanded or reduced in diameter to correct the average diameter to a desired value.

As in the embodiment shown in FIG.
In the case where a radially outward load is applied to the ring to exert a diameter-expanding effect, the ring material 1 is required to be effectively subjected to the diameter-expanding effect.
It is preferable to apply a large bending moment in the direction in which the radius of curvature increases in the region heated and heated by the heating device 10. Therefore, it is preferable to arrange the heating device 10 in a region where the maximum bending moment in the direction in which the radius of curvature is increased acts on the ring member 1 by the load applied to the ring member 1. The region where the maximum bending moment acts is shown in FIG.
In the embodiment, the heating device 10 is disposed at an intermediate point between the two support rollers 21A and 21B. In order to effectively provide the diameter-expanding effect, it is also effective to lower the temperature at the load application point C so that plastic deformation does not occur. In the area where the device 10 is arranged, the temperature is raised to a temperature at which plastic deformation is caused by the bending moment acting on the area, and at the point of application of the load, the temperature is reduced to a temperature at which the plastic moment is hardly generated by the bending moment applied to the point of action. It is preferable to set so that

In the embodiment shown in FIG. 5, the ring member 1 is supported by two support rollers 21A and 21B.
The number of support rollers used can be increased as appropriate. For example, three support rollers may be used as shown in FIG. In other words, the device shown in FIG. 1 can also apply a diametrically outward load to the ring material 1 by increasing the pressing force applied to the support roller 11C, which is the same as in the embodiment of FIG. In addition, the method can be used to implement a method of correcting the average diameter of the ring material to a desired value by causing a diameter expansion action by a load and a diameter reduction action by a heating / cooling operation.

FIG. 7 shows an embodiment in which the number of support rollers is further increased. That is, in this embodiment, the ring member supporting / rotating device 28 that supports the ring member 1 so as to rotate is provided with three support rollers 31A and 31B fixedly provided at a fixed position on one side of the center of the ring member 1. , 3
1C and three support rollers 31D, 31E, and 31F provided diametrically on opposite sides of the center, and the support rollers 31D, 31E, and 31F are pressed by an air cylinder or the like. Means (not shown) are connected. Also in this embodiment, three support rollers 31D, 3
By pressing the ring members 1E and 31F outward in the diametrical direction of the ring member 1 with a pressing means, an outward load is applied to the ring member 1 by the support rollers 31D, 31E and 31F and the opposite support rollers 31A, 31B and 31C. In this state, by rotating the ring material 1 and heating it by the heating device 10, a diameter expansion effect by a load and a diameter reduction effect by a heating / cooling operation are generated as in the embodiment of FIG. Thus, the average diameter of the ring material can be corrected to a desired value. FIG.
As in the embodiment of the present invention, when the load acting points on the ring material 1 are increased, the force applied to the ring material 1 can be dispersed, so that the bending moment in the direction of reducing the radius of curvature generated at each acting point is reduced. The effect of the diameter expansion can be improved.

In each of the embodiments described above, one heating device 10 for heating the ring material 1 is provided. However, the number of the heating devices 10 is not limited to one, and a plurality of heating devices 10 may be provided. The ring material 1 may be heated at a plurality of locations on the circumference.

[0046]

As described above, according to the present invention, a small section in the circumferential direction of a ring material having a metal coating layer is heated by a heating device while the ring material is circumferentially moved with respect to the heating device. By relatively moving the ring material over the entire circumference to heat the ring material over its entire circumference, raising the temperature to a predetermined temperature, and then cooling, the diameter of the ring material can be reduced by a very small amount. The amount of diameter reduction at that time is determined by the heating temperature, the heating width by the heating device, the rotation speed of the ring material, etc., so that by appropriately setting them, the average diameter of the ring material is corrected to a desired value. Can be. For this reason, when the average diameter of a ring material having a thin (and thus extremely small) metal coating layer formed on the outer or inner peripheral surface is larger than the average diameter required for the final product, The average diameter can be corrected to a desired value, and thereafter, the ring material is subjected to finish processing, whereby an effect of producing a ring material having a desired size and a metal coating layer can be obtained.

Further, an outward load is applied to a plurality of load application points circumferentially distant from the ring material, and in this state, the ring material in a region distant from the load application point in the area distant from the load application point is applied. While the section is heated by the heating device, the ring material is moved relative to the heating device in the circumferential direction, the ring material is heated over the entire circumference, cooled to a predetermined temperature, and then cooled. By performing the operation, it is possible to provide the ring material with the effect of expanding the diameter by the load and the effect of reducing the diameter by the heating / cooling operation. By adjusting the diameter of the ring member, it is possible to reduce the diameter of the ring material to a desired diameter or to increase the diameter of the ring material, and to correct the average diameter to a desired value. Therefore, when the average diameter of the ring material having a thin metal coating layer formed on the outer peripheral surface or the inner peripheral surface is deviated from the average diameter required for the final product, the average diameter of the ring material is corrected to a desired value. After that, by applying a finishing process to the ring material, it is possible to produce a ring material having a desired size and a metal coating layer.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a state in which an average diameter of a ring material is corrected using an average diameter correction device according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing the relationship between the ring material 1 in the embodiment shown in FIG.

FIG. 3 is a graph showing a temperature distribution generated in the rotating ring material 1;

FIG. 4 is a graph showing a time-dependent change in the temperature of the ring material on the exit side of the heating device in the embodiment shown in FIG. 1;

FIG. 5 is a schematic perspective view showing a state in which an average diameter of a ring material is corrected using an average diameter correction apparatus according to another embodiment of the present invention.

FIG. 6 is a schematic view showing a load and a bending moment acting on a ring member in the embodiment shown in FIG.

FIG. 7 is a schematic perspective view showing a state in which an average diameter of a ring material is corrected using an average diameter correction apparatus according to still another embodiment of the present invention.

FIG. 8 is a graph showing the relationship between plastic deformation stress and temperature of normalized carbon steel.

[Explanation of symbols]

Reference Signs List 1 ring material 2 base material 3 metal coating layer 8, 18, 28 ring material supporting rotating device 10 heating device 11A, 11B, 11C supporting roller 21A, 21B supporting roller 31A, 31B, 31C, 31D, 31E, 31F supporting roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Yatabe 2-17-8 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Within Dai-ichi High Frequency Industry Co., Ltd. (72) Tadanobu Miyagawa 2-chome Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 17-8 Inside Daiichi High Frequency Industry Co., Ltd.

Claims (7)

[Claims] 1. A heating device heats a small section of a ring material having a metal coating layer on an outer peripheral surface, an inner peripheral surface, or an end surface thereof, and circumferentially moves the ring material relative to the heating device. And heating the ring material over its entire circumference, raising the temperature to a predetermined temperature, and then cooling the ring material, wherein the average diameter of the ring material having a metal coating layer is corrected. 2. An outward load is applied to a plurality of circumferentially spaced load application points of a ring material having a metal coating layer on an outer peripheral surface, an inner peripheral surface or an end surface, and in that state, the load application point is applied. While heating a small section in the circumferential direction of the ring material in a region away from the heating device with the heating device, the ring material is moved relative to the heating device in the circumferential direction, and the ring material is moved over the entire circumference. A method for correcting the average diameter of a ring material, comprising a metal coating layer, wherein the ring material is heated, heated to a predetermined temperature, and then cooled. 3. The heating device is disposed in a region where a maximum bending moment acts in a direction in which a radius of curvature is increased by a load applied to the ring material, and furthermore, a circumferential temperature distribution generated in the ring material is In the area where the heating device is arranged, the temperature is raised to a temperature at which plastic deformation is caused by the bending moment acting on the area, and at the load application point, the temperature is such that the plastic deformation hardly occurs at the bending moment applied to the action point. 3. The method for correcting an average diameter of a ring material according to claim 2, wherein the setting is made to decrease. 4. The ring material according to claim 1, wherein a diameter correction amount of the ring material is adjusted by adjusting a heating width of the ring material in a circumferential direction by the heating device. How to correct the average diameter of the ring material. 5. The ring material according to claim 1, wherein the amount of diameter correction of the ring material is adjusted by adjusting a moving speed of the ring material with respect to the heating device. Mean diameter correction method. 6. A ring material supporting and rotating device for supporting and rotating a ring material having a metal coating layer on an outer peripheral surface, an inner peripheral surface, or an end surface in such a manner as not to hinder an increase in outer diameter, and a circumference of the ring material. A device for correcting the average diameter of the ring material, comprising a heating device for heating a small section in the direction. 7. A state in which a ring material having a metal coating layer on an outer peripheral surface, an inner peripheral surface, or an end surface is subjected to an outward load at a plurality of load application points circumferentially separated on the inner peripheral surface. A ring material supporting / rotating device for supporting and rotating the ring material, and a heating device for heating a small circumferential section of the ring material, the average diameter correcting device for the ring material.