JP-7856922-B2 - Mobile quenching apparatus

JP7856922B2JP 7856922 B2JP7856922 B2JP 7856922B2JP-7856922-B2

Inventors

山根明仁
秦利行
小塚千尋

Assignees

日本製鉄株式会社

Dates

Publication Date: 20260512
Application Date: 20220630

Claims (6)

A device for performing mobile quenching on a shaft-shaped body having a large-diameter section with a relatively large outer diameter and a small-diameter section with a relatively small outer diameter connected by a stepped section, Multiple segmented coils arranged in a ring around a central axis through which high-frequency current flows, A coil drive unit that moves each of the divided coils closer to and further away from the central axis, Equipped with, Each of the aforementioned divided coils comprises a plurality of convex coil portions having a shape that is convex in a direction away from the central axis when viewed along the central axis; Each of the aforementioned convex coil portions, In the line of sight along the direction perpendicular to the central axis, at least a portion of them overlap with each other, From a line of sight along the central axis, the objects are arranged with a gap between them in the radial direction centered on the central axis; A mobile quenching apparatus characterized by the following features.
Each of the aforementioned divided coils is A connecting portion that electrically connects each of the aforementioned convex coil portions, A first conductor portion is electrically connected to one end of each of the convex coil portions around the central axis and extends in the radial direction, A second conductor portion is electrically connected to the other end of each of the convex coil portions around the central axis and extends in the radial direction, Furthermore, The mobile quenching apparatus according to claim 1, characterized in that , in a line of sight along the central axis, the first conductor portion and the second conductor portion are arranged to overlap with the connection portion.
Each of the aforementioned divided coils is a two-turn coil having an inner circumferential convex coil portion relatively close to the central axis and an outer circumferential convex coil portion relatively far from the central axis as its respective convex coil portion; The first conductor portion has a first bent portion that curves in a direction toward the central axis than the position of the outer circumferential convex coil portion and connects to one end of the inner circumferential convex coil portion; The second conductor portion has a second bend that curves from the other end toward the one end, and a third bend that curves from the second bend to connect to the other end of the outer convex coil portion; The mobile quenching apparatus according to feature 2.
Each of the aforementioned divided coils is a three-turn coil having a first convex coil section, a second convex coil section, and a third convex coil section arranged in order in a direction away from the central axis; The first conductor portion and the second conductor portion are arranged to overlap, in line with respect to the connecting portion that connects the first convex coil portion and the second convex coil portion, and the connecting portion that connects the second convex coil portion and the third convex coil portion, in a line of sight along the central axis ; The mobile quenching apparatus according to feature 2.
Each of the aforementioned divided coils is a three-turn coil having a first convex coil section, a second convex coil section, and a third convex coil section arranged in order in a direction away from the central axis; Each of the aforementioned divided coils is A first connecting portion connecting the first convex coil portion and the second convex coil portion, A second connecting portion connecting the second convex coil portion and the third convex coil portion, A first conductor portion is electrically connected to the first convex coil portion and extends in the radial direction, A second conductor portion is electrically connected to the third convex coil portion and extends in the radial direction, Equipped with; At least a portion of the first conductor portion and the second conductor portion is offset in the circumferential direction with respect to the first connection portion and the second connection portion, with respect to the central axis; The mobile quenching apparatus according to feature 1.
The mobile quenching apparatus according to any one of claims 1 to 5, characterized in that the number of each divided coil is two or three.

Description

This disclosure relates to a mobile quenching apparatus. Conventionally, axial bodies are subjected to traverse hardening by induction heating to increase their fatigue strength. Here, traverse hardening refers to hardening a axial body while moving a coil member or the like in the axial direction. Specifically, the shaft is inductively heated by passing an electric current through the coil while moving the coil along the outer surface in the longitudinal direction of the shaft. Then, the shaft is rapidly cooled and hardened by spraying a cooling liquid onto the outer surface immediately after heating. Here, if the shaft is a stepped shaft with a step section in its longitudinal direction where the outer diameter changes from a large diameter to a small diameter or from a small diameter to a large diameter, it is necessary to appropriately adjust the air gap between the outer surface of the shaft and the coil in order to maintain heating efficiency. One device configuration that enables such adjustment involves composing the coil using multiple segmented coils. Specifically, multiple segmented coils are arranged in a circumferential direction along the shaft, and these segmented coils are connected in series to a power supply. Then, while current from the power supply flows through each segmented coil, these segmented coils are moved along the longitudinal direction of the shaft. Just before the segmented coils reach the stepped section, the air gap is maintained at a nearly constant level by moving each segmented coil closer to or further away from the outer surface of the shaft, in accordance with the change in the outer diameter of the shaft. A conventional high-frequency induction heating device using this type of divided coil is disclosed in Patent Document 1 below. The device is equipped with a high-frequency induction heating coil as a divided coil. This high-frequency induction heating coil for heating an axial member employs a configuration in which, "a axial member having a flange portion and a shaft portion erected at the center of the flange portion, the coil for heating an arc portion formed between the flange portion and the shaft portion where they intersect, and the outer circumferential surface of the shaft portion, is provided with a pair of high-frequency induction heating coil components that are arranged opposite each other across the axis of the axial member, and are also arranged opposite the arc portion and the shaft portion at a distance from the arc portion and the shaft portion of the axial member, and each of the pair of high-frequency induction heating coil components has a bent coil portion formed so as to protrude in a direction away from the axis of the axial member." According to the device, "By using a pair of high-frequency induction heating coil components, it becomes possible to arrange the aforementioned pair of high-frequency induction heating coil components in correspondence with all types of axial members having different outer diameters." Japanese Patent Application Publication No. 2008-150640 This is a schematic side view showing a part of a mobile quenching apparatus according to the first embodiment of the present disclosure, with a fractured section.This is a perspective view of one of the segmented coils in the mobile hardening apparatus, viewed from below. The opening angle between the first and second wire sections is 180°, but in this figure, for illustrative purposes, the opening angle is shown narrowed using a broken line.This figure shows the state in which the small diameter portion of the shaft-shaped body is being inductively heated by the split coil, and is a view taken along the line A-A in Figure 1.This figure shows the state in which the divided coil reaches the position of the B-B cross section in Figure 1 and is inductively heating the large diameter portion of the shaft.This is a flowchart showing the mobile quenching method in the same embodiment.This figure shows the state in which a small-diameter portion of a shaft is being induction heated by a mobile quenching apparatus according to a second embodiment of the present disclosure, and is a view taken along the line A-A in Figure 1.This figure shows one of the segmented coils of a mobile quenching apparatus according to the third embodiment of the present disclosure, viewed from below. (a) is a perspective view showing the external appearance of the segmented coil, and (b) is a perspective view showing the flow of coolant and current. The opening angle between the first and second conductor sections is 180°, but in this figure, for illustrative purposes, the opening angle is shown narrowed using a broken line.This figure shows one of the segmented coils of a mobile quenching apparatus according to the fourth embodiment of the present disclosure, viewed from below. (a) is a perspective view showing the external appearance of the segmented coil, and (b) is a perspective view showing the flow o