Induction heating quenching method and induction heating quenching apparatus

Abstract

To provide an induction heating quenching method and an induction heating quenching device for shortening a production cycle time.SOLUTION: A plurality of plate-like members are placed in parallel on a jig, and ends of the plurality of plate-like members are inductively heated at one time by one quenching coil. The ends of the plurality of plate-like members are inductively heated at one time in each row by the one quenching coil by placing two rows of the plurality of plate-like members on the jig so that their ends face each other and moving the jig.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an induction heating quenching method and an induction heating quenching apparatus for quenching the end portion of a plate-like member.

Background Art

[0002] Conventionally, when inductively heating a member that requires partial quenching, induction heating is performed on each member individually using an inductor that matches the shape of the member being processed and the shape of the quenching target area, and quenching is carried out (see Patent Documents 1 to 3).

[0003] Patent Document 1 describes that an induction action part 21 or 51, 52 is opposed to one heated area 11 or a plurality of heated areas 41, 42 defined in an elongated shape in a thin plate article 10 or 40, and by passing a high-frequency current through this induction action part, the entire area of the one or more heated areas is simultaneously inductively heated (see Summary, Claims 1, 2; FIGS. 1, 4).

[0004] Patent Document 2 describes a method for high-frequency quenching a stepped member such as a pole parking having a material area M and a processing area N adjacent to the material area M via a stepped portion 6, for high-frequency quenching the processing area of the stepped member, which is a method of directly energizing the processing area N by abutting a pair of electrode contacts 7, 8 at a part of the material area M and in the vicinity of the stepped portion 6, heating the processing area N, and then cooling the processing area N heated to the required quenching temperature with a quenching coolant 9 to form a quenched hardened layer S in the processing area (see Summary, Claims 1, 3; FIGS. 1, 2).

[0005] Patent Document 3 describes an induction heating and hardening method for a long material 10 in which a first side portion 11 and a second side portion 12 are adjacent at a corner 13, a recess is provided in the first side portion 11 spaced apart from the corner 13, and the first and second side portions 11, 12 and the recess 14 are continuous in the longitudinal direction, using a heating coil 21 for the long material 10 in which a wide conductor 24 facing the first side portion 11 and a narrow conductor 23 facing the recess 14 and protruding toward the recess 14 from the wide conductor 24 are arranged along the longitudinal direction to induce heating of the first side portion 11 and the recess 14 (Abstract, Claim 1; see Figure 1).

[0006] On the other hand, in order to efficiently perform induction heating quenching, multiple workpieces are sometimes quenched simultaneously (see Patent Documents 4 and 5).

[0007] Patent Document 4 describes stacking multiple base metals 8, which are to be processed, pressing electrodes 4 and 5 onto their upper and lower surfaces, covering the outer periphery of the base metals 8 in a substantially sealed state with a case, supplying an inert gas into the case, and then supplying a high-frequency current between the electrodes to quench the base metals 8 (see abstract, claim 1, and Figure 1).

[0008] Patent Document 5 describes a method of simultaneously hardening the hardening regions 11, 11 of multiple workpieces 10 by connecting multiple workpieces 13, 14 with conductive connections 15 such that a closed circuit is formed in which the respective hardening target regions 11 are connected in a series endless manner, and the positional relationship between each workpiece is fixed, thereby temporarily assembling them into a workpiece assembly 13+14. An inductor 17 that generates a magnetic flux in the same direction as the axis of the assembly is placed on the outside of the assembly, and a high-frequency current is applied to the inductor 17 to generate an induced current that circulates around the closed circuit in a manner that increases the coupling coefficient, which is an indicator of the degree of coupling between the inductor and the workpiece (Abstract, Claim 1; see Figure 1). Furthermore, Patent Document 5 states, "In the conventional quenching methods for thin steel sheet formed products described above, in all cases the workpiece is a single unit. Therefore, when processing a large number of items, processing them one by one takes time, and simply increasing the number of items to process in parallel or in parallel processing would increase equipment costs and so on." (Paragraph

[0006] ) [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2005-054225 [Patent Document 2] Japanese Patent Publication No. 2005-105301 [Patent Document 3] Japanese Patent Publication No. 2013182840 [Patent Document 4] Japanese Patent Application Publication No. 7-216457 [Patent Document 5] Japanese Patent Publication No. 2008-45183 [Overview of the project] [Problems that the invention aims to solve]

[0010] The quenching methods described in Patent Documents 1 to 3 involve quenching each workpiece individually. Therefore, they have the problem of not being able to increase production efficiency and being unsuitable for mass production. Patent documents 4 and 5 describe the process of quenching multiple workpieces simultaneously. However, the quenching method described in Patent Document 4 is applicable to workpieces such as base metals with a certain thickness that can be pressure-welded, and cannot be said to be generalizable to plate-shaped members with various shapes. Furthermore, it requires pretreatment in which the processing atmosphere is sealed and replaced with an inert gas, making it difficult to increase production efficiency. The quenching process described in Patent Document 5 requires a complex pre-process to assemble the workpieces in a conductive connection that forms a closed circuit by connecting multiple workpieces in a series in an endless manner, while fixing the positional relationship between each workpiece. Therefore, this process also lacks versatility and makes it difficult to improve production efficiency. Furthermore, while Patent Document 5 describes parallel processing as a method for quenching a large number of thin steel sheet formed products (plate-shaped members) as prior art, it does not specify the exact processing method.

[0011] In view of the above problems, the present invention aims to provide an induction heating quenching method and an induction heating quenching apparatus that can efficiently perform partial quenching of multiple plate-shaped members. [Means for solving the problem]

[0012] To solve the above problems, the present invention employs the following means. (1) An induction heating quenching method for quenching the ends of plate-shaped members by high-frequency induction heating, wherein a plurality of plate-shaped members are placed in parallel on a jig, and the ends of the plurality of plate-shaped members are induction heated at the same time with a single quenching coil. (2) The induction heating quenching method according to (1), wherein a plurality of plate-shaped members are placed in two parallel rows on the jig with their ends facing each other, with the quenching coil in between, and the jig is moved to induce heat the ends of the plurality of plate-shaped members in each row at once with the quenching coil.

[0013] (3) One hardened coil, A jig having two lines on either side of the aforementioned hardened coil, on which multiple plate-shaped members are placed in parallel so that their ends face each other, A moving mechanism moves the ends of multiple plate-shaped members in the first line of the jig between a hardening position where the ends of the plate-shaped members in the first line are hardened by high-frequency induction hardening using the hardening coil, and a hardening position where the ends of other multiple plate-shaped members in the second line are hardened by high-frequency induction hardening using the hardening coil. A detaching and attaching mechanism for carrying out the plurality of plate-shaped members induction-hardened in each of the respective lines, and The detaching and attaching mechanism unloads the plurality of plate-shaped members induction-hardened in the second line while the ends of the plurality of plate-shaped members in the first line are at the hardening position, and places a plurality of plate-shaped members to be newly induction-hardened in parallel on the second line such that their ends face the ends of the plurality of plate-shaped members in the first line, and unloads the plurality of plate-shaped members induction-hardened in the first line while the ends of the plurality of plate-shaped members in the second line are at the hardening position, and places a plurality of plate-shaped members to be newly induction-hardened in parallel on the first line such that their ends face the ends of the plurality of plate-shaped members in the second line. The induction heating hardening apparatus has such mechanisms. (4) The induction heating hardening apparatus according to (3), wherein a distance is ensured between the hardening position in the first line and the hardening position in the second line such that the induction magnetic fields during induction heating by the hardening coil do not interfere with each other.

Advantages of the Invention

[0014] According to the present invention, partial hardening of a plurality of plate-shaped members can be performed without requiring a special pre-process, and thus an induction heating hardening method and an induction heating hardening apparatus with improved production efficiency can be provided.

Brief Description of the Drawings

[0015] [Figure 1] Schematic plan view of an induction heating hardening apparatus according to an embodiment of the present invention [Figure 2] Schematic plan view showing the hardening position and detachment / attachment position of an induction heating hardening apparatus according to an embodiment of the present invention

Mode for Carrying Out the Invention

[0016] (Induction Heating Hardening Method) The induction hardening method according to an embodiment of the present invention (hereinafter referred to as "this embodiment") is an induction hardening method for hardening an end portion of a plate-like member by high-frequency induction heating, and a method of placing a plurality of plate-like members in parallel on a jig and induction heating the end portions of the plurality of plate-like members at once with one hardening coil. Thus, since induction hardening can be performed at once with one hardening coil without requiring a special pre-process, the production efficiency is improved.

[0017] More specifically, the induction hardening method according to this embodiment is a method of placing a plurality of plate-like members in two parallel rows on a jig such that their end portions face each other with one hardening coil interposed therebetween, and by moving the jig, induction heating the end portions of the plurality of plate-like members row by row at once with the one hardening coil. Thus, since induction heating of the plurality of plate-like members placed in two rows can be performed row by row at once with one hardening coil, the production efficiency is further improved.

[0018] Hereinafter, the hardening method according to this embodiment will be specifically described based on FIG. 1. (1) Place a plurality of plate-like members in two parallel rows on two lines (hereinafter referred to as "the first line" and "the second line") provided on the jig such that the end portions, which are the hardening target portions, face each other. (2) Move one hardening coil and the jig relatively, and induction heat and cool the end portions of the plurality of plate-like members in the first line (shown as the "A line" in the figure; hereinafter the same) at once with the one hardening coil to complete the hardening (the cooling jacket is not shown). During that time, the plurality of plate-like members placed on the second line (shown as the "B line" in the figure; hereinafter the same) are not affected by the induction magnetic field generated during the induction heating on the first line by the hardening coil. (3) Next, the one quenching coil and the jig are moved relative to each other, and the ends of the multiple plate-shaped members in the second line are simultaneously induction heated by the quenching coil and then cooled to complete the quenching process. Meanwhile, the multiple plate-shaped members that have been quenched in the first line are removed, and the multiple plate-shaped members to be quenched are placed on the first line. The newly placed multiple plate-shaped members are also not affected by the induction magnetic field generated when the quenching coil is induction heating on the second line. (4) Again, by moving the quenching coil and the jig relative to each other, the ends of the multiple plate-shaped members in the first line are simultaneously induction heated by the quenching coil and then cooled to complete the quenching process. Meanwhile, the multiple plate-shaped members that have been quenched in the second line are removed, and the multiple plate-shaped members to be quenched again are placed in the second line. (5) The following steps (3) and (4) are repeated the desired number of times, and production is stopped when the desired number of hardened products are obtained.

[0019] (Plate-shaped member) The material of the plate-shaped member can be any material that can be hardened, and is not limited, but steel is preferred. The method and apparatus of this embodiment can be used, for example, for hardening S48C (C: 0.45~0.51, Si: 0.15~0.35, Mn: 0.60~0.90, P: 0.030 or less, S: 0.035 or less), which is a carbon steel for machine structures.

[0020] (Induction heating quenching device) Figure 1 shows a schematic plan view of the induction heating quenching apparatus according to this embodiment. This device comprises a hardening coil, a jig having two lines on either side of the hardening coil, each line on which multiple plate-shaped members are placed in parallel so that their ends face each other, a moving mechanism (not shown) that moves the ends of multiple plate-shaped members in the first line of the jig between a hardening position where the ends of other multiple plate-shaped members in the second line are hardened by the hardening coil, and a detachment mechanism (not shown) that unloads the multiple plate-shaped members that have been hardened by high-frequency induction induction in each of the lines.

[0021] The moving mechanism and the attachment / detachment mechanism will be described based on Figure 2. The left diagram of Figure 2 shows that a jig and one hardening coil are moved relative to each other by a moving mechanism (not shown), and the ends of multiple plate-shaped members placed on the first line are in the hardening position by the one hardening coil. While in this state, if multiple plate-shaped members that have completed hardening are placed on the second line, they are removed by a detachment mechanism (not shown) and new members to be hardened are placed on top. The right-hand diagram of Figure 2 shows a state in which the jig and one hardening coil are moved relative to each other by a moving mechanism (not shown), and the ends of multiple plate-shaped members placed on the second line are in the hardening position by the one hardening coil. While in this state, if multiple plate-shaped members that have completed hardening are placed on the first line, they are removed by a detachment mechanism (not shown) and new members to be hardened are placed on top.

[0022] In other words, the attachment / detachment mechanism includes a mechanism for unloading a plurality of plate-shaped members that have been hardened in the second line while the ends of the plurality of plate-shaped members in the first line are in the hardening position, and for placing a plurality of plate-shaped members to be hardened in the second line in parallel so that their ends face each other, and a mechanism for unloading a plurality of plate-shaped members that have been hardened in the first line while the ends of the plurality of plate-shaped members in the second line are in the hardening position, and for placing a plurality of plate-shaped members to be hardened in the first line in parallel so that their ends face each other.

[0023] The hardening coil is typically configured in conjunction with a high-frequency power supply, cooling device, etc. Therefore, it is preferable that the moving mechanism fixes one hardening coil and moves the jig, but it may also fix the jig and move one hardening coil. Furthermore, the hardening coil is not particularly limited as long as it has a shape in which multiple plate-shaped members are placed in parallel on a jig and the ends of the multiple plate-shaped members are simultaneously induction heated by a single hardening coil.

[0024] Furthermore, to improve the uniformity of the hardening, it is preferable to ensure a distance between the hardening position in the first line and the hardening position in the second line such that the induced magnetic field from one line of the hardening coil does not interfere with the material in the other line. [Industrial applicability]

[0025] The induction heating quenching method and induction heating quenching apparatus according to the present invention can significantly improve productivity and can therefore be effectively used for mass production of steel parts.

Claims

[Claim 1] An induction heating quenching method for quenching the ends of plate-shaped members by high-frequency induction heating, wherein multiple plate-shaped members are placed in parallel on a jig, and the ends of the multiple plate-shaped members are simultaneously induction heated with a single quenching coil.

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