JP2002371316A - Method for hardening long workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for hardening a long workpiece in an adequate yield, which can perform induction hardening for the long workpiece fully to both ends. SOLUTION: The method for hardening the long workpiece such as rails fully to both ends W1 and W2, is characterized by setting the supplied electric power to a heating coil 100 for induction heating, when heating a start end W1 and a finish end W2 of the long workpiece, larger than the supplied electric power when heating the other part than both the ends W1 and W2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hardening a long work such as a rail.

[0002]

2. Description of the Related Art For example, induction hardening is performed on rails used in a linear motion system of a positioning device. The induction quenching apparatus used for the induction quenching includes a heating coil for induction heating a rail, which is a fixed long work, a power supply for supplying power to the heating coil, and a part heated by the heating coil. And a moving mechanism for moving the heating coil and the cooling jacket along the long work.

[0003] That is, a cooling jacket is provided upstream of the heating coil, and a portion heated by the heating coil first is subjected to induction quenching by spraying a cooling liquid with the cooling jacket later.

[0004]

However, there are problems as in the above-described conventional method of hardening a long workpiece. First, induction hardening is not performed on both ends of the long workpiece. This is because if the long workpiece does not completely enter the heating coil, the load is small and the output is lower than a predetermined output, and as a result, induction quenching at both ends becomes shallow.

[0005] For this reason, conventionally, a long and long work is prepared in consideration of a portion where induction quenching is not performed, and a portion where induction quenching is not performed in a post-step of induction quenching is used. Work was being done.

In addition, the induction hardening of a long workpiece has a small induction quenching because the heating amount at both ends of the start end and the end end is smaller than that of other parts. Both ends of the long workpiece had to be cut.

That is, at the start end of the induction quenching, the heating coil is opposed from the beginning, so that the amount of heating is larger than at other parts. This is due to the fact that the amount of heating is larger than that of the other parts because they are opposed to each other.

The present invention has been made in view of the above circumstances, and has as its object to provide a method of quenching a long workpiece in which induction hardening can be applied to both ends.

[0009]

According to a first aspect of the present invention, there is provided a method for quenching a long work, the method including induction hardening to both ends of the long work. At the time of heating both ends of the induction hardening of the long work at the start end and the end end, the power setting at the time of heating the portion other than both ends of the long work is set to be larger.

A method for quenching a long work according to a second invention is a method for quenching a long work in which induction hardening is performed to both ends of the long work. When heating both ends of the start end and the end end of the heating coil, the moving speed of the heating coil to be subjected to the induction heating with respect to the long work is set to be lower than the moving speed at the time of heating other than the both ends.

[0011]

FIG. 1 is a graph showing a relationship between a moving distance of a heating coil and an amount of electric power supplied to the heating coil in a method for hardening a long workpiece according to a first embodiment of the present invention. FIG. 2 is a graph showing the relationship between the moving distance of the heating coil and the moving speed of the heating coil in the method for quenching a long workpiece according to the second embodiment of the present invention, and FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing of the general induction quenching apparatus which uses the quenching method of the long workpiece which concerns on a form.

First, the structure of the induction quenching apparatus using the method of quenching a long workpiece is the same as that of the conventional apparatus. That is, a heating coil 100, a power supply 300 for supplying electric power to the heating coil 100, and a cooling jacket 200 attached to the upstream side of the heating coil 100 and spraying a coolant to a portion heated by the heating coil 100.
And a moving mechanism (not shown) for moving the long workpiece W along the axis.

The method for quenching a long work according to the first embodiment of the present invention is based on a method of hardening a long work W such as a rail.
1. A method for quenching a long workpiece in which induction quenching is performed to W1 and W2, wherein a starting end W1 and an ending end W2 of the long workpiece W are provided.
When heating both ends of the long workpiece W, the power supplied to the heating coil 100 for performing the induction heating is set to be larger than the power setting when heating the portion other than the both ends W1 and W2 of the long workpiece W.

First, in this quenching method, as shown in FIG. 1 (A), the electric power until the heating coil 100 completes the movement of the distance A corresponding to the length of the heating coil 100 is applied to other parts. Power setting.

Then, the heating amount of the starting end W1 of the long work becomes equal to the other portions. Thereby, the starting end W
The depth of induction quenching in No. 1 is almost equal to the center. The electric power supplied to the heating coil 100 is equal between the start end W1 and the end end W2.

On the other hand, also at the end W2, when the heating coil 100 reaches a point at a distance A corresponding to the length of the heating coil 100 from the end W2, the power setting is gradually increased, and When it reaches, the power setting at the starting end W1 is made equal. That is, the current flowing in any part of the long workpiece W is made equal.

Then, the amount of heating at the end W2 of the long workpiece becomes equal to that of the other portions. Thereby, the starting end W
Induction quenching in 1 is equal to other parts.

The power at the terminal W1 and the power at the end W2 may be changed stepwise as shown in FIG.

The method of quenching a long workpiece according to the second embodiment of the present invention is different from that of the first embodiment in that the heating coil is not adjusted but the power setting is adjusted. 1
The point is that the moving speed of 00 is adjusted.

That is, the method of quenching a long workpiece according to the second embodiment of the present invention comprises the steps of:
1. A method for quenching a long workpiece in which induction quenching is performed to W1 and W2, wherein a starting end W1 and an ending end W2 of the long workpiece W are provided.
When heating both ends, the moving speed of the heating coil 100 to be subjected to induction heating with respect to the long workpiece W is made smaller than the moving speed of the portions other than the both ends W1 and W2 when heating.

That is, as shown in FIG. 2A, the moving speed until the heating coil 100 reaches a distance corresponding to the length of the heating coil 100 from the starting end W1 of the long workpiece W is different from that of the other parts. Is made smaller than the moving speed at. The movement speed of the heating coil 100 from the start end W1 to the distance A is changed gradually as shown in FIG. 2A or stepwise as shown in FIG. 2B.

Then, from the start end to the above distance,
Since the time that the heating coil 100 is facing is long,
The heating amount of the starting end W1 of the long workpiece W is almost the same as the other portions.

The speed between the start end W1 and the end W2 is constant.

On the other hand, also at the end W2, if the heating coil 100 reaches the point of the distance A corresponding to the length of the heating coil 100 from the end W2, the moving speed is gradually reduced or the speed is gradually reduced. Make it smaller.

Then, during the period from the distance A to the end end W2, the time during which the heating coil 100 faces is long, so that the heating amount of the end end W2 of the long workpiece W is almost equal to that of the other parts. Become equal.

In the above description, the long workpiece W
Is fixed and the heating coil 100 and the cooling jacket 200 are moved. Alternatively, the heating coil 100 and the cooling jacket 200 may be fixed and the long workpiece W may be moved. Further, the long workpiece W and the heating coil 100 and the cooling jacket 200 may be moved in opposite directions. In other words,
It is sufficient that the long workpiece W and the heating coil 100 and the cooling jacket 200 relatively move.

[0027]

The method for quenching a long work according to the present invention is a method for quenching a long work in which induction hardening is performed to both ends of the long work. At the time of heating both ends of the quenching start end and end, the power setting at the time of heating portions other than both ends of the long workpiece is set larger.

For this reason, according to this quenching method, the starting and ending ends of the induction quenching have the same heating amount relative to other portions, so that there is no heat escape and the induction quenching is performed to the same depth. Is done.

Another method of quenching a long workpiece according to the present invention is a method of quenching a long workpiece in which induction hardening is performed to both ends of the long workpiece. When heating both ends of the starting end and the ending end of the heating coil, the moving speed of the heating coil for applying the induction heating to the long workpiece is smaller than the moving speed of the portion other than both ends at the time of heating.

For this reason, according to this quenching method, the starting and ending ends of the induction quenching have substantially the same heating amount as the other portions, so that there is no heat escape and the induction quenching is performed to the same depth. Will be applied.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a moving distance of a heating coil and an amount of electric power supplied to the heating coil in a method of quenching a long workpiece according to a first embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a moving distance of a heating coil and a moving speed of a heating coil in a method of quenching a long workpiece according to a second embodiment of the present invention.

FIG. 3 is a schematic explanatory view of a general induction quenching apparatus using a method of quenching a long work according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 100 heating coil 200 cooling jacket W long workpiece W1 start end W2 end end A Length of heating coil

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K059 AA09 AB19 AB24 AB28 AC37 AD05 CD14 CD65 CD73 CD75 4K042 AA04 BA13 DA01 DB01 DC01 DC05 EA03

Claims (2)

[Claims] 1. A method for quenching a long workpiece in which induction quenching is performed to both ends of the long workpiece, wherein both ends of the start and end of the induction quenching of the long workpiece are heated. A method for quenching a long work, wherein the power is set to be larger than a power setting for heating a portion other than both ends of the long work. 2. A method for quenching a long workpiece in which induction quenching is performed to both ends of the long workpiece, wherein a heating coil for performing induction heating when heating both ends of a start and an end of the long workpiece. A method for quenching a long work, characterized in that the moving speed of the long work is made smaller than the moving speed of a portion other than both ends when heating.