Rail heat treatment device and rail heat treatment method

Patent metadata

Field	Value
Publication number	US-9593393-B2
Application number	US-201214375232-A
Country	US
Kind code	B2
Filing date	Feb 6, 2012
Priority date	Feb 6, 2012
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A rail heat treatment device includes a cooling header, an oscillation mechanism, and a control system including: a storage unit that stores therein at least information required for a oscillation control; and a control unit that obtains a permissible range of required cooling time for a rail that satisfies a permissible range of hardness of the rail based on a correlation expression representing a correlation between the cooling time for the rail with the cooling header and the hardness of the rail after cooling, controls a stroke and a speed of relative reciprocation of the rail and the cooling header based on the permissible range of the required cooling time, and causes the oscillation mechanism to perform the relative reciprocation of the rail and the cooling header by the stroke and at the speed.

First claim

The invention claimed is:

1. A rail heat treatment device comprising:
a cooling header that jets a cooling medium to a rail to be cooled;
an oscillation mechanism that relatively reciprocates the rail and the cooling header along a longitudinal direction of the rail; and
a control system that performs oscillation control of the oscillation mechanism, the control system comprising:
a storage unit that stores therein at least information required for the oscillation control; and
a control unit that obtains a permissible range of required cooling time for the rail that satisfies a permissible range of hardness of the rail based on a correlation expression representing a correlation between the cooling time for the rail with the cooling header and the hardness of the rail after cooling, determines the required cooling time within the obtained permissible range of required cooling time, controls a stroke and a speed of relative reciprocation of the rail and the cooling header based on the determined required cooling time, and causes the oscillation mechanism to perform reciprocation by the stroke and at the speed,

wherein the correlation expression is expressed by the following expression (1):
HV ( h )= K×t+HV ( n )  (1),

where:
HV(h): hardness of the rail after cooling with the cooling medium from the cooling headers,
HV(n): hardness of the rail after natural cooling without the cooling medium,
t: cooling time for the rail with the cooling medium from the cooling headers, and
K: a constant determined according to a type of the rail.

2. The rail heat treatment device according to claim 1 , wherein
the cooling headers are provided in plurality and discontinuously arranged with predetermined intervals along the longitudinal direction of the rail, and
the control system calculates a minimum value of the cooling time for the rail that is decreased due to a discontinuous portion between the cooling headers, and controls the stroke and the speed of the relative reciprocation of the rail and the cooling headers so that the minimum value of the cooling time falls within the permissible range of the required cooling time.

3. The rail heat treatment device according to claim 1 , further comprising:
a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
a conveying device that carries the rail before cooling in the cooling device, and carries out the rail after cooling from a same side of the cooling device as a carrying-in side of the rail.

4. The rail heat treatment device according to claim 1 , further comprising:
a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail;
a first conveying device that carries the rail before cooling in the cooling device; and
a second conveying device that carries out the rail after cooling with the cooling device from an opposite side to a carrying-in side of the rail with the first conveying device.

5. A rail heat treatment method comprising:
obtaining a permissible range of required cooling time for a rail to be cooled that satisfies a permissible range of hardness of the rail based on a correlation expression representing a correlation between the hardness of the rail after cooling and cooling time for cooling the rail by jetting a cooling medium to the rail from a cooling header;
determining the required cooling time within the obtained permissible range of required cooling time;
controlling a stroke and a speed of reciprocation based on the determined required cooling time; and
performing reciprocation by the stroke and at the speed as relative reciprocation of the rail and the cooling header along the longitudinal direction of the rail,
wherein the correlation expression is expressed by the following expression (1):
HV ( h )= K×t+HV ( n )  (1),

where:
HV(h): hardness of the rail after cooling with the cooling medium from the cooling headers,
HV(n): hardness of the rail after natural cooling without the cooling medium,
t: cooling time for the rail with the cooling medium from the cooling headers, and
K: a constant determined according to a type of the rail.

6. The rail heat treatment method according to claim 5 , further comprising:
while taking into consideration a length of a discontinuous portion between cooling headers provided in plurality and discontinuously arranged with predetermined intervals along the longitudinal direction of the rail, calculating a minimum value of the cooling time for the rail that is decreased due to the discontinuous portion; and
controlling a stroke and a speed of relative reciprocation of the rail and the cooling headers so that the minimum value of the cooling time falls within the permissible range of the required cooling time.

7. The rail heat treatment method according to claim 5 , further comprising:
carrying the rail before cooling in a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
carrying out the rail after cooling from a same side of the cooling device as a carrying-in side of the rail.

8. The rail heat treatment method according to claim 5 , further comprising:
carrying the rail before cooling in a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
carrying out the rail after cooling with the cooling device from a side of the cooling device opposite to a carrying-in side of the rail.

9. The rail heat treatment device according to claim 2 , further comprising:
a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
a conveying device that carries the rail before cooling in the cooling device, and carries out the rail after cooling from a same side of the cooling device as a carrying-in side of the rail.

10. The rail heat treatment device according to claim 2 , further comprising:
a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail;
a first conveying device that carries the rail before cooling in the cooling device; and
a second conveying device that carries out the rail after cooling with the cooling device from an opposite side to a carrying-in side of the rail with the first conveying device.

11. The rail heat treatment method according to claim 6 , further comprising:
carrying the rail before cooling in a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
carrying out the rail after cooling from a same side of the cooling device as a carrying-in side of the rail.

12. The rail heat treatment method according to claim 6 , further comprising:
carrying the rail before cooling in a cooling device including the cooling headers provided in plurality and arranged along the longitudinal direction of the rail; and
carrying out the rail after cooling with the cooling device from a side of the cooling device opposite to a carrying-in side of the rail.

Assignees

• Yoshida Yoshikazu
• Takahashi Hideki
• Kojo Rinya
• Matsuoka Ryo
• Kataoka Yuzuru
• Horita Tomoo
• Jfe Steel Corp

Inventors

• Yoshida Yoshikazu
• Takahashi Hideki
• Kojo Rinya
• Matsuoka Ryo
• Kataoka Yuzuru
• Horita Tomoo

Classifications

• C21D9/04 Primary

  for rails · CPC title

• C21D2221/00

  Treating localised areas of an article · CPC title

• C21D11/005

  for cooling · CPC title

• C21D11/00

  Process control or regulation for heat treatments · CPC title

• C21D1/667

  for spray quenching · CPC title