JP6308582B2 - Tongue rail manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a tongrel.

  Conventionally, a heat-treated rail (JIS E 1120) that has been heat-treated over the entire cross-section of the head of the rail to improve wear resistance has been used. An apparatus for heat-treating the rail has also been devised (for example, see Patent Document 1).

Japanese Utility Model Publication No. 62-157756

By the way, as one form of the rail, there is a tongrel used for a point rail or an expansion joint rail. The Tongleil is a specially shaped rail whose cross-sectional shape changes along the longitudinal direction. The Tongleil is manufactured by cutting a left-right asymmetric S (Special) rail having a cross-sectional area larger than that of a normal rail. Therefore, the surface of the Tongrel is exposed at the deep portion of the cross-sectional shape of the S rail, and the processing from the S rail to the Tongrel is more extensive including not only the head of the rail but also the lower neck. For this reason, there is a problem in that the necessary wear resistance cannot be obtained if the portion that is not heat-treated is exposed as the surface of the Tongrel.
This invention is made | formed in view of the said subject, The place made into the objective is to manufacture a tongaryl with high abrasion resistance efficiently.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

(1) It includes a machining step of cutting the S-rail into a cross-sectional shape of the Tongrel after the heat-treatment step of heating with the flame of the burner while feeding the S-rail in the longitudinal direction. A method of manufacturing a tongrel that sets a radiation position of the flame of the burner with respect to the surface of the burner to a position suitable for the quenching layer to reach a deep part constituting the sectional shape of the tongrel in the sectional shape of the S rail (claim) Item 1).
The method for producing a tongrel described in this section is suitable for the quenching layer extending to the deep portion constituting the sectional shape of the tongrel as described above with respect to the radiation position of the flame of the burner with respect to the rail surface. The heat treatment process is performed at the set position. And since S rail is heated efficiently, heat processing will osmose | permeate to the deep part. The S-rail thus heat-treated is finally cut into a cross-sectional shape of the Tongrel, so that in the state processed from the S-rail to the Tongrel, the heat-treated portion is defined as the Tongrel surface. To be exposed.

(2) In the heat treatment step of the above (1), a method for producing a tongrel that emits flame of the burner from above the S rail toward the top of the head and from both sides toward the bottom of the neck ( Claim 2).
The method for producing the Tongrel described in this section is as follows. The burner flame radiates to the surface of the S-rail from the top of the S-rail toward the top and from both sides of the S-rail toward the bottom of the neck. By setting so as to radiate the flame, the S-rail is efficiently heated, and the quenching layer extends to the deep part of the cross-sectional shape of the S-rail that constitutes the cross-sectional shape of the Tongrel.

(3) In the heat treatment step of (2) above, in the heat treatment step, the radial direction of the burner that radiates flame from both sides of the S rail toward the lower neck is orthogonal to the longitudinal direction of the S rail. A manufacturing method of a tongrel inclined in the feeding direction with respect to the direction (Claim 3).
In the manufacturing method of the Tongrel described in this section, the radiation direction of the burner that radiates a flame from both sides of the S rail toward the bottom of the neck is inclined in the feed direction with respect to the direction perpendicular to the longitudinal direction of the S rail. By doing so, the flames of the burner radiated from both sides toward the bottom of the neck interfere with each other, thereby preventing adverse effects such as disturbing the state of the other flame in which both flames face each other. In addition, it is desirable that the flame of the burner that shoots from both sides of the S rail toward the bottom of the neck does not interfere with the flame that radiates from the top of the S rail to the top of the head. It is.

(4) In the heat treatment step of the above (3), the tongs that radiate the flame of the burner at the timing at which the flames of the burner radiated from both sides of the S rail are blocked from each other by the S rail Rail manufacturing method (Claim 4).
In the method for producing the Tongrel described in this section, the flames of the burner are radiated at the timing when the flames of the burner radiated from both sides of the S rail are shielded from each other by the S rail. This prevents adverse effects such as disturbing the state of the other opposing flame.

(5) rail heating means and rail feeding means for feeding the rail in the longitudinal direction with respect to the rail heating means, wherein the rail heating means has a cross-sectional shape of the Tongleil among the cross-sectional shapes of the S rail. The heat processing apparatus provided with the burner which radiates | emits a flame in the surface position of the said S-rail suitable for a hardened layer to reach the deep part which comprises.
(6) In the above item (5), the burner is fed to the rail heating unit by the rail feeding unit, from above the S-rail toward the top of the head and from both sides toward the bottom of the neck, A heat treatment apparatus arranged to emit a flame of the burner.

(7) In the above item (6), the radial direction of the burner that radiates a flame from both sides of the S rail toward the bottom of the neck is the longitudinal direction of the S rail fed to the rail heating unit by the rail feeding unit Heat treatment apparatus arranged to be inclined in the feeding direction with respect to the direction orthogonal to the direction.
When the heat treatment apparatus according to the above (5) to (7) is used in the heat treatment step in the method for producing a tongrel according to the above (1) to (3), the effects of (1) to (3) are obtained. Is what you get.

  Since this invention was comprised in this way, it becomes possible to manufacture a tongarle with high abrasion resistance efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the manufacturing method of the tong leile which concerns on embodiment of this invention, (a) showed the aspect of the flame radiation in the heat processing process with sectional drawing of the part by which roughing of the S rail is not performed (B) shows the cross-sectional shape of the tip of the Tongrel after completion of the machining process, together with the partial cross-sectional shape of the ordinary rail, for convenience, and (c) (d) These show the cross-sectional shape which changes gradually toward the base end part from the front-end | tip part of a Tonglel after completion of a machining process for convenience. It is a schematic diagram of the heat processing apparatus used for the heat processing process of the manufacturing method of the Tongrel based on embodiment of this invention. It is an expanded sectional view in the AA line of FIG. FIG. 4 is a plan view of FIG. 3. It is a perspective view of the AA line vicinity part of FIG. The surface hardness of the S rail after the heat treatment process by the method for producing the Tongrel according to the embodiment of the present invention is illustrated, and (a) is a chart showing the relationship between the surface depth and the hardness of the S rail. (B) shows a graph and a cross section corresponding to each position of the head listed in the chart of (a).

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
In the embodiment of the present invention, a heat treatment step is performed in which heating is performed by a flame of a burner while feeding the S rail in the longitudinal direction. Thereafter, a machining process for cutting the S rail into a cross-sectional shape of the Tongrel is carried out to obtain a Tongrel having a necessary shape. In the heat treatment step, the radiation position of the burner flame F with respect to the surface of the S rail RS whose cross section is shown in FIG. The S-rail RS is heated at a position suitable for the quenching layer to reach the deep part constituting the cross-sectional shape of the Tongrel RT shown in FIG.
Normally, a machining process (rough machining process) for cutting the S-rail to an intermediate shape that does not reach the shape of the Tongreil RT is performed as a pre-process of the heat treatment process. Then, after subjecting the roughed S-rail to a heat treatment step, a machining step (this step) is performed in order to obtain a final shape of the Tongleyl RT.

This tongrel RT has a cross-sectional shape that changes along the longitudinal direction. As an example, from the cross-sectional shape of the distal end portion indicated by reference symbol A in FIG. 1B, to reference characters B to F in FIG. 1C, and further, proximal ends indicated by reference symbols G and H in FIG. It has a shape that gradually changes so that the cross-sectional area gradually increases to the cross-sectional shape of the part. In addition, the code | symbol RN of FIG.1 (b) has shown the partial cross-sectional shape of the normal rail with which a tongrel RT is combined.
And as a radiation position of the flame F of the burner in the heat treatment step, specifically, the flame F1 is radiated from the upper side with respect to the top part RSt of the S rail RS (a position corresponding to the top part RSt before roughing), And it sets so that the flames F2 and F3 may be radiated | emitted from both sides with respect to neck lower part RSn (position corresponded to neck lower part RSn before roughing).

In the heat treatment process, the burner flame is emitted from the S rail RS by the rail feeding means 14 described later to the rail heating means 12 and radiated from both sides of the S rail RS. , F3 are preferably emitted at the timing when they are shielded from each other by the S-rail RS.
In addition, although the fire powers of the flames F2 and F3 radiated to both sides of the lower part of the neck of the S rail RS are, in principle, equal to the left and right, the cross-sectional shape of the Tongrel RT is asymmetrical, so The thermal power of F3 may be changed to keep the quenching layer to the minimum necessary to reach the deep part constituting the cross-sectional shape of the Tongleil RT.

  2 to 5 show a heat treatment apparatus 10 used in the heat treatment process according to the embodiment of the present invention. The heat treatment apparatus 10 includes a rail heating unit 12 and a conveyor as a rail feeding unit 14 that feeds the S rail RS (FIGS. 3 and 4) in the longitudinal direction to the rail heating unit 12. In the heat treatment apparatus 10 of FIG. 2, the S rail RS is sent from the right side to the left side of the drawing by the upstream rail feeding means 14. Then, the S-rail RS heated by the rail heating unit 12 is transferred to the rail feeding unit 14 located downstream of the rail heating unit 12 and is cooled by air from the wind box as the cooling unit 16, and the next It is sent to the process (temporary storage place or machining process). In the figure, a portion indicated by reference numeral 18 is a roller conveyor disposed immediately below the rail heating means 12, and a portion indicated by reference numeral 20 is an exhaust hood for releasing heat generated from the rail heating means 12. .

In the example shown in the drawing, the rail heating means 12 is composed of a first rail heating means 12A and a second heating means 12B. The first rail heating means 12A emits flames F2 and F3 (FIG. 1 (a)) from both sides of the S rail RS toward the neck lower part RSn. Moreover, the 2nd heating means 12B radiates | emits the flame F1 (FIG. 1 (a)) toward the crown part RSt from the upper direction of S rail RS.
Here, in the first rail heating means 12A, the two burners 22 are arranged opposite to each other so as to sandwich the S rail RS from both sides, and each of the burners 22A and 22B has a common metal gas pipe 24. It is held by branch pipes 24A and 24B connected to the tip of each. As apparent from FIGS. 3 to 5, the radial direction of each burner 22 </ b> A, 22 </ b> B is relative to the direction perpendicular to the longitudinal direction of the S rail RS fed to the rail heating unit 12 by the rail feeding unit 14. It is arranged so as to be inclined in the feeding direction.

In the illustrated example, the radial direction of each burner 22A, 22B is arranged so as to be inclined at the same angle toward the upstream side in the feed direction of the S rail RS. Further, the burners 22A and 22B may be arranged so that the inclination angles thereof are different, and these are set as appropriate.
On the other hand, in the second heating means 12B, a burner 28 is arranged on the ceiling portion of the tunnel-shaped heat-resistant housing 26 whose bottom is open, with the burner 28 facing downward. As the second heating means 12B, it is also possible to use a rapid heating furnace used in the prior art (Patent Document 1). Further, the first heating unit 12A may be incorporated in the second heating unit 12B.

  Therefore, in the illustrated example, the heating of the neck portion RSn of the S rail RS by the second heating unit 12B is performed prior to the heating of the S rail RS to the top portion RSt by the second heating unit 12B. On the other hand, by incorporating the first heating means 12A into the second heating means 12B, the heating timing of the crown portion RSt and the lower neck portion RSn of the S rail RS may be set at the same time. Furthermore, the second heating means 12B is disposed downstream of the second heating means 12B, and the heating to the top portion RSt of the S rail RS by the second heating means 12B precedes the first heating. It is good also as heating to the neck lower part RSn of S rail RS by the means 12A performed after that. These heating timings are appropriately set so that the quenching layer extends to the deep part of the S rail RS.

Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained.
That is, according to the manufacturing method of the Tongrel according to the embodiment of the present invention, the radiation position of the flame F of the burners 22 and 28 with respect to the rail surface is configured with the sectional shape of the Tongrel RT among the sectional shapes of the S rail RS. The heat treatment step is performed by setting the position suitable for the quenching layer to reach the deep part. And when S rail RS is heated efficiently, heat processing will osmose | permeate to the deep part of S rail RS. After that, the heat-treated S rail RS is cut into a cross-sectional shape of the Tongrel RT. For this reason, in the state processed from the S rail to the Tongrel RT, it becomes possible to expose the heat-treated portion as the surface of the Tongrel RT, and to obtain the Tongrel RT having sufficient strength. Become. Therefore, it is not necessary to further heat-treat the Tongrel RT to ensure the necessary strength, and it becomes possible to efficiently produce a Tongrel having high wear resistance.

In order to obtain the above effect, the flame F1 of the burner 28 is radiated from the top of the S rail RS toward the top of the head RSt as the radiation position of the flame of the burners 22 and 28 with respect to the surface of the S rail RS, and the S rail The flames F2 and F3 of the burners 22A and 22B are set to radiate from both sides of the RS toward the lower neck RSn.
FIG. 6A shows a chart showing the relationship between the surface depth and hardness of the S-rail RS that has undergone the quenching process according to the embodiment of the present invention, and FIG. 6B shows the relationship between FIG. The graph and the cross section corresponding to each position of the head listed in the chart of FIG. Looking at the relationship between the surface depth and hardness of the three-way cross section indicated by the head 1 to the head 3 in FIG. 6B, the Vickers hardness 300Hv5 is measured at the measurement point of the surface depth 40 mm in the middle of the head. Although it is lower, at other measurement points, it is a value exceeding the Vickers hardness of 300 Hv5, and it is understood that sufficient hardness is obtained up to the deep layer portion.

Moreover, in the manufacturing method of the tongrel according to the embodiment of the present invention, the radiation directions of the flames F2 and F3 of the burners 22A and 22B that radiate flames from both sides of the S rail RS toward the neck lower part RSn are set to the S rail. By tilting the RS in the feed direction with respect to the direction perpendicular to the longitudinal direction, the flames F2 and F3 of the burners 22A and 22B radiated from both sides toward the neck lower part interfere with each other, It is possible to prevent adverse effects such as disturbing the state of the other flame with which the flames F2 and F3 are opposed, and to stably heat the S rail RS. Also, the flames F2 and F3 of the burners 22A and 22B that shoot from both sides of the S rail RS toward the lower part of the neck should not interfere with the flame F1 emitted from the burner 28 from the top of the S rail RS to the top of the head RSt. From this point, this configuration is appropriate.
Further, the flames F2 and F3 emitted from both sides of the S-rail RS are radiated at the timing when the flames F2 and F3 are shielded from each other by the S-rail RS. It is possible to prevent adverse effects such as disturbing the state of the other flame facing F3.

  10: Heat treatment apparatus, 12: Rail heating means, 12A: First heating means, 12B: Second heating means, 14: Rail feeding means, 22, 22A, 22B, 28: Burner, RS: S rail, RSt: The top of the head, RSn: Lower neck, RT: Tongleir, F, F1, F2: Burner flame

Claims (4)

A tong rail manufacturing method comprising a machining step of cutting an S rail into a cross-sectional shape of a Tongrel after a heat treatment step of heating with a flame of a burner while feeding the S rail in the longitudinal direction,
In the heat treatment step, the position of the flame of the burner with respect to the surface of the S rail is set to a position suitable for the quenching layer to reach the deep part constituting the cross sectional shape of the Tongler in the cross sectional shape of the S rail. A process for producing a tongrel. 2. The method for producing a Tongleil according to claim 1 , wherein, in the heat treatment step, the flame of the burner is emitted from above the S rail toward the top of the head and from both sides toward the bottom of the neck. . In the heat treatment step, a radiation direction of a burner that radiates a flame from both sides of the S rail toward a lower neck is inclined in a feeding direction with respect to a direction perpendicular to the longitudinal direction of the S rail. A method for producing a tongrel according to claim 2. 4. The heat treatment step of radiating the flame of the burner at a timing at which the flames of the burner radiated from both sides of the S rail are blocked from each other by the S rail. A method for producing the tongrel as described.

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